Inspiratory Muscle Dysfunction Mediates and Predicts a Disease Continuum of Hypercapnic Failure in Chronic Obstructive Pulmonary Disease.

INTRODUCTION: Advanced chronic obstructive pulmonary disease (COPD) is associated with chronic hypercapnic failure. The present work aimed to comprehensively investigate inspiratory muscle function as a potential key determinant of hypercapnic respiratory failure in patients with COPD. METHODS: Prospective patient recruitment encompassed 61 stable subjects with COPD across different stages of respiratory failure, ranging from normocapnia to isolated nighttime hypercapnia and daytime hypercapnia. Arterialized blood gas analyses and overnight transcutaneous capnometry were used for patient stratification. Assessment of respiratory muscle function encompassed body plethysmography, maximum inspiratory pressure (MIP), diaphragm ultrasound, and transdiaphragmatic pressure recordings following cervical magnetic stimulation of the phrenic nerves (twPdi) and a maximum sniff manoeuvre (Sniff Pdi). RESULTS: Twenty patients showed no hypercapnia, 10 had isolated nocturnal hypercapnia, and 31 had daytime hypercapnia. Body plethysmography clearly distinguished patients with and without hypercapnia but did not discriminate patients with isolated nocturnal hypercapnia from those with daytime hypercapnia. In contrast to ultrasound parameters and transdiaphragmatic pressures, only MIP reflected the extent of hypercapnia across all three stages. MIP values below -48 cmH2O predicted nocturnal hypercapnia (area under the curve = 0.733, p = 0.052). CONCLUSION: In COPD, inspiratory muscle dysfunction contributes to progressive hypercapnic failure. In contrast to invasive tests of diaphragm strength only MIP fully reflects the pathophysiological continuum of hypercapnic failure and predicts isolated nocturnal hypercapnia.

Sleep-related breathing disorders in idiopathic pulmonary fibrosis are frequent and may be associated with pulmonary vascular involvement.

PURPOSE: Sleep-related breathing disorders (SRBD) may be associated with a worse prognosis in idiopathic pulmonary fibrosis (IPF). However, the prevalence of sleep disorders in IPF and the pathophysiological link between SRBD and IPF is unclear. PATIENTS AND METHODS: In this prospective trial, consecutive patients with stable IPF underwent polysomnography and cardiopulmonary exercise testing. Epworth sleepiness scale, Regensburg insomnia scale, and Pittsburgh sleep quality index were evaluated. Exclusion criteria were oxygen supplementation therapy, lung emphysema, and heart failure. For pairwise comparison of categorical data, the two-proportion z-test was applied. Correlation between continuous variables was assessed via the Pearson correlation coefficient. Patients without and with SRBD were compared. To find predictors for SRBD in IPF, multivariable logistic regression was applied. RESULTS: A total of 74 IPF patients were evaluated and 45 patients (11 female, median age 74 years, forced vital capacity 71.3%, DLCO 53.9%) were analyzed. Any kind of sleep disorder was found in 89% of patients. SRBD was present in 49% (81% obstructive sleep apnea, 19% central sleep apnea), insomnia in 40%, and periodic leg movements in 47% of subjects. The SRBD subgroup presented with a significantly lower performance (workload(peak)%pred 86.5 vs. 101.0 (p = 0.036); V'O2(AT) 618.5 ml/min vs. 774.0 ml/min (p = 0.043)) and exhibited a significantly higher V'E/V'CO2(peak) of 43.0 l/l vs. 38.5 l/l (p = 0.037). In search of predictors for SRBD by logistic regression, workload(peak)%pred was identified as a significant variable (p = 0.033). CONCLUSIONS: SRBD is frequent in IPF. Pulmonary vascular limitations may represent the pathophysiological link between IPF and SRBD. Workload(peak)%pred may be an independent risk factor for the occurrence of SRBD.

High sensitivity of PD-L1 analysis from pleural effusion in nonsmall cell lung cancer.

Background: Programmed cell death protein 1 (PD-1)/programmed cell death protein ligand 1 (PD-L1) immune checkpoint inhibitors have been approved for monotherapy of metastatic nonsmall cell lung cancer (mNSCLC) depending on tumour cells' PD-L1 expression. Pleural effusion is common in mNSCLC. The significance of immunocytochemistry PD-L1 analysis from pleural effusion samples is unclear. Aim: The aim of the study was to analyse the sensitivity regarding immunocytochemistry PD-L1 analysis of pleural effusion in NSCLC as compared to immunohistochemistry of pleural biopsies. Patients and Methods: Fifty consecutive subjects (17 female, median age 72.5 years, seven never-smokers) were enrolled in this prospective controlled two-centre study. Inclusion criteria were pleural effusion, suspected or known lung cancer, indication for pleural puncture and thoracoscopy, and written informed consent. Immunocytochemistry and immunohistochemistry PD-L1 analyses were performed with the Dako-PDL1-IHC-22C3pharmDx assay. Analysis for sensitivity, specificity, and positive and negative predictive value was performed for PD-L1 detection from pleural effusion. Results: 50 subjects underwent pleural puncture and thoracoscopy. Pathological diagnoses were lung cancer (48), lymphoma (1) and mesothelioma (1). Sensitivity, specificity, positive predictive value and negative predictive value of PD-L1-testing with expression ≥50% defined as positive were 100% (95% CI 46-100%), 63% (36-84%), 45% (18-75%) and 100% (66-100%), and with expression ≥1% defined as positive 86% (56-97%), 43% (12-80%), 75% (47-92%) and 60% (17-93%). Conclusion: PD-L1 analysis in tumour-positive pleural effusion samples shows a very high sensitivity and negative predictive value, especially regarding PD-L1 expression levels ≥50% (European Medicines Agency approval). Negative results are reliable and help in the decision against a first-line checkpoint inhibitor monotherapy. However, a 1% cut-off level (United States Food and Drug Administration approval) leads to a markedly lower negative predictive value, making other invasive procedures necessary (NCT02855281).

Combining biopsy tools improves mutation detection rate in central lung cancer.

In central exophytic lung cancer, the detection rate of oncogenic mutations and PDL1 positivity may be increased by combined sampling by forceps and EBUS-TBNA. The additional sampling of mediastinal lymph node and ctDNA may not be of additional benefit. https://bit.ly/2Ve41EF.