The aim of this study is to examine the usability of ANI in patients who will be treated in intensive care unit.

The aim of this study is to examine the usability of Analgesia Nociception Index in patients who will be treated in intensive care unit ( a- Cardiovascular b- surgical c- internal diseases), mechanically ventilated and lacking communication. The investigators will examine whether the positive inotropic/vasoconstrictor agents will have any effect on Analgesia Nociception Index.

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

Intensive care patients between 18 and 80 years old. White Turkish Population.