Low Versus Standard Volume EXORA Block in Laparoscopic Cholecystectomy

Analgesic Efficacy of Low-Volume Versus Standard-Volume 0.25% Bupivacaine for Ultrasound-Guided External Oblique and Rectus Abdominis Plane Block in Laparoscopic Cholecystectomy, A Randomized Non-Inferiority Trial

The original EXORA block used high local anesthetic volume (50 mL total), raising concerns about local anesthetic systemic toxicity (LAST). In such a bilaterally administered regional technique, evaluating the efficacy of a reduced-volume approach is warranted to maximize patient safety.

Study Design & Population This is a prospective, randomized, double-blinded trial enrolling patients scheduled for elective laparoscopic cholecystectomy. Following informed consent, patients will be randomly allocated into two equal groups to evaluate different volumes used in a bilateral, ultrasound-guided External Oblique and Rectus Abdominis (EXORA) block.

Interventions Prior to the induction of general anesthesia, patients will receive a bilateral EXORA block using 0.25% bupivacaine.

Group E15: Will receive 15 mL of the local anesthetic on each side. Group E25: Will receive 25 mL of the local anesthetic on each side. Blinding & Allocation Allocation concealment will be maintained using sequentially numbered, opaque, sealed envelopes. The block will be performed by a designated regional anesthesiologist who will not be involved in subsequent patient care. The patient, the surgical team, the intraoperative anesthesiologist, and the postoperative data collectors will remain strictly blinded to the group allocation and the volume injected.

Anesthesia & Perioperative Management Sensory block distribution will be assessed prior to surgery. All patients will receive a standardized general anesthesia protocol for induction and maintenance. Intraoperative hemodynamics will be managed according to standard institutional protocols.

Postoperative Analgesia & Monitoring Upon transfer to the Post-Anesthesia Care Unit (PACU) and throughout the first 24 hours, all patients will receive scheduled, standardized multimodal analgesia (intravenous paracetamol and ketorolac). Postoperative pain will be assessed using the 11-point Numerical Rating Scale (NRS) at rest and during movement at prespecified time points. If the dynamic NRS score is ≥ 4, intravenous morphine (2 mg) will be administered . Patients will be continuously monitored for adverse events, including postoperative nausea and vomiting (PONV), hemodynamic instability, and local anesthetic systemic toxicity (LAST), which will be managed with predefined rescue medications

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status I or II.
• Scheduled for elective laparoscopic cholecystectomy under general anesthesia.

Exclusion Criteria:

• • Patient refusal to participate.

  • Obese patients with a body mass index of more than 35 kg/m2.
  • Known cognitive impairment or use of psychiatric drugs
  • Known allergy to local anesthetics
  • Infection at the needle insertion site.
  • Coagulopathy, or bleeding disorders.
  • Pregnancy
  • History of chronic pain or chronic opioid use.
  • Previous major upper abdominal surgery (which alters the fascial planes and anatomy).

Criteria for Withdrawal from Study Analysis (Drop-outs):

• Conversion to open cholecystectomy during surgery.
• Failed EXORA block