The application of six-minute walk test to identify ‘pre-hypoxemia’ phase in asymptomatic/mild disease COVID-19 patients managed in home isolation or primary health care setting

The clinical spectrum of COVID-19 infection patients extends from being asymptomatic to mild, moderate and severe disease. This classification is largely based on oxygen saturation and respiratory rate. Asymptomatic/mild disease patients are managed in home isolation or COVID care centers. A subgroup of these patients will deteriorate and develop moderate to severe disease. Six-minute walk test is useful in identifying this group of patients by inducing hypoxia in normoxemia patients. This stage of the disease is labelled as ‘pre-hypoxemia’ phase in asymptomatic/mild disease. Identifying this stage in the course of illness of patients will help in intercepting further deterioration at the earliest by timely intervention.