Researchers from the Johns Hopkins University School of Medicine looked at 222 patients who were in 13 ICUs at four Baltimore hospitals between October 2004 and October 2007. All suffered from an acute lung condition. They spent an average of two weeks in the ICU, and all of them spent time on a mechanical ventilator.
The patients' muscle strength was assessed when they left the hospital and again three, six, 12 and 24 months later. More than one-third of them had muscle weakness when they left the hospital, the study found.
While many did show improvement over time, muscle weakness was associated with significant physical limitations and lower quality of life during the follow-up period, the researchers said.
Patients' age and the length of bed rest in the ICU were the most important factors affecting muscle weakness. For every day of bed rest in the ICU, patients had 3 percent to 11 percent less muscle strength in the months after they left the hospital, according to the study in the April issue of Critical Care Medicine.
"Even a single day of bed rest in the ICU has a lasting impact on weakness, which impacts patients' physical functioning and quality of life," senior author Dr. Dale Needham, an associate professor of medicine and of physical medicine and rehabilitation, said in a Hopkins news release.
"We previously thought that bed rest and sedation in an ICU were helpful for patients, but we're finding this approach to care is actually harmful to the long-term recovery of many," he added.
These findings show that ICU patients need to be kept as active as possible, according to the researchers.
"Nothing is free of risk in the ICU, but the harms of bed rest far exceed the potential harms of giving these patients rehabilitation delivered by a skilled clinical team -- even when patients are very sick and on life support," Needham said.
"We must stop making excuses about why a patient can't do rehabilitation today -- he has a CT scan or she's getting dialysis. We need to highly prioritize rehabilitation, which we now see as just as -- if not more -- important than many other tests and treatments we offer our patients in intensive care," Needham concluded.
The Society of Critical Care Medicine offers information for ICU patients and their families.