350 Cyclic AMP-elevating agents prolong the survival of human eosinophils in culture

Anaphylaxis is a consideration in unexplained hypotensive episodes.Sudden onset hypotension can occur in ICU patients.The possible role of anaphylaxis in these patients was investigated by obtaining serum from 22 consecutive ICU patients at 0, 12 and 24 hours after onset of unexplained hypotension.Samples were analyzed by RIA for presence of tryptase.Results indicated that only 3 of 22 hypotensive patients had detectable levels of tryptase at 0 and 12 hrs after onset.Retrospective chart reviews found that all 3 patients had previous drug allergy histories and were receiving suspect antimierobials.The patient with highest serum tryptase (12.9 ng/ml) had a history of penicillin allergy and documented receipt of eefaclor immediately prior to onset of hypotension.There were no known drug allergies in the 19 patients without detectable serum tryptase (10 had sepsis syndrome).These data suggest that mast cell activity is a relatively uncommon cause of hypotension in the ICU setting and support the specificity of serum tryptase levels as an indicator of allergic reactions in that it does not rise with hypotension due to other factors.