Sleep in the ICU: Limiting Elements of Noise in the Critical Care Environment (SILENCE)

Noise levels in intensive care units (ICUs) are about as loud as traffic on a main road, or conversation in a busy restaurant. Patients do not sleep well and often become confused. Patients who become confused stay longer in hospital, and often have health problems after they go home. We want to lower noise levels in the ICU to see if we can improve patients’ sleep and reduce confusion. We will look at changing the noise levels in two ways. We know from talking to patients that they find alarms annoying. The machines that check vital signs (such as heart rate and temperature) will be modified so they do not sound alerts through loudspeakers at the bedside. Instead we will send the signal to a small device, like a phone, set to vibrate. This will be carried by the nurses on the unit. We also know that patient care and general conversation cause noise. We will interview patients and staff to find out which noises are most annoying, and we will look to see where and when these noises happen most. We will then design a staff education programme to try to reduce noise. We will also put screens on the wall showing the current noise level. Before this, we need to test our plan to find out how best to introduce noise-reducing changes into the units. This is called a feasibility study. For the feasibility study we want to show that we can reduce average noise levels by 3dB (about 20%), that our pager-based alarm system works and that the nurses are happy to use it. We also need to check that we can accurately and reliably measure sleep and confusion. Phase 1 will investigate measures of sleep and confusion.