Recent findings indicate that the risk of a psychiatric diagnosis increases after a person suffers a critical illness. More patients than ever are surviving critical illness due to advances in medical care, but critically ill patients are exposed to a great deal of stress, including pain, respiratory distress, and delirium.
Dr. Hannah Wunsch of Columbia University, New York, and colleagues believe that all of these experiences may affect mental health. However, the extent of the psychiatric illness risk after critical illness is unclear.
Researchers looked at psychiatric diagnoses and medication prescriptions before and after critical illness by examining the records of 24,179 critically ill patients in Denmark. All patients had spent time in intensive care units, and needed mechanical ventilation for a non-surgical reason, from 2006 to 2008, and were followed up until 2009.
Their details were compared against about 20,000 other patients treated in hospital, and about 120,000 members of the general population. Various demographic and chronic illness factors were taken into account.
Of the participants, 6.2 percent had one or more psychiatric diagnoses in the five years before their critical illness. This compares with 5.4 percent for other hospital patients and 2.4 percent for the general population.
Among the 9,921 critical illness survivors with no earlier psychiatric history, the risk of new psychiatric diagnosis was dramatically higher than that for other hospitalized patients, at 0.5 percent versus 0.2 percent in the first three months. The rate for the general population was also 0.2 percent. The absolute risk was low, at less than one percent, but this is still 20-fold higher than among the general population.
Many more critically ill patients were given new psychoactive medication prescriptions in the first three months after leaving the hospital, at 12.7 percent versus 5.0 percent for the other hospital patients. The rate for the general population is 0.7 percent. The study appears in the Journal of the American Medical Association.
“Our study provides important data on the burden of psychiatric illness among patients who experience critical illness requiring mechanical ventilation, as well as on the risks of psychiatric diagnoses and treatment with psychoactive medications in the year following intensive care unit discharge,” the authors warn.
“Discharge planning for these patients may require more comprehensive discussion of follow-up psychiatric assessment and provision of information to caregivers and other family members regarding potential psychiatric needs.
“Although the absolute risks were low,” they add, “given the strong association between psychiatric diagnoses, such as depression, and poor outcomes after acute medical events, such as myocardial infarction and surgery, our data suggest that prompt evaluation and management of psychiatric symptoms may be an important focus for future interventions in this high-risk group.”
In an interview, Derek C. Angus, MD, warns, “We already know that psychiatric illness is far larger than that seen by psychiatrists. So the important implication for us was that the risk was 20-fold higher than the general population. The absolute risk managed by psychiatrists suggests that there may be a far larger burden of psychiatric illness not treated by psychiatrists in this patient population.
“The first and foremost implication of our study is we still need to know why. There are a number of possibilities including the biology of the critical illness itself, the fact that the ICU is a very adverse environment that disrupts sleep, there can be a lot of pain, and clinicians can be under high pressure to begin psychoactive medication use in order to manage patients through the critical illness, that could induce a dependency on those drugs thereafter.”
He calls for more active screening for these problems, and more awareness among general practitioners and physicians caring for patients after critical illness of this possibility so they can help patients seek care as soon as possible.
The risk of psychiatric illness after critical illness has also been explored among children. A team from the University of Washington School of Medicine, Seattle, Washington, took details from 17 studies on psychiatric disorders after discharge from the hospital.
They found that the most common psychiatric disorders in this group were post-traumatic stress disorder (PTSD) and major depression. Clinically significant PTSD symptoms were seen in 10 percent to 28 percent of children and depressive symptoms ranged in seven percent to 13 percent.
Previous psychiatric or developmental problems raised the risk, as did having parents with psychiatric symptoms. Age and gender did not appear to affect the risk, but more severe illness and invasive procedures raised the risk.
“Psychiatric morbidity appears to be a substantial problem for pediatric critical illness survivors,” said the team, led by Dimitry S. Davydow, MD. He calls for more understanding of this risk, so the most vulnerable children can be closely monitored.
Wunsch, H. et al. Psychiatric Diagnoses and Psychoactive Medication Use Among Nonsurgical Critically Ill Patients Receiving Mechanical Ventilation. The Journal of the American Medical Association, 19 March 2014, doi:10.1001/jama.2014.2137
Davydow, D. S. et al. Psychiatric morbidity in pediatric critical illness survivors: a comprehensive review of the literature. Archives of Pediatrics and Adolescent Medicine April 2010 doi: 10.1001/archpediatrics.2010.10.