Regional methods of anesthesia in labor pain relief: a systematic review

Abstract

INTRODUCTION: Today epidural anesthesia is the “golden standard” of anesthesia. But what can we do if the application of an epidural catheter is contraindicated? The use of narcotic analgesics can hardly be deemed a worthy alternative. OBJECTIVE: To identify alternative regional methods of anesthesia in labour pain relief. MATERIALS AND METHODS: We have performed a systematic review of literature in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guideline principles. The bibliographic search was conducted in January-March 2022. The search was performed in the MEDLINE, EMBASE, eLibrary.ru, Cochrane Library databases. The search keywords were: anesthesia of childbirth, pudendal block, paracervical block, paravertebral block, quadratic lumbar muscle (QLB) block, erector spinae plane block (ESPB). We found 122 works, and after removing 94 works for various reasons, 28 works were analyzed. RESULTS: We found 122 works, and after removing 94 works for various reasons, 28 works were analyzed. We identified six randomized controlled trials related to the subject matter, but the endpoints were heterogeneous preventing a statistical analysis; therefore, we performed a qualitative review of the literature. Works dedicated to paravertebral and paracervial blocks showed sufficient effectiveness of anesthesia for the second period of labor. Good results of anesthesia of the second period of labor were also described with the use of ESPB and bilateral QLB. Nevertheless, it is impossible to draw statistically significant conclusions on the use of ESPB and QLB due to the small sample. Articles devoted to the use of pudendal block in labour revealed its low effectiveness. CONCLUSIONS: The described results show that paravertebral, ESPB and QLB blocks can be used as alternative regional methods of anesthesia in labour. However, further research is required to assess the effectiveness of their use in childbirth.