Study Design. A single-center retrospective study. Objective. To identify predictors of length of stay (LOS) days in patients undergoing 1 level minimally invasive (MIS) transforaminal lumbar interbody fusions (TLIF). Summary of Background Data. Recent studies suggest intraoperative fluid administration, and colloid and crystalloid administration among other intraoperative variables may prolong LOS days and increase complications. Therefore, an understanding of which preoperative, intraoperative, and immediate postoperative parameters best predict immediate LOS days will help risk stratify patients and guide decision making. Methods. We retrospectively reviewed 104 patients undergoing a MIS TLIF at 1 institution between 2008 and 2010. Two groups were selected on the basis of the time of discharge. Group 1 consisted of patients discharged within 24 hours after surgery and group 2 consisted of patients discharged more than 24 hours after surgery. Multiple regression analysis was performed to determine which preoperative, intraoperative, and postoperative variables were independent predictors of LOS days. Results. Seventy-eight patients (75%) with a LOS greater than 24 hours had significantly higher estimated blood loss, received more crystalloids, had higher total fluids, longer surgical time, lower end of case temperature, lower hemoglobin during hospitalization, and a lower preoperative narcotic use. Multiple regression analysis showed that significant predictors of increased LOS were postoperative creatinine, visual analogue scale score, intraoperative colloids, fluids input at the end of surgical case, crystalloid to colloid ratio, fluid balance, oxycodone (Oxycontin) use, mean percentage of fraction of inspired oxygen, and preoperative hemoglobin. Conclusion. Patients undergoing 1 level MIS TLIF for degenerative conditions can overall expect a short LOS postoperatively. Multiple preoperative, intraoperative, and immediate postoperative factors can prolong the LOS in this group. This information should help the surgical team in optimizing their intraoperative patient management.
