Perioperative sleep disorders mainly refer to the syndrome in which patients undergoing
surgery experience disrupted sleep wake rhythms before and/or after surgery, leading to
abnormal sleep quality or behavior during sleep. Clinical manifestations include
fragmented sleep, easy awakening at night, difficulty falling asleep, insufficient sleep
time, early bedtime, or disrupted sleep rhythm at least one day before or after surgery.
The latest meta-analysis study indicates that the incidence of preoperative sleep
disorders in surgical patients is as high as 60%. After surgery, about 60-70% of patients
will have postoperative sleep disorder (PSD), and even 23% of patients will have sleep
disorder until the fourth day after surgery. Among various surgeries, orthopedic surgery
has a high incidence of PSD due to its long operation time and wide surgical range. In
the study by Duan G and colleagues, the PSD incidence rate of spinal orthopedic surgery
in orthopedics was 35.4%, and the PSD incidence rate of limb surgery was 27%.
Sleep disorders may lead to a range of complications, including cognitive impairment,
delayed postoperative recovery, acute pain, and cardiovascular accidents. In the hospital
environment, factors that lead to poor sleep include pain, anxiety, noise, interference
from hospital staff, continuous ambient lighting, and uncomfortable beds; After
completing the surgery, factors such as the size of the surgery, the use of opioid drugs,
inflammatory mediators, the release of various hormones, and pain contribute to a high
incidence of sleep disorders, with pain being the most common cause, and there is an
interactive relationship between postoperative sleep disorders and pain. It is worth
noting that patients with poor preoperative sleep quality have a higher probability of
developing sleep disorders after surgery. Therefore, it is necessary to comprehensively
consider these factors and take corresponding preventive measures to reduce the incidence
of perioperative sleep disorders.
According to the sleep care guidelines, for postoperative patients entering the ICU,
maintaining a quiet and dim environment and reducing interruptions in nighttime care
activities are recommended to improve sleep quality and efficiency. A meta-analysis shows
that the use of earplugs and eye masks also helps promote sleep in ICU patients. However,
it is evident that this method is not suitable for patients who are admitted to regular
multi person wards after surgery. Although in a meta-analysis, there was insufficient
evidence to suggest that drug therapy can improve the quality or quantity of sleep in
patients with poor postoperative sleep. Even compared to placebo or no treatment, there
is no established drug category or specific drug that is superior to placebo or no
treatment [6]. However, drug therapy is still widely used for patients with perioperative
sleep disorders due to its convenience, strong feasibility, and high patient acceptance.
In current clinical practice, the main drugs used to address perioperative sleep
disorders are sleeping pills and painkillers. Specifically, sleeping pills are mainly
divided into first generation, second generation, and third generation sedative hypnotic
drugs. These drugs mainly exert extensive inhibition on the central nervous system,
causing it to transition from an excited state to an inhibited state. However, their
effect on improving sleep structure is not satisfactory, especially the second-generation
drugs - benzodiazepines, which can change the usual sleep pattern, prolong shallow sleep,
shorten the duration of REM sleep, and delay the appearance of the first REM sleep. This
change, which is similar to the postoperative sleep structure, is more detrimental to the
improvement of patients' sleep, therefore the effect is not satisfactory. As for
painkillers, opioids are the most commonly used class in clinical practice. Even though
they have strong analgesic effects, they have been found to dose dependently inhibit REM
and SWS sleep in normal volunteers and animal experiments. In addition, in Cronin AJ et
al.'s study, postoperative patients suffered from severe sleep disorders even when
avoiding opioid use and pain was well controlled. Therefore, the improvement of sleep in
perioperative patients cannot be limited to the use of the above two drugs.
Pregabalin is a gabapentin class drug that inhibits the influx of calcium ions into the
presynaptic membrane of neurons and reduces the release of excitatory neurotransmitters
(including glutamate, aspartic acid, substance P, calcitonin gene-related peptide,
norepinephrine, serotonin, dopamine, etc.) by binding to the α 2 δ pressure group
containing voltage-gated calcium channels. Its analgesic, anti anxiety, and
anticonvulsant effects are widely used in various clinical diseases. Pregabalin has been
approved for the treatment of neuropathic pain and partial seizures in the United States
and Europe. It can also be used for fibromyalgia in the United States and for the
treatment of generalized anxiety disorder in Europe. While treating patients with this
type of chronic disease, its effect on improving sleep has been discovered. Studies have
found that pregabalin exhibits significant sleep improvement effects from the initial
stage of medication, and its therapeutic efficacy is maintained throughout the entire
treatment phase. Similar sleep improvement effects to alprazolam have also been found in
normal healthy individuals. The mechanism by which pregabalin improves sleep is still
unclear, and it is speculated to be related to its ability to reduce excitatory
neurotransmitters. Currently, there is no relevant research on the impact of pregabalin
on sleep quality in perioperative patients.