Chulay M, Graeber G M
Division of Surgery, Walter Reed Army Institute of Research, Washington, DC 20307-5100.
Heart Lung. 1988 Jan;17(1):15-22.
Limited data are available on the efficacy of a common endotracheal suctioning intervention to prevent decreases in arterial oxygenation (PaO2) after endotracheal suctioning. We evaluated the effect of five hyperinflation breaths with hyperoxygenation, administered before and after endotracheal tube suctioning, in anesthetized, paralyzed sheep with normal lung function and with abnormal lung function induced by pulmonary acid aspiration. Using a second ventilator to deliver hyperinflation and hyperoxygenation prevented PaO2 from falling below control values after endotracheal tube suctioning in animals with either normal or abnormal lung function. The PaO2 rise after hyperinflation and hyperoxygenation in animals with abnormal lung function, however, was less than that observed in animals with normal lung function. Using manual resuscitation bags to deliver the hyperinflation breaths with hyperoxygenation prevented PaO2 from falling below control values after endotracheal suctioning in animals with normal lung function. When lung function was abnormal, however, there were significant PaO2 decreases when manual resuscitation bags were used to deliver the intervention. These results highlight the difference in PaO2 response when hyperinflation and hyperoxygenation suctioning interventions are delivered with mechanical versus manual techniques. These results also emphasize that the response to hyperinflation and hyperoxygenation differs in subjects with normal versus abnormal lung function. Laboratory evaluation of endotracheal tube suctioning interventions should use abnormal lung function models, rather than normal lung function models, to approximate more closely the critically ill patient population that requires suctioning.
