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Topic Name: Physicians say patients are not getting the restorative stages that are required in ICU

Category: Biomedical

Research persons: Dr. Randall Friese, Dr. Ramon Diaz-Arrastia

Location: Southwestern Medical Center, University of Texas, United States

Details

The sleep patterns of patients in the intensive care unit are so superficial that they barely spend any time in the restorative stages of sleep that aid in healing, UT Southwestern Medical Center physicians have found.
“Current clinical-care protocols routinely and severely deprive critically ill patients of sleep at a time when the need for adequate rest is perhaps most essential,” said Dr. Randall Friese, assistant professor of burn/trauma/critical care at UT Southwestern and lead author of a study appearing in today’s issue of The Journal of Trauma: Injury, Infection and Critical Care.
“We haven’t recognized the importance of prescribing sleep,” said Dr. Friese, whose study is one of the first to examine the sleep patterns of surgical and trauma patients. “Patients in the ICU may look like they are sleeping, but they’re not sleeping well. They are not getting the restorative stages that are required.”
Sleep typically occurs at night in successive cyclical stages. Sleep begins in very superficial stages. These stages are followed by deeper, more restorative states, including rapid eye movement (REM) sleep. Although researchers continue to investigate exactly what happens in the brain during REM sleep, they do know that it is critical for restorative sleep.
Dr. Friese monitored the sleep patterns of 16 patients in the ICU at Parkland Memorial Hospital who had suffered traumatic injuries or had undergone intra-abdominal surgical procedures. The patients had been in the ICU two to 10 days. Patients suffering brain injuries were excluded from the study because such injuries typically illicit abnormal sleep patterns. 
After monitoring the patients’ brain waves in a specially equipped bed for up to 24 hours, Dr. Friese found that patients in the ICU received an acceptable amount of sleep time, but that the sleep patterns were fragmented and significantly abnormal. Patients in the ICU spent 96 percent of their sleep cycle in superficial stages, compared to normal sleep, in which up to 50 percent is spent in the restorative stages.
The next step, Dr. Friese said, is to design a clinical trial that makes the ICU environment more conducive to sleep and then monitor the patients’ outcomes. Some proposed steps to decrease disturbances in the ICU include adjusting monitoring machines so that alarms don’t wake up sleeping patients, providing patients ear plugs and eye shields, dimming the lights, and using pharmacological sleeping aids.
“There are two major things contributing to abnormal sleep in these patients – the pathophysiology of the disease process itself and the stressful environment of the ICU,” Dr. Friese said. “If we can neutralize the stressful environment, maybe we can shorten the hospital stay, lower infection risks and increase patient wound healing.”
Dr. Ramon Diaz-Arrastia, professor of neurology and one of the study’s authors, said the investigation demonstrated “that surgical patients in the ICU have essentially no restorative sleep.
“Restorative sleep is most abundant during the later part of sleep – it is sometime between 3 a.m. to 6 a.m. that the bulk of this stage of sleep occurs. It is likely that with some straightforward measures, such as changing the schedule of nursing intervention, we may help these patients attain the restorative sleep that could improve their outcomes.”
Other UT Southwestern researchers involved in the study were senior author Dr. Larry Gentillelo, professor of surgery; Dr. Heidi Frankel, professor of surgery; and Dara McBride, senior research nurse.

Note for Rapid Eye Movement Sleep

Rapid eye movement (REM) sleep is the normal stage of sleep characterized by rapid movements of the eyes. REM sleep is classified into two categories: tonic and phasic. It was discovered by Nathaniel Kleitman and Eugene Aserinsky in the early 1950s. Their seminal article was published September 4, 1953 (Aserinsky E, Kleitman N. Regularly Occurring Periods of Eye Motility, and Concomitant Phenomena, during Sleep. Science 1953:118;273-274). Criteria for REM sleep include not only rapid eye movements, but also low muscle tone and a rapid, low voltage EEG -- these features are easily discernible in a polysomnogram, the sleep study typically done for patients with suspected sleep disorders.
REM sleep in adults typically occupies 20-25% of total sleep, lasting about 90-120 minutes. During a normal night of sleep, we usually experience about 4 or 5 periods of REM sleep; they are quite short at the beginning of the night and longer at the end. It is common to wake for a short time at the end of a REM phase. The relative amount of REM sleep varies considerably with age. A newborn baby spends more than 80% of total sleep time in REM. During REM, the summed activity of the brain's neurons is quite similar to that during waking hours; for this reason, the phenomenon is often called paradoxical sleep. This means that there are no dominating brain waves during REM sleep.
About Intensive Care Unit

An intensive care unit (ICU), critical care unit (CCU) or intensive treatment unit (ITU, popular in the UK) is a specialised department in a hospital that provides intensive care medicine. Many hospitals also have designated intensive care areas for certain specialities of medicine, as dictated by the needs and available resources of each hospital. The naming is not rigidly standardized.
Medicine suggests a relation between ICU volume and quality of care for mechanically ventilated patients.

After adjustment for severity of illness, demographic variables, and characteristics of the ICUs (including staffing by intensivists), higher ICU volume was significantly associated with lower ICU and hospital mortality rates. For example, adjusted ICU mortality (for a patient at average predicted risk for ICU death) was 21.2% in hospitals with 87 to 150 mechanically ventilated patients annually, and 14.5% in hospitals with 401 to 617 mechanically ventilated patients annually.

Researchers
Dr. Randall Friese
Dr. Ramon Diaz-Arrastia