Environmental Protection Agency defines corrosivity as a substance that is Didelphis A genus of marsupials, commonly called opossums, highly acidic (pH 2. Creeping eruption Penetration and migration through sub Dioecious Having the male and female sexes of a species as cutaneous tissues by skin-penetrating nematodes, resulting in separate individuals. Disinfectant An agent intended to destroy or irreversibly Cryptosporidiosis Intestinal infection caused by coccidia inactivate all microorganisms, but not necessarily their spores, (Cryptosporidium spp. Cuticle Outermost, three-layered portion of the body wall of Duodenum the proximal portion of the small intestine nematodes (Ascaris lumbricoides, etc. Cysticercoid the solid larval stage of tapeworms containing Dysentery Frequent watery stools, usually containing blood an invaginated scolex that occurs in arthropod intermediate and/or mucus; associated with inflammation of the intestine, hosts (Hymenolepis, Dipylidium). Epidemic Disease that spreads rapidly and infects many peo ple in a community or area (usually within a short time frame). Ecosystem the fundamental unit in ecology, comprising the living organisms and the nonliving elements that interact in a Epididymitis Inflammation of the epididymis (first part of the defined region. Ectoparasite Organism that lives on or within the skin of its Epimastigote Developmental stage of the family host (lice, mites, ticks). Trypanosomatidae; the base of the flagellum is in front of the nucleus, and as the flagellum passes through the body to emerge Ectopic site Outside the normal location; i. Erythema Diffuse or patchy redness of the skin; blanching on Edema Presence of large amounts of fluid, usually in subcuta pressure as a result of congestion of cutaneous capillaries. Erythrocytic cycle Developmental cycle of malarial parasites Elephantiasis Inflammation and obstruction of the lymphatic within the red blood cells. Exflagellation the extrusion of rapidly waving flagellum-like Encystment Formation of a resistant external wall by proto microgametes from microgametocytes; in human malaria para zoa to enable them to survive drying and adverse environmental sites, this occurs in the blood meal taken by the proper anoph conditions; encysted forms are infective to humans. Exoerythrocytic cycle A part of the malarial life cycle in which the mosquito introduces sporozoites into the vertebrate Endoparasite Parasite that lives within the body of the host; sporozoites penetrate the parenchymal liver cells and host. Eosinophilia Formation of large numbers of eosinophilic Festoon A distinguishing characteristic of certain hard tick leukocytes as a result of some type of immune response; usually species, consisting of small rectangular areas separated by found in helminth infections, particularly with tissue invasion grooves along the posterior margin of the dorsum of both males (visceral larva migrans, trichinosis, filariasis, schistosomiasis, and females. Fever A complex physiologic response to disease mediated Eosinophilic cerebrospinal fluid pleocytosis Increased by pyrogenic cytokines and characterized by a rise in core tem number of eosinophils in cerebrospinal fluid (Angiostrongylus perature, generation of acute-phase reactants, and activation of and Baylisascaris infections; coenurosis, cysticercosis, echino immunologic systems. Flame cell Primitive, ciliated excretory cell in trematodes; the Eosinophilic meningitis Inflammation of membranes of the movement of the cilia on this cell within the miracidium larva brain or spinal cord accompanied by an increased number of (within a schistosome egg) indicates egg viability. Dientamoeba fragilis within helminth eggs such as Enterobius vermicularis and Ascaris lumbricoides). Fundus, ocular the portion of the interior of the eyeball around the posterior pole, visible through the ophthalmoscope. Heterophyids Small intestinal flukes parasitic in humans and animals (Heterophyes and Metagonimus spp. Hexacanth embryo Six-hooked tapeworm embryo (onco Furcocercous Fork-tailed (cercaria of schistosomes). It is present in peripheral blood; fertilization occurs in the mosquito stomach with forma Hives See Urticaria. Gastroenteritis Inflammation of the stomach and small and Host An organism in or on which a parasite lives. Hydatid, alveolar Type of hydatid cyst formed by Genital primordium Ovoid clump of cells that becomes Echinococcus multilocularis; budding is external, as well as the reproductive system (seen in the rhabditiform larvae of internal, and there is no thick outer capsule. Hydatid, polycystic Type of hydatid cyst formed by Geohelminth Any helminth that is transmitted to humans Echinococcus oligarthrus and E. Germicide A general term for an agent that kills pathogenic Hydatid, unilocular Type of hydatid cyst formed by microorganisms on inanimate surfaces. Granuloma Tumorlike nodule of firm tissue formed as a Hydatid cyst Tapeworm larval stage of the genusEchinococcus; reaction to chronic inflammation, usually of lymphoid and epi consists of a large bladder with an inner germinal layer from thelioid cells. Hydrocephalus An abnormal accumulation of fluid in the cerebral ventricles or in the subarachnoid space of the brain Helminth May refer to a nematode (roundworm), cestode (cysticercosis). Hyperparasitemia Infection with Plasmodium falciparum at Hematuria Passage of free hemoglobin in the urine a density of more than 250,000 parasites/l. Hyperpigmentation Intensification of pigment; most obvi Hemoflagellate Any flagellated protozoan blood parasite ous in dark-skinned races (leishmaniasis, onchocerciasis). Hypersensitivity Enhanced state of responsiveness following Hepatitis Inflammation of the liver (amebiasis, schistosomia sensitization to a particular antigen. Hermaphroditism Presence of both male and female repro ductive systems in the same individual; most trematodes and Hypnozoite Exoerythrocytic schizozoite of Plasmodium vivax cestodes are hermaphroditic. Transport of Dangerous Goods by Air and regulates dangerous Kupffer cells Phagocytic epithelial cells lining the sinusoids goods for member airlines and anyone who tenders dangerous of the liver. Lagochilascaris minor An unusual nematode parasite of Immunity the ability of an individual to resist and/or control humans (ingestion of infective eggs from the environment or the effects of antigens (antigen sources could be animal, plant, ingestion of infective larvae in the tissues of an intermediate or mineral). In most cases, the worms are located in the soft tissues Incubation period Time span from introduction of disease of the neck and throat, tonsils, mastoids, and paranasal sinuses causing organisms until symptoms of the disease occur. All cases were in the tropical regions of Induced malaria Malaria infection acquired by blood transfu the Western Hemisphere. Larva currens Cutaneous larva migrans caused by rapidly moving larvae of Strongyloides stercoralis, typically extending Infectious waste Waste containing or assumed to contain from the anal area down the upper thighs; may also be caused pathogens of sufficient virulence and quantity that exposure to by zoonotic species of Strongyloides. Larva migrans, cutaneous/visceral/ocular Disease char acterized by thin, red, convoluted papular or vesicular lines of Infestation Presence of arthropods on the surface of the body; eruption that extend at one end while fading at the other (dog does not refer to endoparasites (Pediculus spp. Visceral larva migrans involves migration Inflammation Result of tissue reaction to injury; symptoms of larvae through the deep tissues, including the eye (dog or cat would be redness, pain, swelling, and fever. Inspissate To thicken or dry a substance by removing liquids Latex allergy Allergic reaction associated with latex glove by evaporation (preparation of certain types of media used to use. The two types of allergic reactions are contact dermatitis grow some of the amebae). Leptomonad Old term for the promastigote stage, which is Jaundice A condition caused by excess bilirubin and long and slender and found in the insect vector for Leishmania bile pigment deposition in the skin, which may give the spp. Leukocytosis Increase in the number of white blood cells, Kala azar Another name for visceral leishmaniasis (Leishmania usually to more than 10,000/mm3. Leukopenia Decrease in the number of white blood cells, usu Karyosome Concentrated clumps of chromatin material ally to less than 4,000/mm3. Keratoconjunctivitis Inflammation of the conjunctiva and Lumen Cavity of hollow, tubular organs, such as the intestine of the cornea. Meningitis Inflammation of the membranes of the brain or Lymphadenitis Inflammation of the lymph nodes (filariasis). Lymphangitis Inflammation of the lymphatic vessels Meningoencephalitis Inflammation of the brain and its sur (filariasis). Merogony Synonym for schizogony, leading to the production of daughter cells (merozoites). Lymphokine One of several kinds of effector molecules released by T lymphocytes when an antigen to which the lym Meront Diplokaryotic cells that grow and divide into daugh phocytes are sensitized binds to the cell surface. Lymph varices Dilated lymph vessels secondary to lymphatic Merozoite Product of schizogonic cycle in malaria; produced blockage (filariasis). Macrogametocyte the mother cell producing the macroga metes, or female elements of sexual reproduction in the sporo Mesentery Tissue that supports the intestinal tract. Metacercaria the infective, encysted larval form of a trema Macronucleus Large, kidney bean-shaped nucleus in tode; found within the tissues of an intermediate host or on plant Balantidium coli (the shape is not always consistent). Macrophage Motile, phagocytic, mononuclear cell that origi Methenamine silver stain Both hot and cold methods; nates in the tissues and may be confused morphologically with involves deposition of silver onto cyst wall (Pneumocystis jir protozoan trophozoites (particularly Entamoeba spp. Malabsorption Poor fat absorption in the upper small bowel Microfilaria Embryos produced by filarial worms (nema (giardiasis). Microgametocyte the mother cell producing the microga Malaria Benign tertian malaria, Plasmodium vivax; malig metes, or male elements of sexual reproduction in the sporozoan nant tertian malaria, Plasmodium falciparum; ovale malaria, and microsporidian protozoa; microgamont. Plasmodium ovale; quartan malaria, Plasmodium malariae; Micrometer (micron) Unit of measure equal to 0. Malarial pigment Composed of hematin and excess protein Miracidium Free-living, ciliated larva released from a trema left over from the metabolism of hemoglobin; appears as brown tode egg and infective for the snail intermediate host. Monocytosis Increase in the number of monocytes in the Malignant tertian malaria Malaria caused by Plasmodium peripheral blood; may be found in both helminth and protozoan falciparum.
