Baseline spirometry parameters as predictors of airway hyperreactivity in adults with suspected asthma.

BACKGROUND: Methacholine challenge tests (MCTs) are used to diagnose airway hyperresponsiveness (AHR) in patients with suspected asthma where previous diagnostic testing has been inconclusive. The test is time consuming and usually requires referral to specialized centers. Simple methods to predict AHR could help determine which patients should be referred to MCTs, thus avoiding unnecessary testing. Here we investigated the potential use of baseline spirometry variables as surrogate markers for AHR in adults with suspected asthma. METHODS: Baseline spirometry and MCTs performed between 2013 and 2019 in a large tertiary center were retrospectively evaluated. Receiver-operating characteristic curves for the maximal expiratory flow-volume curve indices (angle ß, FEV1, FVC, FEV1/FVC, FEF50%, FEF25-75%) were constructed to assess their overall accuracy in predicting AHR and optimal cutoff values were identified. RESULTS: A total of 2983 tests were analyzed in adults aged 18-40 years. In total, 14% of all MCTs were positive (PC20 ≤ 16 mg/ml). All baseline spirometry parameters were significantly lower in the positive group (p < 0.001). FEF50% showed the best overall accuracy (AUC = 0.688) and proved to be useful as a negative predictor when applying FEF50% ≥ 110% as a cutoff level. CONCLUSIONS: This study highlights the role of FEF50% in predicting AHR in patients with suspected asthma. A value of ≥ 110% for baseline FEF50% could be used to exclude AHR and would lead to a substantial decrease in MCT referrals.

Weaning of Severe COVID-19 Mechanically Ventilated Patients: Experience within a Dedicated Unit in Israel.

BACKGROUND: Patients diagnosed with coronavirus disease-19 (COVID-19) who deteriorate to respiratory failure and require mechanical ventilation may later need to be weaned from the ventilator and undergo a rehabilitation process. The rate of weaning COVID-19 patients from mechanical ventilation is unknown. OBJECTIVES: To present our experience with ventilator weaning of COVID-19 patients in a dedicated facility. METHODS: A retrospective cohort study was conducted of 18 patients hospitalized in a COVID-19 dedicated ventilator weaning unit. RESULTS: Eighteen patients were hospitalized in the dedicated unit between 6 April and 19 May 2020. Of these, 88% (16/18) were weaned and underwent decannulation, while two patients deteriorated and were re-admitted to the intensive care unit. The average number of days spent in our department was 12. There was no statistically significant correlation between patient characteristics and time to weaning from ventilation or with the time to decannulation. CONCLUSIONS: Despite the high mortality of COVID-19 patients who require mechanical ventilation, most of the patients in our cohort were weaned in a relatively short period of time. Further large-scale studies are necessary to assess the cost effectiveness of dedicated COVID-19 departments for ventilator weaning.

Multicentric Castleman disease presenting as a chylous pleural effusion.

Castleman disease is a rare lymphoproliferative disorder presenting frequently with constitutional symptoms. Although pleural effusion is common, there is only one case report of an adult patient with chylous pleural effusion. We present the first case report of a hypervascular variant of Castleman disease presenting as a chylous pleural effusion and successfully treated with a combination of anti-interleukin-6 agent and steroids.