The role of prophylactic administration of CPAP in general surgical wards after open visceral surgery in reducing postoperative pneumonia-a retrospective cohort study

Abstract

Background: Postoperative pneumonia is a main adverse event that causes increased postoperative morbidity and prolonged length of hospital stay leading to high postoperative mortality. Continuous positive airway pressure (CPAP) is a type of non-invasive ventilation for the delivery of a positive airway pressure during respiration. In this study, we evaluated the impact of postoperative prophylactic CPAP on prevention of pneumonia in patients after open visceral surgery.

Methods: In this observational cohort study, we compared the rates of postoperative pneumonia in patients who underwent open major visceral surgery from January 2018 till August 2020 in the study and control group. The study group had postoperative prophylactic sessions of CPAP for 15 min, 3-5 times a day and a repeated spirometer training was also performed in the general surgical ward. The control group received only the postoperative spirometer training as a prophylactic measure against postoperative pneumonia. The chi-square test was used to measure the relationships between categorical variables, and a binary regression analysis determined the correlation between independent and dependent variables.

Results: A total of 258 patients met the inclusion criteria who had open visceral surgery for various clinical illnesses. There were 146 men (56.6%) and 112 women with a mean age of 68.62 years. As many as 142 patients received prophylactic CPAP and they were grouped into the study group, whereas 116 patients without prophylactic CPAP were placed in the control group. Overall, the rate of postoperative pneumonia was significantly less in the study group (5.6% vs. 25.9% in the control group; p-value < 0.0001), which could be confirmed by the regression analysis (OR 0.118, CI 95% 0.047-0.295, p < 0.001).

Conclusion: Postoperative intermittent CPAP after open visceral surgery can be performed in a general surgical ward. Our study showed a significant association with a low rate of postoperative pneumonia, especially in high-risk patients. This leads to a significantly shorter postoperative hospital stay especially in high-risk patients after upper gastrointestinal surgery.

Trial registration number: DRKS00028988, 04.05.2022, retrospectively registered.

Keywords: Abdominal surgery; CPAP; Postoperative pneumonia; Risk reduction.