Comparison of Local Anesthetic Concentration in Pericapsular Nerve Group (PENG) Block for Total Hip Arthroplasty Under Spinal Anesthesia: A Randomized Controlled Trial.

Abstract

The pericapsular nerve group (PENG) block is a novel regional technique that provides adequate postoperative analgesia without producing motor weakness during hip surgery. We sought to compare the postoperative analgesic effectiveness of the PENG block with varying concentrations of local anesthetic in total hip arthroplasty. Prospective, randomized, double-blind trial registered with the ClinicalTrials.gov (NCT04900116). Department of Anesthesiology, Istanbul University Faculty of Medicine, Istanbul, Turkey. Ninety-one patients aged 18-80 with an American Society of Anesthesiologists Physical Status Classification of I-III undergoing total hip arthroplasty under spinal anesthesia with a PENG block were included in this study. Patients were divided into 4 groups: Group One received 20 mL of 0.5% bupivacaine; Group 2 received 20 mL of 0.25% bupivacaine; Group 3 received 20 mL of 0.125% bupivacaine; and Group 4 received 20 mL of saline as a control. Visual Analog Scale pain scores, morphine consumption, nausea, vomiting, and quadriceps weakness were evaluated at postoperative hours 0 (the end of surgery), 6, 12, 24, and 48. In addition, we recorded the first ambulation time; breakthrough morphine need; hospitalization duration; patient and surgeon satisfaction; preoperative and postoperative first month Beck-depression scores; and any complications. Groups One and 2 had significantly lower Visual Analog Scale scores and morphine consumption than the control group (P = 0.001 and P = 0.001, respectively). Quadriceps weakness was significantly higher in Group One at postoperative hour 0 (P = 0.011). Nausea and vomiting were significantly lower in Group One than in the other groups at postoperative hours 12 and 24 (P = 0.007 and P = 0.027, respectively). The length of hospital stay was significantly shorter in Group One than in the control group (P = 0.048). This was a single-center study with no standardized quantitative measurement method for assessing quadriceps weakness. The PENG block with 20 mL of 0.5% bupivacaine in total hip arthroplasty provides effective postoperative analgesia by reducing opioid side effects and hospital stay, as evidenced by low pain scores and morphine consumption.