THE WESTERN JOURNAL OF MEDICINE

THE

WESTERN

JOURNAL

OF

MEDICINE

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SEPTEMBER 1991 SEPTEMBER

1991

o

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155 155

o

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Human Immunodeficiency Virus Precautions in Emergency Departments PREVENTING EXPOSURE to the human immunodeficiency virus (HIV) and other blood-borne pathogens is important in emergency departments. Recent studies have shown low compliance rates with barrier precautions recommended by the Centers for Disease Control. It has been suggested that improvements in design of intravenous catheters and phlebotomy equipment could reduce the incidence of needle-stick injuries. Although the seroprevalence rates for HIV and hepatitis vary among institutions, all bodily fluids in all patients should be considered potentially infectious in the emergency setting. The major risk to emergency personnel is needle sticks. Recently developed intravenous catheters now provide an integrated plastic sheath that covers the needle stylet after insertion of the catheter. For patients requiring phlebotomy after catheter insertion, vacuum tube assemblies are available that can be inserted directly into the intravenous catheter. These assemblies fill laboratory tubes directly and do not require the transfer of blood from syringes through needles. Needle-stick injuries may also occur when needles are inserted into intravenous tubing-"piggybacking." New devices provide a needle and sheath assembly that prevents needle-stick injuries in these cases. These devices also include a locking mechanism that prevents accidental dislodgement of the needle from the intravenous tubing. The use of winged-needle intravenous catheters, or "butterflies," should be avoided whenever possible. The disposal of these devices, as well as their removal from laboratory tubes, has resulted in a relatively high rate of needle-stick exposures. If a needle and syringe assembly must be used for a phlebotomy, then a two-handed technique of holding the syringe in one hand and holding blood tubes in the other should never be used. Test-tube racks should hold laboratory tubes, and one hand should be used to fll the upright laboratory tubes. Needles should not be recapped. If immediate disposal is not possible, however, and recapping is necessary, a onehanded technique should always be used. Never hold the cap of a needle in one hand while inserting a needle into the cap with the other. Rather, the cap should be scooped up with the needle while the cap is lying on a flat surface. Convenient plastic receptacles should be placed at the bedsides of all patients for use by health care workers who do intravenous insertions and phlebotomies. These receptacles must be replaced frequently to avoid needle sticks due to overfilled

boxes. Skin and mucous membrane exposure is further prevented by using gloves, masks, protective eyewear, and gowns. These items must be easy to reach and easy to use for all health care personnel, especially in areas where invasive procedures are done or where trauma or cardiac arrest patients are resuscitated. Barrier protection should also be readily available to health care personnel irrigating wounds. Umbrellalike devices that fit onto irrigation instruments are now available and prevent the backsplash associated with high-pressure irrigation devices. Gloves should be worn whenever skin may become contaminated with blood. New personnel must be trained and compliance with infection control protocols monitored in every emergency department. Postexposure counseling and testing of source

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patients and exposed medical staff must be provided. Counseling should include a discussion of confidentiality issues, the frequency of testing, and the use of hepatitis immune globulin and zidovudine (AZT). ALAN GELB, MD San Francisco, California

REFERENCES BaraffLJ, Talan DA: Compliance with universal precautions in a university hospital emergency department. Ann Emerg Med 1989; 18:654-657 Gelb A: HIV infection control issues concerning first responders and emergency physicians. Occup Med 1989; 4(Suppl):61-64 Jagger J, Hunt EH, Brand-Elnaggar J, Pearson RD: Rates of needle-stick injury caused by various devices in a university hospital. N Engl J Med 1988; 319:284-288 Kelen GD: Human immunodeficiency virus and the emergency department: Risks and risk protection for health care providers. Ann Emerg Med 1990; 19:242-248 Marcus R: Surveillance of health care workers exposed to blood from patients infected with the human immunodeficiency virus. N Engl J Med 1988; 319:1118-1123

High-Dose Epinephrine in Cardiac Arrest EPINEPHRINE IS ONE of the few drugs with proven efficacy in cardiac arrest, but its optimal dose is unknown. Epinephrine achieves its beneficial effects by ca-adrenergic vasoconstriction of the peripheral circulation, thereby increasing blood flow through the heart and brain. This was demonstrated in animals in the early 1960s, laying the groundwork for advanced cardiac life support (ACLS) standards. These studies, however, used doses of 100 yg per kg or more, whereas ACLS standards recommend only 7.5 to 15 Ag per kg in humans (0.5 to 1 mg in an adult). There was no further comment or study of this discrepancy during the following decade. A series of careful studies in animals in the 1980s rekindled interest in the optimal dose. Doses of 20 1g per kg were shown not to provide the necessary coronary artery perfusion to resume spontaneous circulation. Doses of 200 jig per kg comfortably met this goal and often produced blood flow approaching normal, nonarrested levels. Case reports of humans suggested that larger doses of epinephrine could cause a return of perfusing rhythm, even in patients with long arrest times and unfavorable cardiac rhythms, but most died of brain damage within 24 hours. Case series of patients with prolonged cardiac arrest have shown that epinephrine doses of 200 /g per kg can substantially raise diastolic blood pressure and coronary artery perfusion pressure, often doubling the latter and achieving levels greater than those needed to resume spontaneous circulation. Standard ACLS doses do not achieve this. High doses of epinephrine of 200 ,g per kg caused at least a brief return of spontaneous circulation in 60% of adults with prolonged cardiac arrest versus 15% who received a standard dose of 15 jug per kg. Therapy was not randomized, however. Children in arrest in whom initial standard ACLS therapy failed and who were then randomly selected for either continued standard doses or high doses of epinephrine were never resuscitated with standard doses. High-dose epinephrine resuscitated 70%, however, and 40% survived. Only 38% of survivors were neurologically intact, but high rates of poor neurologic outcome are typical of children with cardiac arrest. Most recently, 68 patients who were resuscitated from cardiac arrest and who received varying doses of epinephrine at the discretion of the clinician were examined to determine if there was any difference in various cardiovascular, pulmonary, endocrine, neurologic, and other complication rates between those receiving high doses and those

Human immunodeficiency virus precautions in emergency departments.

THE WESTERN JOURNAL OF MEDICINE THE WESTERN JOURNAL OF MEDICINE * * SEPTEMBER 1991 SEPTEMBER 1991 o * 155 155 o * Human Immunodeficiency...
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