- Patients who (i) refuse to participate in the study; (ii) are not able to communicate due to alterations in the level of consciousness, or neurologic, or psychiatric disease; (iii) present with contraindication to any of the drugs used in the present study; (iv) have history of alcohol or drug dependence; (v) are super obese as defined by a body mass index (BMI) ≥ 40; and (vi) undergo operation for recurrent, strangulated, incarcerated or bilateral hernia