Sleep in the intensive care unit.

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.

Noncontinuous positive airway pressure therapies for obstructive sleep apnea.

While continuous positive airway pressure is the first-line treatment for obstructive sleep apnea, many patients find this form of therapy undesirable leading to treatment nonadherence. Both mandibular advancement devices and surgical therapy offer alternative solutions for such patients. This article serves to compare the types of surgical interventions and mandibular advancement devices available, their mechanisms of action, and expected side effects. Emphasis is made on the limitations and challenges in the interpretation of the available literature due to the varying definitions of curative success. The effects of mandibular advancement devices and surgical therapy on the apnea-hypopnea index and oxygen saturation are reviewed. Patient-centered outcomes of sleepiness, quality of life, treatment preference, adherence, and their effects on disease-related outcomes of hypertension are summarized. When available, comparative effectiveness trials between these therapies versus continuous positive airway pressure are emphasized. Patient selection criteria, practice parameters, and treatment limitations are discussed.

ICU delirium: an update.

PURPOSE OF REVIEW: Delirium is frequently encountered in the ICU and is associated with significant adverse outcomes. The increasingly recognized consequences of ICU delirium should enhance efforts to improve recognition and management of this serious problem. We aim to review the recent literature on ICU delirium, including risk factors, detection, management and long-term impact of disease. RECENT FINDINGS: We present the most recent evidence on risk factors for ICU delirium and its persistence. In addition, we aim to clarify some of the confusion surrounding the tools for detection and their limitation in practice. The literature reflects long-term neurocognitive impairments following ICU delirium and supports efforts to reduce these negative outcomes using protocol-driven sedation and ventilator management. Although haloperidol is widely accepted as the preferred pharmacologic treatment for delirium, its use is not seeded in robust evidence. Limited studies reflect the safety of atypical antipsychotics for treatment but lack clear improvement in delirium-related outcomes. We place an emphasis on the use of protocols to reduce the use of sedatives, particularly benzodiazepines in the management of ICU delirium. SUMMARY: Delirium remains an underrecognized and underdiagnosed problem. Detection tools are readily available and easy to use. Further understanding of risk factors is needed to identify most susceptible individuals and plan management, which should include prevention and therapy based on available evidence.

Unilateral pulmonary edema and acute severe mitral regurgitation associated with operatively repaired aortic coarctation.

Cardiogenic pulmonary edema classically presents bilaterally and with a symmetric distribution. Occasionally, cardiogenic pulmonary edema can present unilaterally, which carries an independent risk for mortality, possibly due to the delayed diagnosis. The most common cardiogenic cause of unilateral pulmonary edema is acute mitral regurgitation, frequently described in the setting of acute coronary syndrome. Here we describe a case of unilateral pulmonary edema caused by acute mitral regurgitation outside the setting of acute coronary syndrome.

Hypoventilation in neuromuscular disease.

Hypoventilation in neuromuscular disease is attributed to both respiratory muscle weakness and reduced chemoreceptor sensitivity essential in ventilatory drive. Acute or chronic respiratory failure is seen in a spectrum of neuromuscular disease; whereas some are treatable others are progressive and devastating. Sleep is associated with a reduction in ventilation and hence worsening hypoventilation. Problems with sleep may be an early indicator of further muscle weakness and should prompt the clinician for further investigation, though usefulness of pulmonary function testing, arterial blood gas analysis, and other measures may not be universally predictive. The timing of respiratory failure is variable, but knowledge of the clinical aspects, pathogenesis, and treatment of respiratory failure and hypoventilation may be helpful in evaluating the patient with neuromuscular disease. For those with progressive and terminal disease, additional factors such as end of life care, especially ventilation and cough, may be useful for the patient, caregivers, and treating medical personnel.

Dural venous thrombosis following splenectomy in a patient with hereditary spherocytosis.

Hereditary spherocytosis is a common form of hemolytic anemia sometimes requiring splenectomy in recalcitrant cases. The complications of splenectomy include an increased risk of thrombosis, usually presenting with deep vein thrombosis or pulmonary embolism. However, common complaints such as headache should warn clinicians of involvement in less common sites, primarily the dural venous system. The case of dural venous thrombosis in a patient with hereditary spherocytosis and splenectomy is discussed. The potential mechanisms associated with thrombosis formation in this population and its treatment are discussed.

