TABLE 5.

Summary of randomized studies on the use of saline

Author (reference), study design	Description of groups and interventions	Outcome measures	Summary of main results
Ji et al (38), RCO	Sample: Neurosurgical patients with pneumonia requiring MV (n=21, 16 completed study) Intervention 1: OS Intervention 2: OS with 2 mL of saline Intervention 3: OS with 5 mL of saline	SpO2	SpO2 returned to baseline immediately for intervention 1, at 45 s for intervention 2 and did not return to baseline by 5 min for intervention 3 (P=0.003) NOTE: the SpO2 decreases with saline were not clinically significant at all times (1% to 2%)
Ackerman and Mick (39), RCT	Sample: Patients in ICU with pulmonary infections requiring MV (n=29) Group 1 (n=15): CS Group 2 (n=14): CS + 5 mL bolus of saline	SaO2 Heart rate Blood pressure	Differences (P<0.05) were found only in SaO2 at 4 min, 5 min and 10 min postsuction for group 2 NOTE: It is unlikely that these represent clinically significant changes (decreases of 1% to 2%)
O’Neal et al (40), RCO	Sample: Patients in ICU requiring MV (n=20, 17 completed study) Intervention 1: CS Intervention 2: CS with 5 mL of saline	VAS for dyspnea	No significant difference between interventions for dyspnea

CS Closed suctioning; ICU Intensive care unit; MV Mechanical ventilation; OS Open suctioning; RCO Randomized crossover study; RCT Randomized controlled trial; SaO₂ Arterial oxygen saturation; SpO₂ Oxygen saturation by pulse oximetry; VAS Visual analogue scale