Nitrous oxide analgesia for intubating preterm neonates: A pilot study

Aim: To evaluate the administration of an equimolar mixture of N 2 O and O 2 for intratracheal intubation in preterm neonates with respiratory distress syndrome (RDS). Design: Prospective evaluation of N 2 O/O 2 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: N 2 O/O 2 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 N 2 O/O 2 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. N 2 O/O 2 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: N 2 O/O 2 may be helpful for intubation in preterm neonates. Larger randomized, double‐blind studies are needed for a thorough evaluation of effectiveness and safety.