Preoperative smoking history is associated with decreased risk of early postoperative cognitive dysfunction in patients of advanced age after noncardiac surgery: a prospective observational cohort study

Abstract

Objective Prevention of postoperative cognitive dysfunction (POCD) in patients of advanced age remains unclear. Studies have shown that the cholinergic anti-inflammatory pathway contributes to a decreased risk of POCD and that nicotine stimulates the cholinergic anti-inflammatory pathway. We investigated whether patients of advanced age with a preoperative smoking history have a decreased risk of POCD. Methods In total, 382 patients (190 smokers, 192 nonsmokers) aged ≥60 years who underwent major noncardiac surgery were enrolled. Cognitive function was assessed, and multivariate logistic regression analyses were performed to identify risk factors. Results On postoperative days 5 and 7, 111 (29.05%) and 90 (23.56%) patients exhibited POCD, respectively. A preoperative smoking history was significantly correlated with a decreased risk of POCD. A high serum tumor necrosis factor-α (TNF-α) level on the operative day was significantly associated with an increased risk of POCD. Early POCD was significantly associated with the sufentanil dosage, age, and education level. The hospital stay in patients with and without POCD was 10.54 ± 2.03 and 8.33 ± 1.58 days, respectively. Conclusion A preoperative smoking history was associated with a decreased risk of early POCD, and a high serum TNF-α level was significantly associated with an increased risk of POCD.