Background

Patients in a critical care unit sleep quite poorly even when they appear to be sleeping. Sleep is light and fragmented. Acute lack of sleep causes patients suffering in the form of fatigue, irritability, disorientation and hallucinations. It may also affect their recovery and immune defence. To promote sleep, nurses must be able to evaluate patients’ sleep reliably.

Our aim was to form a comprehensive overview of the sleep evaluation methods in critical care. Our objectives were to determine the content and the quality of the methods as reported by the researchers. This overview hopefully improves the use of the sleep evaluation methods as part of sleep promoting nursing interventions and practices.

The literature search was performed from the Ovid MEDLINE, CINAHL, an ‘All EBM Reviews’, and PsycINFO databases. The search terms sleep, evaluating sleep and critical care were used. An integrative review method was used to analyse the data.

According to the 52 articles of this review, there is a wide variety of methods to evaluate patients’ sleep in critical care by observation, by asking for patient's own perception and by objective measures. Most instruments evaluate only total sleep time or the quality of sleep in general. The validity and reliability of the instruments has been insufficiently reported. Some questionnaires for patients’ perception have been tested and used in several studies.

Sleep evaluation instruments do not cover all dimensions of sleep since they mostly measure total sleep time or estimate the overall quality of sleep. The quality of the sleep evaluation instruments varies from scientifically tested tools to untested instruments. This review will allow nurses to recognise the strengths and limitations of sleep evaluation instruments when selecting one to be used in critical care. Valid information about patients’ sleep enables nurses to facilitate it.