Clinical Chronobiology: A Timely Consideration in Critical Care Medicine

Helen McKenna; Gijsbertus T. J. van der Horst; Irwin Reiss; Daniel Martin


Crit Care. 2018;22(124) 

In This Article

Implementing an Integrated "Chronobundle" to Entrain Faltering Circadian Rhythms in the Critically ill

There is a biological rationale for keeping Zeitgeibers at their "expected" time to minimise harm from desynchronisation of peripheral and central clocks (Figure 2). On the basis of the mechanisms and evidence from human and animal studies outlined, we propose a "chronobundle" to promote chronofitness as part of daily management of critically ill patients, summarised in Figure 2. There is evidence that interventions may have greater benefit in combination, with a systematic review of multicomponent strategies based on environmental modifications demonstrating decreases in delirium incidence (odds ratio 0.47).[83] Some chronobundle elements used to improve sleep in critically ill patients such as the use of ear plugs and eye masks have demonstrated benefit[84] and influenced circulating melatonin levels in a simulated critical care setting.[85] Individualising Zeitgeber timing according to a patient's chronotype may further improve the impact of such interventions. This chronotype-specific approach has been explored as a performance enhancing tactic in both athletes[14] and college students.[86] Information regarding chronotype could be sought from close relatives and friends, and questionnaires exist to quantify responses from specific questions.[11]

Figure 2.

Schematic of a suggested "chronobundle" of care for critically ill patients. Attempt to maintain normal circadian pattern of activity even when patients are critically ill through simple multimodal scheduling and interventions. ICU intensive care unit