JOHNS HOPKINS (US) — More than a third of intensive care patients put on ventilators develop symptoms of post-traumatic stress disorder, a study suggests.
The study of survivors of acute lung injury showed that the PTSD symptoms lasted at least as long as two years in some patients.
“We usually think of PTSD as something you develop if you go to war, are sexually assaulted, or suffer a similar emotional trauma,” says Dale Needham, a critical care specialist at the Johns Hopkins University School of Medicine and senior author of the study. “Instead, it may be as common, or more common, in ICU patients as in soldiers, but it’s something many doctors—including psychiatrists—don’t fully appreciate.”
People with PTSD, a form of anxiety disorder, may feel severely stressed or frightened even when they’re no longer in danger. The symptoms fall into three categories: reliving the traumatic experience (flashbacks, nightmares), avoidance (feeling numb, detached, staying away from people and places that serve as reminders of the experience), and hyperarousal (being easily startled, having difficulty sleeping, irritability).
PTSD can impair quality of life and slow patients’ recovery from a critical illness, keeping victims from returning to work or performing usual activities of daily life.
“Physical weakness usually gets better, but these mental symptoms often just linger,” says study leader O. Joseph Bienvenu, associate professor of psychiatry and behavioral sciences. “We need to pay more attention to preventing and treating PTSD in these patients.”
Since acute lung injury (ALI)—a syndrome marked by excessive fluid in the lungs and frequent multi-organ failure—is considered an archetype for critical illness, the researchers suspect PTSD is common among other ICU survivors as well.
Each year, almost 1 million patients in the United States are hooked up to ventilators in an ICU, and 200,000 are estimated to develop ALI, usually as the result of infection. The lungs of healthy people allow the easy exchange of gases to enable oxygen to enter the bloodstream, and carbon dioxide to exit the body. In ALI patients, the normally light and dry lungs become heavy and soggy like a wet sponge.
ICU survivors with PTSD are unusual in that they often experience flashbacks to delusions or hallucinations they had in the hospital, rather than events that actually occurred, Bienvenu says.
Having a life-threatening illness is itself frightening, but delirium in these patients—who are attached to breathing machines and being given sedatives and narcotics—may lead to “memories” of horrible things that didn’t happen, he adds. “One woman thought her husband and the nurse were plotting to kill her,” Bienvenu recalls.
In the study, published online in Psychological Medicine, researchers observed 520 mechanically ventilated patients with ALI, recruited from 13 intensive care units at four Baltimore hospitals between October 2004 and October 2007. Fifty-three percent survived their hospitalizations, 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 percent) had clinically significant symptoms of PTSD, with the greatest apparent onset occurring by the initial three-month follow-up visit. Sixty-two percent of the survivors who developed PTSD still had symptoms at their two-year visit. Half of this same group was taking psychiatric medications, and 40 percent 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 (a severe response to infection) 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, though the exact reasons why are unknown.
The delirium often associated with ICU stays and post-ICU PTSD may be partially a consequence of inflammation caused by sepsis. 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.
Needham, Bienvenu and others are interested in whether changing care in the ICU can reduce the incidence of PTSD. Needham’s team has reported on studies showing that early physical rehabilitation for ICU patients can speed and enhance recovery, and he says “psychological rehab” now deserves attention. Bienvenu says that educating patients and their primary care doctors about the increased risk for PTSD would be a good step.
The National Institutes of Health’s National Heart, Lung, and Blood Institute supported the research.
Source: Johns Hopkins University