Intensive care units are so noisy and disruptive that patients cannot get the restorative sleep they need to heal, according to a new report.

But if nurses and technicians would simply adjust their schedules and avoid constantly waking patients through the night, patients may do better, the team at the University of Texas Southwestern found.

"We haven't recognised the importance of prescribing sleep," says Dr Randall Friese, who led the study published in the Journal of Trauma: Injury, Infection and Critical Care.

"Patients in the ICU [intensive care unit] may look like they are sleeping, but they're not sleeping well. They are not getting the restorative stages that are required."

Nurses, doctors and technicians argue that their schedules require regular checks on patients, even through the night.

"Current clinical-care protocols routinely and severely deprive critically ill patients of sleep at a time when the need for adequate rest is perhaps most essential," Friese says.