Lung Imaging in COPD Part 1: Clinical Usefulness.

COPD is a condition characterized by chronic airflow obstruction resulting from chronic bronchitis, emphysema, or both. The clinical picture is usually progressive with respiratory symptoms such as exertional dyspnea and chronic cough. For many years, spirometry was used to establish a diagnosis of COPD. Recent advancements in imaging techniques allow quantitative and qualitative analysis of the lung parenchyma as well as related airways and vascular and extrapulmonary manifestations of COPD. These imaging methods may allow prognostication of disease and shed light on the efficacy of pharmacologic and nonpharmacologic interventions. This is the first of a two-part series of articles on the usefulness of imaging methods in COPD, and it highlights useful information that clinicians can obtain from these imaging studies to make more accurate diagnosis and therapeutic decisions.

Association of hypoglossal nerve stimulator response with machine learning identified negative effort dependence patterns.

BACKGROUND: Hypoglossal nerve stimulator (HGNS) is a therapeutic option for moderate to severe obstructive sleep apnea (OSA). Improved patient selection criteria are needed to target those most likely to benefit. We hypothesized that the pattern of negative effort dependence (NED) on inspiratory flow limited waveforms recorded during sleep, which has been correlated with the site of upper airway collapse, would contribute to the prediction of HGNS outcome. We developed a machine learning (ML) algorithm to identify NED patterns in pre-treatment sleep studies. We hypothesized that the predominant NED pattern would differ between HGNS responders and non-responders. METHODS: An ML algorithm to identify NED patterns on the inspiratory portion of the nasal pressure waveform was derived from 5 development set polysomnograms. The algorithm was applied to pre-treatment sleep studies of subjects who underwent HGNS implantation to determine the percentage of each NED pattern. HGNS response was defined by STAR trial criteria for success (apnea-hypopnea index (AHI) reduced by > 50% and < 20/h) as well as by a change in AHI and oxygenation metrics. The predominant NED pattern in HGNS responders and non-responders was determined. Other variables including demographics and oxygenation metrics were also assessed between responders and non-responders. RESULTS: Of 45 subjects, 4 were excluded due to technically inadequate polysomnograms. In the remaining 41 subjects, ML accurately distinguished three NED patterns (minimal, non-discontinuous, and discontinuous). The percentage of NED minimal breaths was significantly greater in responders compared with non-responders (p = 0.01) when the response was defined based on STAR trial criteria, change in AHI, and oxygenation metrics. CONCLUSION: ML can accurately identify NED patterns in pre-treatment sleep studies. There was a statistically significant difference in the predominant NED pattern between HGNS responders and non-responders with a greater NED minimal pattern in responders. Prospective studies incorporating NED patterns into predictive modeling of factors determining HGNS outcomes are needed.

Keep it simple: A novel technique for measuring airflow using a wireless patch.

OBJECTIVES: Despite the growing use of home sleep testing for obstructive sleep apnea (OSA), there are significant barriers that make it difficult for patients. This study aimed to evaluate a new set of wireless patches for the detection of OSA as compared to polysomnography (PSG) respiratory signals. Safety was also evaluated. METHODS: Patients (n = 25; mean age = 51.3; SD = 15.6) undergoing standard PSG evaluation for OSA wore 2 device patches applied on the chest and abdomen to provide surrogates of respiratory effort and derived airflow. Two sets of respiratory data (with common SpO2 and heart rate as a reference from PSG) were created, one from PSG and one from the device patches. Data were scored by a Registered Polysomnographic Technologist. Linear regression analyses and Bland-Altman plots were used to compare the two derived apnea-hypopnea indices (AHI). Bench testing was performed to determine whether the device patch respiratory signal accuracy remained consistent for different body characteristics. RESULTS: There was a significant correlation for AHI between the device patch and PSG (r = 0.979; P < .001; 95% CI 0.952, 1.00). There were also significant correlations between PSG and the device patch for supine AHI (r = 0.866, P < .001, 95% CI 0.610, 0.965) and nonsupine AHI (r = 0.983; <0.001, 95% CI 0.954, 1.00). No differences in respiratory signal accuracy were found with bench testing comparison groups. CONCLUSIONS: These preliminary results suggest that the device patch may be an effective way to measure respiratory dynamics, including derived airflow, to evaluate OSA. Results show promise as a new innovative method for home sleep testing.

Randomized Open Investigation Determining Steroid Dose in Severe COVID-19: The ROIDS-Dose Clinical Trial.

