Delirium - A Dysfunctional Circadian Rhythm

Other interventions than bright light to treat delirium include reducing the volume on telephones, earplugs, grouping patient care activities when possible, appropriate sedation, early mobilization and even ensuring patient orientation with respect to time [10]. However, if one single treatment will ever be the golden bullet needs to be proven yet. In fact, we have to realize that many common clinical scenarios can disrupt circadian rhythms, such as severe illness, stress, noise, surgery, sepsis, drugs, light at night and much more. Therefore, a single therapy might not be sufficient in restoring disrupted circadian rhythms in critical ill patients. More likely, a combination of melatonin agonists, daylight in the ICU during daytime, noise reduction at night, light reduction during the night together with optimized sedation and weaning protocols might help to restore disrupted circadian rhythms and eventually might improve mortality in critical illness [13]. In summary, monitoring of the ICU environment that could provide feedback to caregivers on common offenders (light, noise, temperature, etc.), in addition to systems that are capable to monitor circadian rhythms (actigraphy, melatonin course, etc.), could be important to minimize circadian disruption and consequently the development of delirium in the ICU. Finally, exploring the underlying molecular mechanism of delirium and its association with circadian rhythm proteins bears the potential for novel therapies, which are urgently needed as no specific therapy is available yet