POSTOPERATIVE RESISTANCE TO ATRACURIUM

Supported by two case reports we show that resistance to atracurium ca n develop postoperatively. Both patients had septic complications afte r elective thoracic surgery. A 39-year-old patient developed a bronchi al fistula and a superinfection of the remaining thoracic cavity after pneumonectomy. At the time of rethoracotomy the neuromuscular blockin g potency of atracurium had changed drastically: onset time was length ened (7 vs. 3.5 min), recovery period (DUR 10%) was reduced (14 vs. 28 min) and the maintenance dose had to be trippled (14.3 vs. 5.0 mu g/k g per minute). Following superior robe resection in a 56-year-old pati ent, middle robe gangrene occurred which had to be removed. ln contras t to the first anaesthesia the intubation dose of atracurium had to be increased significantly (70 vs. 40 mg), and even with this amount the neuromuscular blocking effect was not complete. Furthermore to accomp lish a convenient state of relaxation the maintenance dose had to be r aised considerably (11.8-16.5 vs. 5.5 mu g/kg per minute). These repor ts show that even within a short period of time resistance to atracuri um can develop and we must suppose that the severe inflammatory reacti ons caused these changes.