Presented at the Neonatal Society 2009 Summer Meeting.

Morley CJ, Schmölzer GM, Kamlin OCOF, Dawson JA, Davis PG

Neonatal Research, Royal Women’s Hospital, Melbourne, Australia

Objective: Monitoring the effectiveness of ventilation during neonatal resuscitation is difficult because it relies on assessment of “adequate chest rise.” We hypothesized that neonatologists are: (i) unable to assess the expired tidal volume (VTe) or the leak between the face and the mask and (ii) that the VTe and leak are large and variable.

Patients and Methods: Infants born <32 weeks’ gestation receiving ventilation after birth were studied. Tidal volumes, mask leaks and pressures were measured. Sixty seconds after starting ventilation resuscitators were asked to estimate their VTe and mask leak. These were compared with measurements during the previous 30 sec.

Results: Twenty infants were studied and 413 inflations analysed. Ventilation was started at mean (SD) of 105 (79) seconds after birth. Fifteen resuscitators used a Neopuff and five a Laerdal self-inflating bag. The mean (SD) VTe for the Neopuff and Laerdal groups were 9.0 (5.3) mL/kg and 10.3 (8) mL/kg. Five resuscitators could not estimate the VTe. The remaining 15 resuscitators underestimated the median VTe. The peak pressure and the VTe correlated weakly. The mean (SD) facemask leak was 45 (31)% with the Neopuff and 23 (23)% with the Laerdal bag. One resuscitator could not estimated mask leak, in four it was lower than estimated and 15 it was higher.

Conclusion: Paediatricians providing mask ventilation could not accurately assess the VTe or the facemask leak. The peak inflation pressure was unrelated to the VTe because of large and variable mask leaks.