Erector Spinae Plane Block provides greater analgesic effect than transversus abdominal plane block

China: A systematic review published in Frontiers in Medicine has concluded that Erector spinae plane block (ESPB) aids in improving postoperative analgesic efficacy after abdominal surgery. The review also mentioned ESPB being more efficacious in analgesia than transversus abdominal plane block (TAPB).

Abdominal surgeries are complicated mainly due to postoperative pain. The literature highlights the good analgesic effect of epidural analgesia but with limitations. As mentioned previously, nerve blocks are better than central neuraxial blocks and are recommended to relieve pain after primary thoracoabdominal surgeries. Transversus abdominal plane block (TAPB), while inducing, may lead to the piercing of the needle tip in the transversus abdominis, thereby causing injury to the internal organs and peritoneum.

Forero et al. 2016 first reported that ESPB is safe with ease of application. The LA (local anesthesia) is injected into the fascia, which diffuses and causes blockage of the nearby spinal nerve. The LA is given between the erector spinae and the transverse process. ESPB affects spinal nerves (the dorsal and ventral rami), cause temporary sensation loss, and affects rami communicants transmitting sympathetic fibers. This is why ESPB is an "ideal nerve block" for abdominal surgery.

The evidence regarding ESPB's effectiveness is rising because it prevents pain during abdominal surgery. Considering the availability of data, more data is available for its role in thoracic or breast surgery, and limited data is available for abdominal surgeries.

Based on the above background, the team of researchers led by Dr. Gao from the Department of Anesthesiology at Shengjing Hospital at China Medical University, Shenyang, China, did a systematic review and meta-analysis to determine ESPB analgesic effect after abdominal surgery. The review included those RCTs which compared ESPB with either placebo or TAPB.

The key points of the study are:

• The database searched were PubMed, Embase, Cochrane,ClinicalTrials.gov.

• Pain scores were measured at six h, 12h, 24 h and 24-h opioid consumption as the primary outcomes

• Time to first rescue analgesia, hospital stay (length), and PONV were included in the secondary outcomes.

• Standardized mean differences (SMDs) were calculated with 95% confidence intervals (CIs) for primary outcomes, while for secondary outcomes, mean differences (MDs) and risk ratios (RRs) with 95% CIs were calculated.

• 1,502 cases were included in the study (24 trials).

• ESPB significantly reduced pain scores having SMD of −1.25, −0.85, −0.84, and−0.62 at six h, 12h, 24h, and opioid consumption 24 h post-surgery, respectively.

• The time to first rescue analgesia was prolonged in ESPB. (P < 0.0001)

• Five studies, including 240 patients for abdominal surgery, reported that ESPB significantly extended the time to first rescue analgesia to 5.57 h with P = 0.05. This was in comparison with TAPB.

• ESPB decreased the incidence of PONV (postoperative nausea and vomiting). The recorded values were RR of 0.67 and P = 0.04.

• Compared to TAPB, pain scores were reduced significantly at 6, 12, 24h, and 24-h opioid consumption in ESPB.

• The scores at various time points were significantly reduced in ESPB, as presented in the subgroup analysis.

• Four trials for the length of hospital stay of 230 patients undergoing abdominal surgery (ESPB vs. placebo) reported the changes to be insignificant (−0.31 days, P = 0.11)

The researchers said for postoperative pain scores; we recorded that fifteen studies evidenced lowered pain scores at six h ( P < 0.00001). A total of 16 studies had lower pain scores at 12 h (P = 0.0005) and 24 h (P = 0.0004).

Researchers explained that our meta-analysis discussed the beneficial effect and ease of application of postoperative analgesia compared with a placebo. ESPB has been reportedly used in surgeries for the lumbar spine, breast cancer, thoracic and abdominal. This nerve block has no side effects or complications.

The co-researcher said, "Our meta-analysis is evidence that ESPB is an effective nerve block after abdominal surgeries for analgesia." We want to summarise our analysis as beneficial in abdominal surgery and more beneficial than TAPB pertaining to postoperative efficacy.

We recommend ESPB as a valid alternative to TAPB. However, large and well-designed RCTs with extensive follow-up will add confirmation and update more on the findings. They said.

References:

• Gao Y, Liu L, Cui Y, Zhang J, and Wu X (2022) Postoperative analgesia efficacy of erector spinae plane block in adult abdominal surgery: A systematic review and meta-analysis of randomized trials. Front. Med. 9:934866. doi: 10.3389/fmed.2022.934866