The Effects of Tracheal Suction with N-acetylcysteine on Incidence of Ventilator-associated Pneumonia

Background: Correct endotracheal tube suction is one of the effective methods to prevent ventilator-associated infection. Many studies have reported that normal saline and N-acetylcysteine (NAC) in the trachea lead the translocation of bacteria to lower levels and increase the risk of pneumonia. Objectives: The present study sought to examine the effect of tracheal suction with NAC on the incidence of ventilator-associated pneumonia (VAP). Methods: This single-blind randomized clinical trial study was conducted on 60 patients admitted to the intensive care unit (ICU) of the Khatam Al-Anbia Hospital in Zahedan, Iran, in 2020. The patients were selected using the convenience sampling method and assigned into two intervention and control groups by permutation block randomization. Before the intervention, the patients were evaluated using the Modified Clinical Pulmonary Infection Score (MCPIS), and the patients with scores < 5 on this scale were included in the study. Suctioning tracheal secretions in the intervention group was performed by pouring 2 cc of NAC into the tracheal tube during suction. The same suction procedure was performed for the patients in the control group by pouring 2 cc of normal saline into the tracheal tube in a standard way. The intervention was conducted for five days. After the intervention, the MCPIS scale was administered once more for the two groups. The collected data were analyzed using the independent samples t-test and chi-square test with SPSS software (version 25). Results: The independent samples t-test showed no significant difference between the intervention and control groups regarding the incidence of pneumonia (P = 0.31). Conclusions: Despite the effect of NAC on the incidence rate of pneumonia in patients under mechanical ventilation, there was no significant difference between NAC and normal saline in reducing the incidence of pneumonia. However, since NAC leads to no specific complication in patients, it can be safely used in the suction of tracheal lobule secretions in patients under ventilators. In this regard, further studies should examine the use of NAC for suctioning during tracheal tube obstruction by secretions.