A Sufficiently Effective and Low-Risk Plane Block: A Randomized Controlled Trial Evaluating the Modified Parasternal Block in Off-Pump Coronary Artery Bypass Grafting with Sternotomy.

Inflammatory markers were consistently lower in the MPSB group.

Pharmacokinetic analysis revealed a mean peak plasma ropivacaine concentration of 0.88 μg/mL, with the maximum individual concentration reaching 1.76 μg/mL at 5 min post-administration.

The MPSB group demonstrated superior postoperative outcomes, including lower VAS pain scores, earlier return of gastrointestinal function, reduced duration of mechanical ventilation, decreased rescue analgesic requirements in the intensive care unit, shorter hospital stays, and lower incidence of postoperative pulmonary complications.