| Abstract: | The effect of hypocarbia on the recovery from the neuromuscular blockade produced by vecuronium was studied in 20 anesthetized patients. Vecuronium was administered until twitch tension was reduced to between 0-15% of control. Neuromuscular function was then allowed to spontaneously recover during continued normocarbia (end-tidal PCO2 5.5 kPa [41 mm Hg]) in half the patients, and in the other half of the patients hyperventilation producing hypocarbia (mean end-tidal PCO2 of 3.1 +/- 0.4 kPa SD [23 +/- 3 mm Hg] at the completion of twitch force recovery) was initiated at the beginning of spontaneous recovery from neuromuscular blockade. The mean vecuronium recovery index (time for spontaneous recovery from 25-75% of control twitch tension) was slightly but not significantly shorter in the hyperventilated patients (8.4 +/- 1.8 min SD) than in the normally ventilated patients (10.4 +/- 3.4 min SD). We conclude the vecuronium recovery index in anesthetized patients is not significantly changed by hyperventilation with hypocarbia when induced at the beginning of recovery from neuromuscular blockade. |
