Impaired respiratory function reduces haemoglobin oxygen affinity in COVID-19 Keywords: COVID-19; haemoglobin-oxygen affinity; haemoglobin P50; oxyhaemoglobins; PaO2 to fraction of inspired oxygen ratio; SARS-CoV-2 EN COVID-19 haemoglobin-oxygen affinity haemoglobin P50 oxyhaemoglobins PaO2 to fraction of inspired oxygen ratio SARS-CoV-2 e44 e47 4 02/21/23 20230301 NES 230301 Using homology modelling and molecular docking algorithms, Liu and Li predicted the existence of interactions between SARS-Cov-2 and haemoglobin (Hb) and suggested that these interactions may change haemoglobin-oxygen (Hb-O SB 2 sb ) affinity.[1] Hb-O SB 2 sb affinity has been extensively studied in intensive care unit (ICU) patients with COVID-19 (usually intubated and mechanically ventilated) showing normal to increased affinity.[[2], [4]] Higher Hb-O SB 2 sb affinity facilitates Hb oxygenation in the lungs while reducing tissue O SB 2 sb unloading; a reduced Hb-O SB 2 sb affinity has the opposite effect. COVID-19, haemoglobin-oxygen affinity, haemoglobin P50, oxyhaemoglobins, PaO2 to fraction of inspired oxygen ratio, SARS-CoV-2. [Extracted from the article]