[A life-threatening anaphylactic reaction following mannitol]

After uneventful induction of general anesthesia, severe hypotension and cardiac arrest developed in a 39-year-old, non-atopic man following infusion of 20% mannitol 80 min after the beginning of anesthesia. It caused a systolic blood pressure of 40 mmHg during a period of 10 min and tachycardia followed by ventricular fibrillation. Immediate resuscitation measures, i.e., external cardiac compression, rapid infusion of 3,000 ml crystalloid and 1,000 ml colloid, central-venous application of suprarenin (2.4 mg total), lidocaine (100 mg), sodium bicarbonate (100 mmol), and two defibrillations, could alleviate the life-threatening reaction. The patient recovered a few hours later without any further sequelae.

Allergologic studies with all drugs involved revealed a positive and specific reaction in an intradermal skin test to 1:100 diluted mannitol, as did in-vitro leucocyte histamine release to 20% and 2% mannitol. For all the other drugs, skin tests and leucocyte histamine release were negative or unspecific. Available RAST determinations to thiopental and suxamethonium were also negative. The total IgE level was normal.

Reflecting the hypotension induced by histamine, the hematocrit rose from 0.4 to 0.5 even though the patient received a large amount of fluid before and during resuscitation. This can be explained by marked sequestration of plasma in the interstitial compartment, leading to hypovolemia. The clinical course and test results suggest that mannitol was the agent responsible for the anaphylactoid reaction.