ICU Literature Updates

Emerging Role of Melatonin and Melatonin Receptor Agonists in Sleep and Delirium in Intensive Care Unit Patients

In this review, the authors sought to investigate the impact of melatonin and melatonin receptor agonist on delirium prevention. The authors acknowledge the limitations of our understanding on what causes delirium but postulate that sleep deprivation plays a role. This is a timely and good review of the literature on the relationship between melatonin, sleep deprivation and delirium.

www.ncbi.nlm.nih.gov/pubmed/26092575

Sleep in the Neurological Intensive Care Unit: Feasibility of Quantifying Sleep After Melatonin Supplementation with Environmental Light and Noise Reduction

It is widely known that sleep deprivation can be detrimental to critically ill patients. In this investigation, the authors sought to determine the feasibility of quantifying sleep in 12 neurological ICU patients who had received melatonin. Patients were also subjected to light and environmental noise reduction. Like many previous studies, the authors found it hard to quantify sleep in ICU patients. Additionally, the authors discovered that total sleep time was normal, although sleep was fragmented and time spent in slow-wave or rapid eye movement sleep was notably decreased as has been discovered in many other studies. Unfortunately, the authors did not find a difference between the control and intervention group

http://www.ncbi.nlm.nih.gov/pubmed/25647773

The Use of Modafinil in the Intensive Care Unit

In this small case series, the authors address a several issues related to sleep deprivation in the ICU, namely fatigue, depression and excessive daytime somnolence. The investigators sought to determine the use of modafinil, a psycho-stimulant, could improve ICU outcomes by treating some of these conditions. They discovered that through the use of modafinil 200mg each morning patient had greater wakefulness, were able to participate in rehab more and got more sleep at night. This study will need to be repeated on a larger scale to help determine if modafinil can have a true impact on ICU outcomes.

http://www.ncbi.nlm.nih.gov/pubmed/25716122

Sleep in the Intensive Care Unit

This review article focuses on what is known about sleep in patients admitted to ICU. The etiologies of sleep disruption and circadian rhythm abnormalities in the ICU, tools to measure sleep in critically ill patients, sleep-promoting interventions in the ICU, and sleep disturbances that persist or develop after critical illness are reviewed.

www.atsjournals.org/doi/abs/10.1164/rccm.201411-2099CI

Delirium Transitions in the Medical ICU: Exploring the Role of Sleep Quality and Other Factors

In this article, the authors evaluate the elusive link between delirium and sleep deprivation in 223 medical ICU patients over a 201 day period. Patient were also assessed for delirium on a regular basis. Using the Richards-Campbell Sleep Questionnaire, daily perceived sleep quality ratings were measured. Delirium was measured twice a day with the Confusion Assessment Method tool (CAM) for the ICU. In this study, perceived sleep quality was similar in ICU patients who developed delirium and those who did not. Additionally, perceived sleep quality was unrelated to delirium transition. This is another piece of work that fails to establish a link between delirium and sleep deprivation.

http://www.ncbi.nlm.nih.gov/pubmed/25230376

Sleep in the Intensive Care Unit

In this review, from one of the nation’s centers for evaluating sleep in the ICU, Dr. Pisani and colleagues offer a concise update on developments in critical care medicine pertaining to sleep. Specifically, the authors provide a very nice discussion on circadian rhythm in critical illness and a good review of potentially modifiable disruptors to sleep such as noise, patient care activities and light. Additionally, the authors give very helpful descriptions with different methods of analysis of EEG enabling the reading to better understand EEG interpretation for sleep evaluation in ICU patients. Overall this is a welcomed addition to the growing body of review articles focusing on sleep in the ICU.

http://www.ncbi.nlm.nih.gov/pubmed/25594808

Sleep in the Neurological Intensive Care Unit: Feasibility of Quantifying Sleep After Melatonin Supplementation with Environmental Light and Noise Reduction

In the article, the researchers evaluate sleep in the ICU after initiating a multimodal approach to improving sleep. The investigators enrolled 12 patients who were admitted in a neurological ICU. Sleep promoting interventions such as environmental light (eye mask) and noise reduction (headphones) were implemented as well as prescribing melatonin. Unfortunately, for many patients, EEG recordings could not be interpreted. In those patients who recordings could be obtained, the authors found no difference between intervention and non-intervention groups.

http://www.ncbi.nlm.nih.gov/pubmed/25647773

Delirium Transitions in the Medical ICU: Exploring the Role of Sleep Quality and Other Factors

Written by one of the more productive groups in the field, the authors evaluated the link of perceived sleep quality ratings along with other patient and ICU risk factors with the development of delirium on a daily basis in 223 medical ICU patients over a 201 day period. Interestingly, the author’s found no association between daily perceived sleep quality ratings and transition to delirium. As reported in other publications, the authors found infusion of benzodiazepines and opioids in mechanically ventilated patients as risk factors for the development of delirium.

http://www.ncbi.nlm.nih.gov/pubmed/25230376

Sleep in the Intensive Care Unit: A Review

In this article, the authors review and update the reader on what is currently known with regards to staging and measuring sleep. It offers a nice review on the characteristics of sleep in the ICU. There is a very nice section of sleep deprivation and immune function. Most of the article focuses on causes of abnormal sleep in the ICU and reviews much of what is already known. It concludes with a nice review of how to promote sleep in the ICU.

http://www.ncbi.nlm.nih.gov/pubmed/24916753/

Sleep Disturbance in Older ICU Patients

In this study, the authors note aging is associated with specific changes to both the quantity and quality of sleep and that these changes make it hard to adjust sleep and wake rhythms to changing environmental conditions. In the context of the ICU, an environment already known to alter sleep, the authors evaluated sleep in patients admitted to the ICU who were older than age 80. The authors reviewed four studies on sleep in the elderly. This study was helpful in bring much of the resaerch of sleep in elderly ICU patients into one location. However, much is still needed in the study of sleep in this frail and vulnerable population.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4075232/