The Hemodynamic Effect of Epinephrine-Containing Local Infiltration Analgesia After Tourniquet Deflation During Total Knee Arthroplasty: A Retrospective Observational Study

Efficacy of epinephrine in local infiltration analgesia on pain relief and opioid consumption following total knee arthroplasty: a randomized controlled trial

BACKGROUND AND PURPOSE

Local infiltration analgesia (LIA) is one of the effective regimens to reduce pain after total knee arthroplasty (TKA). Epinephrine is a commonly used sympathetic adjunct in LIA. It is expected to enhance the intensity and extend the duration of LIA. The primary aim of the study was to evaluate the efficacy of epinephrine on postoperative pain control after primary TKA.

PATIENTS AND METHODS

A total of 80 patients who underwent primary TKA were randomized into an epinephrine (EN) and a control (C) group. Postoperative visual analogue pain score (VAPS) and morphine consumption were recorded every 6 hours until 48 hours after operation. The VAPS 6-48 hours were compared using repeated measure statistics. The range of motion (ROM) on discharge and complications were also compared between these 2 groups.

RESULTS

The study showed that although VAPS differed statistically between the 2 groups at 12 hours (C higher) and 48 hours (C lower) postoperatively (p = 0.04 and 0.02, respectively), repeated measures analysis revealed that there were no significant differences in 6-48 hours VAPS (p = 0.6). Total morphine consumption in the EN and C groups was 3.4 (SD 3.7) and 4.2 (SD 4.4) mg, respectively (p = 0.4). ROM on discharge was also similar between the groups. No complications were detected in this study.

CONCLUSION

Our study showed that additional epinephrine in LIA had a statistically significant reduction in VAPS at 12 hours and morphine usage during 6-12 hours when compared with the control group. However, the magnitude of difference did not reach minimal clinically importance difference (MCID) value for TKA.

Increase in early wound leakage in total knee arthroplasty with local infiltrative analgesia (LIA) that includes epinephrine: a retrospective cohort study

Background and purpose - After introducing a new local infiltration anesthesia (LIA) protocol with addition of 30 mL ropivacaine 2% and 1 mg epinephrine, we noted an increase in early wound leakage. As wound leakage is associated with prosthetic joint infection, our department aims to minimize postoperative wound leakage. This study evaluates the incidence of early wound leakage and postoperative pain after knee arthroplasty (KA) following adjustment of the LIA protocol with addition of 30 cc ropivacaine 2% and 1 mg epinephrine. Patients and methods - In this retrospective medical dossier study all patients (n = 502) undergoing a primary total or unicondylar knee arthroplasty between January 1, 2018 and July 1, 2019 were included. Patients received an LIA protocol containing 120 mL 2 mg/mL ropivacaine (ROPI- group; n = 256). After October 30, patients received an LIA protocol containing 150 mL 2 mg/mL ropivacaine with 1 mg epinephrine in the first 100 mL (ROPI + group; n = 246). The primary outcome measure was early wound leakage (< 72 hours postoperatively), defined as wound fluid leaking past the barrier of the wound dressing. Secondary outcome measure, 10-point numeric rating scale (NRS) pain (< 72 hours postoperatively) was also assessed. Data was evaluated using logistic regression. Results - The incidence of wound leakage was higher in the ROPI + group: 24% versus 17% in the ROPI- group (p = 0.06). After adjusting for the differences between surgeons the relative risk of this increase was 1.4 (1.0-2.0). The ROPI + and ROPI- group were similar regarding postoperative pain assessment. Interpretation - Adjustment of the LIA protocol with 30 mL 2% ropivacaine and 1 mg epinephrine led to an increase in early wound leakage in knee arthroplasty but no difference in pain scores.