Atracurium during thoracic surgery: Impaired efficiency in septic processes

Objective: The aim of the study was to examine whether the neuromuscular bl ocking potency of atracurium changes in patients with a septic intrathoraci c process. Design: Prospective clinical study. Setting: Community hospital, Participants:Thirty patients who underwent thoracic surgery for resection o f a pulmonary carcinoma were examined. Fifteen patients showed typical sign s of a concomitant bacterial superinfection (infection group), 15 age-match ed patients without infection served as the control (no-infection)group. Interventions: Relaxation was induced with atracurium, 0.6 mg/kg intravenou sly for intubation, followed by a continuous infusion to maintain a 90% neu romuscular blockade. Relaxometry was performed electromyographically using the Datex Relaxograph by stimulating the ulnar nerve next to the wrist. Measurements and Main Results: The onset time was significantly longer (5.3 +/- 2.9 v 3.3 +/- 1.2 minutes; p < 0.05), and the recovery phase (DUR 10%) was significantly shorter (23.5 +/- 8.6 v 36.9 +/- 7.3 minutes; p < 0.001) in the infection group compared with the controls. The infusion rate withi n the first hour of continuous application was 77.4% higher in the infectio n group than in the control group (11.0 +/- 2.9 v 6.2 +/- 1.0 mu g/kg/min; p < 0.001). Conclusion: The study showed that septic intrathoracic processes cause a cl ear reduction of the neuromuscular blocking potency of atracurium. To guara ntee adequate muscle relaxation in such cases, precise neuromuscular monito ring is highly advisable. Copyright (C) 1999 by W.B. Saunders Company.