Incidence of pulmonary embolism in patients with non-invasive respiratory support during COVID-19 outbreak.

While the incidence of thrombotic complications in critically ill patients is very high, in patients under non-invasive respiratory support (NIS) is still unknown. The specific incidence of thrombotic events in each of the clinical scenarios within the broad spectrum of severity of COVID-19, is not clearly established, and this has not allowed the implementation of thromboprophylaxis or anticoagulation for routine care in COVID-19. Patients admitted in a semi-critical unit treated initially with NIS, especially Continuous-Positive Airway Pressure (CPAP), were included in the study. The cumulative incidence of pulmonary embolism was analyzed and compared between patients with good response to NIS and patients with clinical deterioration that required orotracheal intubation. 93 patients were included and 16% required mechanical ventilation (MV) after the NIS. The crude cumulative incidence of the PE was 14% (95%, CI 8-22) for all group. In patients that required orotracheal intubation and MV, the cumulative incidence was significantly higher [33% (95%, CI 16-58)] compared to patients that continued with non-invasive support [11% (CI 5-18)] (Log-Rank, p = 0.013). Patients that required mechanical ventilation were at higher risk of PE for a HR of 4.3 (95%CI 1.2-16). In conclusion, cumulative incidence of PE is remarkably higher in critically patients with a potential impact in COVID-19 evolution. In this context, patients under NIS are a very high-risk group for developing PE without a clear strategy regarding thromboprophylaxis.

Do Low Molecular Weight Agents Cause More Severe Asthma than High Molecular Weight Agents?

INTRODUCTION: The aim of this study was to analyse whether patients with occupational asthma (OA) caused by low molecular weight (LMW) agents differed from patients with OA caused by high molecular weight (HMW) with regard to risk factors, asthma presentation and severity, and response to various diagnostic tests. METHODS: Seventy-eight patients with OA diagnosed by positive specific inhalation challenge (SIC) were included. Anthropometric characteristics, atopic status, occupation, latency periods, asthma severity according to the Global Initiative for Asthma (GINA) control classification, lung function tests and SIC results were analysed. RESULTS: OA was induced by an HMW agent in 23 patients (29%) and by an LMW agent in 55 (71%). A logistic regression analysis confirmed that patients with OA caused by LMW agents had a significantly higher risk of severity according to the GINA classification after adjusting for potential confounders (OR = 3.579, 95% CI 1.136-11.280; p = 0.029). During the SIC, most patients with OA caused by HMW agents presented an early reaction (82%), while in patients with OA caused by LMW agents the response was mainly late (73%) (p = 0.0001). Similarly, patients with OA caused by LMW agents experienced a greater degree of bronchial hyperresponsiveness, measured as the difference in the methacholine dose-response ratio (DRR) before and after SIC (1.77, range 0-16), compared with patients with OA caused by HMW agents (0.87, range 0-72), (p = 0.024). CONCLUSIONS: OA caused by LMW agents may be more severe than that caused by HMW agents. The severity of the condition may be determined by the different mechanisms of action of these agents.

Diagnostic yield of specific inhalation challenge in hypersensitivity pneumonitis.

Reliable methods are needed to diagnose hypersensitivity pneumonitis. The aim of the study was to establish the diagnostic yield of specific inhalation challenge (SIC) in patients with hypersensitivity pneumonitis. All patients with suspected hypersensitivity pneumonitis in whom SIC was performed (n=113) were included. SIC was considered positive when patients showed a decrease of >15% in forced vital capacity (FVC) or >20% in diffusing capacity of the lung for carbon dioxide, or a decrease of 10% to 15% in FVC accompanied by a temperature increase of 0.5°C within 24 h of inhalation of the antigen. SIC was positive to the agents tested in 68 patients: 64 received a diagnosis of hypersensitivity pneumonitis and SIC results were considered false-positive in the remaining four patients. In the SIC-negative group (n=45), 24 patients received a diagnosis of hypersensitivity pneumonitis and SIC results were considered false-negative, and 21 patients were diagnosed with other respiratory diseases. The sensitivity and specificity of the test were 72.7% and 84%, respectively. Having hypersensitivity pneumonitis caused by an antigen other than birds or fungi predicted a false-negative result (p=0.001). In hypersensitivity pneumonitis, positive SIC testing virtually confirms the diagnosis, whereas negative testing does not rule it out, especially when the antigenic sources are not birds or fungi.

Neumonitis por hipersensibilidad a isocianatos. Características clínico-radiológicas y de función pulmonar / Hypersensitivity Pneumonitis Due to Isocyanates: Lung Function, Clinical and Radiological Characteristics

El objetivo del presente trabajo fue describir las características clínico-radiológicas y de función pulmonar de la neumonitis por hipersensibilidad por exposición a isocianatos (NHI). Se estudiaron todos los pacientes con diagnóstico de NHI (n=5) durante los años 1995-2010. En todos ellos se realizó TC torácica y estudio de función pulmonar completo. El diagnóstico se realizó mediante prueba de provocación bronquial específica (PPBE) positiva. Se observó un predominio de varones y una variabilidad de patrones en las alteraciones radiológicas. La PPBE fue positiva por descenso de la FVC o de la DLCO en todos los casos excepto en un paciente, en que se estableció por criterios clínicos. Tan solo en un paciente se constató una IgG positiva a isocianatos. La presentación radiológica de la NHI puede ser distinta de las NH más frecuentes en nuestro medio y cursan con menor afectación clínica en la PPBE(AU)

The objective of this present study was to describe the clinical-radiological and lung function characteristics of hypersensitivity pneumonitis due to exposure to isocyanates (HPI). Included for study were all those patients diagnosed with HPI (n=5) from 1995 to 2010. In all cases, chest CT and complete lung function studies were done. The diagnosis was made with positive specific bronchial provocation tests (BPT). A predominance of males and pattern variability in the radiological alterations were observed. The BPT was positive due to a decline in FVC or DLCO in all cases except in one patient in whom the diagnosis was established with clinical criteria. Positive IgG to isocyanates was confirmed in only one patient. The radiological presentation of HPI may be different from the more common HP in our setting and run their course with less clinical affectation on the BPT(AU)

Hypersensitivity pneumonitis due to isocyanates: lung function, clinical and radiological characteristics.

The objective of this present study was to describe the clinical-radiological and lung function characteristics of hypersensitivity pneumonitis due to exposure to isocyanates (HPI). Included for study were all those patients diagnosed with HPI (n = 5) from 1995-2010. In all cases, chest CT and complete lung function studies were done. The diagnosis was made with positive specific bronchial provocation tests (BPT). A predominance of males and pattern variability in the radiological alterations were observed. The BPT was positive due to a decline in FVC or DL(CO) in all cases except in one patient in whom the diagnosis was established with clinical criteria. Positive IgG to isocyanates was confirmed in only one patient. The radiological presentation of HPI may be different from the more common HP in our setting and run their course with less clinical affectation on the BPT.