[The treatment of status asthmaticus using ketamine--experimental results and clinical experience]

Abstract

Intensive therapy of a patient with status asthmaticus must lead to a reduction of vital threat by improving respiratory and cardiac functions. Because of the bronchodilating effect of ketamine, analgesic sedation with ketamine and benzodiazepines is extremely useful for prolonged ventilation. At the beginning of this treatment it can be necessary to supplement the continuous intravenous infusion of ketamine and diazepam or ketamine and midazolam with small bolus doses of up to 3.5 mg/kg/h of ketamine. Experience has shown that the combination of ketamine and midazolam has better controllability. In some of our patients the bronchodilating effect of ketamine was not sufficient and therefore ventilation with halothane was necessary at least intermittently. In contrast to halothane, ketamine can be combined with vasodilators and sympathomimetics as our own experience has shown. The combined application of ketamine with glycerol trinitrate or sodium nitroprusside is indicated in the event of pulmonary or general hypertension. The use of sympathomimetics--mainly beta-sympathomimetics--antagonizes the negative inotropic effect of ketamine, improves the circulatory system and leads to a direct bronchodilating effect. Progress in treatment was mainly achieved by continuous intravenous infusions of terbutaline (Bricanyl). Aminophylline is very compatible with ketamine, but because of its stimulating effect the use of aminophylline seems to be reasonable only during weaning from the ventilator. Control of the usually deep analgesic sedation and an accompanying optimum drug therapy are only possible with complete cardiorespiratory monitoring including invasive blood pressure measurement and catheterization of the pulmonary artery. In our clinic 24 patients with status asthmaticus were treated. Sixteen asthmatic patients were treated with analgesic sedation using ketamine and benzodiazepines, three of them without intubation and ventilation. In spite of the life-threatening situation and reanimation before admission to the intensive care unit, only one patient died. Our experience has shown that intensive therapy including analgesic sedation with ketamine and benzodiazepines, optimized by application of sympathomimetics and vasodilators, is suitable for overcoming the life-threatening situation of patients with status asthmaticus.