Objective Measurement of the Mechanical Pain Threshold With an Algometer for Predicting Intraoperative Opioid Consumption in Patients Who Will be Operate by Thoracotomy and Sternotomy in Cardiac Surgery

Exclusion Criteria

• •Patient refusal,
• •A body mass index (BMI) \> 30 kg/m²,
• •Allergies to any medication used in typical cardiac anesthesia,
• •Chronic pain or regular use of analgesics,
• •Severe ventricular dysfunction, pulmonary hypertension, poorly controlled arhythmia,
• •Non-elective surgery.
• •Patients enrolled in another study protocol within the previous 3 months,
• •Pregnant or breastfeeding patients,
• •Patients with severe renal or hepatic impairment.
• •Patients for whom the study will be stopped in the event of blood loss greater than or equal to one liter, or for any other severe perioperative surgical complication.