The Effects of Bolus Normal-Saline Instillation in Conjunction with Endotracheal Suctioning

Abstract

Although the instillation of normal saline into the endotracheal tube prior to suctioning is common practice, the only available clinical data to support this practice were obtained in postoperative patients without apparent pulmonary disease. MATERIALS & METHODS: Fifteen critically ill, intubated patients with pulmonary disease were studied to determine the physiologic responses, the amount of material suctioned, and the degree of discomfort associated with two methods of endotracheal suctioning: suctioning with a 5-mL normal-saline instillation (NSI) and suctioning without NSI. Each subject was suctioned by each method, 90 minutes apart. Assessment of hemodynamics, gas exchange, and respiratory mechanics was carried out before, immediately after, and 15 minutes after each method was performed. The volume of material suctioned and subject discomfort were measured after each method was performed. RESULTS: While statistically significant changes in heart rate, blood pressure, respiratory rate, blood gas and pH values occurred immediately after suctioning in both methods, there were no significant differences in these variables between the two methods. The instillation of NSI resulted in coughing and a significant increase in the amount of material suctioned. There was no difference in subject discomfort between the two methods. CONCLUSIONS: We conclude that suctioning with NSI may enhance secretion clearance through cough stimulation, and that its effects on hemodynamics, respiratory mechanics, gas exchange, and patient comfort are not significantly different from the effects of suctioning without NSI.