Evaluation and Management of Obesity Hypoventilation Syndrome. An Official American Thoracic Society Clinical Practice Guideline.

Background: The purpose of this guideline is to optimize evaluation and management of patients with obesity hypoventilation syndrome (OHS).Methods: A multidisciplinary panel identified and prioritized five clinical questions. The panel performed systematic reviews of available studies (up to July 2018) and followed the Grading of Recommendations, Assessment, Development, and Evaluation evidence-to-decision framework to develop recommendations. All panel members discussed and approved the recommendations.Recommendations: After considering the overall very low quality of the evidence, the panel made five conditional recommendations. We suggest that: 1) clinicians use a serum bicarbonate level <27 mmol/L to exclude the diagnosis of OHS in obese patients with sleep-disordered breathing when suspicion for OHS is not very high (<20%) but to measure arterial blood gases in patients strongly suspected of having OHS, 2) stable ambulatory patients with OHS receive positive airway pressure (PAP), 3) continuous positive airway pressure (CPAP) rather than noninvasive ventilation be offered as the first-line treatment to stable ambulatory patients with OHS and coexistent severe obstructive sleep apnea, 4) patients hospitalized with respiratory failure and suspected of having OHS be discharged with noninvasive ventilation until they undergo outpatient diagnostic procedures and PAP titration in the sleep laboratory (ideally within 2-3 mo), and 5) patients with OHS use weight-loss interventions that produce sustained weight loss of 25% to 30% of body weight to achieve resolution of OHS (which is more likely to be obtained with bariatric surgery).Conclusions: Clinicians may use these recommendations, on the basis of the best available evidence, to guide management and improve outcomes among patients with OHS.

Educational video to improve CPAP use in patients with obstructive sleep apnoea at risk for poor adherence: a randomised controlled trial.

BACKGROUND: Suboptimal adherence to CPAP limits its clinical effectiveness in patients with obstructive sleep apnoea (OSA). Although rigorous behavioural interventions improve CPAP adherence, their labour-intensive nature has limited widespread implementation. Moreover, these interventions have not been tested in patients at risk of poor CPAP adherence. Our objective was to determine whether an educational video will improve CPAP adherence in patients at risk of poor CPAP adherence. METHODS: Patients referred by clinicians without sleep medicine expertise to an urban sleep laboratory that serves predominantly minority population were randomised to view an educational video about OSA and CPAP therapy before the polysomnogram, or to usual care. The primary outcome was CPAP adherence during the first 30 days of therapy. Secondary outcomes were show rates to sleep clinic (attended appointment) and 30-day CPAP adherence after the sleep clinic visit date. RESULTS: A total of 212 patients met the eligibility criteria and were randomised to video education (n=99) or to usual care (n=113). There were no differences in CPAP adherence at 30 days (3.3, 95% CI 2.8 to 3.8 hours/day video education; vs 3.5, 95% CI 3.1 to 4.0 hours/day usual care; p=0.44) or during the 30 days after sleep clinic visit. Sleep clinic show rate was 54% in the video education group and 59% in the usual care group (p=0.41). CPAP adherence, however, significantly worsened in patients who did not show up to the sleep clinic. CONCLUSIONS: In patients at risk for poor CPAP adherence, an educational video did not improve CPAP adherence or show rates to sleep clinic compared with usual care. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT02553694.

Inflammatory response mechanisms exacerbating hypoxemia in coexistent pulmonary fibrosis and sleep apnea.

Mediators of inflammation, oxidative stress, and chemoattractants drive the hypoxemic mechanisms that accompany pulmonary fibrosis. Patients with idiopathic pulmonary fibrosis commonly have obstructive sleep apnea, which potentiates the hypoxic stimuli for oxidative stress, culminating in systemic inflammation and generalized vascular endothelial damage. Comorbidities like pulmonary hypertension, obesity, gastroesophageal reflux disease, and hypoxic pulmonary vasoconstriction contribute to chronic hypoxemia leading to the release of proinflammatory cytokines that may propagate clinical deterioration and alter the pulmonary fibrotic pathway. Tissue inhibitor of metalloproteinase (TIMP-1), interleukin- (IL-) 1α, cytokine-induced neutrophil chemoattractant (CINC-1, CINC-2α/ß), lipopolysaccharide induced CXC chemokine (LIX), monokine induced by gamma interferon (MIG-1), macrophage inflammatory protein- (MIP-) 1α, MIP-3α, and nuclear factor- (NF-) κB appear to mediate disease progression. Adipocytes may induce hypoxia inducible factor (HIF) 1α production; GERD is associated with increased levels of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and tumor necrosis factor alpha (TNF-α); pulmonary artery myocytes often exhibit increased cytosolic free Ca2+. Protein kinase C (PKC) mediated upregulation of TNF-α and IL-1ß also occurs in the pulmonary arteries. Increased understanding of the inflammatory mechanisms driving hypoxemia in pulmonary fibrosis and obstructive sleep apnea may potentiate the identification of appropriate therapeutic targets for developing effective therapies.

