Evaluation of patients' sleep by nurses in an ICU

Aims and objectivesTo determine how intensive care unit evaluations of patients' sleep by nurses correspond to polysomnography and if changes in patients' physiologic parameters could be helpful in sleep evaluation. BackgroundThe evaluations of patients' sleep by nurses have not corresponded very well with objective sleep recordings, so there is a need for further knowledge in this field. DesignCorrelational study of patients' sleep, nurses' sleep evaluations and the sleep-related heart rate and blood pressure changes. MethodsThe standard overnight polysomnography was recorded on 21 patients. Simultaneously, nurses marked into an electronic patient care documentation system all the changes noted in the patients' sleep status. Patients' arterial blood pressure and heart-rate data were automatically saved into the electronic patient care documentation. ResultsThe evaluations of patients' sleep/wake state by nurses corresponded to polysomnography 68% of the time. A correlation was found between nurses' evaluations and polysomnography recordings only on total sleep time. There was no correlation in the other sleep aspects (sleep latency, amount of awakenings or movements during sleep). Most patients' blood pressures and heart rate varied according to sleep/wake state. There was less variation if the patient had received noradrenalin for blood pressure control. ConclusionThe evaluations of patients' sleep/wake state by nurses only correspond to the polysomnography two-thirds of the time. Thus, more sophisticated evaluation methods should be developed to aid nurses in sleep evaluations. Sleep-related changes in blood pressure and heart rate can be seen in intensive care unit patients, so using these parameters as part of the patients' sleep evaluation should be further explored. Relevance to clinical practiceThe nurses' evaluation practices of intensive care unit patients' sleep need further development. Monitoring the changes in patients' heart rate and blood pressure may aid in evaluating his/her sleep.