Extracorporeal techniques can focus on virus removal, inflammatory mediators removal and/or organ support. Regrettably, virus removal with these procedures seems to be limited by low virus blood concentration. Inflammatory mediators, on the other hand, usually represent large middle molecules which can be successfully removed with the high cut-off membranes, but such intervention may be associated with unwanted albumin loss. The novel medium cut-off membranes, in turn, provide comparable efficiency in terms of cytokine removal, but with marginal albumin loss. Lowering cytokine storm can also be achieved by integrating sorbent membranes into RRT circuits or as a bypass in extracorporeal membrane oxygenation systems. These may improve mean arterial blood pressure, phagocytic capacity and monocyte tumor necrosis factor production and ability for antigen presentation. Thus, several exctracorporeal blood purification techniques can be applied in the treatment of critically ill COVID-19 patients with AKI, including hemoperfusion to remove inflammatory molecules and viral particles, therapeutic plasma exchange to remove inflammatory mediators and proteins associated with hypercoagulability, and continuous RRTs with adsorptive, medium cut-off or high cut-off membranes (8). A recently published set of practical recommendations for extracorporeal blood purification and organ support in the critically ill COVID-19 patients provide detailed review of the available technology and useful guidance for clinical practice (9). An early application of these strategies seem to mitigate the severity of the disease and prevent development of severe organ dysfunction.
How to prevent transmission of COVID-19 in the hemodialysis unit?
Presenter: Prof. Rita Suri, Quebec, Canada
Panellist: Prof. Mario Cozzolino, Milan, Italy
Hemodialysis (HD) patients appear to be at increased risk for COVID-19 infection and HD units are high-risk areas in this epidemic. Prevention of COVID-19 spread among maintenance HD patients involves identification of infected individuals, prevention of spreading within the HD unit, and reducing the risk outside the unit and at home. Patients should be advised and continuously encouraged to phone ahead the dialysis unit if they are sick, since individually phoning patients the day before their HD treatment has not proved to be effective. There should be a triage station at the dialysis unit entrance where nurses or other trained medical personnel should ask a standard set of questions about symptoms, history of exposure to a close contact with COVID-19 and, if applicable, travel history, and measure body temperature. Patient follow-up should continue vigorously during HD treatment. An example of the screening tool used at the McGill University Health Centre includes questions about the occurrence of fever, chills, cough, shortness of breath, loss of smell, new vomiting, and general unwellness, close contact with COVID-19 infected person in the last 14 days, as well as actual oxygen saturation and body temperature (Figure 2).