Unplanned Exubations in the ICU: Risk Factors and Strategies for Reducing Adverse Events

Effects on Patient and Organizational Outcomes

Regardless of the cause of the UE, there are adverse consequences for both patients and hospitals. Some patients who experience UE have higher rates of in-hospital mortality; however, this is often due to contributing factors associated with severity of injury, the need for reintubation, and underlying chronic diseases [13]. Patients who experience accidental UE have higher incidence of nosocomial pneumonia (27.6% vs. 138%, P = 0.002) [11], longer duration of mechanical ventilation, and increased length of stay (LOS) [7,13]. While some studies report UE can result in serious consequences such as respiratory distress, hypoxia [13], and even death [6,12], others report lower mortality and length of stay when UE occurs, likely due to the fact that many patients are ready for liberation from mechanical ventilation at the time of UE [5,15].

Despite the emergent nature of UE, not all patients experience immediate reintubation. Many instances of UE occur during patient weaning trials or in preparation for planned extubations [5,11], which explains why only 10% to 60% of patients require reintubation [3,5,10,11,15,19,20]. When reintubation is necessary, it results in increased number of ventilator days [10,11], and increased ICU and hospital LOS [1,11]. There is little evidence directly linking reintubation with in-hospital mortality; however, it can cause serious complications such as hypotension, hypertension, arrhythmias, and airway trauma [21]. For hospitals and health care organizations, the need for reintubation results in increased hospital costs, estimated to be $1000 per reintubation event [17,22]. This estimate does not take into account additional costs incurred with increased ICU care, longer periods of mechanical ventilation, and increased LOS. Estimates of these additional costs in pediatric patients are approximately $36,000 [23]. Costs are likely higher in adult patients, due to multiple comorbidities that often accompany the need for mechanical ventilation, as well as increased pharmacy, lab, and diagnostic charges [1].

Risk Factors for Unplanned Extubation

Medical ICU Risk Factors

MICUs traditionally have the highest rates of UE [4,8]. Data from a national prevalence study indicated that there were 23.4 episodes of UE in MICUs per 1000 ventilator days [4]. Approximately 9.5% to 15% of all ventilated patients in the MICU experience UE [4,5,8]. Patients in the MICU who require mechanical ventilation often have complex chronic illness with underlying respiratory disease, which can result in prolonged periods of ventilation and increased risk of UE. Specific risk factors investigated in UE research include patient specific factors (age, gender, diagnosis, comorbidities, agitation, level of consciousness, laboratory values), ventilatory factors (ventilator type and setting, type of tracheal tube, method of tube fixation), as well as type of sedation and use of protocols [5,6,24]. Surprisingly, few variables emerge as significant risk factors for UE among MICU patients. Risk factors associated with UE have included male gender [24], presence of chronic obstructive pulmonary disease (COPD) [24], increased level of consciousness [25], and use of weaning protocols [5]. While gender, COPD, and level of consciousness increase risk of UE, the presence of weaning protocols is shown to decrease risk of UE [5]. Although UE are reported most often in MICUs, few risk factors consistently emerge for this specific cohort, making definitive recommendations for prevention of UE difficult.