The use of
vecuronium and
meperidine on the clinical and metabolic effects of shivering in mechanically ventilated patients after hypothermic
cardiopulmonary bypass (CPB) was compared. Twenty adult male patients undergoing cardiac surgery were randomized to
meperidine, 25 to 75 mg (n = 10), or
vecuronium, 0.1 microgram/kg (n = 10), for the treatment of shivering during postoperative
rewarming.
Vecuronium was continued as an infusion at 1.0 microgram/kg/min for 4 hours.
Meperidine abolished shivering in 50% of patients with a 60% recurrence within 2 hours and did not correct acute
respiratory acidosis when it occurred.
Vecuronium uniformly abolished shivering, corrected acute
respiratory acidosis, and improved mixed venous oxygen saturation (20% v 4%), decreased oxygen consumption (-32% v -7%) and decreased end-tidal
carbon dioxide (-21% v -5%) significantly more than
meperidine (p < 0.005).
Meperidine administration caused a significant decline in systolic blood pressure (121.9 +/- 10.6 mmHg to 106.9 +/- 8.5 mmHg, p = < 0.02). The authors conclude that, during
rewarming after hypothermic CPB, muscle relaxation with
vecuronium reverses both the clinical and metabolic effects of shivering more reliably and effectively than repeated boluses of
meperidine, and with greater hemodynamic stability. Control can be maintained by continuous infusion of
vecuronium with concomitant sedation for up to 4 hours without prolonging intubation time.