Recruitment and PEEP level influences long-time aeration in saline-lavaged piglets: an experimental model.

OBJECTIVES: To evaluate aeration/ventilation in saline-lavaged piglets during a 3-h follow-up after a recruitment maneuver (RM)/PEEP titration compared with PEEP 10 cmH2O without a RM.

BACKGROUND: Lung recruitment and PEEP titration are used to find a PEEP preventing repetitive opening/collapsing of lung.

METHODS: Twenty-one lung-lavaged piglets, mean age 7 weeks and mean weight 10 kg; a RM-group and a PEEP10-group, were ventilated at PEEP 5 cmH2O (baseline) followed by zero PEEP ventilation. In the RM-group, tidal elimination of CO2 and dynamic compliance (Cdyn) guided recruitment and PEEP titration, respectively. A final 3-h ventilation followed using PEEP 2 cmH2O above the first decline of Cdyn and end-inspiratory pressure (EIP) for a target tidal volume (VT) of 10 ml · kg(-1). In the PEEP10-group, PEEP 10 cmH2O without a RM was used during the final 3-h ventilation. CT scans and blood gases were repeated every 30 min. Airway pressures, Cdyn and hemodynamics were continuously recorded.

RESULTS: Aeration improved without differences between groups. The RM-group PEEP level of 10 ± 0.6 cmH2O did not differ from the PEEP10-group. Compared to baseline EIP was lower in the RM-group after 3-h ventilation. In both groups, driving pressure (DP) was lower and Cdyn higher than baseline. In the RM-group, final EIP and DP were lower and Cdyn higher than in the PEEP10-group.

CONCLUSIONS: Both RM/PEEP titration and PEEP elevation resulted in improved aeration without differences between groups at the end point. Lung aeration was achieved at lower EIP and DP and higher Cdyn in the RM-group than in the PEEP10-group.