Circadian rhythm of vital functions in patients with severe cerebral hypoxia at time of admission and discharge in a neurological rehabilitation intensive care unit: a retrospective pilot study

Hypoxic brain injuries are severe consequences of cardiac and pulmonary events requiring resuscitation due to trauma, serious blood loss or suicide attempts. The circadian course of body temperature, heart rate and blood pressure of 24 patients aged 56.2 years (SD 15.1) who were admitted into a neurological rehabilitation intensive care unit after hypoxic brain injury was analysed retrospectively. Chronograms revealed a loss of diurnal variation of the investigated parameters. Particularly, the increase of heart rate and blood pressure during morning hours could not be verified. The results can be explained by damage of oscillatory centres as a consequence of cerebral hypoxia.