Physiologic response to two endotracheal suctioning techniques in newborn lambs with and without acute pulmonary hypertension

BACKGROUND: Endotracheal suctioning may cause sudden increases in pulmonary arterial pressure, which can result in hypoxia secondary to right ventricular failure and/or increased right-to-left shunting. An adaptor that allows suctioning without disconnecting the ventilator has been proposed to prevent these problems; however, its efficacy has not been rigorously studied. OBJECTIVE: To examine the physiologic responses to two endotracheal suctioning techniques in newborn lambs with and without acute pulmonary hypertension. METHODS: A repeated-measures design was used to compare two endotracheal suctioning techniques in seven newborn lambs with and without acute pulmonary hypertension. An adaptor was used in the ventilator-controlled technique, making disconnection of the ventilator during suctioning unnecessary. In the bag-controlled technique, the ventilator was disconnected and ventilation was done with a manual resuscitation bag. Physiologic variables, pulmonary and mean arterial pressure, peak inspiratory pressure, mixed venous oxygen saturation, cardiac index, and arterial blood gas values were recorded before, during, and after endotracheal suctioning. RESULTS: Endotracheal suctioning caused a statistically significant systemic hypertensive response in lambs with and without acute pulmonary hypertension, regardless of which suctioning technique was used. No statistically significant changes occurred in pulmonary arterial pressure using either technique. CONCLUSIONS: Use of an adaptor resulted in no differences in the physiologic responses to endotracheal suctioning. However, endotracheal suctioning was easier to perform using an adaptor because no extra equipment or person was needed.