Effects of hypnosis versus enhanced standard of care on postoperative opioid use after total knee arthroplasty: the HYPNO-TKA randomized clinical trial.

Abstract

Background: Hypnosis decreases perioperative pain and has opioid-sparing potential but has not been rigorously studied in knee arthroplasty. This trial investigates the impact of perioperative hypnosis on inpatient opioid use following total knee arthroplasty.

Methods: This prospective randomized controlled trial was conducted at a single academic medical center. The hypnosis arm underwent a scripted 10 min hypnosis session prior to surgery and had access to the recorded script. The control arm received hypnosis education only. The primary outcome was opioid use in milligram oral morphine equivalents per 24 hours during hospital admission. A secondary analysis was performed for patients taking opioids preoperatively.

Results: 64 primary knee arthroplasty patients were randomized 1:1 to hypnosis (n=31) versus control (n=33) and included in the intent-to-treat analysis. The mean (SD) postoperative opioid use in oral morphine equivalents per 24 hours was 70.5 (48.4) in the hypnosis versus 90.7 (74.4) in the control arm, a difference that was not statistically significant (difference -20.1; 95% CI -51.8 to 11.4; p=0.20). In the subgroup analysis of the opioid-experienced patients, there was a 54% daily reduction in opioid use in the hypnosis group (82.4 (56.2) vs 179.1 (74.5) difference of -96.7; 95% CI -164.4 to -29.0; p=<0.01), equivalent to sparing 65 mg of oxycodone per day.

Conclusion: Perioperative hypnosis significantly reduced inpatient opioid use among opioid-experienced patients only. A larger study examining these findings is warranted.

Trial registration number: NCT03308071.