Use of Chest Wall Electromyography to Detect Respiratory Effort during Polysomnography.

STUDY OBJECTIVES: To evaluate the ability of chest wall EMG (CW-EMG) using surface electrodes to classify apneas as obstructive, mixed, or central compared to classification using dual channel uncalibrated respiratory inductance plethysmography (RIP). METHODS: CW-EMG was recorded from electrodes in the eighth intercostal space at the right mid-axillary line. Consecutive adult clinical sleep studies were retrospectively reviewed, and the first 60 studies with at least 10 obstructive and 10 mixed or central apneas and technically adequate tracings were selected. Four obstructive and six central or mixed apneas (as classified by previous clinical scoring) were randomly selected. A blinded experienced scorer classified the apneas on the basis of tracings showing either RIP channels or the CW-EMG channel. The agreement using the two classification methods was determined by kappa analysis and intraclass correlation. RESULTS: The percentage agreement was 89.5%, the kappa statistic was 0.83 (95% confidence interval 0.79 to 0.87), and the intraclass correlation was 0.83, showing good agreement. Of the 249 apneas classified as central by RIP, 26 were classified as obstructive (10.4%) and 7 as mixed (2.8%) by CW-EMG. Of the 229 events classified as central by CW-EMG, 7 (3.1%) were classified as obstructive and 6 (2.6%) as mixed by RIP. CONCLUSIONS: Monitoring CW-EMG may provide a clinically useful method of detection of respiratory effort when used with RIP and can prevent false classification of apneas as central. RIP can rarely detect respiratory effort not easily discernible by CW-EMG and the combination of the two methods is more likely to avoid apnea misclassification.

Use of pulmonary arterial hypertension-specific therapy in overweight or obese patients with obstructive sleep apnea and pulmonary hypertension.

Pulmonary hypertension (PH) in overweight or obese patients with obstructive sleep apnea (OSA) may be multifactorial. The effect of pulmonary artery hypertension (PAH)-specific drugs on PH and exercise capacity in such patients is unknown. We performed a retrospective review of overweight or obese patients with OSA and PH who were treated with PAH-specific therapy in our PH clinic. We identified 9 female and 2 male patients. The mean age ± SD was 54.9 ± 9.3 years. The mean pulmonary artery pressure at the time of diagnosis of PH was 39.8 ± 16.1 mmHg. The right atrial pressure was 11.1 ± 4.5 mmHg, the pulmonary artery wedge pressure was 14.1 ± 2.9 mmHg, the cardiac index was 2.6 ± 0.5 L/min/m(2), and the pulmonary vascular resistance index was 10.6 ± 7.1 Wood units/m(2). The indications for use of PAH-specific therapy were dyspnea in association with right heart failure (n = 4), persistent PH despite compliance with nocturnal positive airway pressure (PAP) therapy (n = 4), or inability to tolerate PAP therapy (n = 3). PH was treated with an endothelin receptor antagonist (n = 8) or a phosphodiesterase-5 inhibitor (n = 3). The 6-minute walk distance (6MWD) improved significantly, from 234 ± 49.7 to 258 ± 54.6 m (24 m [95% confidence interval (CI): 6.5-341.5 m]; P = 0.014) over a period of 4.4 ± 1.8 months (n = 8) and from 241.7 ± 48.5 to 289.9 ± 91 m (48 m [95% CI: 5.5-90.8 m]; P = 0.033) in those with a longer follow-up period of 12.1 ± 6.4 months (n = 7). The systolic pulmonary artery pressure dropped significantly, from 64 ± 25.2 to 42 ± 10.4 mmHg (22 mmHg [95% CI: 4-40 mmHg]; P = 0.024) over a period of 6.1 ± 4.1 months (n = 7). In conclusion, PAH-specific therapy resulted in significant improvement in both PH and 6MWD.

Inflammatory pseudotumor of the pleura.

Inflammatory pseudotumors are rare solid, non-neoplastic masses that can mimic pulmonary malignancy. It occurs most commonly in children and young adults and is usually found incidentally. There are many reports of the existence of this tumor in various organs in the human body. The occurrence of this tumor exclusively in the pleura has not been described before. We present a case of inflammatory pseudotumor of the pleura and its successful management.

Approach to acute exacerbation of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial pneumonia with a median survival of 3 years after diagnosis. Acute exacerbation of IPF (AE-IPF) is now identified as a life-threatening complication. It presents as worsening dyspnea with new ground glass opacities superimposed upon a radiographic usual interstitial pneumonia (UIP) pattern. It is a diagnosis of exclusion. The prognosis of AE-IPF is poor and treatment strategies lack standardization. In order to rule out any reversible etiology for an acute decompensation of a previously stable IPF patient diagnostic modalities include computerized tomographic angiogram (CTA) coupled with high-resolution computerized tomography (HRCT) imaging of the chest, bronchoalveolar lavage (BAL) and echocardiogram with bubble study. Avoiding risk factors, identifying underlying causes and supportive care are the mainstays of treatment. Anti-inflammatory and immunosuppressant medications have not shown to improve survival in AE-IPF. Most of the patients are managed in a critical care setting with mechanical ventilation. Lung transplantation is a promising option but most institutions are not equipped and not every patient is a candidate.

