How to improve intubation in the intensive care unit. Update on knowledge and devices

Abstract

Tracheal intubation in the critically ill is associated with serious complications, mainly cardiovascular collapse and severe hypoxemia. In this narrative review, we present an update of interventions aiming to decrease these complications. MACOCHA is a simple score that helps to identify patients at risk of difficult intubation in the intensive care unit (ICU). Preoxygenation combining the use of inspiratory support and positive end-expiratory pressure should remain the standard method for preoxygenation of hypoxemic patients. Apneic oxygenation using high-flow nasal oxygen may be supplemented, to prevent further hypoxemia during tracheal intubation. Face mask ventilation after rapid sequence induction may also be used to prevent hypoxemia, in selected patients without high-risk of aspiration. Hemodynamic optimization and management are essential before, during and after the intubation procedure. All these elements can be integrated in a bundle. An airway management algorithm should be adopted in each ICU and adapted to the needs, situation and expertise of each operator. Videolaryngoscopes should be used by experienced operators.

Keywords: Airway; Complications; Intubation; Videolaryngoscope; Videolaryngoscopy.

Fig. 1

Airway management algorithm. The availability of equipment for management of a difficult airway is checked. During the procedure, the patient should be ventilated in case of desaturation < 90%. All the intubation procedures performed in ICU are complicated. To improve first-attempt success, two operators, the use of a metal blade and the use of a malleable stylet (except for channeled videolaryngoscopes) are recommended. A rapid sequence induction is mandatory. In case of predicted difficult intubation (Mallampati score III or IV, OSAS, reduced mobility of cervical spine, limited mouth opening, coma, severe hypoxia, non-anesthesiologist (MACOCHA) score ≥ 3), the use of a videolaryngoscope is recommended if the operator is expert in using it (at least 15 intubations performed using the device), excepted in case of abundant secretions. If the MACOCHA score < 3, the choice of the device is left at the operator discretion (direct laryngoscope or videolaryngoscope). In case of intubation failure, a videolaryngoscope will be used if not used first, and/or an intubating stylet (malleable stylet or long flexible angulated stylet), followed successively using Laryngeal Mask Airway or fastrach, the use of fiberscopy in expert hands and finally the use of rescue percutaneal or surgical airway

Fig. 2

Drugs used for the intubation procedure: pros and cons

Fig. 3

Update of the Montpellier intubation protocol. Briefly, pre-intubation period interventions consist in fluid loading associated with early introduction of vasopressors, preoxygenation with NIV in the case of acute respiratory failure, preparation of sedation by the nursing team and the presence of two operators. NIV is applied during the 3-min preoxygenation phase with an ICU ventilator and a standard face mask. The PSV level is set between 5 and 10 cmH₂O, adjusted to obtain an expired tidal volume of 6 to 8 ml/kg of ideal body weight. The FiO₂ is set at 100% and the PEEP level of 5 cmH₂O. During the intubation period, recommended induction is rapid sequence induction using short acting, well-tolerated hypnotics (etomidate or ketamine), and a rapid-onset muscle relaxant (succinylcholine or rocuronium), with application of cricoid pressure (Sellick maneuver). The Sellick maneuver is performed to prevent gastric contents from leaking into the pharynx, by external obstruction of the esophagus, and associated inhalation of substances into the lungs, as well as vomiting into an unprotected airway. Just after the intubation (post-intubation period), we recommend verification of the tube’s position by capnography (a technique which allows to confirm the endotracheal position of the tube and to verify the absence of esophageal placement), initiation of long-term sedation as soon as possible (to avoid agitation) and use of “protective” mechanical ventilation settings, as defined by the ARDS network