Effect of Endotracheal Tube Plus STYLET Versus Endotracheal Tube Alone on Successful First-Pass Orotracheal Intubation Among Critically Ill Patients: the Randomised STYLETO Study Protocol"

Patients admitted to Intensive Care Units (ICU) often require respiratory support. Orotracheal intubation is one of the most frequent procedures performed in ICU. When performed in emergency settings, intubation is a challenging issue as it may be associated with life-threatening complications in up to one third of cases.Severe hypoxaemia occurring during intubation procedure can result in cardiac arrest,cerebral anoxia, and death.Difficult intubation is known to be associated with life-threatening complications both in operating room and in emergent conditions.ICU intubation conditions are worse than intubation conditions in operative rooms.A non-planned and urgent intubation procedure, severity of patient disease and ergonomic issues explain the morbidity associated with intubation in ICU.To prevent and limit the incidence of severe hypoxemia following intubation and its complications, several intubation algorithms have been developed ,and specific risk factors for difficult intubation in ICU have been identified.

In 2018, a large multicenter study reported first-attempt intubation success rates using direct laryngoscopy of 70% and videolaryngoscopy of 67%. In 2019, a multicentre randomized trial,assessing whether positive-pressure ventilation with a bag-mask device (bag-mask ventilation) during tracheal intubation of critically ill adults prevents hypoxemia, reported a first-attempt success rate of 81%. Other authors reported an overall first-attempt intubation success rate of 74%. The 20% to 40% first-attempt failure rates throughout studies highlight the opportunity to improve the safety and efficiency of this critical procedure. Using a preshaped endotracheal tube plus stylet may have potential advantages over endotracheal tube alone without stylet. The stylet is a rigid but malleable introducer which fits inside the endotracheal tube and allows for manipulation of the tube shape; usually into a hockey stick shape, to facilitate passage of the tube through the laryngeal inlet. The stylet can help to increase success of intubation in operating rooms.

However, some complications from intubating stylets have been reported including mucosal bleeding, perforation of the trachea or esophagus, and sore throat. In 2018, one study has assessed the effect of adding a stylet in case of difficult intubation in prehospital setting.However, in ICU, the systematic use of a stylet is still debated and recent recommendations do not recommend to use or not to use such devices for first-pass intubation. The device chosen for intubation may therefore be a confounding factor between the relation of stylet use and first-attempt success.The routine use of a stylet for first-pass intubation using laryngoscopes in ICU has never been assessed and benefit remains to be established.

The investigators hypothesis that adding stylet to endotracheal tube will increase the frequency of successful first-pass intubation compared with use endotracheal tube alone (i.e, without stylet) in ICU patients needing mechanical ventilation.