Are circadian rhythms important in intensive care?

Practical suggestions are made to help maintain the circadian rhythms of both patients and staff on intensive care synchronised to 24 h.

Abstract

The problems of psychological disturbances amongst intensive care patients and of the stresses experienced by intensive care staff are discussed in relation to the environment of the intensive care unit, the nature of the work and the nature of the patients' treatment. The lack of natural daylight in many units, the repetitive nature of the work and the high level of noise and activity maintained throughout the 24 h can result in a loss of effective rhythmic stimuli for both patients and staff. Further deprivation of rhythmic stimuli will result in some patients from the heavy sedation required to facilitate intermittent positive-pressure ventilation. These factors may result in disturbances to the normal circadian rhythms of both patients and staff and so contribute to the disturbances referred to above as well as to more general disturbances in physiological function. A brief account is given of circadian rhythms in normal man and of the effects of desynchronisation of these rhythms from the environment and from each other. Practical suggestions are made to help maintain the circadian rhythms of both patients and staff on intensive care synchronised to 24 h.