Parasternal Intercostal Plane Blocks for Enhanced Recovery After Cardiac Surgery: A Systematic Review of Technical Refinements and Evidentiary Support.

BACKGROUND

Parasternal intercostal plane (PIP) blocks provide opioid-sparing analgesia within cardiac Enhanced Recovery After Surgery (ERAS) pathways, but non-standardized nomenclature and ambiguous anatomical targets limit their adoption.

METHODS

A systematic search of PubMed, Cochrane, and Embase databases was conducted. Inclusion criteria encompassed randomized controlled trials and observational studies reporting on PIP blocks in adult cardiac surgery to synthesize evidence on their efficacy, technical refinements, and safety.

RESULTS

This review integrated 20 clinical studies (2019-2025). Adopting the El-Boghdadly terminology resolves descriptive inconsistencies by distinguishing superficial (SPIP) and deep (DPIP) techniques. SPIP targets the pectoralis major-intercostal interface (T2-T6), while DPIP accesses the intercostal-transversus thoracis plane (T1-T6). PIP blocks reduced 12-hour postoperative pain (average 1.21-point reduction) and opioid use (average 30.34 milligram morphine equivalents (MME) reduction), though analgesic benefits diminished after 24 hours. SPIP provides a safer profile with minimal internal mammary artery (IMA) injury risk but limited cephalad spread. DPIP achieves broader dermatomal coverage but positions the needle 3-5 mm from the IMA; thus, it should be applied with caution or replaced by SPIP in post-CABG patients. Recovery outcomes demonstrated earlier extubation and shorter intensive care unit stays. However, bupivacaine concentrations approached neurotoxic thresholds ≥2.0 μg/mL in 7.1% of DPIP cases.

CONCLUSION

PIP blocks provide effective opioid-sparing analgesia, requiring meticulous anatomical execution. SPIP is favored for safety, whereas DPIP demands real-time ultrasound guidance and caution in patients with IMA grafts. Future research should optimize dermatomal coverage, refine individualized dosing, and evaluate long-term outcomes.