Quantitative-analysis of computed tomography in COVID-19 and non COVID-19 ARDS patients: A case-control study.

PURPOSE: The aim of this study was to assess whether the computed tomography (CT) features of COVID-19 (COVID+) ARDS differ from those of non-COVID-19 (COVID-) ARDS patients. MATERIALS AND METHODS: The study is a single-center prospective observational study performed on adults with ARDS onset ≤72 h and a PaO2/FiO2 ≤ 200 mmHg. CT scans were acquired at PEEP set using a PEEP-FiO2 table with VT adjusted to 6 ml/kg predicted body weight. RESULTS: 22 patients were included, of whom 13 presented with COVID-19 ARDS. Lung weight was significantly higher in COVID- patients, but all COVID+ patients presented supranormal lung weight values. Noninflated lung tissue was significantly higher in COVID- patients (36 ± 14% vs. 26 ± 15% of total lung weight at end-expiration, p < 0.01). Tidal recruitment was significantly higher in COVID- patients (20 ± 12 vs. 9 ± 11% of VT, p < 0.05). Lung density histograms of 5 COVID+ patients with high elastance (type H) were similar to those of COVID- patients, while those of the 8 COVID+ patients with normal elastance (type L) displayed higher aerated lung fraction.

Lung cancer may increase serum procalcitonin level.

INTRODUCTION: Serum procalcitonin (PCT) is a biomarker used routinely to diagnose infections. Some malignancies are usual false positives for PCT. However, its value and behavior in the setting of lung cancers are poorly known. The objective of this study was to assess PCT positivity in a lung cancer cases series. METHOD: Between November 2011 and September 2012, all cases of newly diagnosed lung cancer with a pre-antineoplastic PCT assay and no patent signs of infection were included in the study. All PCT levels were assessed by immunofluorescent assay in a single laboratory. RESULTS: Eighty-nine patients were included (70.8% male; mean age 62; small-cell cancer 20.2%; stage IV cancer 60.7%). Overall, PCT was positive in 42%. A neuroendocrine component, having 2 or more metastatic sites, having a pleura or a liver metastasis, and being positive for CRP were all significantly associated with positive PCT in univariate analysis. In multivariate analysis, only the presence of a neuroendocrine component remained strongly associated with a positive PCT (AOR=7.24 [CI=95% 1.91-27.51]; P=0.004). Finally, baseline PCT levels <0.5 µg/l were found in 43% of NSCLC with a neuroendocrine component, vs. 9% of cancers with other histology (P=0.0001). CONCLUSION: Lung cancer may cause false positives for procalcitonin, particularly in cases of neuroendocrine cancers or in the presence of multiple metastases. These results should be taken into account for PCT-based decisional algorithms.