Intra-Operative Hypotension is an Important Modifiable Risk Factor for Major Complications in Spinal Fusion Surgery

 

Wael Saasouh, MD^1,3, Steven D. Glassman MD², Leah Y. Carreon MD, MSc², Mladen Djurasovic MD², Desiree Chappell, MSNA, CRNA, FAAN¹, Christy Daniels, MS², Colleen Mahoney, BA², Morgan Brown, MS², Jeffrey Gum, MD²

 

¹ NorthStar Anesthesia, 6225 State Hwy 161 #200, Irving, TX, 75038 USA

² Norton Leatherman Spine Center, 210 East Gray Street, Suite 900, Louisville, KY 40202

³ Outcomes Research Consortium, Cleveland Clinic, 9500 Euclid Ave, L1-407, Cleveland, OH 44195

 

Study Design: Retropsective observational cohort

Objectives: This study examines the association betweenIntraoperative hypotension and  on postoperative complications for major thoracolumbar spine fusion procedures.

Summary of Background Data: Intraoperative hypotension (IOH) with mean arterial pressure (MAP) < 65 mmHg is associated with post-op acute kidney injury (AKI) in general surgery.¹ In spinal deformity surgery, IOH is a contributing factor to MEP changes and spinal cord dysfunction with deformity correction.²

Methods: IRB exemption was obtained. 539 thoracolumbar fusion cases, > 6 surgical levels and > 3 hours duration were identified.  Anesthetic/surgical data included OR time, fluid volume, blood loss, blood product replacement and use of vasopressors.  Arterial-line based MAP data was collected at 1 min intervals. Cumulative duration of MAP < 65 mmHg was recorded. Timing of IOH within the procedure was assessed.  Post-op course and complications including SSI, GI complications, pulmonary complications, MI, DVT, PE, AKI and encephalopathy were noted. Cumulative complications were grouped as “None”, “1-2 complications”, or “>3 complications”.

Results: There was a significant association between occurrence of complications and duration of IOH within the first hour of surgery (8.2 vs 5.6 min, p<0.001) and for the entire procedure (28.1 vs 19.3 min, p=0.008). This association persisted for individual major complications including SSI, acute respiratory failure, PE, ileus requiring NGT and post-operative cognitive dysfunction.

Comparison of patients with 0 vs. 1-2 vs. 3 or more complications demonstrated that patients with 3 or more complications had a longer duration of IOH in the first hour of the surgery and that patients who had no complications received less vasopressor than patients who had 1-2 or 3 or more complications.

Conclusion: This study identifies duration of intraoperative hypotension as a previously unrecognized modifiable risk associated with multiple major complications for multi-level lumbar fusion surgery.

References

1. Sessler DI, Bloomstone JA, Aronson S, et al. Perioperative Quality Initiative consensus statement on intraoperative blood pressure, risk and outcomes for elective surgery. Br J Anaesth. 2019;122(5):563-574. doi:10.1016/j.bja.2019.01.013
2. Yang J, Skaggs DL, Chan P, et al. Raising Mean Arterial Pressure Alone Restores 20% of Intraoperative Neuromonitoring Losses. Spine (Phila Pa 1976). 2018;43(13):890-894. doi:10.1097/BRS.0000000000002461