Controlled Evaluation of Muscle Relaxation in the Ventilated Neonate

Abstract

To assess the effects of muscle relaxation on the critically ill ventilated neonate, pancuronium bromide was administered for a 12-hour period to ten low-birth-weight neonates (960 to 2,000 gm) of 26 to 34 weeks gestation, all of whom required mechanical ventilation and were studied within 48 hours of birth (six to 39 hours). The infants were also studied for a 12-hour period during which no pancuronium bromide was administered. During both study periods, the order of which was randomized, heart rate, blood pressure, Po2, and intracranial pressure were continuously measured. The amounts of handling during the pancuronium and control periods were similar. The results revealed a significantly greater duration of hypoxia (P02 < 50 torr) (56.1 vs 23.6 minutes, P < .001) and hyperoxia (Po2 > 70 torr) during the control period (92.5 vs 13 minutes, P < .001). Durations of intracranial pressure elevation 10 cm H2O above the infant's baseline were significantly less during paralysis (6.7 vs 58.8 minutes, P < .001) as were spikes of intracranial pressure to greater than 25 cm H2O (1.6 vs 24.4, P < .05). There was no significant improvement in blood gas values, fractional inspiratory oxygen, or ventilator settings during muscle relaxation. Pancuronium reduced periods of nonoptimal oxygenation and elevated intracranial pressure and may therefore help to decrease adverse sequelae for the low-birth-weight, ventilated neonate.