Assessment of Intercostal Nerve Block Analgesia for Thoracic Surgery
Authors: Carlos E. Guerra-Londono, Ann Privorotskiy, Crispiana Cozowicz, Rachel S. Hicklen, Stavros G. Memtsoudis, Edward R. Mariano, Juan P. Cata
Journal: JAMA Network Open (2021)

<h3>Importance</h3> The use of intercostal nerve block (ICNB) analgesia with local anesthesia is common in thoracic surgery. However, the benefits and safety of ICNB among adult patients undergoing surgery is unknown. <h3>Objective</h3> To evaluate the analgesic benefits and safety of ICNB among adults undergoing thoracic surgery. <h3>Data Sources</h3> A systematic search was performed in Ovid MEDLINE, Ovid Embase, Scopus, and the Cochrane Library databases using terms for ICNB and thoracic surgery (including<i>thoracic surgery</i>,<i>thoracoscopy</i>,<i>thoracotomy</i>,<i>nerve block</i>,<i>intercostal nerves</i>). The search and results were not limited by date, with the last search conducted on July 24, 2020. <h3>Study Selection</h3> Selected studies were experimental or observational and included adult patients undergoing cardiothoracic surgery in which ICNB was administered with local anesthesia via single injection, continuous infusion, or a combination of both techniques in at least 1 group of patients. For comparison with ICNB, studies that examined systemic analgesia and different forms of regional analgesia (such as thoracic epidural analgesia [TEA], paravertebral block [PVB], and other techniques) were included. These criteria were applied independently by 2 authors, and discrepancies were resolved by consensus. A total of 694 records were selected for screening. <h3>Data Extraction and Synthesis</h3> This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Data including patient characteristics, type of surgery, intervention analgesia, comparison analgesia, and primary and secondary outcomes were extracted independently by 3 authors. Synthesis was performed using a fixed-effects model. <h3>Main Outcomes and Measures</h3> The coprimary outcomes were postoperative pain intensity (measured as the worst static or dynamic pain using a validated 10-point scale, with 0 indicating no pain and 10 indicating severe pain) and opioid consumption (measured in morphine milligram equivalents [MMEs]) at prespecified intervals (0-6 hours, 7-24 hours, 25-48 hours, 49-72 hours, and &gt;72 hours). Clinically relevant analgesia was defined as a 1-point or greater difference in pain intensity score at any interval. Secondary outcomes included 30-day postoperative complications and pulmonary function. <h3>Results</h3> Of 694 records screened, 608 were excluded based on prespecified exclusion criteria. The remaining 86 full-text articles were assessed for eligibility, and 20 of those articles were excluded. All of the 66 remaining studies (5184 patients; mean [SD] age, 53.9 [10.2] years; approximately 59% men and 41% women) were included in the qualitative analysis, and 59 studies (3325 patients) that provided data for at least 1 outcome were included in the quantitative meta-analysis. Experimental studies had a high risk of bias in multiple domains, including allocation concealment, blinding of participants and personnel, and blinding of outcome assessors. Marked differences (eg, crossover studies, timing of the intervention [intraoperative vs postoperative], blinding, and type of control group) were observed in the design and implementation of studies. The use of ICNB vs systemic analgesia was associated with lower static pain (0-6 hours after surgery: mean score difference, −1.40 points [95% CI, −1.46 to −1.33 points]; 7-24 hours after surgery: mean score difference, −1.27 points [95% CI, −1.40 to −1.13 points]) and lower dynamic pain (0-6 hours after surgery: mean score difference, −1.66 points [95% CI, −1.90 to −1.41 points]; 7-24 hours after surgery: mean score difference, −1.43 points [95% CI, −1.70 to −1.17 points]). Intercostal nerve block analgesia was noninferior to TEA (mean score difference in worst dynamic panic at 7-24 hours after surgery: 0.79 points; 95% CI, 0.28-1.29 points) and marginally inferior to PVB (mean score difference in worst dynamic pain at 7-24 hours after surgery: 1.29 points; 95% CI, 1.16 to 1.41 points). The largest opioid-sparing effect of ICNB vs systemic analgesia occurred at 48 hours after surgery (mean difference, −10.97 MMEs; 95% CI, −12.92 to −9.02 MMEs). The use of ICNB was associated with higher MME values compared with TEA (eg, 48 hours after surgery: mean difference, 48.31 MMEs; 95% CI, 36.11-60.52 MMEs) and PVB (eg, 48 hours after surgery: mean difference, 3.87 MMEs; 95% CI, 2.59-5.15 MMEs). <h3>Conclusions and Relevance</h3> In this study, single-injection ICNB was associated with a reduction in pain during the first 24 hours after thoracic surgery and was clinically noninferior to TEA or PVB. Intercostal nerve block analgesia had opioid-sparing effects; however, TEA and PVB were associated with larger decreases in postoperative MMEs, suggesting that ICNB may be most beneficial for cases in which TEA and PVB are not indicated.