Prototype volume-controlled resuscitator for neonates and infants

Twenty-five infants receiving assisted ventilation in an ICU were manually ventilated for 5-min periods using either a new prototype volume-controlled resuscitator (VCR) or a standard self-inflating resuscitator (SIR). Variables monitored during these 5-min periods included heart rate, respiratory rate, mean arterial pressure, mean airway pressure (Paw), end-tidal CO2 (PetCO2), pulse oximetry oxygen saturation, PaO2, and PaCO2. Significant differences in posttrial values for the following variables were: a) PetCO2 (31.2 +/- 9.1 vs. 25.6 +/- 8.2 torr, p less than .001); b) PaCO2 (38.0 +/- 4.9 vs. 33.2 +/- 6.7 torr, p less than .01); and c) pH (7.4 +/- 0.6 vs. 7.5 +/- 0.1, p less than .04) at comparable Paw (9.5 +/- 7.6 vs. 8.0 +/- 6.0, NS). Eighty-four percent (21/25) of infants in the VCR group had normal PaCO2 values (35 to 45 torr) while only 44% (11/25) in the SIR group achieved normocarbia (p less than .001). Measurements of the highest (Pmax) and lowest (Pmin) inspiratory pressure (cm H2O) in 15 patients demonstrated marked variation in Pmax with the SIR. Differences in Pmax (SIR minus VCR) were significant (10.8 +/- 3.7, p less than .02) but not in Pmin (0.5 +/- 3.5, NS). Our study demonstrates that ventilation with the VCR resulted in less hyperventilation with minimal pressure variability as compared with the SIR. Further studies in the neonate are warranted.