Experience With Adaptive Servo-Ventilation Among Veterans in the Post-SERVE-HF Era.

Background: The sleep medicine community has struggled to identify the ideal role for adaptive servo-ventilation (ASV) therapy following a study that found increased mortality in patients with central sleep apnea (CSA) and heart failure with reduced ejection fraction who used ASV therapy. We aimed to identify characteristics of patients who benefit from ASV therapy. Methods: We performed a record review of all patients treated with ASV therapy at the Hampton Veterans Affairs Medical Center in Virginia from January 1, 2015, to April 30, 2020. Clinical and polysomnographic characteristics of patients adherent to therapy were compared with those that were not adherent. Results: Our cohort of 31 patients was entirely male with a mean age of 67.2 years, body mass index of 34.0, and Epworth Sleepiness Scale score of 10.9. Primary CSA was initially diagnosed in 3 patients (10%), comorbid obstructive sleep apnea (OSA) and CSA in 9 (29%), and primary OSA in 19 (61%). Seventeen patients (55%) met minimal adherence criteria with ASV therapy. The obstructive apnea-hypopnea index (AHI), as a proportion of the total pretreatment AHI, was higher in adherent patients (81.5%) vs nonadherent patients (46.7%) (P = .02). The median residual AHI was lower in the adherent group, both as absolute values (1.7 vs 4.7 events/h; P = .004) and as a percentage of the pretreatment AHI (3.1% vs 10.2%; P = .002). Conclusions: Patients using ASV devices regularly have a larger component of obstructive sleep-disordered breathing and obtain greater objective benefit from ASV than those that do not. This understanding may help to identify patients that will most benefit from this debated form of therapy.

Comorbid insomnia and sleep apnea: characterization of the syndrome and understanding its associations with comorbid sleep conditions.

PURPOSE: Obstructive sleep apnea (OSA) is traditionally associated with excessive daytime sleepiness. Insomnia is characterized by hyperarousal, and is seen as a predominant feature in a subgroup of patients with OSA. The aim of this study was to describe the prevalence of comorbid insomnia and sleep apnea (COMISA) in a sleep apnea population and to characterize its features. METHODS: This was a chart review of patients who underwent overnight polysomnography (PSG). All patients completed questionnaires with the Epworth Sleepiness Scale (ESS), and symptoms of insomnia and other sleep-related comorbidities. Patients with OSA on the PSG were included. RESULTS: A total of 296 patients with OSA were included, of which 80% reported at least 1 major symptom of insomnia: 57% reported sleep onset insomnia, 68% sleep maintenance insomnia, and 48% had early morning awakenings. COMISA (OSA plus 2 or more major symptoms of insomnia) was seen in 63%. These patients were more likely to report an abnormal ESS score, gastroesophageal reflux (GER), and restless legs (RL) than those without; no difference was seen in self-reported sleep bruxism. Among the patients with COMISA, 85% reported at least 1 representative symptom of psychophysiological insomnia (PPI); each of the 5 PPI symptoms was present in at least 40% of patients with COMISA. CONCLUSIONS: Insomnia is extremely prevalent in our population of patients with OSA, accompanied by daytime sleepiness and symptoms of PPI, GER, and RL. Further study is needed to determine the interactions between symptoms and OSA treatments in these patients.

Use of sodium bicarbonate and blood gas monitoring in diabetic ketoacidosis: A review.

Diabetic ketoacidosis (DKA) is a severe and too-common complication of uncontrolled diabetes mellitus. Acidosis is one of the fundamental disruptions stemming from the disease process, the complications of which are potentially lethal. Hydration and insulin administration have been the cornerstones of DKA therapy; however, adjunctive treatments such as the use of sodium bicarbonate and protocols that include serial monitoring with blood gas analysis have been much more controversial. There is substantial literature available regarding the use of exogenous sodium bicarbonate in mild to moderately severe acidosis; the bulk of the data argue against significant benefit in important clinical outcomes and suggest possible adverse effects with the use of bicarbonate. However, there is scant data to support or refute the role of bicarbonate therapy in very severe acidosis. Arterial blood gas (ABG) assessment is an element of some treatment protocols, including society guidelines, for DKA. We review the evidence supporting these recommendations. In addition, we review the data supporting some less cumbersome tests, including venous blood gas assessment and routine chemistries. It remains unclear that measurement of blood gas pH, via arterial or venous sampling, impacts management of the patient substantially enough to warrant the testing, especially if sodium bicarbonate administration is not being considered. There are special circumstances when serial ABG monitoring and/or sodium bicarbonate infusion are necessary, which we also review. Additional studies are needed to determine the utility of these interventions in patients with severe DKA and pH less than 7.0.