Pretransplant cardiac investigations in the Irish renal transplant population-the effectiveness of our current screening techniques in predicting cardiac events. Pre-transplant cardiac testing for kidney-pancreas transplant candidates and association with cardiac outcomes. Coronary revascularisation in insulin dependent diabetic patients with chronic renal failure. Screening diabetic transplant candidates for coronary artery disease: identification of a low risk subgroup. Prevalence of cardiovascular disease in kidney transplant candidates: outpatient cardiac evaluation. Distribution of coronary artery disease and relation to mortality in asymptomatic hemodialysis patients. Usefulness of dobutamine stress echocardiography in detecting coronary artery disease in end-stage renal disease. Preoperative dobutamine stress echocardiography versus cardiac arteriography for risk assessment prior to renal transplantation. Role of myocardial perfusion imaging in patients with end-stage renal disease undergoing coronary angiography. Predictors of survival in patients with end-stage renal disease evaluated for kidney transplantation. Outcome of patients with vesicoureteral reflux after renal transplantation: the effect of pretransplantation surgery on posttransplant urinary tract infections. Bilateral nephrectomy with concomitant renal graft transplantation for autosomal dominant polycystic kidney disease. Pretransplant nephrectomy in patients with autosomal dominant polycystic kidney disease. The association of pretransplant native nephrectomy with decreased renal allograft rejection. Concomitant nephrectomy of massively enlarged kidneys and renal transplantation in autosomal dominant polycystic kidney disease. Selective, concurrent bilateral nephrectomies at renal transplantation for autosomal dominant polycystic kidney disease. No impact of cross-reactive group human leucocyte antigen class I matching on long-term kidney graft survival. Deleterious impact of mismatching for human leukocyte antigen-C in presensitized recipients of kidney transplants. Major histocompatibility complex class 1 chain-related antigen a antibodies: sensitizing events and impact on renal graft outcomes. H-Y as a minor histocompatibility antigen in kidney transplantation: a retrospective cohort study. Value of posttransplant antibody tests in the evaluation of patients with renal graft dysfunction. Terminal complement inhibition decreases antibody-mediated rejection in sensitized renal transplant recipients. Renal retransplants: effect of primary allograft nephrectomy on early function, acute rejection and outcome. Impact of failed allograft nephrectomy on initial function and graft survival after kidney retransplantation. Hyperacute rejection of kidney allografts, associated with pre-existing humoral antibodies against donor cells. Ten-year experience of selective omission of the pretransplant crossmatch test in deceased donor kidney transplantation. Renal after cardiothoracic transplant: the effect of repeat mismatches on outcome. A two-year analysis of transplants reported to the United Network for Organ Sharing Registry. Patient and graft outcomes from deceased kidney donors age 70 years and older: an analysis of the Organ Procurement Transplant Network/United Network of Organ Sharing database. Double adult renal allografts: a technique for expansion of the cadaveric kidney donor pool. Outcome of en bloc and single kidney transplantation from very young cadaveric donors. Dual-kidney transplantation with organs from expanded criteria donors: a long-term follow-up. Strategies for compensating for the declining numbers of cadaver donor kidney transplants. Nephrology, dialysis, transplantation: official publication of the European Dialysis and Transplant Association European Renal Association. Kidney transplantation from donors aged 65 years or more as single or dual grafts. Single versus dual renal transplantation from donors with significant arteriosclerosis on pre-implant biopsy. Twenty-year graft survival and graft function analysis by a matched pair study between pediatric en bloc kidney and deceased adult donors grafts. Preservation solutions for static cold storage of kidney allografts: a systematic review and meta-analysis. Assessing the quality of reports of randomized clinical trials: is blinding necessary The clinical and cost-effectiveness of pulsatile machine perfusion versus cold storage of kidneys for transplantation retrieved from heart-beating and non-heart-beating donors. Machine perfusion versus cold storage for the preservation of kidneys donated after cardiac death: a multicenter, randomized, controlled trial. Health outcomes for living kidney donors with isolated medical abnormalities: a systematic review. Effects of preexistent hypertension on blood pressure and residual renal function after donor nephrectomy. American journal of transplantation: official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. Morbidity and mortality in 1022 consecutive living donor nephrectomies: benefits of a living donor registry. Donor-transmitted IgA nephropathy: long term follow-up of kidney donors and recipients. Kidney transplantation with living donors: nine years of follow-up of 628 living donors. Ethnic and gender related differences in the risk of end-stage renal disease after living kidney donation. Effect of hemodialysis before transplant surgery on renal allograft function-a pair of randomized controlled trials. Factors influencing serum creatinine level in 200 kidney recipients in a multivariate analysis. Perioperative fluid management in kidney transplantation: is volume overload still mandatory for graft function Early hemodynamic changes after renal transplantation: determinants of low central venous pressure in the recipients and correlation with acute renal dysfunction. Physiologic impact of low-dose dopamine on renal function in the early post renal transplant period. Effect of postoperative low dose dopamine infusion on early renal allograft function [abstract]. Dopamine and Fluid Load Prevent Acute Renal Failure After Kidney Transplantation [abstract]. Dopamine lowers the incidence of delayed graft function in transplanted kidney patients treated with cyclosporine A. Dopamine treatment of human cadaver kidney graft recipients: a prospectively randomized trial. Routine use of renal-dose dopamine during living donor nephrectomy has no beneficial effect to either donor or recipient.
