Scientific Poster Session II - MeRIT Primer Participants (Completed Research)

Abstract

Spinal cord ischemia (SCI) leading to paresis or paraplegia is a known risk associated with thoracoabdominal aortic aneurysm (TAAA) repair. Preventative SCI bundles that include the use of continuous low-dose naloxone (cLDN-bundle) reduce this risk but may result in higher opioid requirements and more pain. Sub-dissociative ketamine (SDK) provides opioid-sparing analgesia and is not antagonized by naloxone. This study examines whether SDK improves pain control for patients receiving a cLDN-bundle as part of a TAAA repair.

Research Question or Hypothesis:

Does SDK lower pain scores and opioid requirements in patients receiving a cLDN-bundle as part of a TAAA repair?

Study Design:

Randomized, double-blind, placebo-controlled trial

Methods:

Twenty patients undergoing endovascular TAAA repair with a 48-hour cLDN-bundle were randomized to an infusion of SDK (n=10) at 0.2 mg/kg/hour or placebo (n=10). The study infusion was started at induction and continued for 48 hours postoperatively. The primary and secondary outcomes were mean oral morphine equivalents (OMEs) and pain scores for the first 48 hours postoperatively, assessed in 6-hour intervals. Overall mean outcomes were compared between the SDK and placebo groups using a repeated measures general linear mixed model with an auto-regressive covariance structure. Statistical significance was set to p<0.05.

Results:

The 6-hr estimated mean OMEs were lower in the SDK group at 14.7 mg (95% CI 8.6 – 20.8) compared to 33.0 mg (95% CI 26.9 – 39.1) in the placebo group, p=.019. Six-hour estimated mean pain scores were also lower in the SDK group at 1.9 (95% CI .4 – 3.4) versus 4.2 (95% CI 2.6 – 5.8) with placebo, p=.040. No adverse events were seen in the SDK group.

Conclusion:

This study demonstrated that patients undergoing endovascular TAAA repair in conjunction with a cLDN-bundle required fewer OMEs and reported lower pain scores with the use of an SDK infusion, versus placebo.

Presenting Author

Authors