ICU survivors at high risk of developing PTSD symptoms

Thanks to advances in critical care medicine, patients admitted to the intensive care unit today are more likely than ever to survive their stay. Yet outliving the physical trauma or illness that required ICU treatment often leaves long-lasting psychological scars, a new review finds.

"The prevalence of posttraumatic stress disorder symptoms and PTSD in patients following ICU hospitalization is high - about 20 percent," said Dimitry Davydow, MD, the review's lead author. "Considering that about 4 million people visit the ICU every year in the United States alone, it's a significant public health issue."

Davydow is an assistant professor in the Department of Psychiatry and Behavioral Sciences at the University of Washington School of Medicine in Seattle. The review appears in the September-October issue of the journal General Hospital Psychiatry.

Using data from 15 previously published studies, the authors evaluated PTSD symptoms in 1,745 former ICU patients. The studies took place in the United States, United Kingdom, and multiple countries in Europe.

PTSD can occur in people who have experienced or witnessed life-threatening events, such as serious accidents, violent personal assaults or natural disasters. Symptoms - which include nightmares and problems sleeping, flashbacks, irritability, anger and feelings of emotional detachment or numbness - often extend for months or years after the traumatic event, and affect about 6.8 percent of the general U.S. population, according to National Center for PTSD figures.

The trauma of an ICU stay triggers PTSD symptoms in many survivors and negatively can affect a person's quality of life after leaving the hospital, the authors discovered.

In studies that used questionnaires to evaluate patients' symptoms, 22 percent of patients developed PTSD symptoms. In studies that relied on clinician diagnoses, 19 percent of patients developed PTSD after ICU treatment.

Several factors increased the likelihood that a person would develop PTSD after an ICU stay. Having mental health disorders, especially anxiety or depression, before entering the ICU significantly predicted whether a person would develop post-ICU PTSD.

"For people who have a prior history of depression and anxiety disorders such as PTSD and other mental health disorders, stressful situations can bring about exacerbations of their underlying psychiatric illness. To be treated in an ICU, a person is critically ill and often near death, so it's a very severe stressor. That combination may lead to a later exacerbation of their prior psychiatric disorder," Davydow said.

In addition, patients sedated with benzodiazepine medications (such as Valium and Xanax) proved more likely to develop PTSD symptoms after their ICU stay, as did patients who remembered frightening in-ICU experiences after ICU treatment.

"The use of sedatives in the ICU is important because people need to be sedated if they require mechanical ventilation or other invasive procedures," Davydow said. However, some sedatives, such as benzodiazepines, are more likely to produce disorientation, confusion and even psychotic experiences, which can be so frightening for patients that they perceive them as an actual traumatic event, he said.

Although there was some evidence to support an increased risk of PTSD symptoms among female and younger ICU patients, the association was not nearly as strong as what the authors expected based on general psychiatric literature, Davydow said.

"Demographics don't seem to play as much of a role in this population, as opposed to having a prior history of depression or anxiety and what happens in the ICU itself," Davydow said.

James Jackson, Psy.D, a research assistant professor of medicine and psychiatry at Vanderbilt University Medical Center, called the review a thoughtful and exhaustive summary of the relevant research on PTSD in ICU survivors, but said that the evidence is too tentative to recommend one particular medical intervention over another.

One of the review's limitations, which the authors acknowledge, is that the majority of the included studies used screening questionnaires to identify PTSD symptoms, Jackson said.

"Screening tools are not really the gold standard for PTSD assessment. They tell you symptoms or probable PTSD. It is a misnomer that you could arrive at a diagnosis simply by using a screening tool," Jackson said.

"Even if [participants'] symptoms meet the criteria for PTSD, but they're functioning fully on the job, with family and at leisure, then by definition they can't have PTSD," Jackson said. As a result, "We really don't have a sense of the pervasiveness or magnitude of functional impairment due to PTSD symptoms in ICU survivors."

The best action for health care providers is thoughtfully to prepare families for the possibility that their loved one could have psychological difficulties, including problems with anxiety and PTSD after an ICU stay, Jackson said.

"If you or your loved one develops these symptoms -such as nightmares, avoidance and anxiety - seek a consultation with a clinical psychiatrist. There is some real value to early intervention," Jackson said.

The National Institutes of Health and the Canadian Institutes of Health Research provided funding support to reviewers.

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Davydow DS, Gifford JM, Desai SV, i>et al. Posttraumatic stress disorder in general intensive care unit survivors: a systematic review. Gen Hosp Psychiatry. 2008 Sep-Oct;30(5):421-434   [Abstract]