Anaphylactoid reactions to protamine: an often lethal complication in insulin-dependent diabetic patients undergoing vascular surgery.

Protamine is used routinely at our institution during arterial surgery to reverse the anticoagulant effect of heparin. Adverse fatal reactions to protamine are generally believed to be rare. However, major anaphylactoid reactions occurred in 11 of the last 1150 patients receiving this drug at our institution. Nine of these reactions occurred in 325 insulin-dependent diabetic patients (incidence, 3%), whereas only two occurred in the 825 patients not receiving insulin (incidence, 0.2%) (p less than 0.001). Ten of these reactions occurred within 10 minutes of protamine administration (15 to 35 mg), whereas one reaction occurred immediately after administration of a 5 mg test dose of protamine. Systolic blood pressure fell below 60 mm Hg in all of the 11 patients, and three patients had to be resuscitated with closed-chest massage. Initial treatment with epinephrine and steroids was successful in seven cases. Four patients required further resuscitative measures, including closed-chest massage. However, one of the patients died as a result of ventricular fibrillation resistant to treatment. Ten of the 11 patients, including the patient who died, had significant preexisting cardiac disease; six of the surviving 10 patients (60%) had perioperative myocardial infarctions and three died. Thus the total mortality rate was 36% (4/11). These data support the implication that neutral protamine Hagedorn (NPH) insulin produces an adverse reaction through immunologic presensitization of the patient. These data also show that, in the older vascular surgery population with a high incidence of significant cardiac disease, protamine reactions can be potentially lethal. Thus routine use of protamine should be avoided in diabetic patients receiving insulin.

Prevention of succinylcholine induced hyperkalemia by neurolept anesthesia and hexafluorenium in anephric patients.

Forty patients, half of them with normal kidney function, the other half anephric were included in the study. All received diphenhydramine, meperidine and atropine for premedication and droperidol, fentanyl, N2O and O2 for anesthesia. For endotracheal intubation and further relaxation 0.3 mg/kg hexafluorenium, followed in 5 minutes by 0.2 mg/kg succinylcholine were given intravenously. Anesthesia was maintained by 0.5 micrograms/kg increments of fentanyl, muscle relaxation by increments of 0.15 mg/kg or less hexafluorenium and 0.2 mg/kg or less succinylcholine, depending on the surgical time requirements. The drop in serum potassium concentration was sustained and similar in both groups. In the anephric group the drop after induction of neurolept anesthesia was statistically significant. The concentration remained low in both groups over the entire observation period. Unchanged serum sodium excluded hemodilution and the fact that there was no significant change in PvCO2 and pH mitigates against alkalosis as the cause for the observed drop. The anesthesia and muscle relation, as described, appears to be a suitable and hazard free alternative to other techniques.