In the clinic. Obstructive sleep apnea.

This issue provides a clinical overview of Obstructive Sleep Apnea focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic.

Obstructive sleep apnea and the risk for cardiovascular disease.

Obstructive sleep apnea (OSA) is a common disorder with major neurocognitive and cardiovascular sequelae. It is estimated that more than one quarter of the population is at risk for OSA, with increased prevalence noted in populations with hypertension, coronary artery disease, stroke, and atrial fibrillation. A number of epidemiologic and mechanistic studies have recently generated interest in the role of OSA in the pathophysiology of cardiovascular disease, a link that continues to require extensive investigation. This chapter reviews these epidemiologic studies, the current understanding of the mechanisms by which OSA may contribute to the progression of cardiovascular diseases, and the effects of OSA treatment on cardiovascular disease outcomes.

Head CT is of limited diagnostic value in critically ill patients who remain unresponsive after discontinuation of sedation.

BACKGROUND: Prolonged sedation is common in mechanically ventilated patients and is associated with increased morbidity and mortality. We sought to determine the diagnostic value of head computed tomography (CT) in mechanically ventilated patients who remain unresponsive after discontinuation of sedation. METHODS: A retrospective review of adult (age >18 years of age) patients consecutively admitted to the medical intensive care unit of a tertiary care medical center. Patients requiring mechanical ventilation for management of respiratory failure for longer than 72 hours were included in the study group. A group that did not have difficulty with awakening was included as a control. RESULTS: The median time after sedation was discontinued until a head CT was performed was 2 days (interquartile range 1.375-2 days). Majority (80%) of patients underwent head CT evaluation within the first 48 hours after discontinuation of sedation. Head CT was non-diagnostic in all but one patient who had a small subarachnoid hemorrhage. Twenty-five patients (60%) had a normal head CT. Head CT findings did not alter the management of any of the patients. The control group was similar to the experimental group with respect to demographics, etiology of respiratory failure and type of sedation used. However, while 37% of subjects in the control group had daily interruption of sedation, only 19% in the patient group had daily interruption of sedation (p < 0.05). CONCLUSION: In patients on mechanical ventilation for at least 72 hours and who remain unresponsive after sedative discontinuation and with a non-focal neurologic examination, head CT is performed early and is of very limited diagnostic utility. Routine use of daily interruption of sedation is used in a minority of patients outside of a clinical trial setting though it may decrease the frequency of unresponsiveness from prolonged sedation and the need for head CT in patients mechanically ventilated for a prolonged period.

Effectiveness of SIESTA on Objective and Subjective Metrics of Nighttime Hospital Sleep Disruptors.

We created Sleep for Inpatients: Empowering Staff to Act (SIESTA), which combines electronic "nudges" to forgo nocturnal vitals and medications with interprofessional education on improving patient sleep. In one "SIESTAenhanced unit," nurses received coaching and integrated SIESTA into daily huddles; a standard unit did not. Six months pre- and post-SIESTA, sleep-friendly orders rose in both units (foregoing vital signs: SIESTA unit, 4% to 34%; standard, 3% to 22%, P < .001 both; sleeppromoting VTE prophylaxis: SIESTA, 15% to 42%; standard, 12% to 28%, P < .001 both). In the SIESTAenhanced unit, nighttime room entries dropped by 44% (-6.3 disruptions/room, P < .001), and patients were more likely to report no disruptions for nighttime vital signs (70% vs 41%, P = .05) or medications (84% vs 57%, P = .031) than those in the standard unit. The standard unit was not changed. Although sleep-friendly orders were adopted in both units, a unit-based nursing empowerment approach was associated with fewer nighttime room entries and improved patient experience.

Awakenings? Patient and Hospital Staff Perceptions of Nighttime Disruptions and Their Effect on Patient Sleep.

