Early versus delayed postoperative adductor canal block in total knee arthroplasty

Abstract

Background

We hypothesized that patients who received an adductor canal block (ACB) in the operating room following unilateral total knee arthroplasty would have a lower oral morphine milligram equivalent (MME) consumption during the postanesthesia care unit (PACU) phase 1 recovery period compared to patients who received an ACB in the PACU.

Methods

This was a retrospective cohort study of patients who underwent robotic-assisted unilateral total knee arthroplasty under general anesthesia between March 1, 2020, and February 28, 2021, and received postoperative ACB either in the operating room or the PACU.

Results

A total of 36 and 178 patients received postoperative ACB in the operating room and PACU, respectively, and had median and interquartile range MME consumption in the PACU of 22.5 (20–40) mg and 30.0 (20–40) mg (P = 0.76), respectively. Patients who had an ACB performed in the operating room and PACU had median and interquartile ranges of time spent in the PACU of 101 (75–178) minutes and 186 (125–272) minutes (P < 0.01), respectively.

Conclusion

Patients who received an ACB in the operating room did not have a lower OME consumption than patients who received an ACB in the PACU but did have a shorter PACU length of stay.

Keywords:

• Adductor canal block
• morphine milligram equivalent
• total knee arthroplasty

Disclosure statement/Funding

The authors have no financial conflicts of interest to disclose. This study was departmentally funded. Dr. Fettiplace is supported by NIH T32 training grant 5T32GM007592-42.

Additional information

Funding

This study was departmentally funded. Dr. Fettiplace is supported by NIH T32 training grant 5T32GM007592-42.