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with steroids and/or epinephrine (and possibly with noninvasive ventilation and/or heliox) and do not necessarily need to be reintubated. Steroids and/or epinephrine could also be used 24 hours prior to extubation in patients with low cuff leak values. It is also important to note that a low value for cuff leak may actually be due to encrusted secretions around the tube rather than to a narrowed upper airway. Despite this, reintubation equipment (including tracheostomy equipment) should be readily available when extubating patients with a low cuff leak values. The capacity to protect the airway and to expel secretions with an effective cough would seem to be vital for extubation success, although specific data supporting this concept are few. Successful extubations have been reported137 in a select group of brain-injured comatose patients who were judged to be capable of protecting their airways. However, it is difficult to extrapolate this experience to more typical ICU patients, and many would argue that some capability of the patient to interact with the care team should be present before the removal of an artificial airway. Airway assessments generally include noting the quality of cough with airway suctioning, the absence of “excessive” secretions, or the frequency of airway suctioning (eg, every 2 h or more).34,108,138 Coplin et al137 devised an “airway care score,” which semiquantitatively assesses cough, gag, suctioning frequency, and sputum quantity, viscosity, and character that predicted extubation outcome. Peak cough flows of 160 L/min predict successful translaryngeal extubation or tracheostomy tube decannulation in neuromuscular- or spinal cord-injured patients.139 Managing the Patient Who Has Failed a Spontaneous Breathing Test Introduction The failure of a patient to complete an SBT raises 2 important questions. First, what caused the SBT failure, and are there readily reversible factors that can be corrected? Second, how should subsequent mechanical ventilatory support be managed? Specifically, should an SBT be tried again? If so, when? What form of ventilatory support should be provided in between SBTs and should support be at a constant high level or should efforts be made to routinely reduce the level of support gradually (ie, to wean support)? Evaluating evidence addressing mechanical ventilatory support strategies is particularly problematic. This is because trials comparing 2 or more approaches to ventilator management compare not only the modes of ventilation but also how those modes are used. Ideally, trial design should be such that management philosophies and the aggressiveness of support reduction are similar in each strategy being evaluated. Unfortunately, this is often not the case, as investigator experience with one approach has a tendency to result in more favorable “rules” of support reduction for that approach compared to others. Recommendation 5. Patients receiving mechanical ventilation for respiratory failure who fail an SBT should have the cause for the failed SBT determined. Once reversible causes for failure are corrected, and if the patient still meets the criteria listed in Table 3, subsequent SBTs should be performed every 24 hours. Rationale and Evidence (Grade A) Although failed SBTs are often a reflection of persistent respiratory system abnormalities,52 a failed SBT should prompt a search for other causes or complicating factors (see the “Patholophysiology of Ventilator Dependence” section). Specific issues include the adequacy of pain control, the appropriateness of sedation, fluid status, bronchodilator needs, the control of myocardial ischemia, and the presence of other disease processes that either can be readily addressed or else can be considered when deciding to proceed further with discontinuation attempts. Assuming medical management is optimized and that the patient who has failed an SBT still meets the criteria listed in Table 3, the following 2 questions involving subsequent SBTs arise: First, should SBTs be attempted again or should another approach to ventilator withdrawal be attempted? Second, if an SBT is attempted again, when should that be? There are some data on which to base an answer to the first
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