Discussion
postoperative pain, thoracic ESPB, excessive damage, ESPB, Pain, organ dysfunction, pain, lumbar ESPB, infection, trauma
INFECTION, AIDS, ACUTE AND CHRONIC INFLAMMATION
This double-blind, randomized controlled trial (RCT) compares ESPB and classical TLIP block in lumbar posterior decompression and stabilization procedures in terms of stress response cytokines (IL-6 and IL-10), pain scale, and total perioperative opioid consumption. ESPB is effective as analgesia in lumbar spine surgery because it will consistently block the dorsal rami of the lumbar spinal nerves that innervate the back of the vertebra. ESPB also has extensive cranial and caudal spread through the paraspinal muscles from a single injection point, which aids ESPB in covering multiple vertebral levels [The local anaesthetic in ESPB was injected deep into the ESP muscle, protecting the solution from being washed out during the surgical procedure and focusing it on post-lumbar surgery pain [For decades, cytokines have received more attention for physiological changes after trauma or surgery and acute and chronic inflammation. Under physiological conditions, pro- and anti-inflammatory cytokines act as immunomodulatory elements that prevent excessive damage caused by an inflammatory reaction. A dynamic balance relationship between pro- and anti-inflammatory cytokine changes affects organ dysfunction, immunity, infection, wound healing, and postoperative pain [However, our results differed from those of previous research that hypothesized that a deeper injection of ESPB might provide better analgesia. At six hours, postoperative IL-6 and IL-10 levels were not significantly different between the ESPB and classical TLIP block groups (Table These results may be attributed to pain pathways that were mainly involved in the posterior decompression and stabilization procedure. Pain in lumbar spine surgery mainly involves the dorsal rami of the vertebral nerve, which is covered by both blocks [Our research results corroborate the previous statement that unlike thoracic ESPB, lumbar ESPB has limited spread to the ventral area. The deep back muscles in the lumbar spine, longissimus, and multifidus are more substantial and prominent in the lumbar region than in the thoracic region. In the lumbar region, local anaesthetic is concentrated within the thick musculature adjacent to the spine [Opioid doses that were given during the induction and maintenance of general anaesthesia might also contribute to these results. Opioids might have reduced the degree of perioperative pain in both groups, so the differences were not significant.Likewise, we also found no significant difference in pain scales at 1, 6, 12, and 24 h post-operatively between ESPB and classical TLIP block (Table However, we found that the time until first postoperative opioid administration was significantly longer in the classical TLIP block group than in the ESPB group (Table The wider compartment of ESPB and more homogeneous distribution of local anaesthetic on the injection plane in the lumbar region led to a rapid and extensive rate of local anaesthetic absorption in ESPB in comparison with other blocks. Cassai et al. reported that peak lidocaine concentration in blood was achieved 5 min after ESPB injection [The limitations of this study included, first, the type of stress response biomarker that had been examined. This study only examined IL-6 and IL-10 cytokine levels to predict the stress response related to the posterior decompression and stabilization procedure. Further research with other mediators and biomarkers could provide more information to make our obtained data more robust. Second, the sample size was calculated using a study in a different setting, which could lead to our study being underpowered.