The achieve restraint of conscious animals before person aesthetics of this procedure and its acceptance by nel can safely perform euthanasia using injectable personnel and observers should be considered. A paucity of data for wildlife and the potential for Injectable anesthetics may be administered by interspecies variation create challenges for establish multiple routes. However, on the the blowhole, can be an effective method that maxi basis of data for domestic animals, manual cervical mizes personnel safety. Intracardi Approaches to euthanasia that ignore recent ad ac administration is acceptable only in anesthetized, vances in technology, and that do not minimize risks moribund, or unconscious animals. This approach to animal welfare, personnel safety, and the environ requires special, strong, and long needles to ensure ment for a particular set of circumstances, are unac that the heart can be accessed. Advantages of injectable anesthetics are that they act rapidly and personnel experienced with these S7. Their administration Methods that are acceptable for euthanasia of do is logistically simple and aesthetically acceptable in mestic or captive wildlife species in developmental small to medium-sized animals, and public safety is or neonatal stages are generally acceptable for eutha relatively easy to secure. It can also thetically displeasing and potentially unsafe excita be diffcult to determine when stranded marine mam tion phases of anesthesia. References are erally prevent use of inhaled agents for euthanasia of available to assist in identifying appropriate anatomic marine mammals under feld conditions. It can, fcacy is highly dependent on the knowledge, techni however, be used as an adjunctive method to ensure cal expertise, and experience of the operator. Natl thetically displeasing and emotionally distressing for Anim Control Assoc Euthanasia Certifcation Workshop, Day personnel and bystanders. Evaluation of methods for on-farm euthanasia of listics in the Physical Methods section and experts for commercial meat rabbits. The advantages of properly applied manual blunt force trauma are that it results in rapid death, no spe S9 References cial equipment is required, and there is limited poten 1. However, ion animal death: caring for the animal, the client, and the the effcacy of manually applied blunt force trauma veterinarian. Use of the measure of patient-centered communication to analyze eu the operator and it is aesthetically displeasing for per thanasia discussions in companion animal practice. Factors associated with client, staff, and student satisfaction regarding small animal placed, shaped, and dimensioned explosive charg euthanasia procedures at a veterinary teaching hospital. The caring-kill to toxic residues, and protection of personnel from ing paradox: euthanasia-related strain among animal shelter workers. Impact of eu dependent on the knowledge, skills, and experience thanasia rates, euthanasia practices, and human resource of the operator; it is aesthetically displeasing; and practices on employee turnover in animal shelters. Refnement of euthana behavioral, and histologic responses to various euthanasia sia. On the use cage cleaning and in-house transport on welfare and stress of of T61 for euthanasia of domestic and laboratory animals; an laboratory rats. Guidelines for police offcers when responding common procedures in male rats housed alone or with other to emergency animal incidents. Immune deviation fol bolt as a method of euthanasia in larger laboratory animal lowing stress odor exposure: role of endogenous opioids. Effects of sen administration of medication to induce sedation in dogs pri sory stimuli on the incidence of fetal resorption in a murine or to euthanasia. In: the Humane Society of without affecting immunohistochemical endpoints in rats. Anesthesia and sampling from experimental animals with respect to freez analgesia in laboratory animals. Evaluation of isofurane over mice after decapitation, cervical dislocation, potassium chlo dose for euthanasia of neonatal mice. Nat euthanasia in the induction and duration of panic-associated Rev Neurosci 2005;6:507. A hypothermic miniaturized implications of using carbon dioxide mixed with oxygen for stereotaxic instrument for surgery in newborn rats. Use of hypothermia for general anesthe aversion and self-administration of nitrous oxide in rats. Induction of an agement practices on one hundred and thirteen north aesthesia with sevofurane and isofurane in the rabbit. Abnormal concentrations of respiratory gases in thanasia of cattle in a foreign animal disease outbreak. Effcacy of blunt force trau pigs produced by impact with a non-penetrating captive bolt ma, a novel mechanical cervical dislocation device, and a pistol. Return-to-sensibility problems after penetrating of pre-weaned kits, growers, and adult commercial meat rab captive bolt stunning of cattle in commercial beef slaughter bits. Energy requirements for the penetration of tions during captive bolt stunning of rabbits. Investigation into the principal de practices and attitudes of commercial meat rabbit producers.
In this way, health workers can minimize the number of vials that have to be rejected and this will decrease the wastage of vaccine. Health workers can see at a glance when the vaccine has been exposed to high temperature. This refects that the vial has been exposed to an unacceptable level and the vaccine potency reduced beyond acceptable limits. The point to focus on is the colour of the inner square relative to the colour of the outer circle. It is important to use vaccine vial monitors because they help health workers determine whether vaccines have been spoilt by exposure to too much heat. The explanation of what is required to be done is indicated on both sides of this card. The freeze watch indicator The freeze watch indicator tells you when the vaccine has been exposed to freezing temperatures. When ex posed to temperatures below 0C for more than one hour, the vial bursts and releases the coloured liquid, staining the white paper background. The freeze indicator is used to warn of freezing and is packed with vaccines that are sensitive to freezing temperatures, the vial breaks and releases a bright blue or red stain which spreads across the white paper background and the colour change cannot be reversed. If the paper background of the indicator is stained blue or red, the shake test should be performed. Initially, any vial opened during an immunization session could be thrown away after the session, irrespective of the type of vaccine and the number of doses remaining. Which of the opened vaccine vials may be preserved at the end of an immunization session and used the following days and ii. The conditions under which these vaccines may be stored and re-used without any risk. To detect management problems and fnd appropriate solutions during the vaccine use 2. The sacrifced doses are the doses of vaccines that have been lost deliberately for the sake of the immunization to take place. Vaccines wastage rate this represents the quantity of vaccine taken out of the stocks, but not administered to the target population. The calculation of wastage rates is based on vaccines stock management information which must be accurate and reliable. Wastage of doses in unopened vials (wastage due to the system) this wastage depends on the management, storage and handling conditions of vaccines. For each antigen, the quantity of used dose is equal to the sum of the products of number of vials and the number of doses in each vial 2. Issued doses = Total quantity of doses issued from the stock of vaccines for one reason or the other. Used doses = Total quantity of doses contained in all the vials opened during the immunization. For each antigen, the quantity of used dose is equal to the sum of the products of number of vials and the number of doses in each vial. For each antigen, the quantity of issued doses is equal to the difference between the available quantity of doses of vaccines and the quantity of doses of vaccines at the end of the period 2. Administered doses = Doses which have been effectively administered to the target population. Specifc objectives: At the end of the session the health worker will be expected to: 1. Vaccines lose their potency when exposed to high temperature, sunlight or freezing conditions depending on type. An efcient cold chain system requires trained and skilled staf, reliable equipment and adherence to set standards. Termometers Cold Rooms and Freezer Rooms Tese are large rooms, specially constructed for storage of large quantities of vaccines. They have two cooling units; one running while the other is standby, a 24-hour temperature monitoring system with an alarm, a recorder, and a backup generator that will turn on automatically when the regular power is interrupted. Cold rooms are found at the national and regional levels while freezer rooms are only found at the national level. Vaccines are packed leaving space of about 5cm in between the packets for air circulation. This fridge is used at the district vaccine store and at the immunizing facilities with high target population. A sticker is pasted on the front side of the refrigerator to guide on the vaccine arrangement and the arrangement order must be observed at all the times. It is suitable for use at places with higher target population or sub district depots. Sunrays are converted into electric energy, which is then used to supply the refrigerator. The cold life of a cold box varies depending on the type, the number of openings and the ambient temperature. They are used in vaccine carriers, cold boxes or refrigerators to maintain temperatures. Always have at least an extra set of icepacks as a reserve while one set is in use. Thermometers Diferent types of thermometers are used to monitor cold chain temperature. As the refrigerant circulates, it absorbs heat from inside lowering the temperature inside the refrigerator. When the heating unit is supplied with a source of heat the refrigerant boils, evaporates and cir culates through the coiled pipes where it loses heat changing into liquid as it enters the pipe inside the refrigerator. Due to the low boiling properties of the refrigerant it evaporates again as it enters the inside pipes and this results into cooling. Minimum clearances to wall and roof must be at least 30cm and 40cm respectively as shown in fgure 4. Upright refrigerators should be placed on wooden blocks (25 to 50mm) thick to avoid dampness. Charting should therefore be done at the centre of the bold and dotted line in the morning, and at the centre of the broken and bold line for the evening charting as shown on fgure 4. Take necessary action and if unable, refer for further ac tion by a skilled technician. If the fame is accidentally blown out, the fame failure device must shut of the gas supply within one minute. Press in the replacement gasket into the groove, and ensure that the gasket has not left any gap.
