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

Background: 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.

Methods: This is a retrospective cohort study using data from the Canadian Spine Outcomes and Research Network 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.

Results: We included 217 patients in this analysis. The mean LOS was 36.2 hours; 71.98% of patients had a LOS <24 hours. A Kruskal-Wallis test by ranks analysis was conducted and identified 7 elements that correlated with prolonged length of stay (>1 day): age older than 55 (P = 0.027), body mass index >25 (P = 0.045), uncontrolled diabetes (P = 0.015), preoperative use of opioid medication (P = 0.024), American Society of Anesthesiologists classification of 3 (P = 0.023), non-minimally invasive surgical approach, and multilevel procedures. Most (94.1%) of the patients with none of these elements (i.e., age <55, low body mass index, normal/controlled diabetes, minimal preoperative opioid use, American Society of Anesthesiologist classification <3, minimally invasive surgical procedure) had a favorable LOS, <24 hours, compared with 84.8% with 1 risk factor, 80.4% of those with two, 69.8% with three, 53.1% with four, and 31.2% with 5 or more. A small number of patients (14.98%) presented to an emergency department within 90 days of their operation, and there was a 6.28% readmission rate.

Conclusions: 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.