Photo Credit: iStock.com/EvgeniyShkolenko

Dr. Brodkey explains how prolonged disturbances to sleep in the ICU can become a significant issue for patients, leading to psychological or physiologic injury.

To sleep, perchance to dream—ay, there’s the rub,

For in that sleep of death what dreams may come,

When we have shuffled off this mortal coil,

Shakespeare: Hamlet, Act III, Scene 1, lines 64-66

Determinants of outcomes in the ICU tend to be visualized as results of technical interventions; however, more prosaic concerns are equally significant. Patients in the ICU often have poor‑quality and/or interrupted sleep related to factors such as:

• Constant lighting, disturbing light–dark circadian rhythm
• Iatrogenic interventions such as treatments and frequent vital sign measurements
• Invasive supporting devices such as ventilators and pumps
• Disturbing noises related to alarms and device activities
• Persistent symptoms such as anxiety and pain
• Effects of various drugs

Among some patients in some situations, these disturbances may be more of a nuisance than a significant problem leading to psychological or physiologic injury, yet with prolonged sleep disturbance, significant issues are likely to arise.

Delirium: Delirium—manifested by confusion, agitation, hallucinations, and disturbed cognitive functioning—is common among patients in the ICU and is associated with a variety of detriments, including a higher mortality rate, longer use of mechanical ventilators and stays in the ICU, and higher costs. Although delirium is more traditionally associated with hyperactive responses, it is also commonly associated with hypoactivity‑lethargy or sleepiness. Both forms have been significantly associated with poor‑quality sleep among patients in the ICU. Restorative sleep benefits memory, mood, and cognition, leading to less anxiety and depression and a reduced risk for delirium.

Hormonal and metabolic effects: Sleep disturbances are also associated with other problems relevant to a stay in the ICU. Because sleep and the normal circadian rhythm are closely related to the regulation of stress hormones such as cortisol, insulin, and glucagon, disturbances in sleep can lead to irregularities in blood glucose levels and the stress response.

Cardiovascular consequences: Distorted sleep may lead to increased heart rate and blood pressure variability and be associated with increased cardiorespiratory distress.

Immune function: A lack of quality sleep may also be associated with diminished immune system function, leading to a state of relative immunosuppression and possibly compromised wound healing ability.

Improving Sleep in the ICU

For all of these reasons, sleep disturbances in the ICU should be limited as much as possible, and healthy sleep architecture should be pursued. Measures of sleep duration and interruptions should also be considered as part of the ICU’s overall quality assurance and improvement plans. These action plans should, at least initially, rely on nonpharmacological methods and interventions.

Nocturnal noise reduction should be a part of routine ward design and professional care. Limiting conversational volume, closing doors, decreasing alarm volume, and even the provision of “white noise” or earplugs are very simple interventions that may considerably enhance sleep quality.

Allowing natural lighting during daytime hours and dimming ambient lighting at night to maintain near-normal circadian rhythms can be easily performed and may greatly improve sleep quality. Eye masks may help some patients, as well.

Minimizing interventions at night such as limiting measurement of vital signs, blood draws, and medication administration should be relatively easy to accomplish with a strategy of quiet hours at nighttime for both patients and families.

Reducing stimulation, either physical or mental, late in the evening, diminished ventilator weaning, and nocturnal symptom control are conducive to better sleep.

General interventions to control or treat delirium also effectively promote quality sleep. These may include increasing activity and providing therapy more often during daytime hours and regular re‑orientation with signs and clocks as needed. In addition, family involvement, when appropriate, may be very helpful to the patient.

Nonpharmacologic Focus

It is noted that the interventions involved in these plans are, in general, nonpharmacologic and that the regular use of hypnotic drugs will not be generally necessary or effective. Despite this, certain agents are sometimes requested and prescribed and are useful in certain situations and for certain patients. This topic will be reviewed in my next Tales from the ICU column.

Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of Physician’s Weekly, their employees, and affiliates.