For example, getting an infection from dishes used by a patient, even those with an acute respiratory or gastrointestinal infection, is highly unlikely. Fiscal constraints, budget cutbacks, managed care and data supporting the safety of reusing items are the driving forces behind the movement to replace or reuse disposables. Most disposable medical items have never been available because they are expensive and difficult to dispose of safely, especially plastic items. The two exceptions to this are disposable surgical gloves and disposable (plastic) syringes, which have rapidly replaced reusable products. But, as discussed in Chapter 7, even surgeons wearing new surgical gloves had a 14% blood-hand contact (Tokars et al 1995). Wearing new gloves, therefore, does not guarantee that hands will be kept free of contaminating blood or body fluids, even in the absence of accidental breaks or tears. Thus, sterilization (autoclaving) or steaming (high-level disinfection) of previously decontaminated and thoroughly cleaned surgical gloves can produce an acceptable product and, when combined with double gloving, constitutes an appropriate and cost-effective reuse of a disposable item. In Appendix C, guidelines and detailed instructions are provided for the safe reprocessing of surgical gloves. As such, solutions to this problem that require functioning national systems for the management of medical waste and/or increased spending 1 are unlikely to be implemented in the near future (Mujeeb et al 2003). Thus, alternatives that recognize the economic value of used syringes are more likely to be successful in addressing this serious problem. Potential options include discarding the needles after decontamination and then either recycling the plastic syringe or reprocessing it according to recommended infection prevention practices. Recycling Disposable Recycling is a new, potential alternative for the safe disposal of plastic Syringes syringes that is appropriate for use in limited-resource settings. The other alternatives are incineration, encapsulation and safe burying (Chapter 8). In developing countries, however, syringe recycling occurs primarily in the plasticware industry and is unregulated. Incineration produces potentially toxic emissions, including persistent organic pollutants in the case of low-temperature burning (see below) and is expensive. Encapsulation and safe burying not only are expensive, but also they do not reduce the ever-increasing volume of waste. To make syringe recycling (and reprocessing as well) safer for scavengers and plastic workers, healthcare providers must consistently decontaminate 2 assembled needles and syringes after use (Appendix D). Furthermore, if the needles and syringes, as well as sharps containers, are not properly disposed of, the community is at less risk because the needles 3 and syringes were decontaminated before being discarded. Finally, the volume of waste would be significantly reduced, and the cost of disposal less, because the decontaminated needles and syringes could be treated as noninfectious waste. Thus, they could be sold for recycling (if available) or disposed of in dumps or public landfills. This volume is sufficient to completely fill the needle as well as cover the surface of the plunger and bottom of the syringe. Infection Prevention Guidelines 14 5 Reprocessing Disposable (Single-Use) Items Reprocessing While reprocessing disposable plastic syringes is a practical and Disposable Syringes economically viable alternative, to be safe it requires three conditions: (and Needles) 1. A sterile or high-level disinfected needle and syringe is used to give only a single injection. After use, the assembled needle and syringe is decontaminated and placed in a sharps container. The syringe, but preferably not the needle, is processed according to recommended infection prevention practices (thorough cleaning and either sterilization or high-level disinfection). The rationale for reprocessing only the syringe, but not the needle, is the following: x Contaminated needles are responsible for the injuries and the potential risk of acquiring a life-threatening disease. In Appendix E, guidelines and detailed instructions are provided for the safe: x disposal of both needles and syringes, x disposal of needles and processing of syringes, or x processing of both needles and syringes in special situations. To minimize this risk, in recent years disposable (single-use) plastic syringes and hypodermic needles, or one of the newer autodisable syringes that cannot be refilled, have been introduced in most countries. Clearly, wherever economically possible, disposable products should be used and 4 safely disposed of after decontamination. For example, a clinic or hospital using only disposable or autodisable syringes must ensure that adequate supplies are available at all times. An even more serious consequence would be if, rather than stopping services, the same disposable needle and syringe would then be used on more than one patient. A larger problem is how to safely dispose of used needles and syringes, both conventional and autodisposable, if resources for incineration, encapsulation or burying are not available. In many countries, used needles and syringes can be found lying discarded outside healthcare facilities and hospitals, or piled high in boxes in storage rooms. These used needles and syringes constitute an increasing health risk, especially to adults and children seeking items to sell, use or play with. In summary, reprocessing disposable syringes constitutes an appropriate reuse of a disposable (single-use) device and significantly reduces infectious waste, as does reprocessing surgical gloves. Reprocessing syringes also limits costs because only new sterile needles need to be regularly resupplied. Moreover, reprocessing syringes further simplifies resupply problems because boxes of sterile needles, which are smaller and considerably less bulky, can be more easily and less expensively transported. Finally, reprocessing disposable syringes is income generating, which for countries with limited resources is an important advantage. Reprocessing used needles, however, represents an inappropriate reuse of disposables and is responsible for infections (Kane et al 1999; Phillips et al 1971; Simonsen et al 1999). In those situations where it is the only option available, it is critical that reprocessing be done as safely as possible using recommended infection prevention practices and processes (Appendix E). Infection Prevention Guidelines 14 7 Reprocessing Disposable (Single-Use) Items Daschner F. Transmission of hepatitis B, hepatitis C and human immunodeficiency viruses through unsafe injections in the developing world: Model-based regional estimates. Skins and mucous membrane contacts with blood during surgical procedures: Risk and prevention. Regulating the flow of visitors, patients and staff plays a central role in preventing disease transmission in healthcare facilities. An important objective of infection prevention is to minimize the level of microbial contamination in areas where patient care and instrument processing take place. Such areas include: x Procedure areas where patients are examined and procedures. The surgical unit also includes preoperative and recovery rooms as well as several other areas. These include dirty and clean areas where soiled instruments, equipment and other items are first cleaned and either high-level disinfected or sterilized and then stored. Infection Prevention Guidelines 15 1 Traffic Flow and Activity Patterns It is important to direct activity patterns and traffic flow in these areas to keep contaminated areas separate from areas where procedures take place. Activities such as waste disposal, instrument processing and cleaning procedure areas should be carefully planned and organized to minimize the risk of infection to patients and healthcare workers. Equally important are designing and implementing traffic flow patterns that prevent soiled instruments and other items from crossing paths with cleaned, high-level disinfected or sterilized items. Traffic flow also has to do with separating people who have, or are likely to have, communicable diseases from those who are at risk (susceptible). These people pose a great risk to susceptible patients and healthcare workers simply by being present in the same room; therefore, they need to be identified and quickly removed. For example, a child or teenager with a fever, an itchy rash on the head and body, and a negative history for chicken pox is best evaluated in the parking lot outside the hospital or clinic. Because triaging patients who may have a highly infectious disease involves staff quite different from those responsible for planning how to separate clean and dirty instruments, it is not addressed in this chapter. Whole surgical area including the lockers and dressing rooms, preoperative and recovery rooms, peripheral support areas including storage space for sterile and high-level disinfected items and other consumable supplies, corridors leading to restricted areas, the operating room(s), scrub sink areas and the nursing station. Larger facilities (including district and referral hospitals) provide major and minor general surgical procedures in addition to ambulatory procedures.
