Local infiltration analgesia for total knee arthroplasty: Does a mixture of ropivacaine and epinephrine have an impact on hemodynamics? An observational cohort study

Abstract

Purpose: High doses of local anesthetic administered intra-articularly and peri-articularly during local infiltration analgesia (LIA) for total knee arthroplasty (TKA) may have potential effects on patient hemodynamics. The aim of this study was to know if hemodynamic changes are associated with LIA in patients undergoing TKA.

Methods: In a prospective observational design, elective patients undergoing orthopedic surgery for TKA and treated with LIA consisting of a mixture of ropivacaine (300 mg) and epinephrine (1 mg) were investigated for changes in selected hemodynamic parameters: heart rate (HR), non-invasively registered mean arterial blood pressure (MAP), and incidence of arrhythmias during the perioperative course, consisting of the following periods: period 1. from establishment of spinal anesthesia to prior to LIA administration, period 2. from administration of LIA to before release of ischemia tourniquet, period 3. from release ischemia tourniquet to end of surgery, and period 4. from transfer to the post anesthesia care unit to the ward. Statistical analysis was done with ANOVA-RM for the difference in means in repeated measurements, and with the Tukey Test between pairs. Data are presented as mean ± standard deviation. A P value <0.05 was considered significant.

Results: Ninety-nine patients (mean age 77 ± 8 years) were included. HR increased from period 2 to period 3 up to 16% (67 ± 14 to 77 ± 13 bpm, P < 0.001), and from period 2 to period 4 up to 21% (67 ± 14 to 81 ± 12 bpm, P < 0.001). MAP showed no significant changes from period 2 to period 3 (89 ± 13 to 87 ± 13 mmHg, P > 0.50), and from period 2 to period 4 (89 ± 13 to 91 ± 11 mmHg, P > 0.50). No arrhythmias were detected during follow-up.

Conclusions: A mixture of ropivacaine and epinephrine for LIA, despite the high doses administered, does not have a negative impact on hemodynamics.

Keywords: Epinephrine; hemodynamics; local infiltration analgesia; ropivacaine; total knee arthroplasty.

Figure 1

Anesthesia record: Electronic anesthesia record

Figure 2

LIA before inserting the prosthesis: The first 100 mL with 1 mg epinephrine injected in the posterior joint capsule and both collateral ligaments before inserting the prosthesis

Figure 3

LIA after inserting the prosthesis: The rest of the mixture (50 ml) injected along the edges of the bone, where the retractors were placed, inside the capsule, in the quadriceps tendon intra-patellar ligaments and in the soft tissues

Figure 4

LIA subcutaneous tissue: Before wound closure, 50 mL of ropivacaine 0.2% without epinephrine in the subcutaneous tissue

Figure 5

Heart rate sinus rhythm.(bpm). LIA: Local Infiltration Analgesia, PACU: Post anesthesia care unit

Figure 6

Mean arterial blood pressure (mmHg). LIA: Local Infiltration Analgesia, PACU: Post-anesthesia care unit