Utility of venous blood gases in severe sepsis and septic shock.

Acid-base status is frequently assessed in severe sepsis and septic shock. Venous blood gas sampling is proposed as a less-invasive modality but lacks evidence within this population. The objective of this study was to evaluate the correlation and agreement between arterial blood gas (ABG), peripheral venous blood gas (pVBG), and central venous blood gas (cVBG) in severe sepsis and septic shock. We conducted a prospective, observational cohort study in subjects admitted to the medical intensive care unit. Simultaneous blood gas samples, including ABG, pVBG, and cVBG, were analyzed for correlation and agreement. Severity of illness scores revealed a mean (±SD) Sequential Organ Failure Assessment score of 7.9 ± 3.3, Simplified Acute Physiology II score of 49.3 ± 16.5, and a mortality rate of 11.9% in the intensive care unit and 16.4% in the hospital. We found a strong intraclass correlation (>0.85) for pH, partial pressure of carbon dioxide (pCO2), bicarbonate, and base excess for ABG/pVBG, ABG/cVBG, and pVBG/cVBG comparisons. Agreement by the Bland-Altman method was found for pH (bias ± SD, 0.03 ± 0.04, 0.03 ± 0.02, and 0.00 ± 0.03) but not for pCO2, partial pressure of oxygen, bicarbonate, base excess, and oxyhemoglobin saturation. In conclusion, adequate correlation and agreement between ABG/pVBG, ABG/cVBG, and pVBG/cVBG comparisons was found only for pH. The current level of evidence does not support the use of venous blood gas sampling in this setting.

Perceptions and Practices Regarding Sleep in the Intensive Care Unit. A Survey of 1,223 Critical Care Providers.

RATIONALE: Poor sleep affects a majority of critically ill patients and is believed to be associated with adverse intensive care unit (ICU) outcomes such as delirium. While recent guidelines recommend sleep promotion efforts to improve delirium and other ICU outcomes, little is known about critical care providers' beliefs regarding sleep in the ICU. OBJECTIVES: To evaluate providers' perceptions and practices regarding sleep in the ICU. METHODS: From April to July 2014, the Sleep in the ICU Survey was disseminated to ICU providers via institutional e-mail lists and four international critical care society distribution lists. MEASUREMENTS AND MAIN RESULTS: A total of 1,223 surveys were completed by providers from 24 countries. Respondents were primarily nurses (59%) or physicians (39%). Most respondents indicated that ICU patients experienced "poor" or "very poor" sleep (75%) and that poor sleep could affect the ICU recovery process (88%). Respondents also felt that poor sleep was associated with negative ICU outcomes such as the development of delirium (97%), longer length of stay (88%), poor participation in physical therapy (87%), and delayed liberation from mechanical ventilation (83%). The minority (32%) of providers had sleep-promoting protocols; these providers tended to believe their patients slept longer and experienced better sleep quality. CONCLUSIONS: Though most clinicians believe that sleep in the ICU is poor and adversely affects patient outcomes, a minority of the ICUs represented by our respondents have sleep promotion protocols. These findings highlight discordant provider perceptions and practices surrounding sleep in the ICU, as well as a possible lack of available evidence-based guidelines for promoting sleep in the ICU.

Obesity hypoventilation syndrome in the critically ill.

This article summarizes available data on the obesity hypoventilation syndrome and its pertinence to intensivists, outlines clinical and pathophysiologic aspects of the disease, discusses multidisciplinary treatments, and reviews the available literature on outcomes specific to the critically ill patient.

Hypoventilation syndromes.

The hypoventilation syndromes represent a variety of disorders that affect central ventilatory control, respiratory mechanics, or both. Obesity hypoventilation syndrome is a clinically important disorder with serious cardiovascular and metabolic consequences if unrecognized. Hypoventilation in asthma and COPD is caused by mechanical challenges imparted by airflow obstruction and increase in dead space. In neuromuscular disease, respiratory muscle weakness results in hypoventilation. Decreases in thoracic volume and limited expansion of the chest highlight the restrictive ventilatory impairments seen in hypoventilation associated with chest wall disorders. Despite the mechanism, effective hypoventilation treatment targets the underlying disease and use of noninvasive ventilation.