Of the 51 patients with kala azar, all had fever sites were detected down to the level of 288 17. In these cases, ab normal depolarizing patterns are due to the presence of leukocyte-associated malaria hemozoin, a pigment Concentration Procedures which depolarizes the laser light. Abnormal polarizing Cytocentrifugation Technique events have also been described for samples from three individual patients infected by the nematode Mansonella Cytocentrifugation (cytospin), which uses an apparatus perstans. The observed depolarizing pattern consisted for concentrating cells in suspension on a microscope of a normal depolarizing eosinophil population plus an slide, is commonly used in most histopathology laborato abnormal depolarizing population that showed a close ries. This as a fixative, has led to an improved technique for the atypical population was smaller than that of normal detection of Plasmodium spp. Abnormal depolarization of the parasites present in the sediment from 100 l of patterns of M. This new method costs very little to per form and offers the possibility of isolating and identify the membrane filtration technique as modified by ing the main blood-stage parasites in the same sediment. Desowitz and others has proved highly efficient in dem the possible exception would be young trophozoites of onstrating filarial infections when microfilaremias are P. Draw 1 ml of fresh whole blood or anticoagu Knott Concentration Procedure lated blood into a 15-ml syringe containing 10 ml of distilled water. Gently shake the mixture for 2 to 3 min to ensure detect the presence of microfilariae in the blood, especially that all blood cells are lysed. Place a 25-mm Nuclepore filter (5-m poros the disadvantage of the procedure is that the microfi ity) over a moist 25-mm filter paper pad. A 3-m-pore-size filter could be used for trifuge tube containing 10 ml of 2% formalin. Attach the Swinney filter adapter to the syringe sediment as a wet mount at low (100) and high containing the lysed blood. With gentle but steady pressure on the piston, remaining sediment, and allow the films to air push the lysed blood through the filter. Replace Note Use alcohol-cleaned slides for preparation of the the adapter, and gently push the water through films made from the sediment. Remove the adapter again, draw the piston of the syringe to about half the length of the barrel, replace the adapter, and push the air in the barrel Figure 31. Holding the syringe verti cally, replace the adapter and push the methanol followed by the air through the filter to fix the microfilariae and expel the excess methanol. To stain, remove the filter from the adapter, place it on a slide, and allow it to air dry thoroughly. To cover the stained filter, dip the slide in toluene before mounting the filter with neutral mounting medium and a coverslip. Procedures for Detecting Blood Parasites 905 Gradient Centrifugation Technique this hematoxylin technique (Figures 31. The gradient centrifugation technique is another tech nique for the concentration of microfilariae (52). Mix 30 ml of 50% Hypaque with 14 ml of dis of distilled water (saturated solution). Place 4 ml of the Ficoll-Hypaque mixture in a 15-ml plastic centrifuge tube; overlay this mixture Hematoxylin Solution with 4 ml of heparinized venous blood. Microfilariae will be found in the middle Ficoll Ammonium alum Hypaque layer, which separates the overlying plasma (saturated solution). Expose the solution to sunlight and air for ripening in a clear, cotton-plugged bottle for approxi Triple-Centrifugation Method for mately 1 week; then filter and add the following: Trypanosomes Glycerin. Age for 1 month or longer in sunlight, and then run test smears to determine whether the solution is properly 1. Note Remember, you are saving the supernatant fluid in step 2 for subsequent centrifugation; do not accidentally pour this fluid off for disposal. The final sediment after the third centrifugation step is used to prepare stained films for examination. In addition, fresh thick films of blood containing microfilariae can be stained by 906 Chapter 31 immunochromatography-based detection of mixed-species malaria infection in Pakistan. False positive results of a Plasmodium falciparum histidine-rich protein 2-detecting malaria rapid diagnostic test due to high sensitivity in a community with fluctuating low parasite density. The evaluation of a dip stick test for Plasmodium falciparum in mining areas of Venezuela. Epidemiologic tools for malaria surveillance in an urban setting of low endemicity along the Colombian Pacific coast. Rapid malaria screening and targeted treatment of United States bound Montagnard refugees from Cambodia in 2002. Short report: diagnosis of tick-borne relapsing fever by the quantitative Figure 31. Comparative evalu ation of four techniques for the diagnosis of Plasmodium medium; use a no. Genetic diversity depolarizing patterns in three patients with filarial infection. Hyperendemic merase chain reaction and microscopy for the diagnosis of bancroftian filariasis in the Kingdom of Tonga: the appli Plasmodium falciparum malaria in travelers. Plasmodium falci of the stained blood-film, counting-chamber, and membrane parum histidine-rich protein 2-based immunocapture diag filtration techniques for the diagnosis of Wuchereria ban nostic assay for malaria: cross-reactivity with rheumatoid crofti microfilaraemia in untreated patients in areas of low factors. Sensitivity and specificity of dipstick tests for rapid travelers: a 2-year retrospective study in a French teaching diagnosis of malaria in nonimmune travelers. Trial Morphological Study of the Erythrocytic Parasites in Thick with ParaSight-F in the detection of Plasmodium falci Blood Films. Institute for Medical Research, Kuala Lumpur, parum infection in Chennai (Tamil Nadu), India. ParaSight-F dipstick test for malaria diagnosis in a district Blood parasites: problems in diagnosis using automated control program. Efficacy of a rapid test to diagnose high throughput clinical haematology analyser. Plasmodium falciparum antigen histidine-rich protein 2 908 Chapter 31 in blood of pregnant women: implications for diagnosing 63. The use racy of rapid tests for malaria in travelers returning from of a dipstick antigen-capture assay for the diagnosis of endemic areas. Microscopic Africa: diagnosis by quantitative buffy coat analysis and diagnosis of blood parasites following a cytoconcentration in vitro culture of Borrelia crocidurae. A rapid dipstick antigen field evaluation of a new prototype immunochromato capture assay for the diagnosis of falciparum malaria. Parasite Recovery: Culture 3 Methods, Animal Inoculation, and Xenodiagnosis Culture methods Intestinal protozoa Pathogenic free-living amebae Pathogenic flagellates Flagellates of blood and tissue Toxoplasma gondii Plasmodium and Babesia spp. Microsporidia the methods for in vitro culture are often complex, while quality control is difficult and not really feasible for the routine diagnostic laboratory. In certain Animal inoculation institutions, some techniques may be available, particularly when consultative Leishmania spp. Toxoplasma gondii Few parasites can be routinely cultured, and the only procedures that are in general use are for Entamoeba histolytica, Naegleria fowleri, Acanthamoeba Xenodiagnosis spp. Often, when specimens are cultured for potential pathogens, nonpathogenic protozoa could also be recovered. These procedures are usually available only after consultation with the laboratory and on special request. For those who may be interested in trying these techniques, the several different media presented below are representative of those available. Cultures of parasites grown in association with an unknown microbiota are referred to as xenic cultures. If the parasites are grown with a single known bacterium, the culture is referred to as monoxenic. An example of this type of culture would be clinical specimens (corneal biopsy specimens) cul tured with Escherichia coli as a means of recovering species of Acanthamoeba and Naegleria.
Haronga madagascariensis (Haronga). Midamor.
The devascularized tissue extended below to include muscle, which was mainly observed in the left and right paravertebral areas. An increase in surface recovery of the lesion was not observed, despite three successive excisions of the necrotic tissue, which were conducted on days 264, 290 and 306 after exposure. These surgical excisions were combined with local treatment using the vacuum assisted closer technique, which theoretically promotes the neoangiogenesis and the budding of the wound. Figure 100 shows the extension of the superinfected tissue with a necrotic part after the third skin autograft. Fourth skin autograft A surgical excision of the lesion down to the bone was performed, which displayed several dorsal spine vertebrae and the posterior eleventh rib (see Fig. Ninety-nine days after the fourth skin autograft, the open lesion that was not cured by successive grafting procedures remained uncovered down to the bone (see Fig. Consequently, a new therapeutic strategy was taken to cover this area with a vascularized flap. The localization of the radiological lesion at the thoracic level enabled the use of an omentum flap. Omentum flap and fifth skin autograft the omentum is a double fold of peritoneum attached to the stomach by a certain amount of the abdominal viscera. The omentum flap was removed from the peritoneal cavity in order to keep its vascular pedicle connected with the left gastro-epiploic artery. The lesion area was widely abraded, and all tissue with a fragile cicatrization were removed in a large circular area (around 30 cm in diameter). The dorsal spine vertebrae were resected from the eleventh thoracic to the third lumbar vertebra. The omentum flap was transferred from the peritoneal cavity to the level 133 of the lesion on the back through a subcutaneous tunnel excavated after resection of the lateral arc of the tenth left rib (see Fig. In this case, however, as the lesion could not be cured by autografts because of the hypovascularization, a vascularized flap was used for the final covering. He was in a generally good condition, and the covering of the lesion was found to be stable. A complete epidermization and non-morphinic antalgic was used to control the residual pain. Such reviews add to the body of technical and medical knowledge and illustrate principles and criteria used, or which could have been considered, in policy and decision making. The medical management of the victims and the source recovery operation were adequate with the support of the relevant national, regional and local organizations, and with international assistance that combined professional experience in, and knowledge of, radiation protection. Experience from this accident demonstrates a need for nationwide dissemination of information to general practitioners on basic radiation biology, associated clinical symptoms and the medical management of people overexposed to ionizing radiation. A roster of doctors specializing in radiation induced injuries can be kept by general practitioners and regulatory authorities for reference. The major cause of the accident was the improper and unauthorized 90 abandonment of eight Sr radioactive sources in Georgia of which only six have so far been found. In addition, there were no clear labels or radiation signs on the sources that conveyed the potential radiation hazard. However, the removal of the radioactive sources from their original location and positioning them in open areas caused the protective shielding to be lost and consequently exposed the operating personnel to increased dose rates. Equation (16) shows that if there is no suitable shielding available, it is better to locate the operating personnel as far away from the radioactive source as possible. The operating personnel were young and healthy, so it can be stated that V = 10 km/h. Consequently, the following equation to calculate the dose rate can be used: A0 Dr= 2 (20) r where r > R is the distance from the centre of the radioactive source, and 2 A0 = 0. For the calculation of the local dose rate across the surface of the radioactive source at distance x (see Fig. Determining the local dose rate across the surface of the radioactive source at distance x. Institute for Radiological Protection and Nuclear Safety, France Herrera Reyes, E. Nuclear and Radiation Safety Service of the Ministry of