Determinants of response to hypercapnia and to progressive and transient hypoxia in obstructive sleep apnea patients.

BACKGROUND: The knowledge regarding the control of breathing during wakefulness in patients affected by obstructive sleep apnea (OSAS) is still challenging. The aim of this study is firstly to analyze hypoxic and hypercapnic ventilatory response in OSA patients in comparison to controls and secondly, to investigate correlations between chemosensivity and both lung function tests, such as arterial blood gas analysis and spirometric parameters, and clinical characteristics, such as age and BMI. METHODS: Seventeen never treated OSA patients (16M; 53±13.2 years; BMI=34.5±8.1; AHI=45±14.7) underwent nocturnal cardiopulmonary monitoring test, complete lung function tests (spirometry, lung volumes and arterial blood gas analysis on room air). Read's rebreathing test was used to evaluate hypercapnic ventilatory response (HVRCO2); hypoxic ventilatory response (HVRO2) was studied through progressive and transient methods. The response was expressed in terms of slope of linear regression for HVRCO2 and of hyperbolic curve for HVRO2 between minute ventilation (VE) or mean inspiratory flow (VT/Ti) and PetCO2 or PetO2. RESULTS: The OSA group showed increased transient, but not progressive, HVRO2 and a lower HVRCO2. A lower HVRCO2 was predicted by greater values of BMI (P<0.01). Progressive HVRO2 increased with age and lower FEV1/VC, while transient HVRO2 (P<0.05) was inversely correlated with the nocturnal lowest SaO2 (P<0.01). CONCLUSIONS: Nocturnal intermittent hypoxic stimuli increases daytime glomic reactivity to transient hypoxia, while BMI is the main independent determinants of the bulbar response to hypercapnia in normocapnic OSAS patients.

First Detection of SARS-CoV-2 by Real-Time Reverse Transcriptase-Polymerase Chain Reaction Assay in Pleural Fluid.

Coronavirus disease 2019 (COVID-19) is a pandemic infection due to the spread of a novel coronavirus (severe acute respiratory syndrome coronavirus 2), resulting in a wide range of clinical features, from asymptomatic carriers to ARDS. The gold standard for diagnosis is nucleic acid detection by real-time reverse transcriptase-polymerase chain reaction in nasopharyngeal swabs. However, due to limitations in this technique's sensitivity, thoracic imaging plays a crucial, complementary role in diagnostic evaluation and also allows for detection of atypical findings and potential alternative targets for sampling (eg, pleural effusion). Although less common, pleural involvement has been described in a minority of patients. This report describes the first case of reverse transcriptase-polymerase chain reaction detection of severe acute respiratory syndrome coronavirus 2 in pleural fluid obtained by means of ultrasound-guided thoracentesis, and its main characteristics are detailed. Pleural effusion is not a common finding in COVID-19 infection, but a prompt recognition of this potential localization may be useful to optimize diagnostic evaluation as well as the management of these patients.

Chronic Obstructive Pulmonary Disease in Farmers: A Systematic Review.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a significant public health problem but it is unclear whether agricultural work causes an increased risk of disease. The aim of this review was to study COPD risk among farmers and analyze occupational exposures in agricultural workplaces. METHODS: A systematic literature search was conducted to identify epidemiological studies investigating COPD prevalence in farmers. RESULTS: In the 14 studies reviewed, COPD prevalence ranged from 3% to 68% due to different characteristics of study population, working activities, case definition/diagnosis. Livestock farmers were at higher risk and significant associations were observed for exposure to organic dusts, endotoxins, mites, ammonia, and hydrogen sulfide. CONCLUSIONS: Farming work was associated with greater risk of developing COPD. However, considering the several variables that may influence the disease prevalence in farmers, we suggest the adoption of a standardized research strategy.

Empyema caused by Prevotella bivia complicating an unusual case of spontaneous chylothorax.

Spontaneous chylothorax is rare in adults. We present an unusual case that was complicated by Prevotella bivia empyema. Full recovery was achieved with chest tube drainage and prompt treatment with intravenous clindamycin.

Obstructive sleep apnea and heart disease: the biomarkers point of view.

Obstructive sleep apnea syndrome (OSAS) is a highly prevalent disorder. Important risk factors for this disease are represented by obesity, male gender, smoking, some endocrinological disturbances, alcohol intake, use of benzodiazepines, and craniofacial alterations. It is well known that OSAS is a frequent comorbidity as well as a relevant risk factor for cardiovascular diseases (CVD), especially in patients with hypertension, coronary artery disease (CAD), arrhythmias, and heart failure. Furthermore, therapy with continuous positive airway pressure devices (CPAP) has been shown to significantly reduce the incidence of serious cardiovascular consequences. Interactions between OSAS and the cardiovascular system (CVS) can eventually result mainly in coronary atherosclerosis. These two conditions are connected by a complex biomarkers network. An extensive overview of these pathways could be helpful to better understand the causes of cardiovascular impairment in patients with OSAS.