Efficacy of Superficial versus Deep Parasternal Intercostal Plane Blocks in Cardiac Surgery: A Systematic Review and Meta-Analysis

Objectives: To compare the analgesic efficacy of superficial parasternal intercostal plane (S-PIP) block and deep parasternal intercostal plane (D-PIP) to determine which technique provides superior pain relief in cardiac surgery. Design: A systematic search of MEDLINE (via PubMed), Scopus, Embase, Cochrane Library, Web of Science, Google Scholar, and ClinicalTrials.gov from inception until January 18, 2025. Eligible studies included randomized controlled trials (RCTs) and observational studies that compared the S-PIP and D-PIP blocks in patients undergoing cardiac surgery. The primary outcome of the study was postoperative opioid consumption of morphine milligram equivalent (MME) at 24 hours. Secondary outcomes included resting and movement pain scores at 0, 6, 12 and 24 hours, time to first analgesics, incidence of postoperative nausea and vomiting (PONV), extubation time, length of stay (LOS) in the intensive care unit (ICU), and the number of patients requiring rescue analgesics. Main Results: Seven RCTs and 1 observational study, including a total of 510 patients, were identified. The findings demonstrated no statistically significant difference in MME at 24 hours between the S-PIP and D-PIP block groups (mean difference, -1.23; 95% confidence interval, -2.51 to 0.05; p = 0.061). Additionally, there were no significant differences in pain scores, PONV incidence, time to rescue analgesics, extubation time, or ICU LOS of stay between the 2 techniques. Conclusions: S-PIP and D-PIP blocks provide comparable postoperative analgesic efficacy in patients undergoing cardiac surgery.