STUDY OBJECTIVES: Although important to recovery, sleeping in the hospital is difficult because of disruptions. Understanding how patients, hospital physicians, and nurses perceive sleep disruptions and identifying which disruptions are associated with objective sleep loss can help target improvement initiatives. METHODS: Patients and hospital staff completed the Potential Hospital Sleep Disruptions and Noises Questionnaire (PHSDNQ). Cutoff points were defined based on means, and responses were dichotomized. Perceived percent disrupted for each item was calculated, and responses were compared across groups using chi-square tests. Objective sleep time of patients was measured using wrist actigraphy. The association between patient-reported disruptions and objective sleep time was assessed using a multivariable linear regression model controlling for subject random effects. RESULTS: Twenty-eight physicians (78%), 37 nurses (88%), and 166 of their patients completed the PHSDNQ. Patients, physicians, and nurses agreed that pain, vital signs and tests were the top three disrupters to patient sleep. Significant differences among the groups' perceptions existed for alarms [24% (patients) vs. 46% (physicians) vs. 27% (nurses), p < 0.040], room temperature (15% vs. 0% vs. 5%, p < 0.031) and anxiety (18% vs. 21% vs. 38%, p < 0.031). Using survey and actigraphy data from 645 nights and 379 patients, the presence of pain was the only disruption associated with lower objective sleep duration (minutes) [-38.1 (95% confidence interval -63.2, -12.9) p < 0.003]. CONCLUSION: Hospital staff and patients agreed that pain, vital signs and tests were top sleep disrupters. However, pain was associated with the greatest objective sleep loss, highlighting the need for proactive screening and management of patient pain to improve sleep in hospitals.

Implementation of a Professional Society Core Curriculum and Integrated Maintenance of Certification Program.

Medical professional societies exist to foster collaboration, guide career development, and provide continuing medical education opportunities. Maintenance of certification is a process by which physicians complete formal educational activities approved by certifying organizations. The American Thoracic Society (ATS) established an innovative maintenance of certification program in 2012 as a means to formalize and expand continuing medical education offerings. This program is unique as it includes explicit opportunities for collaboration and career development in addition to providing continuing medical education and maintenance of certification credit to society members. In describing the development of this program referred to as the "Core Curriculum," the authors highlight the ATS process for content design, stages of curriculum development, and outcomes data with an eye toward assisting other societies that seek to program similar content. The curriculum development process described is generalizable and positively influences individual practitioners and professional societies in general, and as a result, provides a useful model for other professional societies to follow.

Portable Monitoring for the Diagnosis of OSA.

In-laboratory, attended polysomnography has long been the gold standard for the diagnosis of sleep-disordered breathing (SDB). In recent years, economic pressures and long wait times have driven interest in home sleep testing, which has, in turn, led to the development of algorithms that bypass the sleep laboratory in favor of portable monitoring studies and in-home initiation of positive airway pressure therapy. For appropriately selected outpatients, evidence is accumulating that portable monitors are a reasonable substitute for in-laboratory polysomnography. In the inpatient setting, in which SDB is both highly prevalent and associated with adverse outcomes in certain populations, the literature is evolving on the use of portable monitors to expedite diagnosis and treatment of SDB. This review discusses society guidelines and recent research in the growing field of portable monitoring.

No Exit: Identifying Avoidable Terminal Oncology Intensive Care Unit Hospitalizations.

PURPOSE: Terminal oncology intensive care unit (ICU) hospitalizations are associated with high costs and inferior quality of care. This study identifies and characterizes potentially avoidable terminal admissions of oncology patients to ICUs. METHODS: This was a retrospective case series of patients cared for in an academic medical center's ambulatory oncology practice who died in an ICU during July 1, 2012 to June 30, 2013. An oncologist, intensivist, and hospitalist reviewed each patient's electronic health record from 3 months preceding terminal hospitalization until death. The primary outcome was the proportion of terminal ICU hospitalizations identified as potentially avoidable by two or more reviewers. Univariate and multivariate analysis were performed to identify characteristics associated with avoidable terminal ICU hospitalizations. RESULTS: Seventy-two patients met inclusion criteria. The majority had solid tumor malignancies (71%), poor performance status (51%), and multiple encounters with the health care system. Despite high-intensity health care utilization, only 25% had documented advance directives. During a 4-day median ICU length of stay, 81% were intubated and 39% had cardiopulmonary resuscitation. Forty-seven percent of these hospitalizations were identified as potentially avoidable. Avoidable hospitalizations were associated with factors including: worse performance status before admission (median 2 v 1; P = .01), worse Charlson comorbidity score (median 8.5 v 7.0, P = .04), reason for hospitalization (P = .006), and number of prior hospitalizations (median 2 v 1; P = .05). CONCLUSION: Given the high frequency of avoidable terminal ICU hospitalizations, health care leaders should develop strategies to prospectively identify patients at high risk and formulate interventions to improve end-of-life care.

Risk of sleep apnea in hospitalized older patients.

