Effect of exogenous lipids contamination on blood gas analysis.

Objectives: The purpose of this study was to investigate the effects of contamination of venous blood with a lipid-containing solution on parameters measured by a modern blood gas analyzer. Methods: We collected venous blood from 17 healthcare workers (46 ± 11 years; 53 % women) into three blood gas syringes containing 0 , 5 and 10 % lipid-containing solution. Blood gas analysis was performed within 15 min from sample collection on GEM Premier 5000, while triglycerides and serum indices were assays on Roche COBAS C702. Results: Triglycerides concentration increased from 1.0 ± 0.3 mmol/L in the uncontaminated blood gas syringe, to 39.4 ± 7.8 and 65.3 ± 14.4 mmol/L (both p<0.001) in syringes with 5 and 10 % final lipid contamination. The lipemic and hemolysis indices increased accordingly. Statistically significant variation was noted for all analytes except hematocrit and COHb in the syringe with 5 % lipids, while only COHb did not vary in the syringe with 10 % lipids. Significant increases were observed from 5 % lipid contamination for pO2, SO2 and lactate, while the values of pH, pCO2, sodium, potassium, chloride, ionized calcium, glucose, hematocrit (10 % contamination), hemoglobin and MetHB decreased. All these changes except lactate and CoHb exceeded their relative performance specifications. Conclusions: Artifactual hyperlipidemia caused by contamination with exogenous lipids can have a clinically significant impact on blood gas analysis. Manufacturers of blood gas analyzers must be persuaded to develop new instruments equipped with serum indices.

Performance of Radiologists in the Evaluation of the Chest Radiography with the Use of a "new software score" in Coronavirus Disease 2019 Pneumonia Suspected Patients.

OBJECTIVES: The purpose of this study is to assess the performance of radiologists using a new software called "COVID-19 score" when performing chest radiography on patients potentially infected by coronavirus disease 2019 (COVID-19) pneumonia. Chest radiography (or chest X-ray, CXR) and CT are important for the imaging diagnosis of the coronavirus pneumonia (COVID-19). CXR mobile devices are efficient during epidemies, because allow to reduce the risk of contagion and are easy to sanitize. MATERIAL AND METHODS: From February-April 2020, 14 radiologists retrospectively evaluated a pool of 312 chest X-ray exams to test a new software function for lung imaging analysis based on radiological features and graded on a three-point scale. This tool automatically generates a cumulative score (0-18). The intra- rater agreement (evaluated with Fleiss's method) and the average time for the compilation of the banner were calculated. RESULTS: Fourteen radiologists evaluated 312 chest radiographs of COVID-19 pneumonia suspected patients (80 males and 38 females) with an average age of 64, 47 years. The inter-rater agreement showed a Fleiss' kappa value of 0.53 and the intra-group agreement varied from Fleiss' Kappa value between 0.49 and 0.59, indicating a moderate agreement (considering as "moderate" ranges 0.4-0.6). The years of work experience were irrelevant. The average time for obtaining the result with the automatic software was between 7 s (e.g., zero COVID-19 score) and 21 s (e.g., with COVID-19 score from 6 to 12). CONCLUSION: The use of automatic software for the generation of a CXR "COVID-19 score" has proven to be simple, fast, and replicable. Implementing this tool with scores weighed on the number of lung pathological areas, a useful parameter for clinical monitoring could be available.

Calcium-Dependent Src Phosphorylation and Reactive Oxygen Species Generation Are Implicated in the Activation of Human Platelet Induced by Thromboxane A2 Analogs.

The thromboxane (TX) A2 elicits TP-dependent different platelet responses. Low amounts activate Src kinases and the Rho-Rho kinase pathway independently of integrin αIIbß3 and ADP secretion and synergize with epinephrine to induce aggregation. Aim of the present study was to investigate the role Src kinases and the interplay with calcium signals in reactive oxygen species (ROS) generation in the activatory pathways engaged by TXA2 in human platelets. All the experiments were performed in vitro or ex vivo. Washed platelets were stimulated with 50-1000 nM U46619 and/or 10 µM epinephrine in the presence of acetylsalicylic acid and the ADP scavenger apyrase. The effects of the ROS scavenger EUK-134, NADPH oxidase (NOX) inhibitor apocynin, Src kinase inhibitor PP2 and calcium chelator BAPTA were tested. Intracellular calcium and ROS generation were measured. Platelet rich plasma from patients treated with dasatinib was used to confirm the data obtained in vitro. We observed that 50 nM U46619 plus epinephrine increase intracellular calcium similarly to 1000 nM U46619. ROS generation was blunted by the NOX inhibitor apocynin. BAPTA inhibited ROS generation in resting and activated platelets. Phosphorylation of Src and MLC proteins were not significantly affected by antioxidants agents. BAPTA and antioxidants reduced P-Selectin expression, activation of integrin αIIbß3and platelet aggregation. TXA2-induced increase in intracellular calcium is required for Src phosphorylation and ROS generation. NADPH oxidase is the source of ROS in TX stimulated platelets. The proposed model helps explain why an incomplete inhibition of TP receptor results in residual platelet activation, and define new targets for antiplatelet treatment.