Patients require intubation and mechanical ventilation for airway protection, or when a disease process impairs their respiratory capabilities. While most Emergency Medicine (EM) practitioners can easily recognize patients who require intubation, they are often less familiar with the weaning and extubation process.
Weaning is the act of decreasing oxygenation and ventilation support via the mechanical ventilator, and allowing the patient to assume greater control of breathing. Extubation is the liberation from mechanical ventilation, and involves the discontinuation of respiratory support and removal of the endotracheal tube. An unplanned extubation is defined as an inadvertent removal of the endotracheal tube, either by the patient or practitioner. Studies have shown that up to 48% of patients with an unplanned extubation do not require reintubation.1,2 A failed extubation is defined as the need for reintubation with 48 to 72 hours, and occurs in up to 30% of patients. Failed extubations can be due to airway pathology, continuation of an extrapulmonary cause of respiratory failure, or the presence of another disease impairing respiration.3–9 Patients who require early reintubation have an increased risk of mortality, hospital and ICU lengths of stay, and airway complications.4,6,7
Unnecessary delays in weaning and extubation can increase ventilator-associated complications, including pneumonia, barotrauma, and volutrauma.10–13 Conversely, premature weaning and extubation carry their own set of complications.13,14 Therefore, the clinician must weigh the risks and benefits of early weaning and extubation versus the potential need for reintubation.
WEANING AND EXTUBATION IN THE EMERGENCY DEPARTMENT
Several studies have cited the increased utilization of the Emergency Department (ED) in recent years,14–16 as well as an increased number of critically ill patients admitted to the intensive care unit (ICU) from the ED.17,18 In addition to the higher volumes and sicker patient population, the length of stay in the ED has also increased.19
WEANING FROM MECHANICAL VENTILATION
Withdrawing Oxygenation and Ventilation Support
Weaning is the act of decreasing oxygenation and ventilation support via the mechanical ventilator, such that the patient assumes greater control of breathing. There are several well-described modes of weaning and required parameters to facilitate a successful extubation.
Oxygenation can be optimized by increasing the positive end-expiratory pressure (PEEP) and/or the fraction of inspired oxygen (FiO2) in patients with hypoxic respiratory failure. Briefly, extrinsic, or applied PEEP provides additional pressure above atmospheric pressure to prevent collapse of the alveoli at end-expiration,25–31 increasing the functional residual capacity (FRC). PEEP is useful in a variety of disease processes. Excessive PEEP, however, can result in complications, including alveolar injury, lung parenchymal injury, and deleterious cardiovascular effects.31,32 The goal, therefore, is to improve alveolar recruitment and arterial oxygenation while using the ...