Aspiration of capsule endoscope and successful bronchoscopic extraction.

Capsule endoscopy is a novel tool for the diagnosis of small intestinal disorders. Recently, a new complication of the procedure in the form of the capsule's aspiration into the lungs has been reported. The aspiration of capsule endoscope can lead to a variety of complications including respiratory failure. A low threshold to suspect this complication and urgent bronchoscopic extraction in appropriate patients can prevent serious sequelae.

Management of infectious processes of the pleural space: a review.

Pleural effusions can present in 40% of patients with pneumonia. Presence of an effusion can complicate the diagnosis as well as the management of infection in lungs and pleural space. There has been an increase in the morbidity and mortality associated with parapneumonic effusions and empyema. This calls for employment of advanced treatment modalities and development of a standardized protocol to manage pleural sepsis early. There has been an increased understanding about the indications and appropriate usage of procedural options at clinicians' disposal.

A rare cause of hypoxia in a patient with liver cirrhosis.

Pulmonary syndromes in the setting of hepatic disease with portal hypertension include portopulmonary hypertension (POPH), hepatopulmonary syndrome (HPS) and hepatic hydrothorax. POPH is defined as pulmonary arterial hypertension with portal hypertension in the absence of other causes of pulmonary arterial hypertension. HPS is a defect in arterial oxygenation as a result of pulmonary micro vascular dilatation in the setting of liver disease. We discuss a case of 63-year-old female with liver cirrhosis, exertional dyspnea and hypoxia associated with coexistence of POPH and HPS. The coexistence of POPH and HPS is rare entity which can generate a renewal of interest in further understanding the intricate pathologies behind these diseases.

Systemic inflammation and its response to treatment in patients with asthma.

BACKGROUND: Asthma is an obstructive airway disease characterized by airway inflammation. OBJECTIVE: To measure systemic inflammation in asthma patients, and to assess the effect of treatment on systemic inflammation. METHODS: In 30 newly diagnosed non-randomized adult asthma patients we measured systemic inflammation markers (serum high-sensitivity C-reactive protein, total leukocyte count, and erythrocyte sedimentation rate) before and after a 6-week standard treatment with inhaled steroids and inhaled ß(2) agonist. The comparison group comprised 20 healthy control subjects. All the subjects were non-smokers. RESULTS: The measured systemic inflammation markers were higher in the asthma patients: high-sensitivity C-reactive protein 4.8 ± 6.0 mg/dL vs 1.5 ± 1.4 mg/dL, P < .001; total leukocyte count 8,936 ± 2,592 cells/µL versus 7,741 ± 1,924 cells/µL, P < .001; erythrocyte sedimentation rate 24.8 ± 12.3 mm/h versus 15.3 ± 6.5 mm/h, P < .001. In the asthma patients, high-sensitivity C-reactive protein negatively correlated with percent-of-predicted FEV(1) (r = -0.64, P = .001), percent-of-predicted forced vital capacity (FVC) (r = -0.39, P = .03), FEV(1)/FVC% (r = -0.71, P < .001), and percent-of-predicted forced expiratory flow during the middle half of the FVC maneuver (FEF(25-75)) (r = -0.51, P = .004). Total leukocyte count negatively correlated with percent-of-predicted FEV(1) (r = -0.64, P = .001), percent-of-predicted FEV(1)/FVC (r = -0.74, P < .001), and percent-of-predicted FEF(25-75) (r = -0.58, P = .001). Body mass index positively correlated with high-sensitivity C-reactive protein (r = 0.65, P < .001). Multiple linear regression showed significant correlation of high-sensitivity C-reactive protein (r(2) = 0.75) with age (ß = 0.31, P = .008), body mass index (ß = 0.99, P = .001), family size (ß = 0.33, P = .008), and weight (ß = -0.45, P = .01). The systemic inflammation markers decreased significantly (P < .001 for all comparisons) after 6 weeks of treatment: high-sensitivity C-reactive protein decreased from 4.8 ± 6.0 mg/dL to 2.4 ± 5.4 mg/dL, total leukocyte count decreased from 8,936 ± 2,592 cells/µL to 6,960 ± 1,785 cells/µL, and erythrocyte sedimentation rate decreased from 24.8 ± 12.3 mm/h to 15.8 ± 10.1 mm/h. CONCLUSIONS: Inhaled steroids plus inhaled ß(2) agonist significantly reduced systemic inflammation in asthma patients.