Environmental Protection of Georgia Nabakhtiani, G. Nuclear and Radiation Safety Service of the Ministry of Environmental Protection of Georgia Nadezhina, N. Burnasyan Federal Medical Biophysical Center, Russian Federation Nogueira de Oliveira, C. If a second dose of hepatitis B vaccine is required before this age, monovalent Hepatitis B vaccine should be used. Booster Vaccination the administration of the booster dose should be given at 12 to 23 months as stated in the Canadian Immunization Guide. Because of the uncertainty as to which component of the vaccine might be responsible, no further vaccination with any of these components should be given. Alternatively, because of the importance of tetanus vaccination, such individuals may be referred to an allergist for evaluation. In these circumstances, pertussis vaccination should be discontinued and the vaccination should be continued with diphtheria-tetanus, Hepatitis B, polio, and Hib vaccines. Elective immunization of individuals over 6 months should be deferred during an outbreak of poliomyelitis. As with any other vaccine, a protective immune response may not be elicited in all vaccinees for all component antigens in the vaccine. As for all diphtheria, tetanus and pertussis vaccines, each injection should be given deep intramuscularly and each injection of the immunization series should be made at a different site. As with other injectable vaccines, epinephrine injection (1:1000) and other appropriate agents used for the control of immediate allergic reactions must be immediately available should an acute anaphylactic reaction occur. For this reason, the vaccinee should remain under medical supervision for 30 minutes after immunization. It is good clinical practice that vaccination should be preceded by a review of the medical history (especially with regard to previous vaccination and possible occurrence of undesirable events) and a clinical examination. Where passive protection is required, Tetanus Immune Globulin and/or Diphtheria Antitoxin may also be administered at separate sites. Because of the substantial risks of complications from pertussis disease, completion of a primary series of vaccine early in life is strongly recommended. Page 6 of 37 There may be circumstances, such as high incidence of pertussis, in which the potential benefits outweigh possible risks, particularly since these events have not been proven to cause permanent sequelae. Antipyretic treatment should be initiated according to local treatment guidelines. Syncope (fainting) can occur following, or even before, any vaccination as a psychogenic response to the needle injection. Hepatitis B vaccination may not prevent hepatitis B infection in individuals who had an unrecognized hepatitis B infection at the time of vaccine administration. The expected immunological response may not be obtained after vaccination of immunosuppressed patients. In children with progressive neurological disorders, including infantile spasms, uncontrolled epilepsy or progressive encephalopathy, it is better to defer pertussis (Pa or Pw) immunization until the condition is corrected or stable. However, the decision to give pertussis vaccine must be made on an individual basis after careful consideration of the risks and benefits. Vaccinees with a history of febrile convulsions should be closely followed up as such adverse events may occur within 2 to 3 days post vaccination. Respiratory Although a moderate or severe illness with or without fever is a reason to defer vaccination, minor illnesses such as mild upper respiratory infections with or without low-grade fever are not a contraindication. The potential risk of apnea and the need for respiratory monitoring for 48-72h should be considered when administering the primary immunization series to very preterm infants (born after at least 24 weeks of gestational age) and particularly for those with a previous history of Page 8 of 37 respiratory immaturity. As the benefit of vaccination is high in these infants, vaccination should not be withheld or delayed. Interference with laboratory testing the Hib component of the vaccine does not protect against diseases due to capsular serotypes other than type b of Haemophilus influenzae or against meningitis caused by other organisms. Excretion of capsular polysaccharide antigen in the urine has been described following administration of Hib vaccines, and therefore antigen detection may not have a diagnostic value in suspected Hib disease within 1-2 weeks of vaccination. Other tests should be performed in order to confirm Hib infection during this period.
As patients become more the motor examination in a stuporous or co deeply stuporous, muscle tone tends to de matose patient is, of necessity, quite different crease and these pathologic forms of rigidity are from the patient who is awake and cooperative. Rather than testing power in specic muscles, it is focused on assessing the overall respon siveness of the patient (as measured by motor Motor Reexes response), the motor tone, and reexes, and identifying abnormal motor patterns, such as Muscle stretch reexes (sometimes erroneously hemiplegia or abnormal posturing. Motor Tone As the level of consciousness becomes further depressed, however, the muscle stretch re Assessment of motor tone is of greatest value in exes tend to diminish in activity, until in pa patients who are drowsy but responsive to tients who are deeply comatose they may be voice. On the sessed in the neck by gently grasping the head other hand, in patients who are drowsy or with two hands and moving it back and forth or confused, some abnormal cutaneous reexes up and down, and in the lower extremities by may be released. These may include extensor grasping each leg at the knee and gently lifting plantar responses. Rooting, the movement is slowed to a near stop by the glabellar, snout, palmomental, and other re resistance, at which point the resistance col exes are often seen in such patients. Par ever, these responses become increasingly kinsonian rigidity remains equally intense de common with advancing age in patients with spite the movement of the examiner (lead-pipe out cognitive impairment, so they are of lim 136 rigidity), but is usually diminished when the ited value in elderly individuals. On the patient is asleep or there is impairment of con other hand, the grasp reex is generally seen sciousness. In contrast, during diffuse meta only in patients who have some degree of bi 137 bolic encephalopathies, many otherwise nor lateral prefrontal impairment. It is elicited mal patients develop paratonic rigidity, also by gently stroking the palm of the patient with called gegenhalten. The pull reex is a variant in which the movement increases, as if the patient were the examiner curls his or her ngers under the willfully resisting the examiner. Many elderly Examination of the Comatose Patient 73 patients with normal cognitive function will Like paratonia, prefrontal reexes are normally have a mild tendency to grasp the rst time the present in young infants, but disappear as the 135 reex is attempted, but a request not to grasp forebrain matures. Patients who are unable to inhibit the reex invariably have prefrontal pathology. Grasping disappears when the lesion tient does not respond to voice or gentle shak involves the motor cortex and causes hemi ing, arousability and motor responses are tes paresis. The maneuvers used tient who can cooperate with the exam; it dis to provide adequate stimuli without inducing appears as the patient becomes more drowsy. Motor responses to noxious stimulation in patients with acute cerebral dysfunction. Patients with forebrain or diencephalic lesions often have a hemiparesis (note lack of motor response with left arm, externally rotated left foot, and left extensor plantar response), but can gen erally make purposeful movements with the opposite side. Lesions involving the junction of the diencephalon and the mid brain may show decorticate posturing, including exion of the upper extremities and extension of the lower extremities. As the lesion progresses into the midbrain, there is generally a shift to decerebrate posturing (C), in which there is extensor posturing of both upper and lower extremities. An appropriate re mals, these patterns of motor response may be sponse is one that attempts to escape the stim produced by brain lesions of several different ulus, such as pushing the stimulus away or kinds and locations and the patterns of motor attempting to avoid the stimulus. The motor response in an individual to any one of these response may be accompanied by a facial gri lesions may vary across time. It types of responses can be produced by supra is necessary to distinguish an attempt to avoid tentorial lesions, although they imply at least the stimulus, which indicates intact sensory incipient brainstem injury. There is a tendency and motor connections within the spinal cord for lesions that cause decorticate rigidity to be and brainstem, from a stereotyped withdrawal more rostral and less severe than those caus response, such as a triple exion withdrawal of ing decerebrate rigidity. In general, there is the lower extremity or exion at the ngers, much greater agreement among observers if wrist, and elbow. The stereotyped withdrawal they simply describe the movements that are response is not responsive to the nature of the seen rather than attempt to t them to com stimulus. The fully developed occur in patients with severe brain injuries or response consists of a relatively slow (as op even brain death. It is also important to assess posed to quick withdrawal) exion of the arm, asymmetries of response. Failure to withdraw wrist, and ngers with adduction in the upper on one side may indicate either a sensory or a extremity and extension, internal rotation, and motor impairment, but if there is evidence of vigorous plantar exion of the lower extremity. Such withdraw on both sides, accompanied by facial fragmentary patterns have the same localizing grimacing, may indicate bilateral motor im signicance as the fully developed postural pairment below the level of the pons. The decorticate pattern is generally pro Most appear only in response to noxious stim duced by extensive lesions involving dysfunc uli or are greatly exaggerated by such stimuli. Such patients typically have represents the response to endogenous stim normal ocular motility. A similar pattern of uli, ranging from meningeal irritation to an oc motor response may be seen in patients with cult bodily injury to an overdistended bladder. In addition, the two matose patients with decorticate posturing 139 sides of the body may show different patterns recovered. The arms are held in adduction and ex from experimental physiology to certain pat tension with the wrists fully pronated. Tonic First, these terms imply more than we really neck reexes (rotation