The effect of normal saline instillation on cardiorespiratory parameters in intubated cardiothoracic patients

Abstract

Objective. The objective of this study was to describe the effect of normal saline instillation (NSI) on cardiorespiratory parameters in intubated cardiothoracic patients. 

Methods. A comparative design was employed to meet the study objectives. Simple random sampling was used to assign patients to study groups, namely a research group (non-NSI) and a control group (NSI). The data-capturing tool was based on the literature review. Descriptive and comparative statistics were employed to analyse the data. Findings were assessed according to p<0.05.

Results. Findings indicated that there were no statistically significant differences in heart rate, blood pressure, arterial partial pressure of oxygen (PaO2), arterial oxygen saturation as measured by blood gas analyser (SaO2) and serum bicarbonate level (HCO3 –) when NSI was used or not used during endotracheal suctioning (p=0.05). Statistically significant differences were found in pH and patient return rate to baseline arterial oxygen saturation as measured by pulse oximetry (SpO2) after 30 minutes of suctioning: 63.6% of patients in the NSI group failed to return to baseline SpO2 v. 37.5% of patients in the non-NSI group (χ2 p=0.035; Fisher’s exact p=0.048). There was a decrease in pH when NSI was used during suctioning. Although these differences were statistically significant, clinically they were not significant.

Conclusion. It can be concluded that NSI had no effect on cardiorespiratory parameters in intubated cardiothoracic patients. Even though the patient population was at high risk of haemodynamic disturbance and hypoxia during this manoeuvre, there was no meaningful clinical effect; however, the sample size was too small to establish safety