Comparing the effectiveness of US-guided thoracic paravertebral block versus erector spinae plane block as postoperative analgesia in adult patients undergoing elective open upper abdominal surgery under general anesthesia at two tertiary governmental hospitals, Ethiopia, 2025 G.C. multicenter prospective cohort study

Abstract

ABSTRACT BACKGROUND: Managing pain well after surgery is an important part of perioperative care because untreated pain can have serious effects on the body, mind, and ability to function. Ultrasonography-guided thoracic paravertebral block and erector spinae plane block have become popular for their safety and ability to help avoid opioid use. However, there is still no agreement and local evidence comparing these methods in resource-limited settings. The purpose of this study was to compare the effectiveness of ultrasound-guided thoracic paravertebral block and erector spinae plane block as pain relief methods for adult patients who had elective open upper abdominal surgery. METHODS AND MATERIALS: A multicenter prospective cohort study conducted at two tertiary hospitals in Ethiopia involved 76 adult patients who underwent scheduled open upper abdominal surgery under general anesthesia from July to October 2025 G.C. Participants were split into either the thoracic paravertebral block group or the erector spinae plane block group, based on the clinical assessment of the attending anesthetist. Data were gathered through interviews and structured questionnaires and analysed using SPSS version 26. The statistical methods utilised include chi-square or Fisher's exact test for categorical variables and Shapiro-Wilk and Levene's tests for assessing normality and variance homogeneity, respectively. Independent two-sample t-tests for group comparisons. A repeated measures ANOVA was employed to compare variations in visual analogue scale scores between groups over time. RESULTS: The postoperative visual analogue scale scores at several time points at rest or during movement were comparable at several time points, specifically at 0h, 2h, 6h, and 24h, in the ESPB group compared with the TPVB group (except at 12h, p < 0.001). The time to first rescue analgesic was significantly lower in the ESPB group compared with the TPVB group (774.1±25.73 min, 748.1±32.99 min, p<0.001). Similarly, total analgesic consumption was lower in the ESPB group (38 mg [IQR9]) compared with the TPVB (38 mg [IQR37]), with a statistically significant difference (p=0.001). The incidence of postoperative nausea and vomiting was comparable between the two groups (p>0.05). CONCLUSION: ESPB and TPVB provided comparable postoperative pain scores both at rest and during movement, except at the 12-hour mark. ESPB had a longer duration of analgesia before the first rescue analgesic and reduced total analgesic consumption within 24 hours compared with TPVB. KEYWORDS: Erector Spinae Plane Block, Postoperative Pain, Thoracic Paravertebral Block, Visual Analog Scale, Upper Abdominal Surgeries