The effect of endotracheal suction on regional tidal ventilation and end-expiratory lung volume

Purpose To examine the impact of different endotracheal tube (ETT) suction techniques on regional end-expiratory lung volume (EELV) and tidal volume ( V T ) in an animal model of surfactant-deficient lung injury. Methods Six 2-week old piglets were intubated (4.0 mm ETT), muscle-relaxed and ventilated, and lung injury was induced with repeated saline lavage. In each animal, open suction (OS) and two methods of closed suction (CS) were performed in random order using both 5 and 8 French gauge (FG) catheters. The pre-suction volume state of the lung was standardised on the inflation limb of the pressure-volume relationship. Regional EELV and V T expressed as a proportion of the impedance change at vital capacity (% Z VCroi ) within the anterior and posterior halves of the chest were measured during and for 60 s after suction using electrical impedance tomography. Results During suction, 5 FG CS resulted in preservation of EELV in the anterior (non-dependent) and posterior (dependent) lung compared to the other permutations, but these only reached significance in the anterior regions ( p