Background: The systemic stress response to surgery is a complex physiological process characterized by neuroendocrine, sympathetic, and inflammatory activation. While necessary for survival, this response can lead to adverse outcomes such as hyperglycemia, immune suppression, cardiovascular complications, and delayed recovery. Regional anesthesia (RA) has been shown to modulate this stress response more effectively than general anesthesia (GA) by blocking nociceptive signaling and attenuating the release of stress mediators. Objectives: This review aims to elucidate how RA influences the systemic stress response, highlighting its clinical benefits in reducing postoperative pain, improving hemodynamic stability, minimizing inflammatory responses, and preserving immune function. Additionally, this review examines evidence from clinical trials supporting using RA to improve surgical outcomes, particularly in high-risk populations. Methods: A comprehensive narrative review of the literature was conducted to explore the physiological impact of RA on the systemic stress response and its associated clinical outcomes. Studies comparing RA to GA across various surgical procedures were evaluated, focusing on neuroendocrine modulation, sympathetic inhibition, inflammatory attenuation, and the implications for pain management, cardiovascular and pulmonary function, and immune preservation. Results: RA significantly attenuates the neuroendocrine response by reducing the release of cortisol and catecholamines, thereby improving hemodynamic stability and reducing myocardial oxygen consumption. RA also inhibits the sympathetic nervous system, leading to improved cardiovascular outcomes. Furthermore, RA mitigates the inflammatory response by reducing pro-inflammatory cytokine levels, reducing the risk of systemic inflammatory response syndrome (SIRS), sepsis, and pulmonary complications. Clinical studies and meta-analyses consistently demonstrate that RA reduces postoperative pain, opioid consumption, and the incidence of cardiovascular and pulmonary complications, particularly in elderly and high-risk patients. Conclusions: RA offers a significant advantage in modulating the systemic stress response to surgery, improving postoperative outcomes by reducing pain, enhancing cardiovascular stability, and preserving immune function. Its benefits are particularly pronounced in high-risk populations such as the elderly or those with pre-existing comorbidities. Given the growing evidence supporting its efficacy, RA should be considered a critical component of multimodal perioperative care strategies aimed at minimizing the systemic stress response and improving recovery. Future research should optimize RA techniques and identify patient-specific factors to enhance therapeutic benefits.

Background: This study aimed to compare the effect of the ultrasound-guided bilateral and bilevel erector spinae plane block (ESPB) on pain scores, opioid requirement, intraoperative motor-evoked potentials (MEPs), and stress response to surgery expressed by the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) versus standard analgesia methods following idiopathic scoliosis surgery. Methods: This was a prospective, double-blinded, randomized controlled trial. Sixty patients aged 10 to 18 years and physical status ASA 1 or 2 were randomized into 2 equal groups, each receiving an ESPB or sham block. The primary outcome was the pain scores (Numerical Rating Scale, NRS) within 48 hours after spinal correction and fusion surgery for idiopathic thoracic scoliosis. The secondary outcomes were total opioid consumption, NLR, and PLR levels at 12 and 24 hours postoperatively and intraoperative MEPs. Results: ESPB patients presented lower NRS scores, signifying less pain, at all time points (30, 60, 90, 120 min; and 6, 12, 24, and 48 h after surgery), all P<0.0001. The total opioid consumption, the incidence of nausea or vomiting, and the need for remifentanil and propofol during surgery were significantly lower in the ESPB group. The surgery-induced stress response expressed by NLR and PLR was considerably lower in the ESPB group. ESPB did not affect the intraoperative MEP’s amplitude. Conclusions: ESPB is effective for postoperative analgesia, can reduce opioid consumption in patients undergoing scoliosis surgery, and reduces the stress response to surgery. ESPB does not interfere with neuromonitoring. Level of Evidence: Level I.

Background: The immediate postoperative period after total hip arthroplasty can be associated with significant pain. Therefore, this study aimed to evaluate the effect of pericapsular nerve block on pain management and functional recovery after total hip arthroplasty. Methods: This prospective, randomized, double-blinded, placebo-controlled trial was conducted on 489 adult patients scheduled for total hip arthroplasty, ASA 1–2, operated under spinal analgesia. Participants were assigned to receive either a pericapsular nerve group (PENG) block with 20 mL of 0.5% ropivacaine or a sham block. Results: The primary outcome measure was the postoperative NRS score in motion. The secondary outcomes were cumulative opioid consumption, the time to the first opioid, and functional recovery. Demographic characteristics were similar in both groups. Intraoperative pain scores were significantly lower in patients who received the PENG block than in the control group (p < 0.0001). Also, the time to the first opioid was considerably longer in the PENG group (p < 0.0001). Additionally, 24% of PENG patients did not require opioids (p < 0.0001). Conclusions: The pericapsular nerve group showed significantly decreased opioid consumption and improved functional recovery. Pericapsular nerve group block improved pain management and postoperative functional recovery following total hip arthroplasty.

