We evaluated the effects of two-hand versus one-hand ventilation on tidal volume (V T ) delivered during bag-valve ventilation at various resistances and compliances. Method: Thirteen persons used an adult resuscitation bag to ventilate a lung model. In random order, they ventilated at all combinations of the following: one hand and two hands; compliances of 0.02, 0.05, and 0.1 L/cm H 2 O; resistances of 62.9, 28.24, 6.8, and 2.33 cm H 2 O/L/s (representing endotracheal tube ID of 4, 5, 7, and 9 mm). Results: V T during two-hand ventilation was a mean of 0.25 L greater than V T during one-hand ventilation (P<0.001). There was also a significant increase in V T when compliance was increased and when resistance was decreased (P<0.001 by analysis of variance in each case). When compliance was increased from 0.02 to 0.1 L/cm H 2 O and resistance was decreased from 62.9 to 2.33 cm H 2 O/L/s, two-hand V T increased from 0.79 ± 0.14 to 1.03±0.15 L-and one-hand V T increased from 0.56 ± 0.11 to 0.79± 0.18 L. Conclusion: Because of the significant difference in tidal volume delivered by one-hand and two-hand bag-valve ventilation, the bag should be compressed with two hands.
Hess et al. (Sun,) studied this question.