In addition, Ackerman and Gugerty17 examined oxygen
saturation in 26 critically ill patients using a singlecase
experimental design. The subjects were suctioned
both with and without saline instillation. A statistically
significant difference was noted in the oxygen saturation
at 45 seconds. The investigators noted that oxygen
saturation of patients who received 5 mL of saline
instillation returned to the near-baseline values only after
5 minutes, whereas patients who did not receive saline
had better oxygen saturation values, which were above
the baseline value. Similar findings were also noted in
follow-up studies by Ackerman,1,2 who found that
instillation of saline before suctioning had statistically
significant negative effects on oxygen saturation compared
with no saline use. These findings were statistically
significant at 2, 3, 4, and 5 minutes after suctioning. In
1997, a group of researchers found a statistically
significant decrease in partial pressure of arterial oxygen
(Pao2) when saline was used before suctioning in patients
with no history of pulmonary disease.18