Abstract
Background
Pre-operative and postoperative analgesia in total hip arthroplasty (THA) involves multimodal analgesia using differing classes of drugs and varying introductions of these agents. Postoperative opioid-related events can slow recovery and increase patients' length of stay. Long-acting local anesthetics can reduce early postoperative pain at the surgical site, potentiating a decrease of opioid intervention needed postoperatively. Decreasing opioid use while maintaining adequate pain control could reduce opioid-related events, increase patient time to first ambulation and decrease length of stay. The purpose of this study was to compare liposomal bupivacaine to bupivacaine for postoperative analgesia.
Methods
Between November 2012 and February 2013, 57 consecutive patients that underwent THA and hip resurfacing received either an intraoperative injection of liposomal bupivacaine or bupivacaine alone. All patients received a combination of medications prior to the procedure including celecoxib 400 mg by mouth, pregabalin 75 mg by mouth and 1gm of intravenous acetaminophen. The study group received 20 cc of liposomal bupivacaine, combined with 40 cc 0.25% bupivacaine with epinephrine and 20 cc of normal saline. The control group received 60 ml of 0.25% bupivacaine with epinephrine. Data was prospectively collected including average visual analog pain scale (VAS), opioid consumption, time to first ambulation, hospital length of stay measured by days, and post-operative opioid-related adverse drug events.
Results
The study group included 27 consecutive patients who received liposomal bupivacaine and the control group included the previous 30 consecutive patients who received bupivacaine alone (Figure 1). Both groups had average VAS scores of 2.8 during the first 24 hours after surgery and 3.3 during the time frame of 24 to 48 hours after surgery (Figure 2). The study group average morphine equivalent use during the first 24 hours after surgery was 31.7 mg, and the control group 53.4 mg (p <0.05) (Figure 3). From 24 to 48 hours from surgery, the average morphine equivalent use in the study group was 46.4 mg, and the control group 64.9 mg, although this difference did not reach statistical significance. The study group median length of stay was 1.9 days; the control group median length of stay was 2.5 days (p = 0.051). The study group had a total of 16 patients able to ambulate > 20 ft on the day of surgery, compared to the control group with four patients (p <0.05). Four times as many patients were able to ambulate the day of surgery in the study group. During hospitalization, the study group had 13 patients who required antiemetic therapy for nausea, and the control group four (p <0.05).
Conclusion
Administration of liposomal bupivacaine demonstrated dramatically decreased opioid consumption during the first 24 to 48 hours, while maintaining equivalent pain scores following THA. In addition, length of stay was decreased from 2.5 to 1.9 days with the use of liposomal bupivacaine. Compared to the control group, four times as many patients in the study group were able to ambulate ≥ 20 ft the day of surgery.
