Alarms buzzing, respirators whooshing, phones ringing, pagers beeping, elevators pinging, staffers talking, patients groaning—there’s a constant cacophony in the intensive care unit (ICU). Add the strain of all that noise to the frequent interruptions for tests plus the stress of being severely ill or injured, and you’ll understand why many ICU patients lose the ability to think clearly, usually within 72 hours of being admitted.

Problem: Mild confusion and disorientation can quickly progress to delirium, a moderate-to-severe state of confusion characterized by fluctuating symptoms including agitation, inattention, withdrawal, poor memory, speech difficulties and/or hallucinations. Delirium affects from 20% to more than 80% of ICU patients, depending on the severity of their condition…and those who do develop delirium tend to have longer hospital stays and lower survival rates.

Encouraging news: A recent study suggests an easy way to reduce delirium risk. Researchers figured that patients would be able to think better if they could sleep better. (Earlier studies showed that ICU patients often suffer severe sleep fragmentation and an absence of restful slow-wave and REM sleep.) So, to reduce ICU sensory overload, the researchers assigned one group of patients to wear earplugs at night…a control group did not get earplugs.

Results: 60% of patients in the control group showed cognitive disturbances ranging from mild confusion to full delirium. In contrast, only 35% of earplug users developed cognitive problems…and when symptoms did arise, they generally did so later in the patients’ ICU stays. Furthermore, nearly half of earplug wearers reported a good sleep after the first night, compared with only one-quarter of those who did not use earplugs.

The researchers pointed out that a number of other factors besides noise contribute to delirium (including age, smoking, medication use and illness severity), so earplugs do not guarantee a delirium-free hospital stay. Nonetheless, this simple strategy is clearly worth a try. Bottom line: If someone you know is admitted to the ICU, bring a gift of earplugs when you visit. The type of foamy polyurethane earplugs used in the study, which reduce perceived sound by 33 decibels, are inexpensive, easy to use and readily available at drugstores and online.