Analgesia Nociception Index for Pain Monitoring in Intensive Care Units

Inclusion Criteria: * Intensive Care Cardiovascular Patients Group 1 - Patients aged from 18 to 80 years, scheduled for elective isolated coronary bypass graft (CABG) for 2-4 vessel disease, without any perioperative complications, and who were postoperatively monitored via the analgesia nociception index in the cardiovascular intensive care will be included. * Intensive Care Internal Diseases Group 2 - Patients aged from 18 to 80 years, intubated or tracheostomized, In mechanical ventilation with Pressure-Controlled Ventilation mode, under perfusion neuromuscular blocker, Normothermic, non-cooperative and/or sedated and neuromuscular blocker * Intensive Care Patients (Obese) Group 3 - Post Bariatric surgery, over 40 BMI Exclusion Criteria: * Intensive Care Cardiovascular Patients Group 1 Patients who required emergency surgery, had significant preoperative chronic pain, had autonomic nervous system anomalies and patients with rhythm will be excluded from the study. * Intensive Care Internal Diseases Group 2 Ramsey sedation scale under 5, cooperative, with spontaneous breathing effort and extremity movement, non sinusal cardiac rhythm * Intensive Care Patients (Obese) Group 3 - patients under 40 BMI