Measuring quality of sleep in critically ill patients in the ICU: A pilot study

Rationale: Sleep deprivation is known to lead to several clinical and
physiologic manifestations also found in delirium; however, its role in the
development of delirium in the intensive care unit (ICU) is controversial.
Delirium in the ICU is among others associated with sleep deprivation, quality
of sleep and perhaps caused by a disrupted circadian rhythm.
This circadian rhythm is normally found in many physiological processes in
healthy individuals and can be easily determined by measurement of core body
temperature (CBT) following a 24-hours cycle and melatonin levels. In ICU
patients this rhythm is known to be disturbed or even abolished.1-4 It is
important to know if or to what extend the sleep of the patients at the
intensive care is affected or adversely influenced, and if this is of influence
on the incidence of delirium. Future interventional studies will focus on
methods to improve circadian rhythm to minimize sleep deprivation and incidence
of delirium.
First the feasibility of the proposed method of quantifying and
qualifying sleep through polysomnography (PSG) and simultaneously determining
circadian rhythm through blood melatonin assay and CBT-measurement, needs to be
investigated in a pilot study.

Objective: In this pilot study experience will be obtained in the simultaneous
use of PSG, melatonin assay, CBT-measurement and assessment in ICU patients.

Study design: Prospective observational study

Nature and extent of the burden and risks associated with participation,
benefit and group relatedness: No known risk is involved in participation.
Patients will receive standard intensive care with added non-invasive PSG.