Respiratory and other systemic complications of coronavirus disease 2019 in adults: A narrative review

To review and summarize the health complications known to be caused by the coronavirus disease 2019 (COVID-19) and theirpathophysiology. A thorough search was conducted for articles on the complications of COVID-19 from December 30th, 2019through November 20th, 2020. August using the PubMed, Google Scholar, and World Health Organization (WHO) databases.and it was supplemented with inclusion of pertinent articles till May 30th, 2021 Articles that did not have patient data, thosewhich included data of patients < 18 years of age, studies limited to pregnant patients, and studies limited to only specificco-morbidities and organ dysfunctions were excluded to avoid selection bias and heterogeneity in study population. A total of108 studies were included in the narrative review. These studies reported numerous complications of COVID-19 with the mostcommon being acute respiratory acute respiratory distress syndrome (ARDS) (19.5%–72%), myocardial injury (13.6%–36%),cytokine storm (5%–10%), acute kidney injury (AKI) (4%–54.7%), acute liver injury (14%–62.4%), and venous thromboembolism(VTE) (4%–20%). Our review extensively illustrates the incidence, predictors, and pathophysiology of respiratory, cardiovascular,immunological, hepatobiliary, coagulative, neurological, and renal complications of COVID-19. Enhancing the host immuneresponses against viral infection and modulating the inflammatory responses, along with appropriate support of respiratoryfunction; as well as the management of complications involving multiple organ systems potential leading to multi-organ failure,are all important aspects to be considered for the recovery of critically ill patients with COVID-19.