Risk factors for postoperative delirium in patients with Stanford type A aortic dissection: a systematic review and meta-analysis

Background Delirium is a common postoperative complication among patients who undergo Stanford Type A aortic dissection (TAAD). It is associated with increased mortality, as well as other serious surgical outcomes. This study aimed to analyze the risk factors for delirium in TAAD patients. Methods Pubmed, Web of science, Embase, the Cochrane Library and CINAHL were searched by computer to collect literatures on risk factors for postoperative delirium (POD) after TAAD. The retrieval period was from the establishment of the database to September 2022. After literature screening, two reviewers independently assessed the quality of the included studies using the Newcastle-Ottawa Scale (NOS). Data were extracted according to standard protocols, and then meta-analysis was performed using Revman 5.3 software. Results A total of 9 articles, comprising 7 case-control studies and 2 cohort studies, were included in this analysis. The sample size consisted of 2035 patients. POD was associated with increased length of ICU stay (MD 3.24, 95% CI 0.18-6.31, p = 0.04) and length of hospital stay (MD 9.34, 95% CI 7.31-11.37, p < 0.0001) in TAAD patients. Various perioperative risk factors were identified, including age (MD 4.40, 95% CI 2.06-6.73, p = 0.0002), preoperative low hemoglobin levels (MD - 4.44, 95% CI - 7.67 to - 1.20, p = 0.007), body mass index (MD 0.92, 95% CI 0.22-1.63, p = 0.01), history of cardiac surgery (OR 3.06, 95% CI 1.20-7.83, p = 0.02), preoperative renal insufficiency (OR 2.50, 95% CI 1.04-6.04, p = 0.04), cardiopulmonary bypass (CPB) duration (MD 19.54, 95% CI 6.34-32.74, p = 0.004), surgery duration (MD 44.88, 95% CI 5.99-83.78, p = 0.02), mechanical ventilation time (SMD 1.14, 95% CI 0.34-1.94, p = 0.005), acute physiology and chronic health evaluation (APACHE II) score (MD 2.67, 95% CI 0.37-4.98, p = 0.02), postoperative renal insufficiency (OR 2.82, 95% CI 1.40-5.68, p = 0.004), electrolyte disturbance (OR 6.22, 95% CI 3.08-12.54, p < 0.0001) and hypoxemia (OR 3.56, 95% CI 1.70-7.44, p = 0.0007). Conclusions POD can prolong ICU stay and hospital stay in TAAD patients. This study identified a number of risk factors for POD after TAAD, suggesting the possibility of early identification of high-risk patients using relevant data.