Critically ill patients often receive sedatives, which may delay liberation from mechanical ventilation and intensive care unit discharge. Daily interruption of sedatives alleviates these problems, but the impact of this practice on long-term psychological outcomes is unknown. We compared psychological outcomes of intensive care unit patients undergoing daily sedative interruption (intervention) with those without this protocol (control). Assessments using (1) the Revised Impact of Event Scale (evaluates signs of posttraumatic stress disorder [PTSD]), (2) the Medical Outcomes Study 36 item short-form health survey, (3) the State-Trait Anxiety Inventory, (4) the Beck Depression Inventory-2, (5) and the Psychosocial Adjustment to Illness score (overall quality of adjustment to current or residual effects of illness) were done by blinded observers. The intervention group had a better total Impact of Events score (11.2 vs. 27.3, p=0.02), a trend toward a lower incidence of PTSD (0% vs. 32%, p=0.06), and a trend toward a better total Psychosocial Adjustment to Illness score (46.8 vs. 54.3, p=0.08). We conclude that daily sedative interruption does not result in adverse psychological outcomes, reduces symptoms of PTSD, and may be associated with reductions in posttraumatic stress disorder.

Sleep is an important physiologic process, and lack of sleep is associated with a host of adverse outcomes. Basic and clinical research has documented the important role circadian rhythm plays in biologic function. Critical illness is a time of extreme vulnerability for patients, and the important role sleep may play in recovery for intensive care unit (ICU) patients is just beginning to be explored. This concise clinical review focuses on the current state of research examining sleep in critical illness. We discuss sleep and circadian rhythm abnormalities that occur in ICU patients and the challenges to measuring alterations in circadian rhythm in critical illness and review methods to measure sleep in the ICU, including polysomnography, actigraphy, and questionnaires. We discuss data on the impact of potentially modifiable disruptors to patient sleep, such as noise, light, and patient care activities, and report on potential methods to improve sleep in the setting of critical illness. Finally, we review the latest literature on sleep disturbances that persist or develop after critical illness.

Sudden unexpected death in epilepsy (SUDEP) is increasingly recognized as a common and devastating problem. Because impaired breathing is thought to play a critical role in these deaths, we sought to identify forebrain sites underlying seizure-evoked hypoventilation in humans. We took advantage of an extraordinary clinical opportunity to study a research participant with medically intractable epilepsy who had extensive bilateral frontotemporal electrode coverage while breathing was monitored during seizures recorded by intracranial electrodes and mapped by high-resolution brain imaging. We found that central apnea and O 2 desaturation occurred when seizures spread to the amygdala. In the same patient, localized electrical stimulation of the amygdala reproduced the apnea and O 2 desaturation. Similar effects of amygdala stimulation were observed in two additional subjects, including one without a seizure disorder. The participants were completely unaware of the apnea evoked by stimulation and expressed no dyspnea, despite being awake and vigilant. In contrast, voluntary breath holding of similar duration caused severe dyspnea. These findings suggest a functional connection between the amygdala and medullary respiratory network in humans. Moreover, they suggest that seizure spread to the amygdala may cause loss of spontaneous breathing of which patients are unaware, and thus has potential to contribute to SUDEP.

Daily interruption of sedative infusions in critically ill patients undergoing mechanical ventilation reduces intensive care unit length of stay and, in turn, decreases the incidence of complications of critical illness associated with prolonged intubation and mechanical ventilation.

is due to increased vagal output to the heart (40). However, breathing measurements were not made during spontaneous or heat-induced seizures in either of these DS mouse models, so it is unclear whether abnormal breathing contributes to SUDEP. Here we studied patients with DS and mice with an Scn1a R1407X/+ mutation (39) to evaluate a potential role of postictal breathing dysfunction in SUDEP.