BACKGROUND/OBJECTIVES: To assess the prevalence of undiagnosed obstructive sleep apnea (OSA) among general medical inpatients and to investigate whether OSA risk is associated with in-hospital sleep quantity and quality. DESIGN: Prospective cohort study. SETTING: General medicine ward in academic medical center. PARTICIPANTS: 424 hospitalized adult patients ≥ 50 years old without a sleep disorder diagnosis (mean age 65 years, 57% female, 72% African American). MAIN MEASURES: The Berlin questionnaire, a validated screen for determining risk of OSA, was administered to hospitalized medical patients. Sleep duration and efficiency were measured via wrist actigraphy. Self-reported sleep quality was evaluated using Karolinska Sleep Quality Index (KSQI). KEY RESULTS: Two of every 5 inpatients ≥ 50 years old (39.5%, n = 168) were found to be at high risk for OSA. Mean in-hospital sleep duration was ∼ 5 h and mean sleep efficiency was 70%. Using random effects linear regression models, we found that patients who screened at high risk for OSA obtained ∼ 40 min less sleep per night (-39.6 min [-66.5, -12.8], p = 0.004). These findings remained significant after controlling for African American race, sex, and age quartiles. In similar models, those patients who screened at high risk had ∼ 5.5% less sleep efficiency per night (-5.50 [-9.96, -1.05], p = 0.015). In multivariate analysis, patients at high risk for OSA also had lower self-reported sleep quality on KSQI (-0.101 [-0.164, -0.037], p = 0.002). CONCLUSION: Two of every 5 inpatients older than 50 years screened at high risk for OSA. Those screening at high risk have worse in-hospital sleep quantity and quality. COMMENTARY: A commentary on this article appears in this issue on page 1067.

A brief survey of patients' first impression after CPAP titration predicts future CPAP adherence: a pilot study.

BACKGROUND: CPAP adherence patterns are often established very early in the course of therapy. Our objective was to quantify patients' perception of CPAP therapy using a 6-item questionnaire administered in the morning following CPAP titration. We hypothesized that questionnaire responses would independently predict CPAP adherence during the first 30 days of therapy. METHODS: We retrospectively reviewed the CPAP perception questionnaires of 403 CPAP-naïve adults who underwent in-laboratory titration and who had daily CPAP adherence data available for the first 30 days of therapy. Responses to the CPAP perception questionnaire were analyzed for their association with mean CPAP adherence and with changes in daily CPAP adherence over 30 days. RESULTS: Patients were aged 52 ± 14 years, 53% were women, 54% were African American, the mean body mass index (BMI) was 36.3 ± 9.1 kg/m(2), and most patients had moderate-severe OSA. Four of 6 items from the CPAP perception questionnaire- regarding difficulty tolerating CPAP, discomfort with CPAP pressure, likelihood of wearing CPAP, and perceived health benefit-were significantly correlated with mean 30-day CPAP adherence, and a composite score from these 4 questions was found to be internally consistent. Stepwise linear regression modeling demonstrated that 3 variables were significant and independent predictors of reduced mean CPAP adherence: worse score on the 4-item questionnaire, African American race, and non-sleep specialist ordering polysomnogram and CPAP therapy. Furthermore, a worse score on the 4-item CPAP perception questionnaire was consistently associated with decreased mean daily CPAP adherence over the first 30 days of therapy. CONCLUSIONS: In this pilot study, responses to a 4-item CPAP perception questionnaire administered to patients immediately following CPAP titration independently predicted mean CPAP adherence during the first 30 days. Further prospective validation of this questionnaire in different patient populations is warranted.

Effect of mild, asymptomatic obstructive sleep apnea on daytime heart rate variability and impedance cardiography measurements.

Dysregulation of autonomic nervous system dynamics is important in the pathophysiology of cardiovascular risk in obstructive sleep apnea (OSA). Heart rate variability (HRV) and impedance cardiography measures can estimate autonomic activity but have not gained traction clinically. The hypothesis of this study was that even in a cohort of patients with mild, asymptomatic OSA without overt cardiovascular disease, daytime HRV metrics and impedance cardiography measurements of preejection period would demonstrate increased sympathetic and decreased parasympathetic modulation compared to matched controls. Obese subjects (body mass index ≥30 kg/m(2)) without any known cardiovascular or inflammatory co-morbidities were recruited from the community. Subjects underwent standard in-laboratory polysomnography followed by simultaneous electrocardiographic and impedance cardiographic recordings while supine, supine with paced breathing, and after standing. Seventy-four subjects were studied, and 59% had OSA (apnea-hypopnea index ≥10 events/hour), with a median apnea-hypopnea index of 25.8 events/hour. Subjects with OSA had significantly decreased daytime time- and frequency-domain HRV indexes, but not significantly different preejection periods, compared to controls. Apnea-hypopnea index was a significant independent predictor of time-domain HRV measures in all awake conditions, after controlling for age, gender, blood pressure, fasting cholesterol levels and glycosylated hemoglobin. In conclusion, these results demonstrate reductions in cardiac vagal modulation, as measured by multiple daytime time-domain markers of HRV, in patients with asymptomatic OSA compared to controls. Further prospective outcomes-based studies are needed to evaluate the applicability of these metrics for noninvasive screening of obese patients with asymptomatic OSA, before the onset of overt cardiovascular disease.