A qualitative and quantitative evaluation of perioperative sleep

Sleep is essential to preserve health and is especially important during
recovery from illness.[1] Abnormal sleep can aggravate inflammation and pain,
can induce mental disorders like delirium and has a substantial effect on
mood.[2]-[4]

During the perioperative period a patient is prone to develop sleep problems.
Up to 20% of patients who underwent outpatient surgery report the occurrence of
sleep problems,[5] in clinically operated patients the rate of sleep problems
is up to 23%.[6] Objective measurements show disturbances of the structure of
sleep (the *sleep architecture*) in the postoperative period.[7]-[14] These
sleep disturbances typically persist until the fourth postoperative day, but
may last well up to several weeks.[15]

Perioperative disturbance of sleep is caused by several factors. At least four
factors are presumed to have a significant effect on sleep.
1. Anesthesia or the anesthetic drugs could cause a shift in the circadian
rhythm, a "jetlag". Hormone secretion, body temperature and sleep-wake timing
are, among other things, regulated by the circadian rhythm and disruption can
lead to various pathological conditions affecting postoperative recovery.
2. Surgery causes a great amount of physiological stress, with the release of
inflammatory proteins and stress hormones.[18] This is known to disrupt normal
sleep architecture.[19], [20]
3. The hospital environment with an abundance of night-time light and sound
causes a severe fragmentation of sleep and thereby prevents a normal cycling of
sleep stages.[21]-[23]
4. The primary illness and its treatment can cause major sleep problems. Many
kinds of medication have side effects causing sleep disturbance and pain
associated with the primary illness, e.g. hip arthrosis, can cause significant
sleep fragmentation.[24]

A reduction of sleep in the perioperative period may lead to an increased risk
of complications, a longer length of stay and a delayed return to daily
activities or work. Besides their effect on physiology, sleep problems have a
strong influence on patient experience and satisfaction. Nevertheless,
professionals in clinical medicine have little concern for the quality of sleep
during the perioperative process. This reflects a lack of clinical data,
fundamental knowledge, and awareness among health care professionals

Aim: The aim of this study is to investigate if and to what extent current
clinical perioperative practice disrupts postoperative sleep. Postoperative
short-term (one week) and long-term (three months) change in sleep patterns,
quality and circadian rhythm will be assessed in orthopedic patients. This
study is the foundation for future studies, directed at understanding the
consequences of sleep disruption for recovery process after surgery. In the
future, we would like to test interventions that aim to diminish perioperative
sleep disruption and as a result improve the recovery process.

Objectives:
* To quantify a difference in sleep efficiency, quality and fragmentation
between preoperative baseline measurements and measurements one week and three
months after surgery.
* To create a framework for future studies investigating the consequences of
disturbed sleep for recovery after surgery and at investigating interventions
to diminish the perioperative disturbance of sleep to improve the recovery
process.

The study is designed as a single-center prospective observational cohort study
at the Orthopedic, Traumatology and Anesthesia departments of the Erasmus MC.
Measurements will be performed in patients homes and on the orthopedic and
traumatology ward. The appropriate amount of patients are expected to be
included in nine months.

The study is observational in nature and poses no risk to participants. The
burden put on participants consists of the following. On three moments in time
participants will wear an actigraphy wristband and fill out several short
questionnaires over a course of six days. The wristband is waterproof, but can
be taken off for showering and will be taken off during surgery. The
questionnaires should all together take not more than 10 minutes per day to
complete.