The role of continuous renal replacement therapy (Crrt) in Coronavirus disease 2019 (Covid-19) patients

Even without the presence of the novel Coronavirus disease 2019 (COVID-19), acute kidney injury has been a serious problem in medicine for decades, with mortality rate up to 70% among those who eventually required renal replacement therapy, and the number has not changed significantly for the last 30 years despite major advances in technology and experience. On the other hand, even without acute kidney injury, COVID-19 was a major cause of death globally in the year 2020, but the occurrence of acute kidney injury among COVID-19 patients is an independent risk factor of increased mortality. Continuous renal replacement therapy has been recommended to treat acute kidney injury in COVID-19 patients instead of conventional intermittent hemodialysis. Moreover, its use might have another beneficial role in stopping the progression of severe COVID-19 by removing pro-inflammatory cytokines during cytokine storm syndrome, which is postulated as the pathophysiology behind severe and critically severe cases of COVID-19. This review will cover a brief history of continuous renal replacement therapy and its modalities, before digging up more into its use in COVID-19 patients, including the optimum filtration dose and timing, membrane filtration used, vascular access, anticoagulation therapy, and drug dosing adjustment during continuous renal replacement therapy.