Endotracheal tube size does not affect time to extubation in adult cardiac surgery

Managed care over the last 20 years has brought considerable attention to the impact of clinical variables on time to extubation in adult cardiac surgery. One variable that has not yet been analyzed is the endotracheal tube (ETT) size. Our retrospective electronic database review was performed on adult subjects that had a primary, non-emergent cardiac surgery in the last four years. The records of 936 patients were analyzed to find 193 patients meeting inclusion criteria. Due to the low number of 7.0 ETTs used in the study, this group was eliminated from analysis. The means for times to extubation for the two remaining groups were 7:45 standard deviation (SD) 4:27 (hrs:min) and 7:30 SD 4:48 (hrs:min) for patients managed with 8.0 and 9.0 ETTs respectively, with no statistically significant differences between the tube sizes p=0.2389. Analysis of variance did not demonstrate a statistically significant impact with age (p=0.3199), gender (p=0.5394), body mass index (BMI) (p=0.4060), nor intravenous (IV) anesthetic adjuvants midazolam (p= 0.4815) or opiates (p=0.3617) used in the operating room (OR), but length of time on cardiopulmonary bypass did play a role (p=0.0274). These data suggest that the size of the ETT utilized during cardiovascular surgery in adult patients does not play a role in the length of time of postoperative ventilation.