The Effect of Superficial Parasternal Intercostal Plane Block on Pulmonary Function Tests After Cardiac Surgery

Postoperative pulmonary complications are a significant concern after cardiac surgery, with post-sternotomy pain contributing to impaired pulmonary function and increased risk of these complications. Parasternal intercostal plane blocks have recently emerged as a promising analgesic option for cardiac surgery, but their impact on pulmonary function tests (PFTs) has yet to be evaluated.

This prospective, single-center, double-blind, randomized controlled trial will recruit 100 adult patients undergoing elective cardiac surgery. Baseline pulmonary function, including FEV1, FVC, and PEF, will be measured preoperatively and reassessed on the first postoperative day to evaluate the primary outcome: percentage change in PFT values. Secondary outcomes include pain scores, opioid consumption, incidence of postoperative pulmonary complications during hospitalization, duration of cardiothoracic intensive care and hospital stays, and 30-day mortality.

This study aims to determine whether adding a superficial parasternal intercostal plane (sPIP) block to standard care better preserves pulmonary function in adult patients undergoing elective cardiac surgery.

Inclusion criteria

• Patients who are scheduled to undergo elective cardiac surgery via sternotomy (i.e., coronary artery bypass graft, valvular surgery, and combined surgery).
• Body Mass Index (BMI) above 20 and below 40 kg m-2
• Age above 18 years.
• Eligible to sign informed consent.

Exclusion criteria

• Emergency surgery.
• Redo surgery.
• Off-pump surgeries.
• Pregnancy.
• Preoperative mechanical circulatory support (i.e., intra-aortic balloon pump, extracorporeal membrane oxygenation, ventricular assist devices).
• Preoperative chronic pain (i.e., fibromyalgia, chronic neuropathic pain).
• Contraindication for regional analgesia (i.e., known allergy to LA, skin lesions in the injection site).
• Known allergy to one or more of the components of multimodal analgesia (i.e., opioids, paracetamol, tramadol, dipyrone).
• Preexisting severe pulmonary disease (i.e., an obstructive lung disease with FEV1 below 49%, restrictive lung disease with FVC below 49%, pulmonary hypertension).

Criteria For Discontinuing (Postoperative Exclusion Criteria):

• Prolonged cardiopulmonary bypass (CPB) of more than three hours.
• Transfusion of more than three units of blood products.
• Severe coagulation disturbance requiring prothrombin complex concentrate or recombinant factor VII.
• Left ventricular failure with vasoactive-inotropic score (VIS) at the end of the surgery of ≥ 20.
• Right ventricular failure requires inhaled nitric oxide.
• Need for mechanical circulatory support (i.e., intra-aortic balloon pump, extracorporeal membrane oxygenation).
• Patients requiring mechanical ventilation for more than 24 hours postoperatively.