Normal saline instillation with suctioning and its effect on oxygen saturation, heart rate, and cardiac rhythm

Although the researches indicated disadvantages of using normal saline (NS) before suctioning, it still used by nurses in many Iranian critical care units.

The purpose of this study was to determine the effect of NS instillation on multiple trauma patients’ oxygen saturation, heart rate and cardiac rhythm.:

A cross-over design was used to allow sample to be as their own control. This study was approved by Kerman Medical University.

50 multiple trauma patients who were admitted in intensive care unit and mechanically ventilated for at least 24 hours were randomly assigned to suctioning with or without NS. Surveyed parameters were measured and recorded at intervals of 1, 2, and 5 minute before and after suctioning by standard monitoring apparatus. EKG tapes recorded initiate 5 second before suctioning and continue during suctioning approximately 20 second.

A Kolmogorov-Smirnov test indicated that the data were sampled from a population with normal distribution. The comparison between the two groups in three measured factors was done using a descriptive analysis, and independent ttest, and cross table with chi-square test.

Oxygen saturation in both groups was changed. In group 2(with NS), there was a decrease in oxygen saturation, whereas in another group, except at interval of 1 minute, there was an increase in oxygen saturation. This difference was statistically significant. In both groups, heart rate was increased after suctioning at three intervals. In both group there was not found dangerous arrhythmia.

This study suggests that instillation of NS before suctioning can cause adverse effect on oxygen saturation but has no effect on heart rate and cardiac rhythm. It seems that Iranian nurses believed that using NS have positive effects on suctioning. Such an attitude could be changed by some educational programs by which nurses can improve their knowledge about disadvantages of using NS with suctioning; and become aware of the strategies they can use to qualify suctioning.