Peritoneal dialysis for acute kidney injury: Equations for dosing in pandemics, disasters, and beyond.

BACKGROUND: Peritoneal dialysis (PD) is a viable option for renal replacement therapy in acute kidney injury (AKI), especially in challenging times during disasters and pandemics when resources are limited. While PD techniques are well described, there is uncertainty about how to determine the amount of PD to be prescribed toward a target dose. The aim of this study is to derive practical equations to assist with the prescription of PD for AKI. METHODS: Using established physiological principles behind PD clearance and membrane transport, a primary determinant of dose delivery, equations were mathematically derived to estimate dialysate volume required to achieve a target dose of PD. RESULTS: The main derivative equation is VD = (1.2 × std-Kt/V × TBW)/(tdwell + 4), where VD is the total dialysate volume per day, std-Kt/V is the desired weekly dose, TBW is the total body water, and tdwell is the dwell time. VD can be expressed in terms of dwell volume, vdwell, by VD = (0.3 × std-Kt/V × TBW) - (6 × vdwell). Two further equations were derived which directly describe the mathematical relationship between tdwell and vdwell. A calculator is included as an Online Supplementary Material. CONCLUSIONS: The equations are intended as a practical tool to estimate solute clearances and guide prescription of continuous PD. The estimated dialysate volume required for any dose target can be calculated from cycle duration or dwell volume. However, the exact target dose of PD is uncertain and should be adjusted according to the clinical circumstances and response to treatment. The equations presented in this article facilitate the adjustment of PD prescription toward the targeted solute clearance.

Ensuring Sustainability of Continuous Kidney Replacement Therapy in the Face of Extraordinary Demand: Lessons From the COVID-19 Pandemic.

With the exponential surge in patients with coronavirus disease 2019 (COVID-19) worldwide, the resources needed to provide continuous kidney replacement therapy (CKRT) for patients with acute kidney injury or kidney failure may be threatened. This article summarizes subsisting strategies that can be implemented immediately. Pre-emptive weekly multicenter projections of CKRT demand based on evolving COVID-19 epidemiology and routine workload should be made. Corresponding consumables should be quantified and acquired, with diversification of sources from multiple vendors. Supply procurement should be stepped up accordingly so that a several-week stock is amassed, with administrative oversight to prevent disproportionate hoarding by institutions. Consumption of CKRT resources can be made more efficient by optimizing circuit anticoagulation to preserve filters, extending use of each vascular access, lowering blood flows to reduce citrate consumption, moderating the CKRT intensity to conserve fluids, or running accelerated KRT at higher clearance to treat more patients per machine. If logistically feasible, earlier transition to intermittent hemodialysis with online-generated dialysate, or urgent peritoneal dialysis in selected patients, may help reduce CKRT dependency. These measures, coupled to multicenter collaboration and a corresponding increase in trained medical and nursing staffing levels, may avoid downstream rationing of care and save lives during the peak of the pandemic.