Abstract and Introduction
Coronavirus disease 2019 (COVID-19) was first associated with a cluster of pneumonia cases during December 2019 in Wuhan, China. After rapid spread of the disease across China and to several countries, the World Health Organization declared a global health emergency on January 30, 2020, followed by a global pandemic on March 11, 2020.
Coronaviruses are a large family of viruses that are widespread among birds and mammals and cause a variety of illnesses. The virus that causes COVID-19 is an enveloped single-strand RNA zoonotic virus associated with a severe respiratory syndrome. Spread occurs via human-to-human transmission primarily by inhalation of large respiratory droplets associated with coughing, sneezing, singing, or talking (these heavy droplets may travel 6 feet [1.8 m] or more but fall relatively quickly), or tiny aerosolized particles (< 5 μm in diameter) that are light and thus can stay suspended in the air for hours, especially in stagnant air. Less commonly, virus particles can be transmitted through contact with infected surfaces (fomites) or feces.[1,3–6]
Following a short incubation (median 4–5 days), clinical features most often include fever, fatigue, dry cough, dyspnea, mild pneumonia, myalgia, and anorexia. Less common symptoms include sore throat, dizziness, headache, diarrhea, and other gastrointestinal symptoms.[1,2,4,7,8] In an early report of more than 70 000 cases in China, most cases were mild (> 80%), but severe (14%) and critical (5%) cases required hospital admission and intensive care. Some patients' condition deteriorated rapidly within 1 week of illness onset. Severe cases were characterized by dyspnea, respiratory rate greater than 30/min, oxygen saturation less than 93%, and lung infiltrates exceeding 50% within 24 to 48 hours of illness onset; critical cases involved respiratory failure, sepsis, and/or multiple organ dysfunction. Mortality rates were estimated at 2.3% of confirmed cases. Major risk factors for severe disease and mortality include increasing age and various comorbidities (eg, hypertension, heart disease, prior stroke, diabetes, chronic lung and kidney disease, immunosuppression).[1,2,4,8,10]
Absent a vaccine and effective treatment, research has been focused on developing COVID-19 diagnostic and antibody tests and on testing therapies such as remdesivir, convalescent plasma, and the antimalarial drugs chloroquine and hydroxychloroquine, which are also used for autoimmune diseases such as lupus erythematosus or rheumatoid arthritis. Given that little evidence is available on therapies for COVID-19, the PICO (patient problem, intervention, comparison, and outcome) question for this evidence synthesis was, Is chloroquine or hydroxychloroquine safe and effective in reducing the severity of COVID-19 symptoms and disease mortality?
Am J Crit Care. 2020;29(6):489-492. © 2020 American Association of Critical-Care Nurses