Serial ultrasound-guided Stellate ganglion block using bupivacaine, dexamethasone, and methylcobalamin to treat Complex Regional Pain Syndrome type II : a case report ad interim

Abstract

BACKGROUND: Stellate ganglion block (SGB) has been widely used as a therapeutic approach for refractory complex regional pain syndrome (CRPS), but clinical outcome varies, long-term pain-relieving effect is unknown, and most studies employed local anesthesia per se. We would like to address if the combination of bupivacaine (Bupi), dexamethasone (Dex), and methylcobalamin (MeCbl) can provide a clinically meaningful reduction of pain intensity and quality, as well as improving patient’s sleep and functional qualities in a sustainable fashion.

CASE PRESENTATION: We performed a monthly serial SGB to a painful CRPS type II patient using Bupi and Dex in the first 2 months, then added MeCbl into the regimen until the fifth month onward. We measured weekly baseline pain intensity using baseline and evoked NRS, pain quality and affective using McGill Short-Form Questionnaire (SF-MPQ), sleep quality using Pittsburgh Sleep Quality Index (PSQI), and functional activities using Pain Disability Index (PDI) questionnaire during pre-procedure until the end of the fourth week post procedure. All spectra of pain assessments were also compared between pre- and post-addition of MeCbl and tested using independent t test analysis. Repeated SGBs were safely performed in the absence of significant adverse effects. A dramatic reduction of all spectra of pain measurements, comprising baseline (-62,5%), evoked (-60%) NRS, SF-MPQ (-39.4%), PSQI (-53.3%), and PDI (-56.9%) was observed immediately after procedure. The addition of MeCbl was able to further reduce the baseline (mean reduction 1.38 [-12.5%]; 95% CI 0.53 – 2.22; p=0.003), evoked (mean reduction 1.17 [-20%]; 95% CI -0.16 – 2.50; p=0.048) NRS, SF-MPQ (mean reduction 3.38 [-24.2%]; 95% CI 0.70 – 6.05; p=0.016), PSQI (mean reduction 1.29 [-13.4%]; 95% CI -0.22 – 2.8; 0.089), and PDI (mean reduction 9.75 [-26.2%]; 6.96 – 12.54; p<0.0001), compared to the first week of first injection. Clinical improvements were stable and sustainable until the end of observation period.

CONCLUSIONS: Monthly serial US-guided SGB with Bupi, Dex, and MeCbl were proven to be safe, clinically effective, and sustainable to ameliorate baseline and evoked pain intensity and quality, as well as improving sleep quality and functional activities of a subject with CRPS type II.