Acute lung injury in critical neurological illness

Acute lung injury and acute respiratory distress syndrome have been reported in a significant proportion of patients with critical neurologic illness. Our aim was to identify risk factors for acute lung injury/acute respiratory distress syndrome in this population.

Prospective, observational study.

A 22-bed, adult neurosciences critical care unit at a tertiary care hospital.

Primary neurologic disorder, mechanical ventilation >48 hrs.

None.

A total of 192 patients were enrolled with a range of neurologic disorders. Among these, 68 (35%) were diagnosed with acute lung injury/acute respiratory distress syndrome. In a multivariate logistic regression analysis, independent risk factors for acute lung injury/acute respiratory distress syndrome were pneumonia (odds ratio [95% confidence interval] 3.12 [1.5-6.0], p = .002), circulatory shock (2.2 [1.07-4.57], p = .03), and absence of a gag or cough reflex (3.41 [1.34-8.68], p = .01). Neither neurologic diagnosis nor neurologic severity, assessed with the Glasgow Coma Scale, was significantly associated with the development of acute lung injury/acute respiratory distress syndrome.

Acute lung injury/acute respiratory distress syndrome occurred in more than one third of mechanically ventilated neurosciences critical care unit patients. Loss of the cough or gag reflex is strongly predictive of acute lung injury/acute respiratory distress syndrome, while neurologic diagnosis and Glasgow Coma Scale are not. Lower brainstem dysfunction, a clinical marker of neurologic injury not captured by the Glasgow Coma Scale, is a risk factor for acute lung injury/acute respiratory distress syndrome and could inform decisions regarding airway protection and mechanical ventilation.