Intraoperative Hypothermia is Associated with an Increased Intensive Care Unit Length-of-Stay in Patients Undergoing Elective Open Abdominal Aortic Aneurysm Surgery: A Retrospective Cohort Study

Abstract

Intraoperative hypothermia in open elective abdominal aortic aneurysm repair may be associated with increased hospital morbidity. This retrospective, single centre study investigated whether there was an association between intraoperative hypothermia in open elective abdominal aortic aneurysm repair and postoperative in-hospital morbidity. The data of 119 patients who underwent open infrarenal abdominal aortic aneurysm repair between January 2006 and January 2011 were collected. The electronic databases from the hospital, intensive care unit, transfusion medicine and operating theatres were linked by the patient's unique identifiers including date of birth and unit record number. Intraoperative nasopharyngeal temperature measurements were collected manually from paper-based anaesthetic records. The study group included 102 out of the 119 patients. Sixty-six patients (64.6%) had intraoperative hypothermia as defined by temperature <36°C. Intraoperative temperature was not predictive of hospital length-of-stay or any of the other perioperative complications such as acute renal failure, acute respiratory complications, acute myocardial infarction, transfusion requirements or postoperative infection. In the normothermic group, the number of hours in the intensive care unit was 35% lower (ratio of means=0.65; 95% confidence interval 0.51 to 0.84; P=0.0008), even after adjusting for possible confounders such as age, duration of anaesthesia, size of aneurysm, comorbidities and transfusion. Intraoperative hypothermia is a persisting problem and more aggressive warming strategies may need to be identified and employed to achieve normothermia.