of the head causes hy know about the site of the underlying neuro perextension of the arm on the side toward Examination of the Comatose Patient 75 which the nose is turned and exion of the repeatedly conrmed. The physiologic basis of other arm; extension of the head may cause ex this motor pattern is not understood, but it may tension of the arms and relaxation of the legs, represent the transition from the extensor pos while exion of the head leads to the opposite turing seen with lower midbrain and high pon response) can usually be elicited. As with de tine injuries to the spinal shock (accidity) or corticate posturing, fragments of decerebrate even exor responses seen from stimulating posturing are sometimes seen. De the main purpose of the foregoing review of cerebrate posturing in experimental animals the examination of a comatose patient is to dis usually results from a transecting lesion at the tinguish patients with structural lesions of the level between the superior and inferior colli brain from those with metabolic lesions. It is believed to be due to the release of vestibulospinal postural reexes from fore imaging. The level of brainstem dys require an extensive laboratory evaluation to de function that produces this response in humans ne the cause. When focal neurologic ndings may be similar, as in most cases decerebrate are observed, it becomes imperative to deter posturing is associated with disturbances of mine whether there is a destructive or compres ocular motility. However, electrophysiologic, sive process that may become life threatening radiologic, or even postmortem examination or irreversibly damage the brain within a matter sometimes reveals pathology that is largely of minutes. Therefore, the physician should be more severe nding than decorticate postur come familiar with the few focal neurologic ing; for example, in the Jennett and Teasdale ndings that are seen in patients with diffuse series, only 10% of comatose patients with head metabolic causes of coma, and understand their injury who demonstrated decerebrate postur implications for the diagnosis of the metabolic 139 problem. Most patients with decere brate rigidity have either massive and bilateral forebrain lesions causing rostrocaudal deteri oration of the brainstem as diencephalic dys Respiratory Responses function evolves into midbrain dysfunction (see Chapter 3), or a posterior fossa lesion that the range of normal respiratory responses compresses or damages the midbrain and ros includes the Cheyne-Stokes pattern of breath tral pons. However, the same pattern may oc ing, which is seen in many cognitively normal casionally be seen in patients with diffuse, but people with cardiac or respiratory disorders, fully reversible, metabolic disorders, such as particularly during sleep. Patients with severe sleep Extensor posturing of the arms with accid apnea may stop breathing for 10 seconds or so or weak exor responses in the legs is typically every minute or two. Their color may become seen in patients with injury to the lower dusky during the oxygen desaturation that ac brainstem, at roughly the level of the vestibular companies each period of apnea. This must be cause the seizure usually results in the release distinguished from sepsis, hepatic encephalop of adrenalin, the pupils typically are large after athy, or cardiac dysfunction, conditions that of a seizure. The may suppress all brainstem responses, includ nature of the primary insult is determined by ing pupillary light reactions, and simulate brain whether the blood pH is low (metabolic aci death (see Chapter 6). For this reason, it is dosis with respiratory compensation) or high critical to do urinary and blood toxic and drug (primary respiratory alkalosis). Pupillary Responses Ocular Motor Responses A key problem with interpreting pupillary re sponses is that either metabolic coma or di Typical oculocephalic responses, as seen in a encephalic level dysfunction may cause bilat comatose patient with an intact brainstem, are erally small and symmetric, reactive pupils. In fact, brainstem oculoce still have impairment that can be attributed to phalic responses (as if the eyes were xed on a either a diencephalic lesion or to symmetric point in the distance) are nearly impossible for forebrain compression. As a result, it is generally therefore are a useful differential point in iden necessary to do an imaging study (see below) tifying psychogenic unresponsiveness. On the within the rst few hours in most comatose other hand, oculocephalic responses may be patients, even if the cause is believed to be come particularly brisk in patients with hepatic metabolic. Very small pupils may be indicative of pon Certain drugs may eliminate oculocephalic tine level dysfunction, often indicating an and even caloric vestibulo-ocular responses.
Sound preparation enables the hospital to continue to function and reduces stress and confusion among staff. This plan should be an extension of the normal hospital routines and not a complete change in the system. The roles allocated to individual staff should remain as close as possible to their familiar daily work. A system of coordination and communication with other health facilities receiving casualties may make it possible to transfer wounded from a hospital which is overwhelmed to another which has received comparatively few patients. Alternatively, other health facilities may be able to provide help in the form of additional personnel. Extra hospital staff are needed; the plan should include how to contact those who are off duty. Bear in mind that an influx of wounded may occur at a time when hospital staff are having difficulty getting to work because it is too dangerous to go out in the streets. This low figure permits hospital staff to become familiar with the system, documentation and equipment. Civilian casualties are likely to arrive at the hospital without having received first aid and without the help of an ambulance service. In this case the less seriously injured arrive first; therefore, the hospital is often where the first triage of the wounded is performed. All patients arriving at the hospital during an influx of casualties go through the triage process. Clinical assessment to determine which patients take priority for limited surgical time and resources. The organization and management involved in admitting large numbers of wounded to the hospital. He or she must have experience and understanding of war wounds,anoverview of all aspects of the functioning of the hospital and an ability to make clear decisions under stress. A surgeon can make an accurate surgical assessment of each patient, but might give preference to those cases corresponding to his or her own specialty. An anaesthetist may be able to leave the operating theatre to help with clinical assessment. In practice many of these patients will have abdominal or thoracic injuries or wounds of peripheral blood vessels. In practice this applies to the majority of casualties: most compound fractures and penetrating head injuries. In practice this includes superficial wounds managed under local anaesthesia in the emergency room. These include the moribund, or patients with multiple major wounds whose management could be considered wasteful of scarce resources, including operating time and blood. When evacuation time to the hospital is longer than 24 hours, few patients fall into Category I. Triage serves to ensure that patients are admitted systematically and nothing is overlooked. Thus there must be a designated triage area; the admission room can be used for the most seriously wounded. As a simple rule, stretcher cases should go directly to the admission room while walking wounded can go to the triage area. The narrow entry door helps restrict the number of people coming into the hospital. The situation needs constant reassessment to determine the need for additional staff, supplies and ward areas. In addition, the person in charge of triage must be aware of events outside the hospital. Other people may try to enter the hospital out of curiosity or concern; casualties may be brought in by friends or relatives; the population may be in a state of panic and consider the hospital a safe place. Minimizing the number of people entering the hospital reduces the confusion considerably. There may be many people involved in admitting the patients and providing the initial treatment, but the clinical assessment and allocation of a triage category must be done by the person in charge of triage, who must see all the patients. Suspend the routine operating list and other routine activities until the situation is resolved. Be prepared to organize the early discharge of patients currently in the hospital to make space. Arrange for staff to take breaks, and make sure that food and drink are provided for them. While this is not an ideal time to introduce untrained people to the hospital, it can be difficult to refuse. Keep dead bodies in the mortuary until they are identified and handed over to relatives or to the local community for proper burial. Keep a list of admitted or treated patients so that people who come looking for their relatives or friends can be informed. The local authorities may require information about the number of admissions and deaths. Some find it difficult to accept that they need to rest; this must be insisted on. Following clinical assessment the triage category may be marked on the forehead in Roman numerals. Routine measurement of pulse, blood pressure, and respiration rate is not always necessary. Remove all clothing and examine the whole patient (small penetrating wounds are often overlooked). Note abdominal distension or tenderness in injuries of abdomen, chest or buttocks. The number of casualties cannot be foreseen; waiting until all patients have arrived before deciding which should be taken first to the operating theatre only wastes time. The person in charge of triage must keep in close contact with the operating theatre. The only difference is the modification of the admission sheet for use as a triage card. Sets of documents should be prepared for individual patients, clearly numbered with a triage number from 001 to 100 and kept in a box in readiness (see Fig. This has proved to be the most satisfactory way of making sure that the card does not become separated from the patient. Age (adult/child/infant) and sex Medical assessment (brief) Type of injury Triage category All treatment given (antibiotics, tetanus toxoid, etc. This covers all the essential documentation, the objective being to keep track of the patients in the short term. The full details (for the admission book, completing information on the admission sheet) can be completed later when there is more time. The person in charge keeps a list where basic details on each patient are recorded (the triage coordination sheet, see Fig.
