Clinical Research Directory

Inclusion Criteria: * Patients age between 18 and 75. * Patients with American Society of Anesthesiologists (ASA) II and III status. * Patients diagnosed with truncal chronic post herpetic neuralgia( neuropathic pain persistent for more than 3 months from the onset of rash appearance ) Exclusion Criteria: * Patients unable to comprehend the informed consent. * Patients on long term opioid regimens. * Patients with impairment in hepatic (Alanine aminotransferase (ALT) \>50 U/L, and/or Aspartate aminotransferase (AST): \>45 U/L) or renal functions( creatinine level ≥1.5 mg/dL) * Patients on anti-coagulation regimens. * Patients with coagulation abnormalities (i.e. international normalized ratio (INR) ≥1.5 and/or platelets ≤50000) * Local infection in the site of the block. * Patients with body mass index (BMI) \> 35.