Nitrous oxide analgesia for intubating preterm neonates: a pilot study

Abstract

Aim: To evaluate the administration of an equimolar mixture of N2O and O2 for intratracheal intubation in preterm neonates with respiratory distress syndrome (RDS).

Design: Prospective evaluation of N2O/O2 in premature neonates with RDS.

Setting: Tertiary neonatal unit from March to August 2003.

Patients: Twenty-six of 79 neonates admitted for RDS within 48 h of birth.

Intervention: N2O/O2 was administered until muscle tone was suppressed. Surfactant was given intratracheally. Patients were extubated as soon as possible.

Main outcome measures: The time needed for N2O/O2 to suppress muscle tone, an evaluation of sedation/analgesia through movements of the limbs, and indicators of stress-related haemodynamic change, all recorded by an independent observer.

Results: In the 26 patients, gestational age was 30.5 (25th, 75th percentile: 30, 32) wk and median body weight was 1540 (1220, 1900) g. Postnatal age at intubation was 2 (2, 3) h. N2O/O2 administration time was 8 (6, 10) min (range 4-15 min). Sedation/analgesia was complete in 77% of patients. No significant differences between pre-procedure and post-procedure values were found for heart rate (p=0.29) or mean arterial blood pressure (p=0.13) (paired Wilcoxon test). Time needed for intubation was 30 (20, 37) s (range 10-60 s). Side effects included transient agitation (3/26) and retching (2/26). Extubation occurred 5 (5, 10) min (range 2-15 min) after surfactant instillation. Apnoeas occurred in 3/26 patients within 2 h after extubation. Two patients required reintubation to repeat surfactant administration within 24 h after extubation.

Conclusion: N2O/O2 may be helpful for intubation in preterm neonates. Larger randomized, double-blind studies are needed for a thorough evaluation of effectiveness and safety.