The Effect of White and Pink Noise on Hospitalized Older Adults

The purpose of this study is to determine if using an over-the-counter, commercially available sleep noise machine playing pink or white noise will reduce the incidence of delirium in hospitalized patients over the age of 65. Delirium is an acute change in cognition which commonly occurs in hospitalized older adults, and is linked with sleep-wake cycle disturbance. Delirium is associated with increased morbidity and mortality as well as longer hospital stays. This project will record Nursing Delirium Screening (Nu-DESC) scores for those receiving the intervention and comparing them to baseline data. Reducing delirium rates using a noninvasive, inexpensive method in a hospital setting could have a significant impact on patient outcomes and potentially reduce costs associated with longer hospital stays.

This protocol is based on two concepts. The first is that white/pink noise aids in promoting both sleep quality and quantity and the second is that poor sleep is associated with delirium. Therefore, it stands to reason that improving sleep may decrease the rate of delirium. It is well documented that the elderly are affected by delirium more than other demographics, therefore the benefits to this group would be the greatest in terms of decreasing morbidity and mortality.

White/pink noise was first described as a successful sleep intervention more than 30 years ago in a cardiac intensive care unit study. From that time to present there have been many studies that describe positive effects on sleep by noise machines as a single intervention, but typically they are bundled with other interventions such as earplugs and eye masks. Within the last 5 years, there has been a resurgence in the clinical study of white/pink noise on sleep quality and many of these studies use the gold standard of polysomnography, which employs many sensors to continuously monitor brain waves and sleep patterns. These studies also show a positive impact on both duration and quality of sleep.

More than 15 recent studies were identified that found a correlation between the sleep cycle and delirium. In these studies, sleep disturbance is present in the majority of patients with delirium. There is a clear link between sleep-wake cycle disturbance and delirium, but it is unclear whether an interrupted sleep-wake cycle causes delirium or vice versa. Despite the uncertainty, studies do show that sleep-enhancing interventions decrease rates of delirium and the duration of the delirium. The principal investigator would like to determine if white/pink noise can improve sleep quality and/or quantity, thereby decreasing the incidence of delirium.