Introduction Treatment with dexamethasone reduces mortality in patients with coronavirus disease 2019 (COVID-19) pneumonia requiring supplemental oxygen, but the optimal dose has not been determined. Objective To determine whether weight-based dexamethasone of 0.2 mg/kg is superior to 6 mg daily in reducing 28-day mortality in patients with COVID-19 and hypoxemia. Materials and methods A multicenter, open-label, randomized clinical trial was conducted between March 2021 and December 2021 at seven hospitals within Northwell Health. A total of 142 patients with confirmed COVID-19 and hypoxemia were included. Participants were randomized in a 1:1 ratio to dexamethasone 0.2 mg/kg intravenously daily (n = 70) or 6 mg daily (n = 72) for up to 10 days. Results There was no statistically significant difference in the primary outcome of 28-day all-cause mortality with deaths in 12 of 70 patients (17.14%) in the intervention group and 15 of 72 patients (20.83%) in the control group (p = 0.58). There were no statistically significant differences among the secondary outcomes. Conclusion In patients with COVID-19 and hypoxemia, the use of weight-based dexamethasone dosing was not superior to dexamethasone 6 mg in reducing all-cause mortality at 28 days. Clinical trial registration This study was registered under ClinicalTrials.gov (identifier: NCT04834375).

Comparison of obstructive sleep apnoea prevalence and severity across WHO pulmonary hypertension groups.

INTRODUCTION: Pulmonary hypertension is classified into five groups in the WHO classification system. Patients with pulmonary hypertension often have comorbid obstructive sleep apnoea (OSA), yet the prevalence and severity of OSA in each of the WHO pulmonary hypertension groups have not been well established. METHODS: To compare the prevalence and severity of OSA between WHO pulmonary hypertension groups, we performed a retrospective cohort study, including patients who had polysomnography or a home sleep study and confirmed pulmonary hypertension on right heart catheterisation. The primary outcomes of OSA prevalence and severity were measured by median apnoea hypopnea index (AHI) or respiratory event index (REI) and were compared by WHO pulmonary hypertension group. Multivariable negative binomial regression was used to evaluate the association between the outcome of OSA severity by AHI or REI and WHO group. RESULTS: Among the cohort of 132 patients, OSA was common in all WHO pulmonary hypertension groups but was most common and most severe in WHO group II pulmonary hypertension. Median AHI or REI in WHO group II was 12.0 events/hour compared with 2.8 in group I, 3.7 in group III, 10.0 in group IV and 6.4 in group V. Multivariable negative binomial regression showed about a twofold increase in AHI or REI in WHO group II compared with WHO group I pulmonary hypertension. DISCUSSION: Our findings demonstrate that OSA deserves greater consideration as a treatable comorbidity that may affect pulmonary haemodynamics and quality of life in patients with pulmonary hypertension across all WHO groups.

Sleep architecture in patients with interstitial lung disease with and without pulmonary hypertension.

PURPOSE: Sleep disturbance is common in patients with advanced interstitial lung disease (ILD) often complicated by pulmonary hypertension (PH) and may contribute to poor quality of life. The etiology of sleep disturbance and the relationship between PH and sleep architecture in patients with ILD remains unknown. METHODS: We performed a retrospective cohort study comparing sleep architecture on polysomnography in patients with ILD with and without PH, defined as mean pulmonary artery pressure on right heart catheterization ≥ 20 mmHg. We tested the hypothesis that patients with ILD and PH would have increased wake time after sleep onset (WASO) compared to patients with ILD without PH using univariate analysis and multivariable linear regression. RESULTS: In our cohort of patients with ILD who underwent polysomnography (N = 49), patients with PH had lower total diffusion capacity for carbon monoxide (DLCO) (9.28 vs. 12.87 ml/min/mmHg, P = 0.04) and percent DLCO (39% vs. 53%, P = 0.03). On polysomnography, patients with PH had increased percentage of total sleep time with saturation < 90% (T90) (17% vs. 6%, P = 0.03), decreased N2 sleep (181 vs. 233 min, P = 0.03), decreased %N2 sleep (59% vs. 66%, P = 0.04), increased %N1 sleep (22% vs. 14%, P = 0.02), decreased sleep efficiency (62% vs. 72%, P = 0.03), and increased WASO (133 vs. 84 min, P = 0.01). In multivariable analysis, PH was associated with a 43-min increase in WASO (95% CI 6.2-80.2, P = 0.02). CONCLUSION: Patients with ILD and PH have decreased total and %N2 sleep, increased %N1 sleep, decreased sleep efficiency, and increased WASO, likely indicating increased sleep fragmentation.

