Mikkelsen ME, Christie JD, Lanken PN, Biester RC, Thompson BT, Bellamy SL, Localio AR, Demissie E, Hopkins RO, Angus DC: The adult respiratory distress syndrome cognitive outcomes study: long-term neuropsychological function in survivors of acute lung injury. Am J Respir Crit Care Med 2012, 185:1307-1315.
Cognitive and psychiatric morbidity is common and potentially modifiable after acute lung injury (ALI). However, practical measures of neuropsychological function for use in multicenter trials are lacking.
The objectives were to determine whether a validated telephone-based neuropsychological test battery is feasible in a multicenter trial and to determine the frequency and risk factors for long-term neuropsychological impairment.
A prospective, multicenter cohort study of a subset of survivors from the Fluid and Catheter Treatment Trial (FACTT) was conducted.
The FACTT enrolled patients from 38 North American hospitals between June 2000 and October 2005.
To be eligible for the ALI Cognitive Outcomes Study (ACOS), subjects had to be enrolled in the FACTT and the EA-PAC (Economic Assessment of the Pulmonary Artery Catheter) trial. The FACTT enrolled mechanically ventilated adults who met the American-European Consensus Conference criteria for ALI.
In an adjunct study to the Acute Respiratory Distress Syndrome Clinical Trials Network Fluid and Catheter Treatment Trial, neuropsychological function at 2 and 12 months after hospital discharge was assessed.
The primary outcome was the result of a validated telephone battery of standardized neuropsychological tests administered to consenting, English-speaking subjects at 2 and 12 months after hospital discharge.
Of 406 eligible survivors, 261 patients were approached to participate and 213 consented. One hundred twenty-two subjects, including 102 subjects at 12 months, were tested at least once. Memory, verbal fluency, and executive function were impaired in 13% (12 of 92), 16% (15 of 96), and 49% (37 of 76) of long-term survivors, respectively. Long-term cognitive impairment was present in 41 (55%) of the 75 survivors who completed cognitive testing. Depression, post-traumatic stress disorder, and anxiety were present in 36% (37 of 102), 39% (40 of 102), and 62% (63 of 102) of long-term survivors, respectively. Enrollment in a conservative fluid management strategy (P <0.005) was associated with cognitive impairment, and lower partial pressure of arterial oxygen during the trial was associated with cognitive (P <0.02) and psychiatric (P <0.02) impairment.
Neuropsychological function can be assessed by telephone in a multicenter trial. Long-term neuropsychological impairment is common in survivors of ALI. Hypoxemia is a risk factor for long-term neuropsychological impairment. A fluid management strategy is a potential risk factor for long-term cognitive impairment; however, given the select population studied and an unclear mechanism, this finding requires confirmation.