Maximizing first pass success when intubating the critically ill patient: use a stylet!

Abstract

Tracheal intubation is one of the most commonly performed procedures in the intensive care unit (ICU) [1]. In a recent prospective observational study (INTUBE study) including 2964 patients across 29 countries, adverse event occurred after intubation in 45.2% of patients, including cardiovascular instability in 42.6%, severe hypoxemia in 9.3%, and cardiac arrest in 3.1% [2]. A significantly higher mortality was noted in those who experienced a peri-intubation adverse event compared to those who did not. Critically ill patients therefore represent the highest risk patients to intubate. Factors that contribute to increasing the risk of complications include the complex environment, varying levels of airway operator skills, and, most importantly, the critical illness of the patient [3, 4]. Many critically ill patients that require tracheal intubation have a physiologically difficult airway. These physiological derangements, most notably cardiovascular instability and hypoxemia, are often exacerbated during airway management and the initiation of invasive mechanical ventilation, resulting in the development of serious adverse events [5]. This baseline physiologic risk is further exaggerated when more than one attempt at tracheal intubation is required [2, 6, 7]. Moreover, a study including 650 patients undergoing emergency tracheal intubation showed difficult intubation to be an independent predictor of mortality [8]. Therefore, the goal of tracheal intubation, especially in critically ill patients, is to achieve first pass success without adverse events. A recent prospective observational study in 1513 emergency tracheal intubations showed that first pass success without adverse events was reduced to a similar extent in patients with anatomically and physiologically difficult airways, highlighting the importance of physiological optimisation along with the use of tools to overcome anatomical difficulty [9]. Several reviews and guidelines provide recommendations to achieve these targets, to enhance patient safety [3, 4, 10–14]. Difficulty in either visualizing the glottic opening or delivery of the tracheal tube to the laryngeal inlet may affect first pass success. Various devices and tools such as videolaryngoscopes, stylets, and tracheal tube introducers (bougies) have been proposed to improve first pass success [3, 4, 10, 11]. First pass success was 79.8% in the INTUBE study [2]. Similarly, a large emergency department registry of 17,583 emergency intubations demonstrated a first pass success of 85%, despite an increasing use of videolaryngoscopy [15]. These findings highlight the opportunity for further efforts to improve first pass success. However, in a recent meta-analysis comparing videolaryngoscopy with direct laryngoscopy that included nine randomized-controlled trials with over 2000 critically ill patients, the use of a videolaryngoscope did not improve first pass success, even when evaluating the studies according to the experience of the operator [16]. There was heterogeneity in the studies included and some were of low quality. Thus, while the routine use of a videolaryngoscope for tracheal intubation in ICU remains controversial, it clearly improves glottic visualization as compared with direct laryngoscopy making it an important tool for difficult airway management [17]. *Correspondence: [email protected] 1 Department of Anesthesiology, Critical Care and Pain, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India Full author information is available at the end of the article