Arterial Blood Oxygenation during and after Endotracheal Suctioning in the Apneic Patient

Arterial oxygenation during and for three minutes after endotracheal suctioning was studied in 22 patients with no known pulmonary disease. Patients were anesthetized and pulmonary ventilation automatically controlled. Variables tested were duration of suction, FiO2and fit of suction catheter in the endotracheal tube. There were significantly greater decreases in PaO2with prolonged suction. Patients breathing 25 per cent oxygen had significantly greater decreases in PaO2during suctioning than patients breathing 40 per cent oxygen. Full impaction of the suction tube in the endotracheal tube did not produce changes in PaO2significantly different from those which occurred when a 16-gauge catheter was used. Hyperinflation sustained for ten seconds following suctioning resulted in significantly smaller relative decreases in PaO2than no hyperinflation. The decreases in PaO2 were significantly smaller during and after apnea alone than during and after apnea with suction.