Application of ultrasound-guided thoracic paravertebral block or intercostal nerve block for acute herpes zoster and prevention of post-herpetic neuralgia: A case-control retrospective trial

Objectives - Ultrasound (US)-guided intercostal nerve block (ICNB) is an easier approach with a very low incidence of complications for different surgeries; nevertheless, only a few studies estimate the effect of ICNB for acute HZ. To explore the US-guided ICNB for management of herpes zoster (HZ)-related acute pain and possible prophylaxis for post-herpetic neuralgia (PHN) taking the conventional thoracic paraverteral block (TPVB) as control. Methods - A total of 128 patients with HZ were retrospectively stratified into antiviral treatment (AVT) plus US-guided TPVB (TPVB group), AVT plus US-guided ICNB (ICNB group) or AVT alone (control group) based on the treatment they received. HZ-related illness burden (HZ-BOI) over 30 days after inclusion as the primary endpoint was determined by a severity-by-duration composite pain assessment. Rescue analgesic requirement, health-related quality of life, PHN incidence, and adverse events were also recorded. Results - Significantly lower HZ-BOI scores within post-procedural 30 days using the area under the curve were reported with TPVB and ICNB compared with the control group: mean difference of 57.5 (p < 0.001) and 40.3 (p = 0.003). No difference was reported between TPVB and ICNB (p = 1.01). Significant greater improvements in PHN incidence, EQ-5D-3L scores, and rescue analgesic requirements were observed during follow-up favoring two trial groups, while comparable between two trial groups. No serious adverse events were observed. Conclusions - US-guided ICNBs were as effective as TPVBs for acute HZ. The ICNB technique was an easier and time-efficient approach as opposed to conventional TPVB, which might be encouraged as a more accessible preemptive mean for preventing PHN.