A new study, published online ahead of print publication in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine, shows that cognitive and psychiatric impairments are common amongst long-term survivors of acute lung injury (ALI), and these impairments can be evaluated by using a telephone-based test battery.

Leading researcher, Dr. Mark E. Mikkelsen, MD, MSCE, assistant professor of medicine at the University of Pennsylvania, explained:

“Neuropsychological impairment is increasingly being recognized as an important outcome among survivors of critical illness, but neuropsychological function in long-term ALI survivors has not been assessed in a multi-center trial, and evidence on the etiology of these impairments in ALI survivors is limited. To overcome the constraints of in-person assessment, we developed a telephone battery of standardized neuropsychological tests that could be administered by a non-expert and used it to assess a subset of 122 ALI survivors from the Acute Respiratory Distress Syndrome Clinical Trials Network Fluid and Catheter Treatment Trial.”

He continued saying:

“We found that neuropsychological function can be assessed by telephone in a multi-center trial, and that long-term neuropsychological impairment is common in these patients. We also found that hypoxemia was associated with an increased risk for long-term cognitive and psychiatric impairment.”

The test battery was conducted in patients 2 and 12 months after they were discharged from hospital. The 12-month outcome revealed that 13% of survivors had impaired memory, whilst 16% had impaired verbal fluency and 49% had impaired executive functions, i.e. a range of cognitive abilities need to effectively function day by day. 41 of 75 or 55% of survivors had cognitive impairment, which was determined as impairment in terms of memory, verbal fluency and/or executive function. Furthermore they noted that 36% of patients suffered from depression, whilst 39% suffered from post-traumatic stress disorder 62% of long-term survivors suffered from anxiety.

The findings also demonstrated a substantial link between enrollment in a conservative fluid-management strategy and the development of cognitive impairment, whilst lower partial pressure of arterial oxygen during the trial was related to a substantially higher risk of psychiatric as well as cognitive impairment.

The researchers acknowledge that the study had a few limitations, such as small sample size and using self-reports for several measures. Dr. Mikkelsen commented:

blockquote> “Although it is plausible that use of a conservative fluid-management strategy was associated with an increased risk for long-term cognitive impairment, based on the small sample size and an unclear mechanism, this finding warrants confirmation.”

He concluded:

“Our study confirms earlier research showing that cognitive and psychiatric morbidity are common among long-term survivors of ALI. We are indebted to the NIH for supporting EA-PAC, the parent study of the present study, and for recognizing the importance of assessing a multitude of long-term outcomes to properly understand survivorship and ultimately to improve the lives of critically ill survivors.”

Written By Petra Rattue