5% of ICU patients experience "cascade" of illnesses with extended stay

May 8, 2016

Some patients in the intensive care unit spend weeks moving from one crisis to the next in a cascade of critical illness that sometimes has little connection to the original reason they were placed in the unit.

These patients seem to never quite improve enough to get out of the ICU, but also aren't dying. This group comprises 5% of ICU patients, but they consume 33% of ICU resources, and likely a vastly greater proportion of compassion and emotional resources. That's according to a new study led by University of Michigan physician Theodore Iwashyna and published this week in The Lancet.

The study's authors have coined a new term to describe the condition of those patients: Persistent Critical Illness, abbreviated PerCI. The study provides a new way to identify and group patients for further study.

Iwashyna carried out the study while on sabbatical in Australia. He and his collaborators from the VA Ann Arbor Healthcare System and Monash University in Melbourne, Australia, used data from over one million critically ill patients at 182 ICUs across Australia and New Zealand between 2000 and 2014. They identified 51,509 patients with PerCI and found that after ten days in the ICU, usual clinical predictive tools lost their power to predict death. The patient's pre-hospital state, such as age, gender, and health conditions, was more effective at predicting survival.

Iwashyna says further study is needed to figure out how to break the cycle of crisis and allow patients to recover sooner or be allowed to die with dignity.

"It feels to many of us clinically, the person who goes from problem to problem, we deal with each of those problems as if they were brand new. But they're not. They're part of this cascade. And so what we're trying to do here is open a line of research that asks the question of can we treat those people who are stuck in this cascade differently, in such a way that we can break them out of the cascade," says Iwashyna.

Iwashyna emphasizes that more research is necessary to understand the causes of Persistent Critical Illness and develop new treatment approaches.

"One possibility is that people get stuck in a position where we're not exercising them, we're not giving them food, we're not waking them up, and so we take more control of their body and provide more support than it needs," he said. "The support we provide with machines is never as nuanced as the support the body provides itself. And so if we don't get the machines out of the room when someone no longer needs them, I think that increases the risk of harm."