Endotracheal suctioning: open versus closed with and without positive end-expiratory pressure

An open system of delivery of supplemental oxygen was compared with a closed system during endotracheal suction (ETS) at zero end-expiratory pressure (ZEEP) and 10 cm H2O positive end-expiratory pressure (PEEP). Four protocols in a 2 x 2 design were administered in random order to 12 anesthetized and oleic acid-injured animals. Statistically significant differences were found between protocols for arterial carbon dioxide tension (PaCO2), arterial oxygen saturation (SaO2), airway pressure (Paw), right atrial pressure (Pra), intrathoracic pressure (Pit), arterial pressure, and right ventricular afterload. Intrathoracic pressure and systolic aortic pressure differed between open and closed systems. Statistically significant differences between ZEEP and PEEP were found for PaCO2, SaO2, Paw, Pra, Pit, aortic pressure, and right ventricular afterload. Suctioning through a closed system made little difference in subject responses, but clinically significant differences existed when suctioning subjects on and off PEEP.