Prediction of outcome has always been a goal of medicine. Recently, economic forces, ethical concerns, and resource allocation have spurred mathematically complex prognostic formulas. Efforts to simplify prognostic determination have focused on simple characteristics or events that can be detected easily. The need for additional ventilatory support or airway protection after initial discontinuation of such support has been proposed to be a simple identifier of mortality risk in critically ill patients.
Current data available on reintubation confirm that the differences in patient characteristics from the medical ICU, surgical ICU, and trauma ICU extend to ventilatory mechanics. A group of severely ill medical ICU patients (overall survival, 38%) had a significant relationship between reintubation and an increased rate of complications. Mortality in the reintubated group was not reported; pulmonary compromise was the most frequent cause for reintubation (32.5%), whereas airway obstruction accounted for only 12.5% of extubation failures, with stridor occurring in 5 of 6 patients, accounting for 18% of the study population, but only 4 of whom were reintubated.
The surgical ICU patients described by Demling et al had a remarkably low reintubation rate of 4%, but this group had a 40% mortality. Reintubation in this group occurred at 48 h, without airway compromise, and indicated continued progressive cardiopulmonary decline. As in the surgical ICU patients, the trauma group had low reintubation rate of 3%. Mortality was one of ten patients, and no patients had stridor reported; air leak and laryngoscopy were employed in the group with inhalation injury to avoid stridor.
Our experience with reintubation in critically ill trauma patients found that reintubation was not a predictor for death. Trauma patients are typically younger, without chronic cardiopulmonary dysfunction, and have acute and limiting physiologic disturbances. The patients in this study, although severely injured by accepted scoring systems, still underwent aggressive weaning and termination of ventilatory support in about 3 days. The 7% reintubation rate appears acceptable by literature standards, and certainly the lack of adverse outcome suggests that perhaps even more aggressive weaning is possible to avoid complications associated with prolonged mechanical ventilation, such as nosocomial pneumonia.
This study is subject to the limitations inherent in any retrospective data analysis, although the patients were prospectively identified and followed up at the time of reintubation in quality assurance data. A prospective study may also cause alterations in mechanical ventilation weaning or termination practices if reintubation, a nonblindable event, is defined as the marker of outcome.
There were more upper airway problems than previous reports. These were treated generally by tracheostomy after reintubation and carried little or no threat to life. Additionally, because of the acute nature of traumatic injury and/or multiple organ dysfunction syndrome, with relatively short-term effects on ventilatory physiology, it was possible to reextubate several of these patients. Those requiring prolonged ventilatory support had tracheostomy performed. Thus, reintubation was not a predictor for mortality, but of need for longer ventilatory support or airway protection in our trauma patient population. We do not consider tracheostomy a complication, but rather an effective respiratory therapeutic maneuver, which is effected at the earliest convenience. Tracheostomy facilitates pulmonary toilet, improves patient comfort, and reduces dead space ventilation and airway resistance to allow weaning from mechanical ventilation.
Stridor was increased in our patients for reasons that remain unclear. Stridorous patients were intubated, on average, 21 h longer than those who did not develop stridor, although this was not statistically significant. Laryngeal edema occurs in up to 15% of patients intubated orotracheally, secondary to local trauma at the area, either from intubation or the presence of the endotracheal tube, inciting an inflammatory response and edema, which compromise the airway. Steroids delivered preextubation do not reduce the incidence of laryngeal edema, and in this study, laryngeal edema was more frequent in female patients and patients intubated greater than 36 h. In pediatric patients, postextubation stridor is increased in patients with facial bums, and in those patients in whom no air leak was present with cuff deflation immediately prior to extubation. Similarly, in the report of Demling et al, most extubation failure occurred in patients with smoke inhalation injury.
We did not routinely assess preextubation air leak since there were no thermal injuries. There was no difference in sex distribution between the groups of patients with and without stridor. Unfortunately, the numbers of patients in these groups are small, and significance may be achievable only in larger populations. We were unable to ascertain traumatic intubations, either in the field or elsewhere, from the records available.
The development of nosocomial pneumonia leads to increased costs and mortality, and is probably the most frequent cause of death in the intubated patient. Because patients with underlying severe diseases are more likely to develop, and to die from pneumonia, it is understandable that medical ICU patients would have a higher mortality from pulmonary compromise, and reintubation would act as a marker for severity of disease, rather than a provocative insult. Similarly, nontraumatic surgical ICU patients have more underlying disease, more pneumonia, and greater mortality, making extubation failure a marker of this. The younger trauma patient, with fewer chronic diseases, has other causes for respiratory compromise such as stridor. The reintubated patients in this study did not have increased incidences of pneumonia or pulmonary complications.
Reintubation in the traumatized ICU patient is not a predictor of mortality; reintubation implies the need for prolonged airway protection and/or ventilatory support and leads to tracheostomy. Aggressive termination of ventilatory support would be possible in the trauma patient as opposed to the medical ICU or surgical ICU patient, as there is little adverse outcome from reintubation when required.