A 60-year-old male with chronic obstructive lung disease, limited exercise tolerance, and new onset pneumonia required tracheal intubation because of hypoxemic respiratory failure. Optimal positioning for direct laryngoscopy (DL) performed by an experienced practitioner using a Macintosh 3 blade yielded a Cormack–Lehane (C/L) 3 view, despite external laryngeal pressure and head elevation. Intubation was achieved on the third laryngoscopy attempt with the aid of a tracheal tube introducer (commonly known as the bougie). After 6 days of assisted ventilation, the patient was weaned to a FiO2 of 0.4, positive end expiratory pressure of 5 cm H2O, and pressure support of 5 cm H2O. The pulmonary infiltrates were much improved. His respiratory rate was 24 breaths per minute. A cuff-leak test was performed.
What Is a High-Risk Extubation?
Adverse respiratory events are more frequently associated with extubation than intubation yet until recently, extubation has received little attention.1-6 A stratification of the risk associated with extubation has been proposed,5,7 and although unsupported by randomized clinical trials, the need for an extubation strategy has been advocated by expert panels.5,8,9 There are two dimensions to the risk of extubation: will the patient tolerate extubation and if not, how easily can the airway be managed. The extubation of patients with easily managed airways who are not physiologically compromised, can be regarded as low risk. At the opposite end of the risk continuum are those with difficult airways who are also physiologically challenged—these patients are higher risk.7 The space between is a zone of uncertainty but it behooves the practitioner to be mindful and anticipate potential difficulties. Many patients fall somewhere along an extubation risk continuum and the practitioner must exercise judgment and strategize how best to minimize complications.
Risk prediction is an inexact science. Regarding extubation failure, patients are at a greater risk if their work of breathing is increased, oxygenation or ventilation are marginal, dead space or CO2 production are increased, airway obstruction is a possibility, or the ability to protect their airway is compromised. Even under controlled conditions, prediction of the difficult airway suffers from moderate10 to poor11 sensitivity and specificity. When extubation fails and patients require emergency airway intervention, the additional difficulties include the lack of time, information, personnel, and equipment as well as the availability of and tolerance to medications that may facilitate ventilation and intubation. A previously easily managed airway may be quite difficult under such conditions. And one that had been difficult is very likely to be more difficult or worse. Examples include the patient in whom the larynx could not be seen (Cormack–Lehane view ≥3), who required multiple attempts, practitioners, or techniques, those with airways that have subsequently become more difficult (e.g., neck swelling, airway edema, macroglossia) or ...