Purpose: Neutrophile-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are the inflammatory biomarkers of the stress response. In this study, we aimed to evaluate the effects of erector spinae plane block (ESPB) on posterior lumbar decompression and stabilization by comparing NLR, PLR, postoperative pain, opioid consumption, and functional recovery between sham block and ESPB. Methods: This was a prospective, double-blinded, randomized controlled trial in a tertiary referral hospital. Sixty patients were randomized into two equal groups, each receiving either a sham block or ESPB. The primary outcome was the NLR and PLR 12 h and 24 h after lumbar posterior decompression and stabilization. The secondary outcomes were total opioid consumption and pain score 24 h postoperatively. Also, functional recovery determined by getting out of bed, verticalization, and walking by the balcony were reviewed as secondary outcomes. Results: Significant differences existed between the sham block and ESPB group in NLR (29.08 ± 12.29 vs. 16.97 ± 10.38; p < 0.0001) and PLR (556.77 ± 110.32 vs. 346.43 ± 117.34; p < 0.0001) 12 h after surgery. Also, there was a significant difference in NLR (p = 0.0466) and PLR (p < 0.0001) 24 h after surgery. In addition, there was a substantial difference in pain score, total opioid consumption, and functional recovery. Conclusion: ESPB performance during spinal surgery lowers NRL and PLR ratios 12 h and 24 h after surgery. In addition, ESPB provides better analgesia and improves functional recovery compared to sham block following posterior lumbar decompression and stabilization.

Introduction: This study aimed to investigate pain management, functional recovery, and stress response expressed by the neutrophile-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) after the popliteal artery and posterior knee capsule infiltration (iPACK) block combined with adductor canal block (ACB) in total knee arthroplasty (TKA). Patients and Methods: This was a prospective, double-blinded, randomised, controlled trial in a tertiary referral hospital. Three hundred and sixty-six patients were randomly allocated into the sham block group and iPACK combined with the ACB group. The primary outcome was postoperative pain scores. The secondary outcomes were opioid consumption, functional recovery expressed by a range of motion, and quadriceps strength. Also, the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were calculated. Results: There were significant differences between the sham block and iPACK + ACB group in pain scores p < 0.0001 at all time points. Therefore, there was a significant difference in opioid consumption (p < 0.0001) and functional recovery (p < 0.0001). Also, NLR and PLR levels 12 h (p < 0.0001) and 24 h (24 h) after surgery (p < 0.0001) were much lower in the iPACK + ACB group. Conclusion: After total knee arthroplasty, the iPACK combined with ACB block group improved pain management, functional recovery, and stress response. Therefore, we strongly recommend this technique as a part of a multimodal analgesia protocol in knee surgery.

Introduction: Total knee arthroplasty (TKA) is commonly performed in patients with end-stage osteoarthritis or rheumatoid arthritis of the knee to reduce joint pain, increase mobility, and improve quality of life. However, TKA is associated with moderate to severe postoperative pain, which remains a significant clinical challenge. Surgeon-administered PAI and anesthesiologist-administered iPACK have proven viable alternatives to conventional peripheral nerve blocks. This review aims to discuss which IPACK block or periarticular injection, combined or not with different peripheral nerve blocks, has better effects on postoperative rehabilitation, patient satisfaction, and overall outcome. Material and methods: The literature review was performed on standards of care, current therapeutic options, a pain management protocol, and innovative treatment options for patients undergoing total knee arthroplasty. The literature was reviewed through four electronic databases: PubMed, Cochrane Library, Google Scholar, and Embase. Results: The initial search yielded 694 articles. Fifty relevant articles were selected based on relevance, recentness, search quality, and citations. Six studies compared PAI to peripheral nerve block (PNB), and eight studies checked the effectiveness of adding PNB to PAI. Three studies compared iPACK to PNB, and ten reviewed the point of adding PNB to iPACK. Conclusions: The literature review indicates that the best analgesic effect is obtained by combining PAI or iPACK with a peripheral nerve block, particularly with ACB, due to its analgesic, motor-sparing effect, and satisfactory analgesia.