In this randomized trial, the investigators will test the hypothesis that combining regional analgesia techniques-which have the potential to improve the quality of postoperative recovery following median sternotomy-with PIFB will accelerate recovery. Additionally, it is anticipated that RIFB, an alternative fascial plane block, will demonstrate non-inferior (at least as effective as) performance compared to RSB, thereby providing flexibility and ease of application in clinical practice.

Advances in anesthesiology throughout the first quarter of the 21st century have significantly enhanced perioperative care quality and mitigated complication risks. In particular, ultrasound (US)-guided fascial plane blocks have become prominent and widely preferred methods for providing postoperative pain control in current practice. Today, fascial plane blocks form the cornerstone of multimodal analgesia strategies developed to avoid complications associated with neuraxial analgesia methods.

Thoracic fascial plane blocks (TFB) have become one of the revolutionary advancements in cardiac anesthesia practice and have been widely adopted in cardiac surgery patients.

The pectointercostal fascial plane block (PIFB), a type of TFB, was first described by De la Torre et al. in patients undergoing breast surgery. This new technique involves blocking the anterior cutaneous branches of the T2-6 intercostal nerves, which are responsible for sensory innervation of the sternal region.

PIFB is an effective method for controlling sternotomy pain in patients undergoing open-heart surgery. The technique offers several advantages, including its minimally invasive nature, its proximity to the sternotomy line, and the flexibility to be administered at any perioperative time point following anesthesia induction without requiring the patient to change position. Furthermore, unlike neuraxial analgesia techniques, this approach circumvents serious complications associated with neuraxial techniques, such as nerve injury, dural puncture, or epidural hematoma.

In addition to median sternotomy, chest drains placed in the subxiphoid region following cardiac surgery are also a significant source of postoperative pain. This pain may result from factors such as the skin incision, continuous irritation of surrounding tissues, and direct damage to the rectus abdominis muscle caused by the chest drains. Severe postoperative pain developing in the epigastric region can disrupt respiratory mechanics, increasing the risk of pulmonary complications and leading to a delay in the extubation process.

Although the rectus sheath block (RSB) is classified as a "Plan A" block among abdominal wall blocks, when combined with the PIFB, it can provide extensive analgesia in the anterior chest wall. Anatomically, the RSB targets the anterior cutaneous branches of the T7-12 intercostal nerves, providing somatic analgesia to the anteromedial abdominal wall and the periumbilical region. In other words, the RSB can play a complementary role in analgesic efficacy by targeting areas outside the PIFB's area of effect.

In this context, RSB has become a complementary and critical component of a multimodal analgesia strategy when combined with PIFB for the management of pain associated with median sternotomy and subxiphoid thoracic drains in cardiac surgery patients.

Recently, the rectointercostal fascial plane block (RIFB) has been described as a complementary block following sternotomy, providing analgesic efficacy similar to the RSB, particularly in the subxiphoid region. The RIFB provides effective analgesia in the subxiphoid region by blocking the anterior and lateral cutaneous branches of the intercostal nerves originating at the T6-9 levels. Although it is a relatively new technique, the absence of reported complications in case reports and series in the literature suggests that RIFB represents a safe and viable alternative.

In recent studies on peripheral nerve blocks, the concept of "quality of recovery" has become a focal point among key endpoints. However, the effect of different TFB techniques used in perioperative cardiac surgical management on quality of recovery has not yet been clearly established.

A review of the literature indicates that while PIFB administered alone after cardiac surgery provides effective analgesia in the sternal region, it is limited in managing pain caused by thoracic drains, particularly in the subxiphoid region. It is anticipated that inadequate postoperative analgesia will negatively impact the quality of patient recovery.

In this randomized trial, the investigators will test the hypothesis that combining regional analgesia techniques-which have the potential to improve the quality of postoperative recovery following median sternotomy-with PIFB will accelerate recovery. Additionally, it is anticipated that RIFB, an alternative fascial plane block, will demonstrate non-inferior (at least as effective as) performance compared to RSB, thereby providing flexibility and ease of application in clinical practice.

Inclusion Criteria:

• Patients who have provided written informed consent
• Open-heart surgery performed under elective conditions via median sternotomy with cardiopulmonary bypass (on-pump)
• American Society of Anesthesiologists (ASA) physical status class II or III
• Aged 18-70 years

Exclusion Criteria:

• Off-pump surgical procedure
• Emergency or repeat cardiac surgery
• Known allergy to induction agents or local anesthetics
• Body mass index (BMI) >35 kg/m²
• Coagulopathy
• Infection at the surgical site
• Left ventricular ejection fraction (LVEF) <40%
• Renal insufficiency (estimated glomerular filtration rate <60 mL/min/1.73 m²) or hepatic insufficiency [Presence of major systemic diseases such as acute decompensated cirrhosis characterized by bilirubin >12 mg/dL, INR >2.5, or hepatic encephalopathy, in accordance with the European Association for the Study of the Liver-Chronic Liver Failure Consortium criteria]
• Psychiatric disorders
• History of chronic pain or regular use of analgesics (corticosteroids, analgesics, anticonvulsants)
• Cognitive impairments that could interfere with the assessment of postoperative pain
• Patients with impaired physical and verbal performance

Patients aged 18-70 years, with ASA physical status II-III, who are scheduled to undergo elective open-heart surgery via median sternotomy with cardiopulmonary bypass at a tertiary care city hospital.