The first breath during resuscitation of prematurely born infants.

Background: The first five initial inflation pressures and times during resuscitation of prematurely born infants are frequently lower than those recommended and rarely result in tidal volumes exceeding the anatomical dead space. Greater volumes were produced when the infant was provoked to inspire by an inflation (active inflation).

Aims: To assess factors associated with a shorter time to the first active inflation.

Study Design: Respiratory function monitoring was undertaken during resuscitation, peak inflation pressures (PIP), inflation times and the infant's respiratory activity were simultaneously recorded.

Subjects: Infants with a gestational age<34weeks requiring resuscitation at birth.

Outcome Measures: The relationships of the PIP and inflation time of the first five inflations and first active inflation to the time to the first active inflation.

Results: Recordings from 47 infants, median gestational age of 29 (23-34) weeks, were analysed. The median PIP of the first five inflations was 27 (range 9-37) cmH2O and inflation time 1.22 (range 0.32-4.08) s. The median PIP of the first active inflation was 25 (range 19-37) cmH2O and inflation time 1.35 (0.35-3.67) s. The median time to the first active inflation was 7 (range 0-50) seconds and was inversely correlated with the PIP (p=0.001) and inflation time (p=0.018) of the first five inflations and the PIP (p=0.001) and inflation time (p=0.008) of the first active inflation.

Conclusion: The magnitude of the inflation pressures and times of the first five inflations inversely correlate with the time to the first breath during resuscitation.