Optimization of Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea With Ultrasound Assessment of Tongue Movement.

BACKGROUND: Hypoglossal nerve stimulation (HGNS) is an Food and Drug Administration-approved therapy for obstructive sleep apnea. Initial programming of HGNS is based on the observation of anterior tongue movement, which may not reflect opening at the retroglossal airway. We developed an ultrasonographic technique to assess the base of tongue movement with HGNS to be used to optimize the initial voltage settings. STUDY QUESTION: This study aimed to investigate the use of ultrasound to assess tongue movement with HGNS and related this measure to the apnea hypopnea index (AHI) on subsequent home sleep apnea testing or in-laboratory polysomnography with therapy. STUDY DESIGN: Seventeen subjects (n = 17) implanted with HGNS were enrolled at least 1 month postimplantation. Ultrasonographic measures were then used to optimize HGNS voltage to produce observable base of tongue protrusion without producing discomfort. Responders were defined as a reduction in AHI > 50% and an AHI of <20 events/h. RESULTS: There were 17 subjects, 11 men and 6 women, with age = 64.6 ± 9.8 years, body mass index = 27.9 ± 2.7 kg/m2, and pretreatment AHI = 36.5 ± 14.4/h, T-90% = 10.7 ± 14.8%. The mean hyoid bone excursion (HBE) in responders = 1.0 ± 0.13 cm versus 0.82 ± 0.12 cm in nonresponders (P = 0.017). HBE was correlated with AHI during HGNS treatment (coef. -0.54, P = 0.03). Best subsets regression analysis using treatment-based AHI as the dependent variable and age, body mass index, baseline AHI, HBE, and HGNS voltage as independent variables showed that HBE (coef. -44.6, P = 0.044) was the only independent predictor of response. Receiver operator curve analysis showed that HBE > 0.85 cm had a sensitivity of 83.3% and specificity of 80.0% with a positive likelihood ratio of 4.17 to predict responder status. CONCLUSION: We demonstrated that ultrasound assessment of HBE during HGNS programming is a useful tool to optimize therapy.

Space invader: pleural penetration of a hypoglossal nerve stimulator sensor lead.

The mainstay of treatment for obstructive sleep apnea is positive airway pressure therapy, which may be difficult for some patients to tolerate leading to compromised adherence and requiring alternative therapies. Hypoglossal nerve stimulation has become an option for those who meet implantation criteria. Implantation of the device is an ambulatory surgical procedure and is generally well-tolerated, though rare adverse events have been reported. We report an unusual complication of hypoglossal nerve stimulation in a patient who had initial success with this therapy. After 3 years of treatment, the sensor lead penetrated into the pleural space. Components of the hypoglossal nerve stimulation were explanted, and a new sensor lead and generator were reimplanted. The new device was activated, and therapy was successfully resumed. This case demonstrates that there is a potential for a delayed complication of sensor lead penetration into the pleural space, which has only rarely been reported. CITATION: Lou B, Hahn S, Korotun M, Quintero L, Shikowitz M, Greenberg H. Space invader: pleural penetration of a hypoglossal nerve stimulator sensor lead. J Clin Sleep Med. 2021;17(11):2329-2332.

Advances in Treatment of Sleep-Disordered Breathing.

BACKGROUND: Sleep-disordered breathing, composed of obstructive sleep apnea (OSA) and central sleep apnea (CSA), affects millions of people worldwide carrying with it significant morbidity and mortality. Diagnosis is made by polysomnography, and severity of sleep apnea is determined by the apnea-hypopnea index (AHI). Positive airway pressure (PAP) therapy has been the gold standard in treating both OSA and CSA. PAP therapy can greatly reduce AHI burden as well as morbidity and mortality and improve quality of life. AREAS OF UNCERTAINTY: However, patients report difficulties adhering to PAP therapy because of discomfort with mask interface, sensation of excessive pressure, and claustrophobia. Although other options exist to treat sleep apnea, such as mandibular advancement oral appliance devices, positional therapy, and surgery, these additional therapeutic modalities as current options have limitations. Emerging technology is now available to overcome hindrances to standard therapy. DATA SOURCES: A literature search was performed from the following databases: PubMed, Cochrane Library (Cochrane Database of Systematic Reviews), and Cochrane Central Register of Controlled Trials, and FDA device database (clinicaltrial.gov). THERAPEUTIC ADVANCES: Other modalities of treating sleep-disordered breathing now include the hypoglossal nerve stimulator, which stimulates the hypoglossal nerve during sleep to alleviate airflow obstruction by contracting the genioglossus muscle thus treating OSA. Similarly, the phrenic nerve stimulator restores a more stable breathing pattern during sleep by stimulating the phrenic nerve to activate the diaphragm during CSA. Both nerve stimulators have been shown to reduce AHI severity and improve quality of life for patients suffering from sleep-disordered breathing. CONCLUSIONS: PAP therapy, although the gold standard, has limitations in the treatment of sleep apnea. New modalities such as hypoglossal nerve stimulator and phrenic nerve stimulator may help to overcome difficulties with adherence and offer new options for treatment of both obstructive and central sleep apnea.

