Overnight noise levels in intensive care units often exceed levels recommended by the World Health Organization, according to US researchers.
A study by Yale University School of Medicine reviewed 70 ICU patient charts and clinical activities between midnight and 4am.
Results showed significant in-room activity, such as vital sign recording, and sound level maximums that exceeded 83 decibels every hour in every room monitored.
They concluded sleep disruption was prevalent and may be linked to delirium and immune dysfunction, as well as potentially worse outcomes due to patient sleep deprivation.
The study was presented last week at the annual meeting of the American College of Chest Physicians in Atlanta.