Assessment of ultrasound-guided intercostal nerve block for acute herpes zoster and its' possible prophylaxis for postherpetic neuralgia: a retrospective and case-controlled trial.

Background: This study aimed to compare the intercostal nerve block (ICNB) and thoracic paravertebral block (TPVB) for acute herpes zoster-associated pain (ZAP) and possible prophylaxis for post-herpetic neuralgia (PHN).

Methods: This study enrolled 128 patients with ZAP. Their records were stratified into standard antiviral treatment (AVT) plus US-guided TPVB (the TPVB group), AVT plus US-guided ICNB (the ICNB group) or AVT alone (the control group). Herpes zoster (HZ)-related burden of illness (HZ-BOI) within the post-procedural 30 days was defined as the primary endpoint, determined by a composite of pain severity and follow-up duration. Procedure time, rescue analgesic requirement, PHN incidence, health-related quality of life and side effects were also recorded.

Results: Significantly lower HZ-BOI-AUC₃₀ was reported in the TPVB and ICNB groups as compared to the control group, with a mean difference of 57.5 (P < 0.001) and 40.3 (P = 0.003), respectively. However, there was no difference between the TPVB and ICNB groups (P = 0.978). Both TPVB and ICNB reported significantly greater improvements in PHN incidence, EQ-5D-3L scores and rescue analgesic requirements during follow-up, as opposed to the control AVT. Shorter procedure time was observed in ICNB as compared to TPVB (16.47 ± 3.39 vs. 11.69 ± 2.58, P < 0.001).

Conclusions: Both US-guided TPVBs and ICNBs were effective for ZAP, and accounted for possible prophylaxis for PHN, as compared to AVT alone. The ICNB approach could be recommended as an alternative to conventional TPVB with a better consumed procedure time and side effect profile.a.