Digital Health Technology and Telemedicine-Based Hospital and Home Programs in Pulmonary Medicine During the COVID-19 Pandemic.

BACKGROUND: The current coronavirus disease 2019 (COVID-19) pandemic has caused a significant strain on medical resources throughout the world. A major shift to telemedicine and mobile health technologies has now taken on an immediate urgency. Newly developed devices designed for home use have facilitated remote monitoring of various physiologic parameters relevant to pulmonary diseases. These devices have also enabled home-based pulmonary rehabilitation programs. In addition, telemedicine and home care services have been leveraged to rapidly develop acute care hospital-at-home programs for the treatment of mild-to-moderate COVID-19 illness. AREAS OF UNCERTAINTY: The benefit of remote monitoring technologies on patient outcomes has not been established in robust trials. Furthermore, the use of these devices, which can increase the burden of care, has not been integrated into current clinical workflows and electronic medical records. Finally, reimbursement for these telemedicine and remote monitoring services is variable. DATA SOURCES: Literature review. THERAPEUTIC ADVANCES: Advances in digital technology have improved remote monitoring of physiologic parameters relevant to pulmonary medicine. In addition, telemedicine services for the provision of pulmonary rehabilitation and novel hospital-at-home programs have been developed. These new home-based programs have been adapted for COVID-19 and may also be relevant for the management of acute and chronic pulmonary diseases after the pandemic. CONCLUSION: Digital remote monitoring of physiologic parameters relevant to pulmonary medicine and novel hospital-at-home programs are feasible and may improve care for patients with acute and chronic respiratory-related disorders.

Post-implant care pathway: lessons learned and recommendations after 5 years of clinical implementation of hypoglossal nerve stimulation therapy.

Hypoglossal nerve stimulation (HNS) therapy is now an established and widely-available obstructive sleep apnea (OSA) treatment alternative for continuous positive airway pressure (CPAP)-intolerant patients. Additionally, the HNS body of literature is robust with strong data on safety, efficacy, and durability-from the 5-year STAR Trial outcomes, to post-approval studies of independent institutions, to the multicenter ADHERE registry which recently reported outcomes on over 1,000 patients and is poised to enroll 5,000 HNS patients total. Nevertheless, now with thousands of implanted patients across hundreds of certified centers, and that number growing rapidly, the post-implant management of the HNS patient represents the next critical frontier. Post-implant patient management (therapy titration, troubleshooting, adjustments, and adherence monitoring) across a longitudinal care model is key to ensuring long-term therapy success and optimizing patient outcomes and health benefits. As with CPAP, patient education and close clinical monitoring are often essential to successful long-term management. Although many HNS patients are clear responders with excellent comfort and adherence as well as effective improvement in symptomatic and objective outcome measures, and even a smaller subset is clear non-responders, there is a growing body of patients somewhere in the middle: good outcomes but not great; partial but incomplete response. These are the patients in whom a standardized best-practice approach to treatment monitoring and targeted therapy modifications is likely critical to optimizing long-term outcomes.

Serial Diaphragm Ultrasonography to Predict Successful Discontinuation of Mechanical Ventilation.

