Plasmatic Concentrations of Propofol and Remifentanil in Obese and Non Obese Patients.

Comparison of Plasmatic Concentrations of Propofol and Remifentanil During Monitored Anesthesia in Obese and Non Obese Patients.

This prospective monocentric phamacokinetics study aims to compare plasmatic concentrations of Propofol and Remifentanil required to target a specific range of monitored anesthesia and analgesia during sus-mesocolic surgery in obese and non obese patients.

Remifentanil and Propofol are administered intravenously as an opioid pain reliever and hypnotic pain reliever during anesthesia. Their advantages are numerous: short half-life allowing anesthesia and rapid awakening, little accumulation, allowing to adapt the level of anesthesia or sedation to each patient, few side effects.

Entropy° is an index derived from the electroencephalographic signal of patients, validated for the evaluation of the level of narcosis during general anesthesia.

ANI ° (nociception index analgesia) is an index using the ventilatory physiological variability of the sinus rhythm validated to monitor patient's analgesia during general anesthesia.

These non-invasive means of analgesia and sedation monitoring allows the clinician to ensure satisfactory levels of anesthesia by administering products at minimum effective doses.

The authors propose to determine whether, for a comparable target effect (analgesia and monitored sedation), plasmatic concentrations and administration rates of propofol and remifentanil necessary during general anesthesia for a comparable surgical stimulus are the same in populations of obese and non obese patients.

Inclusion Criteria:

Obese patients group:

• Age ≥ 18 years old
• Severe and morbidly obese patients (35kg / m2≤IMC <55kg / m2).
• Patients undergoing general anesthesia for laparoscopic susmesocolic surgery (bariatric surgery or cholecystectomy).
• Patients who have given their consent in the manner described by the public health law of August 9, 2004.
• Patients benefiting from a Social Security scheme.

Group of non-obese patients:

• Age ≥ 18 years old
• Patients with normal weight or slightly overweight (19 <BMI <30).
• Patients receiving general anesthesia for laparoscopic susmesocolic surgery (cholecystectomy).
• Patients who have given their consent in the manner described by the public health law of August 9, 2004.
• Patients benefiting from a Social Security scheme.

Exclusion Criteria:

• Patient refusal
• Age <18 years old
• Protected adults and vulnerable persons
• Pace maker
• General anesthesia in the 24 hours preceding this surgery
• Proven or suspected dysautonomia
• Premedication by gabapentin Neurontin °
• Locoregional peri-medullary analgesia technique used concomitantly during the pre- and intraoperative period.
• Unbalanced dysrhythmic heart disease (AC / FA; extrasystoles; non-sinus rhythm)
• Pregnant or breastfeeding woman
• Intubation impossible planned
• Hypersensitivity to the products used
• Allergy to peanut or soy