Patient Selection Criteria in Ambulatory Spine Surgery: Single Canadian Provincial Experience

Abstract

Ambulatory spinal surgery is a care delivery model meant to improve patient outcomes and reduce in-hospital length of stay (LOS). We reviewed the experience of implementing an outpatient spine surgery program in Manitoba, Canada and highlight elements that can be used to reduce LOS and re-presentation to hospital. This is a retrospective cohort study utilizing data from the Canadian Spine Outcomes and Research Network (CSORN) and independent chart review of adult patients undergoing outpatient spinal surgery between 2015 and 2018. Patient demographics, comorbidities, perioperative course, LOS and readmissions were analyzed. 217 patients were included in this analysis. The mean LOS was 36.2 hours; 71.98% of patients had a LOS less than 24 hours. A Kruskal-Wallis test by ranks analysis was conducted, and identified seven elements that correlated with prolonged length of stay (over 1 day): age over 55 (p = 0.027), BMI > 25 (p = 0.045), uncontrolled diabetes (p = 0.015), preoperative use of opioid medication (p = 0.024), ASA of 3 (p=0.023), non-MIS approach, and multi-level procedures. 94.1% of patients with none of these elements (i.e age < 55, low BMI, normal/controlled diabetes, minimal preoperative opioid use, ASA<3, MIS procedure) had a favorable LOS, less than 24h, compared to 84.8% with one risk factor, 80.4% of those with two, 69.8% with three , 53.1% with four, and 31.2% with 5 or more. 14.98% of patients presented to an emergency room within 90 days of their operation, and there was a 6.28% readmission rate. We identified several patient and surgical criteria that correlate with prolonged length of stays following planned ambulatory spine surgery. Our work provides some empiric evidence to help guide surgeons on which patients and approaches are ideal for ambulatory surgery.