Respiratory conditions in coronavirus disease 2019 (COVID-19): Important considerations regarding novel treatment strategies to reduce mortality

Abstract

A novel virus named 2019 novel coronavirus (2019-nCoV/SARS-CoV-2) causes symptoms that are classified as coronavirus disease (COVID-19). Respiratory conditions are extensively described among more serious cases of COVID-19, and the onset of acute respiratory distress syndrome (ARDS) is one of the hallmark features of critical COVID-19 cases. ARDS can be directly life-threatening because it is associated with low blood oxygenation levels and can result in organ failure. There are no generally recognized effective treatments for COVID-19, but treatments are urgently needed. Anti-viral medications and vaccines are in the early developmental stages and may take many months or even years to fully develop. At present, management of COVID-19 with respiratory and ventilator support are standard therapeutic treatments, but unfortunately such treatments are associated with high mortality rates. Therefore, it is imperative to consider novel new therapeutic interventions to treat/ameliorate respiratory conditions associated with COVID-19. Alternate treatment strategies utilizing clinically available treatments such as hyperbaric oxygen therapy (HBOT), packed red blood cell (pRBC) transfusions, or erthropoiesis-stimulating agent (ESA) therapy were hypothesized to increase oxygenation of tissues by alternative means than standard respiratory and ventilator treatments. It was also revealed that alternative treatments currently being considered for COVID-19 such as chloroquine and hydroxychloroquine by increasing hemoglobin production and increasing hemoglobin availability for oxygen binding and acetazolamine (for the treatment of altitude sickness) by causing hyperventilation with associated increasing levels of oxygen and decreasing levels of carbon dioxide in the blood may significantly ameliorate COVID-19 respiratory symptoms. In conclusion, is recommend, given HBOT, pRBC, and ESA therapies are currently available and routinely utilized in the treatment of other conditions, that such therapies be tried among COVID-19 patients with serious respiratory conditions and that future controlled-clinical trials explore the potential usefulness of such treatments among COVID-19 patients with respiratory conditions.

Keywords: 2019-nCoV; EPO; Pulmonary; SARS-CoV-2.

Fig. 1

A summary of hemoglobin-based delivery of oxygen molecules to peripheral tissues in a normal patient's capillary and in a COVID-19 patient's capillary. Hb = hemoglobin; O₂ = oxygen; SaO₂ = arterial oxygen saturation; SvO₂ = venous oxygen saturation. The oxygen tension of tissues will dedictate whether one of several oxygen molecules will be released from oxyhemoglobin (HbO₂) and diffuse from the capillary (pink area) into the tissue. The fraction of HbO₂ relative to total Hb in arterial blood is the SaO₂, which is normally > 95%. Normal mixed SvO₂ is about 65–75%. A decrease in SvO₂ usually indicates low tissue oxygen tension, resulting in increased extraction of oxygen molecules from Hb.

Fig. 2

A summary of novel treatments considered to improve hemoglobin-based delivery of oxygen molecules to peripheral tissues in a COVID-19 patient's capillary. Hb = hemoglobin; O₂ = oxygen. It is hypothesized that hyperbaric oxygen therapy will significantly increase O₂ levels in the blood independently of Hb levels and improve tissue oxygenation. It is also hypothesized that packed red blood cell transfusions or injected erthropoiesis-stimulating agents will significantly raise blood Hb levels by increased numbers of red blood cells and improve tissue oxygenation.