INTRODUCTION: Diaphragm excursion and contraction velocity measured using ultrasonography have been used to assess diaphragm function. We aimed to evaluate the performance of diaphragm ultrasonography during weaning from mechanical ventilation (MV). METHODS: Diaphragm ultrasonography was performed on 73 mechanically ventilated patients who were being considered for extubation on three separate occasions: (1) on assist control mode (A/C) during consistent patient triggered ventilation, (2) following 30 min during a spontaneous breathing trial (SBT), (3) 4-24 h following extubation. Right hemidiaphragm excursion and contraction velocity were measured on A/C, during SBT, and following extubation. These measurements were correlated with the outcome of extubation. RESULTS: Twenty patients failed extubation: 6 of whom required re-intubation and 14 of whom required non-invasive ventilatory support. During SBT, the mean diaphragm excursions were 1.7 ± 0.82 cm in the group who failed extubation compared to 2.1 ± 0.9 cm in the group who were successfully extubated (p = 0.06). To predict successful extubation, a decrease in diaphragm excursion of < 16.4% between A/C and SBT had a sensitivity of 84.9% and a specificity of 65%. The area under curve (AUC) for receiver operative characteristics for above cut-off was 0.75. Diaphragm contraction velocity performed poorly in predicting weaning outcome. CONCLUSIONS: Diaphragm excursion measured during SBT is an imperfect predictor of the outcome of extubation. Maintenance of diaphragm excursion between A/C and SBT has good performance characteristics by AUC analysis. Diaphragm contraction velocity has poor ability to predict outcome of extubation.

Selective inhibition of endothelial NF-κB signaling attenuates chronic intermittent hypoxia-induced atherosclerosis in mice.

BACKGROUND AND AIMS: Chronic intermittent hypoxia (CIH) exposure causes atherosclerosis, although the underlying mechanisms are poorly understood. This study defines the role of endothelial intrinsic NF-κB signaling in the atherogenic response to CIH. METHODS: We created ApoE-ECI-κBmt mice that are deficient in the apolipoprotein E gene (ApoE-/-) and overexpress an I-κBα mutant (I-κBmt) selectively in endothelial cells. ApoE-/- and ApoE-ECI-κBmt mice were fed a normal chow diet (NCD) or high cholesterol diet (HCD) and exposed to sham or CIH, and atherosclerotic lesions were quantified. RESULTS: CIH exposure activated NF-κB in aortas, and induced the expression of endothelial-specific and NF-κB-dependent genes, E-selectin and vascular cell adhesion molecule (VCAM)-1, in the aortas and hearts. Endothelial I-κBmt overexpression in ApoE-ECI-κBmt mice significantly inhibited CIH-induced NF-κB activity, and suppressed E-selectin and VCAM-1 expressions, confirming endothelial NF-κB inhibition in ApoE-ECI-κBmt mice. ApoE-/- mice, on NCD, developed mild atherosclerotic lesions spontaneously, and developed advanced and larger areas of atherosclerotic plaques when exposed to CIH. ApoE-/- mice also developed advanced atherosclerotic lesions when fed an HCD alone. The HCD-induced atherosclerotic plaques became more advanced, and plaque area was doubled in mice exposed to HCD + CIH. Endothelial I-κBmt overexpression in ApoE-ECI-κBmt mice attenuated spontaneously developed atherosclerotic lesions, abrogated CIH-induced atherosclerosis and mitigated CIH-mediated facilitation of HCD-induced atherosclerosis. CONCLUSIONS: These results suggest that endothelial intrinsic NF-kB signaling may play a pivotal role in CIH-induced atherosclerosis.

Diaphragm Excursion-Time Index: A New Parameter Using Ultrasonography to Predict Extubation Outcome.

BACKGROUND: The diaphragmatic response to increased mechanical load following withdrawal of mechanical ventilation is critical in determining the outcome of extubation. Using ultrasonography, we aimed to evaluate the performance of the excursion-time (E-T) index-a product of diaphragm excursion and inspiratory time, to predict the outcome of extubation. METHODS: Right hemidiaphragm excursion, inspiratory time, and E-T index were measured by ultrasonography during mechanical ventilation: (1) on assist-control (A/C) mode during consistent patient-triggered ventilation, (2) following 30 min during a spontaneous breathing trial (SBT), and (3) between 4 and 24 h following extubation. These measurements were correlated with the outcome of extubation. Patients in the "failure" group required reintubation or noninvasive ventilation within 48 h of extubation. RESULTS: Of the 73 patients studied, 20 patients failed extubation. During SBT, diaphragm excursion was 1.65 ± 0.82 and 2.1 ± 0.9 cm (P = .06), inspiratory time was 0.89 ± 0.30 and 1.11 ± 0.39 s (P = .03), and the E-T index was 1.64 ± 1.19 and 2.42 ± 1.55 cm-s (P < .03) in the "failure" and "success" groups, respectively. The mean change in E-T index between A/C and SBT was -3.9 ± 57.8% in the failure group and 59.4 ± 74.6% in the success group (P < .01). A decrease in diaphragmatic E-T index less than 3.8% between A/C and SBT had a sensitivity of 79.2% and a specificity of 75%, to predict successful extubation. CONCLUSIONS: Diaphragm E-T index measured during SBT may help predict the outcome of extubation. Maintenance or increase in diaphragm E-T index between A/C and SBT increases the likelihood of successful extubation.

