Inability to sleep is one of the most distressing factors for patients in the intensive care unit (ICU). Sleep is perceived as light and awakenings are numerous. Nurses' documentations of sleep are narrow, mainly concentrating on the quantity and general quality. Nurses should diversely evaluate, document and promote sleep to provide patient centered care.

To investigate the content of nurses' documentation about the sleep of ICU patients, patients' own perceptions of sleep, and the correspondence of the two.

Nurses' documentations (n = 90) were analysed retrospectively with quantitative content analysis. A cross-sectional survey of patients' (n  = 114) perspectives was collected with the five-item Richards-Campbell Sleep Questionnaire (RCSQ), on a visual analogue scale from 0 (the poorest quality sleep) to 100 (optimum sleep). The data was analysed statistically. Correspondence was tested with cross-tabulation.

Nurses documented sleep quantity for 71% and quality for 27% of patients, along with the needs assessment, used interventions and their effect on sleep. Patients' perspectives varied widely. Sleep depth was rated the lowest and falling asleep highest of the RCSQ sleep domains. Age of the patients correlated positively with general quality of sleep, sleep depth and falling asleep. Nurses' documentations and patients' perceptions correlated in over half of the cases.

Nurses' documentation of ICU patients' sleep is not systematic or comprehensive and corresponds only partially with patients' own perception. The sleep of non-intubated patients is light and awakenings are frequent. Documentation of ICU patients' sleep should include the whole nursing process, i.e. needs assessment, interventions used, and evaluation of sleep and the effects of the interventions, along with patients' own perspective to promote patient-centered care.

Evaluation and documentation of patients' sleep must include patients' own perception to be comprehensive. Nurses' documentation should include all elements of nursing process.