REDUCED HYPOXIC CHEMOSENSITIVITY IN PARTIALLY PARALYZED MAN - A NEW PROPERTY OF MUSCLE-RELAXANTS

Background: It was hypothesized that non-depolarizing neuromuscular bl ocking agents impair hypoxic chemosensitivity in man. Methods: In thir ty randomly allocated male volunteers the hypoxic and hypercarbic vent ilatory responses were measured during partial paralysis (TOF ratio 0. 70) due to either atracurium (n=10), pancuronium (n=10) or vecuronium (n=10). Results: Hypoxic ventilatory responses were depressed by 30 6, 28 7 and 29 6% (mean SD) at steady-state infusion of atracurium, panc uronium and vecuronium, respectively. At a TOF ratio of >0.90, the HVR was not different from control measurements. Conclusion: It is conclu ded that non-depolarizing neuromuscular blocking agents impair hypoxic ventilatory regulation. Further experimental studies are warranted to fully describe the mechanism(s) responsible for this interaction. (C) Acta Anaesthesiologica Scandinavica 40 (1996)