Comparison of liposomal bupivacaine and modified cocktail analgesia for postoperative pain control after transforaminal lumbar interbody fusion: a prospective, double-blind, randomized controlled trial.

Abstract

Objective: Postoperative incisional pain remains a major clinical challenge after transforaminal lumbar interbody fusion (TLIF). Liposomal bupivacaine (LB) and modified cocktail analgesia have shown analgesic efficacy in other surgical settings, but their comparative value in TLIF remains unclear. This study compared the analgesic effectiveness of LB versus a modified cocktail regimen administered via an erector spinae plane block (ESPB) in patients undergoing TLIF.

Methods: In this prospective, double-blind, randomized controlled trial, 181 patients were screened and 118 eligible patients were randomized equally to the LB group or the modified cocktail group (n = 59 each). In both groups, the study drug was administered via ESPB at the surgical level. The LB group received 266 mg LB diluted to 80 ml. The modified cocktail group received ropivacaine, epinephrine, dexamethasone, magnesium sulfate, and sodium bicarbonate. All other perioperative management was identical. The primary outcome was total postoperative rescue morphine consumption. Secondary outcomes included time to first rescue analgesia; 24-hour morphine consumption; number of rescue analgesia events; patient-controlled analgesia (PCA) activations and consumption; visual analog scale (VAS) pain scores at rest and during activity at 3, 6, 12, 24, 36, 48, and 72 hours; time to first ambulation; ambulation distance; length of hospital stay; and postoperative complications.

Results: The LB group required significantly less total postoperative rescue morphine than the modified cocktail group (mean 16.2 [SD 11.6] vs 22.6 [SD 12.0] mg, p = 0.020). No significant differences were noted in the median time to first rescue analgesia (20.6 [IQR 8.3-36.6] vs 10.0 [IQR 3.2-27.9] hours, p = 0.074), mean morphine consumption within 24 hours (7.1 [SD 2.5] vs 7.2 [SD 2.5] mg, p = 0.894), or mean number of rescue analgesia events (2.4 [SD 1.4] vs 3.3 [SD 2.1] events, p = 0.058). The LB group had markedly fewer PCA activations (mean 7.3 [SD 6.4] vs 17.6 [SD 10.1] activations, p < 0.001) and lower total PCA drug use (mean 33.4 [SD 23.1] vs 62.8 [SD 27.8] ml, p < 0.001). Significant intergroup differences in VAS pain scores appeared only at 24 and 36 hours postoperatively.

Conclusions: Both LB and the modified cocktail regimen administered via ESPB effectively reduced early incisional pain after TLIF. The modified cocktail provided satisfactory analgesia within 24 hours at substantially lower cost, whereas LB offered more prolonged analgesia up to 36 hours, with reduced opioid consumption and PCA demand. Chinese Clinical Trial Registry no.: ChiCTR2400089275 (https://www.chictr.org.cn/index.html).