Prediction of Hemodynamic Response to Intubation by ANI Variation During Standardized Stimulation

Background: The Analgesia Nociception Index reflects the balance between analgesia and nociception and allows early detection of a defect in analgesia. Orotracheal intubation is responsible for a sometimes deleterious hemodynamic reaction. The Analgesia Nociception Index could allow an individual adjustment of the investigator's anesthetic inductions during this period.

Objective: The objective of this study is to investigate if there is a correlation between variations in the ANI following a standardized nociceptive stimulus and the occurrence of hemodynamic or somatic reactions during orotracheal intubation without muscle relaxation.

Materials and Methods: Prospective, interventional, analytical, monocentric, piloted study carried out in the operating theatre after obtaining patient's informed consent between January 2014 and November 2014. Under steady state total intravenous anaesthesia with propofol and remifentanil at constant dosage (entropy between 40 and 60) tetanus stimulation of the ulnar nerve was performed followed by orotracheal intubation. The variation of ANI and hemodynamic parameters as well as the somatic response associated with both maneuvers were collected.

Inclusion criteria

• Any patient requiring general anaesthesia with tracheal intubation by direct laryngoscopy
• Intubation Difficulty Assessment Score < 7
• BMI between 17 and 30 Kg/m2
• Socially insured patient
• Patient 18 years of age or older
• Patient with signed consent
• Patient with a sinus heart rhythm

Exclusion criteria

• Patient refusing to participate in the study
• Pregnant woman
• Patient with a pace maker (any mode)
• Patient treated with Beta Blocker
• Known Dysautonomia
• Diabetes
• Spontaneous ventilation anaesthesia
• Allergy to any of the required medications