Use of dexmedetomidine to facilitate extubation in surgical intensive-care-unit patients who failed previous weaning attempts following prolonged mechanical ventilation: a pilot study.

INTRODUCTION: Dexmedetomidine is a selective alpha-2 adrenergic receptor agonist that exhibits sedative, analgesic, anxiolytic, and sympatholytic effects without respiratory-drive depression. We prospectively evaluated the use of dexmedetomidine to facilitate the withdrawal of mechanical ventilation and extubation in 5 trauma/surgical intensive-care-unit patients who had failed previous weaning attempts due to agitation and hyperdynamic cardiopulmonary response. METHODS: Intravenous infusion of dexmedetomidine commenced at 0.5 or 0.7 microg/kg/h without a loading dose. Background sedation and analgesia with propofol, benzodiazepines, and opiates was discontinued or reduced as tolerated. Dexmedetomidine infusion was titrated between 0.2 and 0.7 microg/kg/h to maintain a stable cardiopulmonary response and modified Ramsay Sedation Score between 2 and 4. RESULTS: Following dexmedetomidine administration, propofol infusion was weaned and discontinued in 4 patients. In the fifth patient, benzodiazepine and opiate infusions were reduced. Ventilatory support in all patients could be weaned to continuous positive airway pressure of 5 cm H2O without agitation, hemodynamic instability, or respiratory decompensation. All patients were extubated while receiving dexmedetomidine infusion (mean dose of 0.32 +/- 0.08 microg/kg/h). One patient required reintubation for upper-airway obstruction. CONCLUSION: Dexmedetomidine appears to maintain adequate sedation without hemodynamic instability or respiratory-drive depression, and thus may facilitate extubation in agitated difficult-to-wean patients; it therefore deserves further investigation toward this novel use.

The development of acute lung injury is associated with worse neurologic outcome in patients with severe traumatic brain injury.

OBJECTIVE: The purpose of this study was to determine the incidence of acute lung injury (ALI) in trauma patients with severe traumatic brain injury (TBI), to evaluate the impact of ALI on mortality and neurologic outcome after severe traumatic brain injury (TBI), and to identify whether the development of ALI correlates with the severity of TBI. METHODS: Clinical data were collected prospectively over a 4-year period in a Level I trauma center. Patients included in the study met the following criteria: mechanical ventilation > 24 hours, head Abbreviated Injury Scale score >or= 3, no other body region Abbreviated Injury Scale score >or= 3, and age between 18 and 54 years. ALI was defined using international consensus criteria. Glasgow Outcome Scale scores were assessed at 3 and 12 months. Bivariate comparisons were made between ALI and non-ALI groups. Multivariate analysis with stepwise logistical regression was used to assess independent factors on mortality. The patient's admission head computed tomographic (CT) scan was graded using the Marshall system, and the presence and size of specific intracranial abnormality was noted. Glasgow Coma Scale (GCS) score, Marshall CT scan score, and intracranial abnormality were correlated with the development of ALI. RESULTS: One hundred thirty-seven patients with isolated head trauma were enrolled in the study over a 4-year period. Thirty-one percent of patients with severe TBI developed ALI. Head trauma patients with ALI had a significantly higher ISS, a greater number of days on the ventilator, and a worse neurologic outcome for those who survived their hospitalization. Mortality was 38% in the ALI group and 15% in the non-ALI group (p = 0.004). Only 3 of 16 (19%) of the deaths within the ALI group were directly related to ALI. By multivariate analysis, only the presence of ALI, older age, and lower initial GCS score were associated with higher mortality. There was no association between ISS, the presence of arterial hypotension (arterial systolic pressure < 90 mm Hg) at admission to the hospital, or the amount of blood transfused and mortality. No correlation was found between the severity of head injury (GCS score, Marshall score, or intracranial abnormality) and development of ALI. CONCLUSION: The development of ALI is a critical independent factor affecting mortality in patients suffering traumatic brain injury and is associated with a worse long-term neurologic outcome in survivors. The risk of developing ALI is not associated with specific anatomic lesions diagnosed by cranial CT scanning.