Anaphylactic shock is categorized as a “true emergency.” It is a life-threatening medical emergency whose onset can be rapid. Anaphylactic shock occurs when a person is exposed to something to which he is extremely allergic. For the PHCP who must work in remote environments and who is employing advanced techniques such as drug therapy, it is essential to be able to recognize and correct the development of anaphylactic shock.
After exposure to the offending antigen, possibly an insect bite or administered medication, the patient may develop a range of signs and symptoms, including shortness of breath, hypotension, cyanosis, rashes, dizziness, nausea, hives, and unconsciousness. When death does occur, it is usually the result of upper airway obstruction or shock. Anaphylactic shock requires the injection of medication to combat the allergic reaction, establishment of an IV, and, possibly, endotracheal intubation if the airway is swelling shut.
In treating the patient suffering from anaphylaxsis, all basic life-support procedures are initiated first. Secondly, epinephrine, the drug of choice for treating anaphylaxsis, is administered, since it inhibits the release of vasoactive substances. Administration of 0. 3 to 0. 5 ml of epinephrine in a 1:1,000 solution, subcutaneously or intramuscularly, should im prove respiratory distress and other compl icat ions (Photo 63).1 If shock is already present, it is more effective to administer the e p i n e p h r i n e intra ven ous ly in a dose of 1 to 2 ml in a 1:10,000 solution.2
Photo 63:Epinephine in a 1:1,000 solution.
Hypotension associated with anaphylactic shock should be treated with Ringers Lactate for volume expansion. An antihistamine such as Benadryl administered intravenously will help in counteracting the peripheral effects of some of the vasoactive substances in the bloodstream. In cases such as a bee sting, local absorption of the reaction-causing antigens may be retarded with the application of a constrictive band just above the bite and injection of epinephrine into the site (Photo 64)
Photo 64: Use of a constrictive band just above the insect bite site with subcutaneous injection into the site with epinephrine.
1 Thomas Clarke Kravis and Carmen Germaine Warner, Emergency Medicine (Rockville, MD: Aspen Systems Corporation, 1983), p.311.
2 Ibid.p.311.