It the frontotemporal cortex and right basal gan also occurs with systemic infectious processes glia of patients with subclinical hepatic ence or as a component of encephalitis, during 5 phalopathy. They may have an Pathophysiology of Signs and Symptoms of Coma 7 increased number of hours of sleep and may be de-efferented, but there is a history of sub drowsy between sleep bouts. Even when maximally aroused, the so that they may be treated appropriately by level of cognitive function may be impaired. At the bedside, Such patients can be differentiated from those discussion should be with the patient, not, as with psychiatric impairment, such as catato with an unconscious individual, about the pa nia or severe depression, because they can be tient. Patients with large midpontine lesions of aroused by vigorous stimulation to respond to ten are awake most of the time, with greatly simple stimuli. The patient may havioral responsiveness, and there may be some grimace in response to painful stimuli and limbs overlap among them. Therefore, it is generally may demonstrate stereotyped withdrawal re best to describe a patient by indicating what sponses, but the patient does not make local stimuli do or do not result in responses and the izingresponsesordiscretedefensivemovements. However, it is difcult to equate the lackofmotor responses tothe depth ofthe coma, Subacute or Chronic Alterations as the neural structures that regulate motor re of Consciousness sponses differ from those that regulate con sciousness, and they may be differentially im Dementia denes an enduring and often pro paired by specic brain disorders. Conventionally, the paralysis of all four limbs and the lower cranial term implies a diffuse or disseminated reduc nerves. This condition has been recognized at tion in cognitive functions rather than the im least as far back as the 19th century, but its dis pairment of a single psychologic activity such tinctive name was applied in the rst edition of as language. The development of multiple cogni tions of this condition for the diagnosis of coma tive defects manifested by both: (1) Memory and for the specialized care such patients re impairment (impaired ability to learn new in quire. Although not unconscious, locked-in pa formation or to recall previously learned infor tients are unable to respond to most stimuli. A mation); (2) One (or more) of the following high level of clinical suspicion is required on cognitive disturbances: aphasia (language dis the part of the examiner to distinguish a locked turbance), apraxia (impaired ability to carry out in patient from one who is comatose. The most motor activities despite intact motor function), common cause is a lesion of the base and teg agnosia (failure to recognize or identify objects mentum of the midpons that interrupts des despite intact sensory function), disturbance in cending cortical control of motor functions. Usually, the term de may be taught to respond to the examiner by mentia is applied to the effects of primary dis using eye blinks as a code. Rare patients with orders of the cerebral hemispheres, such as subacute motor neuropathy, such as Guillain degenerative conditions, traumatic injuries, Barre syndrome, also may become completely and neoplasms. In some patients, however, it may be applies to chronic conditions carrying limited an essentially permanent condition. Many patients with either etative state,like comatosepatients, show no evi acute or chronic alterations of consciousness dence of awareness of self or their environment. However, when awakened, Unlike brain death, in which the cerebral hemi consciousness is clearly clouded. In the truly spheres and the brainstem both undergo over hypersomniac patient, sleep appears normal whelming functional impairment, patients in and cognitive functions are normal when pa vegetative states retain brainstem regulation of tients are awakened. Hypersomnia results from cardiopulmonary function and visceral autono hypothalamic dysfunction, as indicated later in mic regulation. Other terms in the literature designating the usually associated with bilateral frontal lobe dis vegetative state include coma vigil and the apa ease and, when severe, may evolve into akinetic llic state. Brain death is dened as the irreversible 14 Akinetic mutism describes a condition of loss of all functions of the entire brain, such silent, alert-appearing immobility that charac that the body is unable to maintain respiratory terizes certain subacute or chronic states of and cardiovascular homeostasis. Although vig altered consciousness in which sleep-wake cy orous supportive care may keep the body pro cles have returned, but externally obtainable cesses going for some time, particularly in an evidence for mental activity remains almost en tirely absent and spontaneous motor activity is lacking. Pathophysiology of Signs and Symptoms of Coma 9 otherwise healthy young person, the loss of diagnosis of structural coma depends on the brain function eventually results in failure of the recognition of the signs of injury to structures systemic circulation within a few days or, rarely, that accompany the arousal pathways through after several weeks. Structural processes that impair the dead for some time prior to the cessation of the function of the arousal system fall into two ca heartbeat is attested to by the fact that the or tegories: (1) supratentorial mass lesions, which gan in such cases is usually autolyzed (respirator may compress deep diencephalic structures and 15 brain) when examined postmortem. Because hence impair the function of both hemispheres, function of the cerebral hemispheres depends and (2) infratentorial mass or destructive le on the brainstem (see ascending arousal system sions, which directly damage the arousal system section below), and because cerebral hemi at its source in the upper brainstem. The re sphere function is extremely difcult to assess mainder of Chapter 1 will systematically exam when the brainstem is nonfunctioning, physi ine the major arousal systems in the brain and cians in the United Kingdom have developed the physiology and pathophysiology of consci 16 the concept of brainstem death, dened as ousness. Once the exam Acute alterations of consciousness are dis ination is completed, the examiner should be cussed in Chapters 2 through 5. Subacute and able to determine whether the source of the chronic alterations of consciousness are discus impairment of consciousness is caused by a sed in Chapter 9. The neurologic exam whether the cause of the impairment is struc ination of a patient with impaired conscious tural or metabolic, and what treatments must ness, fortunately, is brief, because the patient be instituted to save the life of the patient. Since cannot detect sensory stimuli or provide vol the last edition of this monograph in 1980, untary motor responses. In appropriate and reactivity of the pupils, (4) the eye move clinical circumstances, if the initial examina ments and oculovestibular responses, and (5) tion suggests structural brain damage, a scan the skeletal motor responses. From this infor may identify the cause of the alteration of con mation, the examiner must be able to recon sciousness and dictate the therapy. However, struct the type of the lesion and move swiftly when the scan does not give the cause, there is to lifesaving measures. Before reviewing the no simple solution; usually no single laboratory components of the coma examination in detail, test or screening procedure will sift out the however, it is necessary to understand the ba criticalinitialdiagnosticcategoriesaseffectively sic pathways in the brain that sustain wakeful, as a careful clinical evaluation. Only from this perspective If the cause of coma is structural, it generally is it possible to understand how the compo is due to a focal injury along the course of the nents of the coma examination test pathways neural pathways that generate and maintain a that are intertwined with those that maintain normal waking brain. He was brought up in Austrian Trieste, studied medicine in Vienna, and in 1906 took a post in the Psychiatric Clinic under Professor Julius von Wagner-Jauregg. In 1916 during World War I, he began seeing cases of a new and previously unrecorded type of encephalitis and published his rst report of this illness in 1917. Although subsequent accounts have often confused this illness with the epidemic of inuenza that swept through Europe and then the rest of the world during World War I, von Economo was quite clear that encephalitis le thargica was not associated with respiratory symptoms, and that its appearance preceded the onset of the latter epidemic. Von Economo continued to write and lecture about this experience for the remainder of his life, until his premature death in 1931 from heart disease. Based on his clinical observations, von Economo proposed a dual center the ory for regulation of sleep and wakefulness: a waking inuence arising from the upper brainstem and passing through the gray matter surrounding the cerebral aqueduct and the posterior third ventricle; and a rostral hypothalamic sleep promoting area. These observations became the basis for lesion studies done by 20 21 22 Ranson in 1939, by Nauta in 1946, and by Swett and Hobson in 1968, in which they showed that the posterior lateral hypothalamic lesions in monkeys, rats, and cats could reproduce the prolonged sleepiness that von Economo had observed. The rostral hypothalamic sleep-promoting area was conrmed exper 21 imentally in rats by Nauta in 1946 and in cats by Sterman and Clemente in the 23 1960s. A photograph of Baron Constantin von Economo, and excerpts from the title page of his lecture on the localization of sleep and wake promoting systems in the brain. These indi viduals would develop episodes of sleep attacks during which they had an over whelming need to sleep. He noted that they also had attacks of cataplexy in which they lost all muscle tone, often when excited emotionally. Von Economo noted accurately that these symptoms were similar to the rare condition previously identied by Gelinaux as narcolepsy. He also noted that they had developed symptoms of narcolepsy after recovering from encephalitis lethargica with pos terior hypothalamic lesions. Wilson even described examining a patient in his ofce, with the young house ofcer McDonald Critchley, and that the patient indeed had atonic paralysis, with loss of tendon reexes and an extensor plantar response during the attack. However, the most convincing found that after a transection between the me body of evidence was assembled by Baron Con dulla and the spinal cord, a preparation that he 19 stantin von Economo, a Viennese neurologist called the encephale isole,orisolatedbrain,ani who recorded his observations during an epide malsshowed a desynchronized(lowvoltage,fast, mic of a unique disorder, encephalitis lethargica, i. When awakened, they could interact in a showed a synchronized, or high-voltage, slow relatively unimpaired fashion with the examiner, wave pattern indicative of deep sleep and the but soon fell asleep if not continuously stimu animalswerebehaviorallyunresponsive. Many of these patients suffered from concluded that the forebrain fell asleep due to oculomotor abnormalities, and when they died, the lack of somatosensory and auditory sen they were found to have lesions involving the sory inputs. He did not address why the ani paramedian reticular formation of the midbrain mals failed to respond to visual inputs either at the junction with the diencephalon.