Cross-sectional analysis of the utility of pulmonary function tests in predicting emphysema in ever-smokers.

Emphysema is largely an under-diagnosed medical condition that can exist in smokers in the absence of airway obstruction. We aimed to determine the sensitivity and specificity of pulmonary function tests (PFTs) in assessing emphysema using quantitative CT scans as the reference standard. We enrolled 224 ever-smokers (current or former) over the age of 40. CT of thorax was used to quantify the low attenuation area (% emphysema), and to measure the standardized airway wall thickness. PFTs were used individually and in combination to predict their ability to discriminate radiographic emphysema. Significant emphysema (>7%) was detected in 122 (54%) subjects. Twenty six (21%) emphysema subjects had no evidence of airflow obstruction (FEV(1)/FVC ratio <70%), while all subjects with >23% emphysema showed airflow obstruction. The sensitivity and specificity of spirometry for detecting radiographic emphysema were 79% and 75%, respectively. Standardized airway wall thickness was increased in subjects with airflow obstruction, but did not correlate with emphysema severity. In this cohort of lifetime ever-smokers, PFTs alone were inadequate for diagnosing emphysema. Airway wall thickness quantified by CT morphometry was associated with airflow limitation, but not with emphysema indicating that the heterogeneous nature of lung disease in smokers may represent distinct phenotypes.

The NAMES assessment: a novel combined-modality screening tool for obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) remains underdiagnosed, despite our understanding of its impact on general health. Current screening methods utilize either symptoms or physical exam findings suggestive of OSA, but not both. The purpose of this study was to develop a novel screening tool for the detection of OSA, the NAMES assessment (neck circumference, airway classification, comorbidities, Epworth scale, and snoring), combining self-reported historical factors with physical exam findings. METHODS: Subjects were adults without previously diagnosed OSA, referred to a community sleep center for suspicion of OSA. General health, Epworth Sleepiness Scale (ESS), and Berlin questionnaires were completed, and a physical exam focusing on modified Friedman (MF) grade, body mass index (BMI), and neck circumference (NC) was performed prior to polysomnography. OSA was defined by a respiratory disturbance index ≥15. Each variable was dichotomized, and cutoff values were determined for the NAMES tool in a pilot group of 150 subjects. The NAMES score was calculated from NC, MF, comorbidities, ESS, and loud snoring values. The performances of the NAMES, Berlin questionnaire, and ESS screening tests in predicting OSA were then compared in a validation group of 509 subjects. RESULTS: In the pilot population, the cutoff value for the composite NAMES tool was calculated at ≥3 points. In the validation group, NAMES demonstrated similar test characteristics to the Berlin questionnaire, and sensitivity was better than that seen with the Epworth scale. The addition of BMI and gender to the tool improved screening characteristics. CONCLUSIONS: The NAMES assessment is an effective, inexpensive screening strategy for moderate to severe OSA.

Single injection of P-selectin or P-selectin glycoprotein ligand-1 monoclonal antibody blocks neointima formation after arterial injury in apolipoprotein E-deficient mice.

BACKGROUND: Emerging data suggest that P-selectin, by controlling adhesion of white blood cells, may be important in limiting the response to vascular injury. METHODS AND RESULTS: We tested the hypothesis that transient inhibition of P-selectin with either anti-P-selectin monoclonal antibody (mAb) or anti-P-selectin glycoprotein ligand-1 (PSGL-1) mAb would reduce neointima formation in the setting of carotid denudation injury in atherosclerosis-prone apolipoprotein E-/- mice. Neointima formation at 28 days was reduced significantly, by 50% or 80%, by a single injection on the day of injury of 100 or 200 microg P-selectin mAb RB 40.34 and by 55% by a single injection of 100 microg PSGL-1 mAb 4RA10 (P< or =0.005). In addition, there was a significant reduction in neointimal macrophage content. CONCLUSIONS: These findings demonstrate that transient P-selectin or PSGL-1 blockade at the time of arterial injury significantly limits plaque macrophage content and neointima formation in a dose-dependent manner after carotid denudation injury in apolipoprotein E-/- mice.