Histamine release during the induction of anesthesia with propofol in allergic patients: A comparison with the induction of anesthesia using midazolam-ketamine

Objective: A prospective randomized controlled study was performed for patients with a history of allergy to evaluate the effect of the induction of anesthesia with propofol against histamine release, skin reactions, hemodynamic changes and other clinical symptoms, while also comparing these parameters during the induction of anesthesia with midazolam-ketamine for patients with a history of allergy. ¶Subjects: We examined 40 patients undergoing oral surgery, who had a history of allergy and/or the percentage of eosinophils in the leukocytes was more than 3%. ¶Methods: Forty patients were randomly allocated into two groups and thus received either midazolam-ketamine (M-K group, n = 20) or fentanyl-propofol (propofol group, n = 20) for the induction of anesthesia. Venous blood samples (4 ml each) were obtained before induction as a control and at 0.5, 1, 3, 5 minutes after the administration of each induction agent, and then furthermore at 0.5, 1, 3, 5 minutes after tracheal intubation in order to measure the plasma histamine level by using the HPLC post-label system. In addition, the blood pressure and heart rate were also simultaneously recorded. Skin reactions were also evaluated by two anesthesiologists. ¶Results: The incidence of 50% histamine release during the induction of anesthesia with propofol occurred in 15% of the patients with a history of allergy. Sixteen patients out of 20 (80%) showed a decrease in the systolic blood pressure after the administration of propofol without any evidence of histamine release. The incidence of 50% histamine release, skin reactions and an increase in the heart rate between the two groups were not statistically significant after the administration of each anesthetic agent. Moreover, some patients also demonstrated histamine release after tracheal intubation. Hemodynamic changes after tracheal intubation showed a similar tendency in both groups. No significant difference was observed regarding the incidence of histamine release, skin reactions and hemodynamic changes between both groups after tracheal intubation. ¶Conclusions: Propofol was found to show a similar incidence of histamine release during the induction of anesthesia using midazolam-ketamine, and thus was also found to be a useful induction agent against histamine release for patients with a history of allergy when hydroxizine was used as a premedication.