Analgesic Efficacy of Erector Spinae Plane Block vs External Oblique Intercostal Plane Block in Subcostal Cancer Surgeries

Inclusion Criteria: * Age (18-65) Years. * Both sexes. * Body mass index (BMI): (20-40) kg/m2. * American Society of Anesthesiology (ASA) physical status II, III. * Type of surgery; unilateral subcostal incision in hepatectomy and nephrectomy. Exclusion Criteria: * Patient refusal. * Subcostal incisions that are crossing the midline or midline incision. * Age \<18 years or \>65 years * BMI \<20 kg/m2 and \>40 kg/m2 * Known sensitivity or contraindication to drugs used in the study * Contraindication to regional anesthesia e.g. local infection at the site of introduction, pre-existing peripheral neuropathies, and coagulopathy. * Pregnancy. * Physical status ASA IV * patients on chronic analgesic therapy (daily morphine ≥30 mg or equivalent dose of other opioids or tramadol or any medication for neuropathic pain) * patients with a history of drug abuse * patients with neuropsychiatric diseases; patients with a history of chronic pain syndromes that may enhance sensitivity to pain, for example, fibromyalgia * All patients who are going to have severe intra- or post-operative bleeding or will require postoperative mechanical ventilation are also excluded from the study.