A significant amount of arterial hypoxia and hypocapnia are brought on by SARS-Cov-2 virus-induced lung injury. If these circumstances caused a change in the affinity of hemoglobin for oxygen, the literature was unclear. 

For a study, researchers investigated the arterial blood gas analysis (BGA) results for 517 hospitalized COVID-19 patients whose oxyhemoglobin dissociation curves (ODCs) were measured at the time of admission (i.e., before treatment). 

In comparison to a typical normal p50 (pOχ2at 50% saturation of hemoglobin) of 27 mmHg, 76% had a lower standardized p50 (p50s), and 85% had a lower in vivo p50 (p50i). P50s and P50i showed statistically significant changes between baseline values and values obtained at all of these time periods in a 33-patient subgroup with follow-up BGAs after 3, 6, 9, 12, 15, and 18 days of therapy. Patients who had p50 levels under 27 mmHg (P = 0.012) at the time of admission had a greater chance of surviving, according to the 30-day Kaplan-Meier survival curves of COVID-19 patients stratified by p50i level. 

Unknown if the COVID-19 patients’ altered hemoglobin affinity for oxygen was a direct or indirect result of the virus’s impact on hemoglobin.

Reference: onlinelibrary.wiley.com/doi/10.1111/bjh.18431