ICU Literature Updates from November 2013

Improvement of Intensive Care Unit Sound Environment and Analyses of Consequences on Sleep: An Experimental Study

In this study, the authors evaluated if modification of the ICU sound environment in a way feasible could improve sleep. Study participants were healthy male volunteers who were exposed to originally recorded ICU noise and peak reduced ICU noise. These different noise exposures where evaluated for their impact on sleep. Using polysomnography over four nights, subjects were evaluated after exposure to two nights of different maximum sound levels. The authors discovered that during ICU exposure nights, sleep was more fragmented with less slow wave sleep, more arousals and more time awake. Unfortunately, the reduction of maximal A-weighted levels from 64 to 56 dB was not enough to have a clear improved effect on sleep quality in this study.

Sleep, Anxiety and Fatigue in Family Members of Patients Admitted to the Intensive Care Unit: A Questionnaire Study

In the hustle and bustle on the intensive care unit, family members can often be stressed. Despite intensivist best efforts, family members can experience health problems related to a family member’s ICU experience. In this timely and important study, the authors remind us not to only be mindful of our patient’s sleep deprivation, but also their loved one’s (our other patients) sleep experience. In this study, the author’s state that one of the first ways families suffer is loss of sleep. Using the General Sleep Disturbance Scale (GSDS), Beck Anxiety Index (BAI) and Lee Fatigue Scale (NRS-F), the authors created a questionnaire to evaluate sleep fatigue and anxiety during the intensive care unit admission. 94 people responded to the survey, 43.6% of whom were children. 43.5% of the respondents stated sleep quality was poor to very poor. Only 15.2% stated sleep was good/very good. Anxiety, tension and fear were the biggest contributors to poor sleep. The most common suggestion to improve sleep was more information regarding the patient’s health and relaxation techniques. Hence, when thinking of sleep in the ICU, do not forget the patient’s family and their ICU related sleep disturbances.

Non-Pharmacologic Interventions to Improve the Sleep of Hospitalized Patients: A Systematic Review

While not looking at the ICU directly, evaluating non-pharmacologic interventions to improve the sleep of hospitalized patients is a discussion that could be of great benefit to the intensivist. In this review, the authors evaluated 13 studies, including four randomized controlled trials with over 1150 patients. As with many reviews of the literature, the authors found great heterogeneity in the trials with regards to interventions, patient populations, outcome measures and length of follow up. The authors found that daytime light exposure improved sleep quality 7–18%, improved sleep hygiene improved sleep 5% and relaxation techniques improved sleep 0–38%. These finding are interesting and may help the hospital physician determine where initial interventions to improve sleep can be made. However, the authors comment that there is insufficient evidence that any non-pharmacologic intervention improves sleep in general inpatients and further studies are needed.