TY - JOUR T1 - Absence of relevant clinical effects of SARS-COV-2 on the affinity of hemoglobin for O2 in patients with COVID-19 JO - Archivos de Bronconeumología T2 - AU - Pascual-Guàrdia,Sergi AU - Ferrer,Antoni AU - Díaz,Óscar AU - Caguana,Antonio O. AU - Tejedor,Elvira AU - Bellido-Calduch,Salomé AU - Rodríguez-Chiaradia,Diego A. AU - Gea,Joaquim SN - 15792129 M3 - 10.1016/j.arbr.2021.10.010 DO - 10.1016/j.arbr.2021.10.010 UR - https://www.archbronconeumol.org/en-absence-relevant-clinical-effects-sars-cov-2-articulo-S1579212921003840 AB - Pulmonary involvement in COVID-19 is frequently associated with alterations in oxygenation. The arterial partial pressure of oxygen (PaO2) is the most clinically used variable to assess such oxygenation, since it decisively influences the oxygen transported by hemoglobin (expressed by its percentage of saturation, SaO2). However, two recent studies conducted respectively in silico and using omic techniques in red blood cells of COVID-19 patients have suggested that SARS-CoV-2 could decrease the affinity of oxygen for the hemoglobin (which would imply that PaO2 would overestimate SaO2), and also reduce the amount of this carrier molecule. ObjectiveTo evaluate this hypothesis in blood samples from COVID-19 patients. MethodsBlood gases of all COVID-19 patients performed in our laboratory in two months were included, as well as those from two control groups: synchronous patients with negative PCR for SARS-CoV-2 (SCG) and a historical group (HCG). Both SaO2 and venous saturations (SvO2) measured by cooximetry (COX) were compared separately with those calculated using the Kelman (K), Severinghaus (SV) and Siggaard-Andersen (SA) equations in each group. ResultsMeasured and calculated SaO2 and SvO2 were practically equivalent in all groups. Intraclass correlation coefficients (ICC) for SaO2 in COVID-19 were 0.993 for COX-K and 0.992 for both COX-SV and COX-SA; being 0.995 for SvO2 for either COX-K, COX-SV or COX-SA. Hemoglobin and ferritin were slightly higher in COVID-19 compared to SCG and HCG (hemoglobin, p < 0.001 for both; ferritin, p < 0.05 for SCG and p < 0.001 for HCG). ConclusionUnder clinical conditions SARS-CoV-2 does not have an appreciable influence on the affinity of oxygen for the hemoglobin, nor on the levels of this carrier molecule. Therefore, PaO2 is a good marker of blood oxygenation also in COVID-19. ER -