Instillation of Normal Saline Before Suctioning in Patients with Pulmonary Infections: A Prospective Randomized Controlled Trial.

Abstract

Objective To determine the effect of instillation of normal saline before suctioning on oxygen saturation, heart rate, and blood pressure in patients with pulmonary infections. Methods A prospective randomized controlled trial was conducted in the surgical, medical, and burn/trauma ICUs of an academic medical center. Eighteen men and 11 women (mean age = 60 years) receiving mechanical ventilation who met the criteria for pulmonary infection were randomly assigned to 2 groups. One group had instillation of a 5-mL bolus of normal saline before suctioning; the other did not. Suctioning was done as needed during an 8-to 12-hour period. Oxygen saturation, heart rate, and blood pressure were measured noninvasively immediately before and after suctioning, at 1-minute intervals for 5 minutes after suctioning, and at 10 minutes after suctioning. Results Instillation of normal saline had an adverse effect on oxygen saturation, which worsened over time. Differences in saturation between the 2 groups were significant at 4, 5, and 10 minutes after suctioning. Differences in heart rate and blood pressure were not significant. Conclusion Instillation of normal saline before suctioning has an adverse effect on oxygen saturation and should not be used routinely in patients receiving mechanical ventilation who have pulmonary infection.