Intratidal recruitment/derecruitment persists at low and moderate positive end-expiratory pressure in paediatric patients

Abstract

In paediatric patients positive end-expiratory pressure (PEEP) is traditionally set lower than in adults. We investigated whether moderately higher PEEP improves respiratory mechanics and regional ventilation. Therefore, 40 children were mechanically ventilated with PEEP 2 and 5cmH₂O. Volume-dependent compliance profiles were analysed as a measure of intratidal recruitment/derecruitment. Regional ventilation was assessed using electrical impedance tomography. Mean compliance was 17.9±9.9mLcmH₂O^-1 (PEEP 2cmH₂O), and 19.0±10.9mLcmH₂O^-1 (PEEP 5 cmH₂O, p<0.001). Strong intratidal recruitment/derecruitment occurred in 40% of children at PEEP 2 cmH₂O, and 36% at PEEP 5 cmH₂O. Children showing strong recruitment/derecruitment were 33 (PEEP 2 cmH₂0) and 20 (PEEP 5 cmH₂0) months younger than children showing moderate recruitment/derecruitment. A higher PEEP improved peripheral ventilation. In conclusion, mechanically ventilated paediatric patients undergo intratidal recruitment/derecruitment which occurs more prominently in younger than in older children. A PEEP of 5cmH₂O does not fully prevent intratidal recruitment/derecruitment but homogenizes regional ventilation in comparison to 2cmH₂O.

Keywords: Children; Compliance–volume curve; Functional residual capacity; Lung compliance; Mechanical ventilation; Protective ventilation; Respiratory system mechanics.