Spinal versus general anesthesia for lumbar spine surgery in high risk patients: Perioperative hemodynamic stability, complications and costs.

Objective: More stable perioperative hemodynamic conditions, lower costs and a lower perioperative complication rate were reported in young healthy patients undergoing lumbar spine surgery in spinal anesthesia (SA) compared to general anesthesia (GA). However, the benefits of SA in high risk patients (ASA≥II suffering from cardiovascular and/or pulmonary pathologies) undergoing this surgery are unclear. Our objective was to analyze whether SA leads to an improved perioperative hemodynamic stability and to a more cost-effective management compared to GA in high risk patients undergoing this surgery.

Methods: In a retrospective analysis 146 ASA II-III patients who underwent lumbar spine surgery in SA were compared with 292 ASA I-III patients who were operated in GA between 2000 and 2014. Hemodynamic effects, hospitalization times, complications, and costs according to the Swiss billing system were assessed. The data extraction was conducted according to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) initiative for cohort studies.

Results: The patients in the SA group were older (75years (±9.6) vs 69 (±11.5), p<0.001), had a lower BMI (25.8kg/m2 (±4.8) vs 27.2 (±4.7), p=0.003) and showed a higher ASA score (3 vs 2, p<0.001). However, SA was associated with significantly better perioperative hemodynamic stability with less need for intraoperative vasopressors (15% vs 57%, p<0.001), volume supplementation (1113ml ±458 vs 1589±644, p<0.001) and transfusions (0% vs 4%, p<0.001). Additionally, the number of hypotension episodes was lower in the SA group (15% vs 47%, p<0.001). Furthermore, the SA group showed a significantly shorter duration of surgery (70min (±1.2) vs 91 (±41), p<0.001), lower postoperative nausea and vomiting (PONV) (4% vs 28%, p<0.001) and pain in the post anesthesia care unit (PACU) (visual analogue scale (VAS) 2.3 (±1.1) vs 0.8 (±0.8), p<0.001), whereas pain after 24h did not differ (VAS 0.9 (±1) vs 0.8 (±1.1), p=ns). The postoperative complication (7% vs 5%, p=0.286) and revision rates (4% vs 5%, p=0.626) were similar in both groups. Total costs (United States Dollars (USD) 6377 (±2332) vs 7018 (±4056), p=0.003) and PACU time were significantly lower in the SA group (35min (±12) vs 109 (±173), p<0.001).

Conclusions: Lumbar spine surgery in cardiovascular high risk patients with SA is safe, allows good perioperative hemodynamic stability and might lead to lower health care costs. Further prospective studies are needed to confirm these findings.