Transient advanced mental impairment: An underappreciated morbidity after aortic surgery

Objectives: To determine the incidence, risk factors, and associated morbidity of transient advanced mental impairment (TAMI) after aortic surgery. Methods: We retrospectively studied the charts of 188 consecutive patients undergoing elective aortic reconstruction during a recent 6-year period at a university hospital. All patients were lucid on admission and nonintubated at the time of evaluation at least 2 days after operation. TAMI was defined as disorientation or confusion on 2 or more postoperative days. Preoperative, intraoperative, and postoperative clinical variables were examined statistically for associations with TAMI. Results: Fifty-three patients (28%) had development of TAMI 3.9 ± 2.8 days after operation. Stepwise logistic regression analysis selected the following independent predictors for TAMI: age >65 years (odds ratio [OR], 7.9; 95% confidence interval [CI], 2.7 to 23.7), American Society of Anesthesiology physical status classification >3 (OR, 2.8; 95% CI, 1.3 to 5.9), diabetes mellitus (OR, 3.4; 95% CI, 1.2 to 9.8), old myocardial infarction (OR, 2.4; 95% CI, 1.1 to 5.3), and hypertension (OR, 2.3; 95% CI, 1.0 to 5.3). Alcohol consumption was not significantly associated with TAMI. In the postoperative period, patients with TAMI were more likely to have hypoxia (P < .001), a need for reintubation (P < .001), pneumonia (P < .001), congestive heart failure (P = .003), and kidney failure (P = .05). In addition, patients with TAMI had a longer duration of endotracheal intubation (3.7 ± 7.8 vs 0.6 ± 1.2 days, P < .001), stay in the intensive care unit (8.9 ± 9 vs 3.9 ± 2 days, P < .001), and postoperative hospital stay (14.8 ± 11 vs 9.2 ± 5 days, P < .001) than patients without TAMI. Twenty (38%) patients with TAMI were discharged to intermediate-care facilities, compared with 11 (8%) patients without TAMI (P < .001). Postoperative variables conferring the largest relative risks for development of TAMI included oxygen saturation less than 92% (5.4), the need for reintubation (3.3), congestive heart failure (3.3), and pneumonia (3.2). TAMI, conversely, conferred the largest relative risks for development of postoperative congestive heart failure (15.3), the need for reintubation (9.3), pneumonia (7.1), and the need for ICU readmission (3.8). Conclusions: These data show that TAMI is prevalent among patients undergoing aortic reconstruction and is associated with dramatically increased morbidity and postoperative hospitalization rates.