Normal V is 4 l/min of air and normal Q is 5 l/min of blood. These two variables, V and Q, determine oxygen (O 2) and carbon dioxide (CO 2) levels in the blood. Ventilation (V) refers to the flow of air into and out of the alveoli, while perfusion (Q) refers to the flow of blood to alveolar capillaries. Gas exchange occurs in alveoli, and for effective gas exchange to occur, alveoli must be ventilated and perfused.
Pulmonary ventilation is the process of air flowing into the lungs during inspiration (inhalation) and out of the lungs during expiration (exhalation). Pulmonary Ventilation-Perfusion Mismatch in COVID-19 Despite having limitations, these modalities provide vital information on blood volume distribution, pulmonary embolism, pulmonary vasculature and are useful to assess severity of lung disease and effectiveness of treatment in COVID-19 patients. This review summarizes the capacity of these imaging modalities to assess ventilation-perfusion mismatch in COVID-19. Imaging helps to access the severity of infection, lung performance, ventilation-perfusion mismatch, and informs strategies for medical treatment. Advanced imaging modalities such as computed tomography, single-photon emission tomography, and electrical impedance tomography use a sharp algorithm visualizing pulmonary ventilation-perfusion mismatch in the abnormal and in the apparently normal parenchyma. Although useful for their portability X-ray and ultrasound serving on the frontline to evaluate lung parenchymal abnormalities are unable to provide information about pulmonary vasculature and blood flow redistribution which is a consequence of hypoxemia in COVID-19. Imaging can aid the physician in assessing severity of COVID-19. A severe pulmonary ventilation-perfusion mismatch usually triggers moderate to severe COVID-19 cases.
Patients also respond differently to prescribed medicine and to prone Vs supine bed positions. COVID-19 hypoxemic patients although sharing a same etiology (SARS-CoV-2 infection) present themselves quite differently from one another.
0 kommentar(er)
