Reduced hypoxic chemosensitivity in partially paralysed man. A new property of muscle relaxants?

BACKGROUND

It was hypothesized that non-depolarizing neuromuscular blocking agents impair hypoxic chemosensitivity in man.

METHODS

In thirty randomly allocated male volunteers the hypoxic and hypercarbic ventilatory 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 306, 287 and 296% (mean SD) at steady-state infusion of atracurium, pancuronium and vecuronium, respectively. At a TOF ratio of > 0.90, the HVR was not different from control measurements.

CONCLUSION

It is concluded 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.