Ultrasound-Guided Liposomal vs. Conventional Bupivacaine Erector Spinae Plane Block Plus Gabapentin for Postherpetic Neuralgia.

Abstract

This study aimed to compare efficacy and safety of ultrasound-guided erector spinae plane block (ESPB) using liposomal (LB) versus conventional bupivacaine (CB), each plus standardized gabapentin, in patients with postherpetic neuralgia (PHN). A total of 116 PHN patients were randomized to ESPB-LB or ESPB-CB; both groups received standardized gabapentin. The primary outcome was resting pain assessed by Numeric Rating Scale (NRS). Secondary outcomes were 72-h event-free time (time to first rescue medication or resting NRS ≥ 4), cumulative rescue opioid exposure in morphine milligram equivalents (MME), sleep by the Pittsburgh Sleep Quality Index (PSQI), health-related quality of life by the Patient-Reported Outcomes Measurement Information System (PROMIS), Patient Global Impression of Change (PGIC), and adverse events (AEs). ESPB-LB achieved lower resting NRS at day 1, day 3 and day 7 (all p < 0.05), with no between-group differences at day 30 or day 60. Event-free time favored LB (median 54.10 h vs. 18.95 h; log-rank p = 0.002). LB reduced cumulative MME at 48 h and 72 h, with convergence by days 7-60. PGIC favored LB at days 7 and 30, converging by day 60. Sleep and health-related quality of life improved similarly with no between-group differences; AEs were comparable, and no serious events occurred through day 60. In PHN, ESPB-LB plus gabapentin provided an early advantage characterized by superior early analgesia, higher early responder rates, longer opioid-free analgesia within 72 h, and short-term opioid sparing versus ESPB-CB, while longer-term outcomes and safety profiles were similar between groups.