Circadian Rhythm Disruption in the Critically Ill

Abstract

Circadian disruption often demonstrates serial degradation: initially, the amplitude attenuates along with delayed circadian phase. With increasing acuity of illness, circadian rhythmicity may be lost entirely. Causes of chronodisruption may be environmental or internal to the patient. In particular, inadequate daytime illumination and nocturnal light pollution disrupt healthy circadian periodicity. Internal causes of circadian arrhythmia include critical illness itself and subjective experience of distress and pain. Observational studies of windowed rooms and real-time ambient lighting have found that physiologic light-dark patterns may support recovery from critical illness. Studies of early morning bright light or evening melatonin agonists have found improved rates of delirium, enhanced sleep, and lower arrhythmia prevalence. The current evidence base emphasizes that lighting and melatoninergic interventions deserve to be tested in full-scale trials.

Prevalence for delirium in stroke patients: A prospective controlled study

“…This phenomenon in patients with an acute stroke might be caused by cerebral dysregulation and associated with reduced perfusion, hypoxia, and disturbed neurotransmitters (Maldonado, 2008). Especially delirium during the night is discussed by disturbed melatonin circulation (Oldham, Lee, & Desan, 2016) and might explain the result of a delirium only during the night. Another hypothesis might be early infections during onset of stroke causing delirious episodes, for example, by aspiration and first cerebral responses, especially in patients with poststroke immunodepression (Famakin, 2014).…”

Effectiveness of Melatonin for the Prevention of Intensive Care Unit Delirium

“…Although the etiology of delirium is unknown, sleep disruption has been thought to contribute to ICU delirium. These patients often have altered sleep patterns due to environmental noise, abnormal lighting, and overuse of sedating medications …”

“…It has been shown that critically ill patients with sleep deprivation have a disrupted circadian rhythm and decreased melatonin production . Exogenous melatonin is being evaluated as a potential agent to restore sleep patterns and help prevent and/or treat delirium in hospitalized patients . Previous studies have demonstrated that the administration of nightly low‐dose exogenous melatonin to elderly patients in hospital wards resulted in a lower incidence of delirium .…”

“…These patients often have altered sleep patterns due to environmental noise, abnormal lighting, and overuse of sedating medications. 7,[16][17][18] Melatonin is a hormone released by the pineal gland and has major roles in sleep regulation and management of the circadian rhythm. 17 It has been shown that critically ill patients with sleep deprivation have a disrupted circadian rhythm and decreased melatonin production.…”

Cycles of circadian illuminance are sufficient to entrain and maintain circadian locomotor rhythms in Drosophila

“…For example, emergency rooms and intensive care units (ICUs) need constant lighting to monitor the health of patients. Because severe disruption of the circadian clock and sleep loss affect many processes, such as the immune response, hormone secretion, and mental ability, exposure to constant light ultimately impairs the recovery of patients in the ICU1314. Limiting the use of LAN, therefore, is not the solution for these kinds of problems.…”