Anaphylaxis

Abstract

The clinical syndrome of anaphylactic shock is a disorder produced by multiple mechanisms and pharmacological and environmental factors. The syndrome may be produced by both immunologic and nonimmunologic mechanisms and is due to the release of preformed biologically active mediators and the generation of biologically active mediators. The main mediator appears to be histamine. Although there are a number of defined predisposing factors, the majority of first reactions appear unpredictably. The mainstay of treatment is the use of epinephrine, volume replacement, and positive pressure ventilation. The follow-up and documentation of details of the reaction and exhaustive efforts to determine the precipitating factor are important aspects of the subsequent safety of the patient. History may be of more value than diagnostic testing. The use of H1 and H2 blockers, with steroids and sympathomimetics, may reduce the risk or magnitude of reactions in patients with a past history of a reaction.

Fortnightly Review: Treatment of acute anaphylaxis

“…Isolated animal hearts and cardiac muscle preparations are adversely affected by hista-mine and other anaphylactic mediators 15. In addition, some causes of the clinical syndrome of anaphylaxis such as some reactions to protamine and aggregate anaphylaxis due to protein solutions produce right ventricular failure and pulmonary hypertension 16.…”

Adverse Reactions to Plasma Volume Expanders

“…It is theoretically possible that the vasodilatation that is the most common severe feature in such reactions may be missed in a hypovolaemic patient. It is further possible that the endogenous catecholDrug Safety 5 (2) 1990 amine, endorphin, and corticosteroid response to shock both produces blocking of mediator effects and opposes the effects of mediators on target organs (Fisher 1987). Secondly, although multicentre and large population studies have determined incidences of reactions to specific plasma volume expanders they are relatively rare events, and as such confidence limits for reaction rates (which are rarely if ever calculated) will be large.…”

“…Steroids are usually given as drugs of second choice, and antihistamines may be useful in control of persistent cutaneous or cardiovascular signs (Fisher 1987). An important and often overlooked aspect of treatment is the provision of a warning bracelet for patients who react to plasma volume expanders.…”

“…Modifications to the pasteurisation technique in Australia appear to have reduced the risk. A rare syndrome occurring after cardiopulmonary bypass, in which there is massive leak of plasma through pulmonary capillaries, has been attributed to both plasma protein fractions and protamine; but a direct cause and effect relationship between the disorder and the putative causes has not been established (Fisher 1987).…”

Anaphylactic shock: mechanisms and treatment.

“…Whilst the 1 in 10000 dilution is favoured by some, a further tenfold dilution to 1 in 100 000 is suggested by many authors in order to minimize adverse reactions.2944-4657 Thus Barach and Nowak recommend using 1 mL of 1 in 10 000 adrenaline diluted to 10mL, giving a final concentration of 10pgmL ' , administered under A.FT 7 Brown ECG monitoring at the rate of 10 pg or 1 mL min-' 4-This may be followed by an infusion from [1][2][3][4] …”