The PaCO2/FiO2 ratio as outcome predictor in SARS-COV-2 related pneumonia: a retrospective study.

BACKGROUND AND AIM: Respiratory failure in SARS-CoV-2 patients is characterized by the presence of hypoxemia and hypocapnia without relevant dyspnea. To date, the use of respiratory parameters other than PaO2/FiO2 ratio to stratify the risk of worsening of these patients has not been sufficiently studied.  Aim of this work was to evaluate whether the ratio between partial pressure levels of carbon dioxide (PaCO2) and the fraction of inspired oxygen (FiO2) measured at emergency department (ED) admission is predictive of the clinical course of patients suffering from SARS-CoV-2 pneumonia. METHODS: We retrospectively studied 236 patients with SARS-CoV-2 pneumonia evaluated at the ED of the Perugia Hospital. The end-points were: in-hospital mortality, need for invasive mechanical ventilation (IMV) and length of in-hospital stay (LOS). Clinical, blood gas and laboratory data were collected at ED admission. RESULTS: Of the 236 patients 157 were male, the mean age was 64 ± 16. Thirtythree patients (14%) needed IMV, 49 died (21%). In the univariate analysis, the PaCO2/FiO2 ratio was inversely associated with the need for IMV (p <0.001), mortality (p <0.001) and LOS (p = 0.005). At the multivariate analysis the PaCO2/FiO2 ratio was found to be predictive of the need for IMV, independently from age, gender, number of comorbidities, neutrophils, lymphocytes, glomerular filtrate, d-dimer, LDH and CRP. CONCLUSIONS: the PaCO2/FiO2 ratio is predictive of the risk of respiratory failure worsening in patients with SARS-CoV-2 pneumonia, independently from other several confounding factors.

Determinants of low levels of brain natriuretic peptide in morbid obesity.

BACKGROUND & AIMS: morbid obesity is associated with cardiovascular comorbidity. A noteworthy feature of this relationship could regard low levels of brain natriuretic peptide (BNP). The study investigates the relationship between BNP and obesity-related markers in a morbid obese population, along with echocardiographic and vascular parameters. METHODS: in 154 morbid obese patients we evaluated anthropometric parameters, glycometabolic/lipid profile, bioimpedentiometry, echocardiography, visceral fat area and flow-mediated dilation (FMD) by ultrasonography. RESULTS: we divided population in two groups on the basis of median BMI levels; patients with higher BMI had significantly lower BNP (p = .008), FMD (p = .014) and HDL-C (p = .001) and showed a more impaired heart function. A similar trend emerged subdividing patients on the basis of median visceral fat area. BNP showed a significant inverse correlation with BMI (p < .001), left ventricular mass (p = .026) and inter-ventricular septum thickness (p = .007) and a significant positive correlation with FMD (p = .008), HDL-C (p = .022), and ejection fraction (p = .013). BMI and triglycerides were independent predictors of BNP levels. CONCLUSIONS: patients with higher BMI show lower BNP levels associated with greater total body fat amount. The correlation of BNP with endothelium-dependent vasodilation and cardiac impairment could represent another link between obesity and cardiovascular damage.