Association between smoking and postoperative delirium in surgical patients with pulmonary hypertension: a secondary analysis of a cohort study

Abstract

Abstract Background Previous studies have declared that smoking was a risk factor for postoperative delirium (POD), but others have inconsistent results. Up till now, the association between smoking and POD has not been verified. This study investigates the relationship between smoking and POD in patients with pulmonary hypertension (PHTN) in the United States. Methods Patients with PHTN who underwent non-cardiac, non-obstetric surgery were enrolled in the original research completed by Aalap C. et al. We further excluded the patients undergoing intracranial surgery and the patients with sepsis and perioperative stroke to avoid interference with POD assessment. The generalized linear model and generalized additive model were used to explore the relationship between smoking and POD. The propensity score adjustment was used for sensitivity analyses. Results Five hundred thirty-nine patients were included in this study. The overall incidence of POD was 3.0% (16/539). After adjusting the potential confounders (age, systemic hypertension, coronary artery disease, COPD, length of surgery, intrathoracic surgery, vascular surgery), a positive relationship was found between smoking status and POD (OR = 4.53, 95% CI: 1.22 to 16.86, P = 0.0243). In addition, the curvilinear relationship between smoking burden (pack-years) and POD is close to a linear relationship. Conclusion Smoking probably shows a positive correlation with POD in patients with PHTN.