REMICrush is a French multicentric non inferiority simple blind randomized clinical trial that will compare the use of Remifentanil to muscle relaxant (reference treatment) for anesthetic rapid sequence intubation in terms of major complications (difficult intubation, gastric liquid aspiration, desaturation, hemodynamics reaction, ventricular arrhythmia, anaphylactic reaction).

BACKGROUND: Rapid sequence intubation is the reference anaesthetic procedure for patient at risk of pulmonary aspiration of gastric contents (for example emergency procedure, bowel obstruction, obese patients, gastroesophageal reflux …) or difficult airway management. Nowadays the use of Succinylcholine (CELOCURINE), a neuromuscular blockade with a short duration of action, is recommended in this indication. However, several adverse events are frequently reported, especially anaphylactic reaction, restraining its use for rapid sequence intubation. Other adverse effects such as extended neuromuscular block, malignant hyperthermia or severe hyperkaliemia prohibit its use. In this case the use of another neuromuscular blockade, Rocuronium (ESMERON), is an alternative solution. Unfortunately, this other molecule causes as many anaphylactic event as Succinylcholine (1 anaphylactic event for 3000 uses) and produce a long duration of neuromuscular block. Incidence of anaphylactic reaction is increasing in France and mostly severe reactions. Its utilization is therefore reduced to 31 to 55% of crush induction despite the recommendations. Remifentanil is an opioid agent with very shorts delay and duration of action. Several study have shown similar intubation conditions in planned surgery with the use of Remifentanil instead of neuromuscular blockade and less hemodynamic reactions. Remifentanil is already approved for anesthetic induction and recognized as an alternative to neuromuscular blockade for the intubation of children. Use of remifentanil has shown satisfying intubation conditions for adults but its incidence of major complications compared to succinylcholine remains unknown.

Study hypothesis: The investigators thus hypothesized that Remifentanil is non inferior to neuromuscular blockade in terms of major complications after a crush induction.

Methods: A multicenter simple blind randomized controlled trial. 11 centers will participate in this project.

Experimental treatment arm: During anesthetic induction remifentanil will be injected immediately after hypnotic drug through bolus intravenous injection by a peripheral or verified central venous access, at 3 to 4 µg/kg. Orotracheal intubation will be performed 30 to 60 seconds later by a graduated anesthesiologist or a resident with 4 validated semesters.

Control arm treatment: A neuromuscular blockade will be injected right after the hypnotic drug. Whether succinylcholine (CELOCURINE) at 1mg/kg or Rocuronium (ESMERON) at 1mg/kg in a bolus intravenous injection by a peripheral or verified central venous access. Orotracheal intubation will be performed after occurring of fasciculations with succinylcholine or 30 to 60 seconds after injection of Rocuronium by a graduated anesthesiologist or a resident with 4 validated semesters.

Objective and judgment criteria: The primary objective is to demonstrate non inferiority of Remifentanil compared to neuromuscular blockade in terms of major complications after a crush induction. Primary endpoint is the rate of tracheal intubation without major complications as defined by 1/ tracheal intubation with less than 2 laryngoscopies 2/ no aspiration during the 10 minutes after induction 3/ no desaturation under 95% during the 10 minutes after induction 4/ no hypo or hypertension as defined by a Median blood pressure<50 mmHg or >110 mmHg 5/ NO ventricular arrhythmia involving an emergency treatment or cardiac arrest during the 10 minutes after induction 6/ No grade III or IV anaphylactic reaction after the 10 minutes after induction.

Statistical analyses:

A 80% incidence of intubation without major complication was hypothesized. Non inferiority has been set under a superior limit of 7% for the primary endpoint 95% of the proportions difference between intervention and control group. In order to achieve 80 power with a 5% alpha risk, 1150 patients (575 for each arms) are to be included.

Inclusion Criteria:

• - male or female
• aged from 18 to 80 years old
• surgery requiring general anaesthesia with tracheal with oro-tracheal intubation
• Rapid sequence intubation indication
• aspiration risk defined as : fasting < 6h00, digestive occlusion, functional ileus, vomiting < 12h00, orthopaedic trauma < 12h00, severe gastric reflux, gastroparesis and/or dysautonomia and or gastro-oesophagus surgery
• signed informed consent sheet ; or emergency procedure if impossible

Exclusion Criteria:

• planned impossible intubation
• suspected/known allergy to neuromuscular blockade or remifentanil
• Neuromuscular disease forbidding neuromuscular blockade use
• Prolonged neuromuscular block former episode
• Malignant hyperthermia former episode
• Pre-operative respiratory failure (spO2< 95%)
• Pre-operative hemodynamic failure (use of vasopressor)
• cardiac arrest
• A woman of childbearing age who has an active pregnancy and/or clinical signs suggestive of an active pregnancy and/or does not have a contraceptive or contraceptive method and has had unprotected sex within 15 days of the last menstrual period.
• Patients under justice protection
• Use of etomidate for anesthetic induction