Mechanical ventilation consists of two parts: the ventilator and the delivery device, most commonly an endotracheal tube (ETT). Similarly, there are two parts to liberation from mechanical ventilation: reducing and then eliminating the assistance provided by the ventilator and removing the ETT.
Although much attention is paid to when to intubate patients, significantly less attention is paid to when and how to extubate them. For those accustomed to literature searches using databases such as Ovid, there is not even a MeSH heading for “extubate” or “extubation.” There is similarly less guidance on how to reduce the patient's reliance on the ventilator, that is, weaning. While weaning is—or should be—a precursor to extubation, the reverse is not always true, that is, a patient not ready for extubation still may be weaned. For example, a patient with a penetrating neck injury with a rapidly expanding hematoma requires an ETT for airway protection, but may only require minimal, if any, support from the ventilator. Either way, given the risk and expense of intubation and mechanical ventilation,1,2 there should be no delay in ventilator weaning and patients should be extubated as soon as possible.
Before deciding on whether to wean or extubate a particular patient, one must recall why the patient was intubated in the first place. Many patients are intubated for respiratory failure, either for a primary pulmonary problem (e.g., pneumonia), a problem with another organ system (e.g., myocardial infarction, fluid overload from renal failure), or a systemic problem (e.g., sepsis). Other patients are intubated for airway protection, either from altered mental status (e.g., drug overdose) or because of impending airway collapse (e.g., anaphylaxis, smoke inhalation, trauma). The reason for intubation will have a direct bearing on when, and if, a patient may be weaned or extubated.
The majority of patients extubated in the ED are those who either self-extubate or were intubated for a state reversed with time in the ED, for example, drug overdose. A recent study showed that ED extubation in such conditions can be safe and can successfully reduce the need for additional resources such as an ICU bed, or even admission altogether.3 Otherwise, it falls to the intensivist to wean and extubate the patient.
Clinical progress and, in fact, early research in the area support the progression from weaning to extubation. Although recent efforts have questioned the approach albeit with equivocal results,4–6 traditionally extubation is the last step in liberating a patient from mechanical ventilation.
Since a failed extubation (defined as an extubation followed by an unplanned reintubation) carries significant mortality and morbidity,7,8 an assessment should be taken to determine which patients will remain extubated and which will fail and require emergent reintubation. For the latter, instead of extubation, further treatment of the patient's underlying condition(s) or additional weaning steps should be undertaken, with continual reassessment for readiness to extubate. ...