One in three patients with acute lung injury who survived stays in an ICU and required use of a mechanical ventilator showed substantial post-traumatic stress disorder symptoms that lasted for up to two years, according to a study.
Because ALI is considered an archetype for critical illness, the researchers suspect PTSD is common among other ICU survivors as well.
“We usually think of PTSD as something you develop if you go to war, are sexually assaulted or suffer a similar emotional trauma,” Dale Needham, MD, PhD, the studys senior author and a critical care specialist at the Johns Hopkins University School of Medicine, said in a news release.
“Instead, it may be as common, or more common, in ICU patients as in soldiers, but its something many doctors — including psychiatrists — dont fully appreciate.”
The unusual thing about PTSD in ICU survivors is they often experience flashbacks about delusions or hallucinations they had in the hospital, rather than events that actually occurred, said O. Joseph Bienvenu, MD, PhD, the studys lead investigator and an associate professor of psychiatry and behavioral sciences at Johns Hopkins. Having a life-threatening illness is itself frightening, but delirium in these patients may lead to recollections of traumatic events that did not happen, he added.
“One woman thought her husband and the nurse were plotting to kill her,” Bienvenu said.
For the study, the Johns Hopkins team observed 520 mechanically ventilated patients with ALI, recruited from 13 ICUs at four Baltimore hospitals between October 2004 and October 2007. Of the patients in the cohort, 53% survived their hospitalization, and 186 patients had at least one research visit over the subsequent two-year follow-up period.
The researchers found that 66 of the 186 patients (35%) had clinically significant symptoms of PTSD, with the greatest apparent onset occurring by the initial, three-month follow-up visit. Of survivors who developed PTSD, 62% still had symptoms at their two-year visit. Half of those with PTSD were taking psychiatric medications, and 40% had seen a psychiatrist in the two years since being hospitalized with ALI.
The researchers also found that patients with depression before hospitalization were twice as likely to develop PTSD, and that those who spent more time in the ICU were more likely to experience symptoms.
Those who had sepsis during their ICU stay and those who were given high doses of opiates were more likely to develop PTSD as well. Those given corticosteroids while in the ICU were less likely to develop PTSD, although the researchers did not determine why.
The delirium often associated with ICU stays and post-ICU PTSD may partially be a consequence of inflammation caused by sepsis, the researchers noted. This inflammation may lead to a breakdown in the blood-brain barrier, which alters the impact on the brain of narcotics, sedatives and other drugs prescribed in the ICU.
Bienvenu said patients who have these risk factors need special attention. Simply educating them and their primary care physicians about the increased risk for PTSD would be a step in the right direction, he added.
The study appeared Feb. 26 on the website of the journal Psychological Medicine. The study abstract is available at http://bit.ly/Wg5fwA.