• Kevin Wheeler, Megan Wallace, Marcus Kitchen, Arjan Te Pas, Andreas Fouras, Muhammad Islam, Melissa Siew, Robert Lewis, Colin Morley, Peter Davis, and Stuart Hooper.
• The Ritchie Centre, Monash Institute for Medical Research, Monash University, Melbourne, Australia. kevin.wheeler@dhhs.tas.gov.au
• Pediatr. Res. 2013 Jun 1; 73 (6): 734-41.

BackgroundWe investigated the effects of positive end-expiratory pressure (PEEP) and tidal volume (VT) on lung aeration, pulmonary mechanics, and the distribution of ventilation immediately after birth using a preterm rabbit model.MethodsSixty preterm rabbits (27 d) received volume-targeted positive pressure ventilation from birth, with one of the 12 combinations of PEEP (0, 5, 8, or 10 cm H2O) and VT (4, 8, or 12 ml/kg). Outcomes included functional residual capacity (FRC), peak inflating pressure (PIP), dynamic compliance (Cd), and distribution of ventilation.ResultsIncreasing PEEP from 0 to 10 cm H2O increased FRC by 4 ml/kg, increased Cd by 0.2 ml/kg/cm H2O, and reduced PIP by 5 cm H2O. Increasing VT from 4 to 12 ml/kg increased FRC by 2 ml/kg, increased Cd by 0.3 ml/kg/cm H2O, and increased PIP by 4 cmH2O. No effect of VT on FRC occurred at 0 or 5 PEEP, and no effect of PEEP occurred at VT = 4 ml/kg. At 0 PEEP, increasing VT increased the proportion of gas entering the smaller apical regions, whereas at 10 PEEP, increasing VT increased the proportion of gas entering basal regions, from 47% to 63%.ConclusionBoth PEEP and VT have independent, additive effects on FRC, lung mechanics, and the distribution of ventilation during the immediate newborn period.

10 keywords...

hide…