Obstructive sleep apnea as a risk factor for type 2 diabetes mellitus.

Obstructive sleep apnea (OSA) is independently associated with cardiovascular and cardiometabolic risk in several large epidemiologic studies. OSA leads to several physiologic disturbances such as intermittent hypoxia, sleep fragmentation, and increase in autonomic tone. These disturbances have been associated with insulin resistance and type 2 diabetes mellitus (T2DM) in animal and human studies. Studies also suggest a bidirectional relationship between OSA and T2DM whereby T2DM itself might contribute to the features of OSA. Moreover, successful treatment of OSA may reduce these risks, although this is controversial. The purpose of this article is to review 1) the links and bidirectional associations between OSA and T2DM; 2) the pathogenic mechanisms that might link these two disease states; 3) the role of continuous positive airway pressure therapy in improving glucose tolerance, sensitivity, and resistance; and 4) the implications for clinical practice.

Chronic intermittent hypoxia exposure-induced atherosclerosis: a brief review.

Obstructive sleep apnea (OSA) is highly prevalent in the USA and is recognized as an independent risk factor for atherosclerotic cardiovascular disease. Identification of atherosclerosis risk factor attributable to OSA may provide opportunity to develop preventive measures for cardiovascular risk reduction. Chronic intermittent hypoxia (CIH) is a prominent feature of OSA pathophysiology and may be a major mechanism linking OSA to arteriosclerosis. Animal studies demonstrated that CIH exposure facilitated high-cholesterol diet (HCD)-induced atherosclerosis, accelerated the progression of existing atherosclerosis, and induced atherosclerotic lesions in the absence of other atherosclerosis risk factors, demonstrating that CIH is an independent causal factor of atherosclerosis. Comparative studies revealed major differences between CIH-induced and the classic HCD-induced atherosclerosis. Systemically, CIH was a much weaker inducer of atherosclerosis. CIH and HCD differentially activated inflammatory pathways. Histologically, CIH-induced atherosclerotic plaques had no clear necrotic core, contained a large number of CD31+ endothelial cells, and had mainly elastin deposition, whereas HCD-induced plaques had typical necrotic cores and fibrous caps, contained few endothelial cells, and had mainly collagen deposition. Metabolically, CIH caused mild, but HCD caused more severe dyslipidemia. Mechanistically, CIH did not, but HCD did, cause macrophage foam cell formation. NF-κB p50 gene deletion augmented CIH-induced, but not HCD-induced atherosclerosis. These differences reflect the intrinsic differences between the two types of atherosclerosis in terms of pathological nature and underlying mechanisms and support the notion that CIH-induced atherosclerosis is a new paradigm that differs from the classic HCD-induced atherosclerosis.

Resolution of severe obstructive sleep apnea after treatment of anti-muscle kinase receptor-positive myasthenia gravis despite 60-pound weight gain.

Obstructive sleep apnea (OSA) in patients with myasthenia gravis (MG) may be caused by reduced pharyngeal dilator muscle activity. We report a patient with anti-muscle kinase receptor MG with severe OSA and hypoventilation that resolved upon successful treatment of MG despite a 60-lb weight gain.

Obstructive sleep apnea: an unexpected cause of insulin resistance and diabetes.

Obstructive sleep apnea (OSA) is prevalent with type 2 diabetes. Conversely, nondiabetic patients with OSA are at increased risk of developing insulin resistance and diabetes. These disorders independently contribute to increased cardiovascular and cerebrovascular morbidity and mortality. The pathophysiology of OSA may help explain these associations. Evidence demonstrates that treatment of OSA with continuous positive airway pressure may lead to improvement in insulin sensitivity, hemoglobin A1c, systemic hypertension, and other components of the metabolic syndrome. Recognizing and treating OSA in patients with insulin resistance or diabetes ameliorates OSA-related symptoms and improves cardiometabolic risk.

Status cataplecticus precipitated by abrupt withdrawal of venlafaxine.

Status cataplecticus is a rare manifestation of narcolepsy with cataplexy episodes recurring for hours or days, without a refractory period, in the absence of emotional triggers. This case highlights a narcoleptic patient who developed status cataplecticus after abrupt withdrawal of venlafaxine.