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

The Usefulness of Preoperative Measurement of the Mechanical Pain Threshold for Predicting Intraoperative Opioid Consumption

The study aims to test the relationship between the preoperative pain threshold and the intraoperative need for opioids.

The objective of the study is to try to predict a patient's analgesic needs based on their objectively determined preoperative pain threshold.

The investigators will include patients scheduled for elective cardiovascular surgery.

The investigators will investigate the correlation between the preoperative pain threshold and intraoperative/postoperative opioid consumption in a highly standardized anesthesia setting.

Inclusion Criteria:

• ASA 3 patients with scheduled cardiac surgery by thoracotomy or sternotomy

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.