Oxyhemoglobin Dissociation Curve in COVID-19 Patients

Objective: Coronavirus disease-2019 (COVID-19) is a disease that can progress with hypoxemia and severe respiratory distress in some patients. The oxyhemoglobin dissociation curve (ODC) is critical to understanding the effects of O2 exchange. This study aimed to evaluate the relationship between the ODC and oxygen-carrying capacity of hemoglobin (Hb) in COVID-19 patients.Materials and Methods: In the study, ODCs were created by examining the data obtained from the arterial blood gas analyses of 686 intensive care unit (ICU) and non-ICU COVID-19 patients retrospectively.Results: It was concluded that patients with COVID-19 and other respiratory distress patients had a slight right-leaning trend in the ODC compared with the standard curve. The P50 value of the ICU group was higher than the other groups (mean: 30.74 mmHg, n=131, p=0.047). While the percentage of oxyhemoglobin (mean: 65.44% vs 69.81%, p=0.015), the amount of glucose (mean: 163.39 mg/dL vs 195.36 mg/dL, p=0.002) and pH (median: 7.38 vs 7.41, p=0.007) in the non-ICU group was higher compared with the control group, the carboxyhemoglobin percentage (mean: 1.66% vs 1.13%, p=0.000), PCO2 (42.02 mmHg vs 39.44 mmHg, p=0.015), potassium (mean: 4.33 mmol/L vs 4.04, p=0.026), and sodium (mean: 138.10 mmol/L vs 135.80 mmol/L, p=0.000) were lower. The methemoglobin percentage of the ICU group was lower (p=0.000) than the other groups.Conclusion: The ODC of COVID-19 and other respiratory distress patients shifts slightly to the right, indicating that patients have partial respiratory difficulties.