#6825 ECOLOGICAL APPROACH FOR KIDNEY REPLACEMENT THERAPY IN CRITICAL CARE: SLED MAY BE A STRATEGY

Abstract

Abstract Background and Aims Dialysis has an enormous environmental impact, not only for disposable consumables, but also for the water and energy consumption. Despite increasingly evidence regarding comparable outcomes between continuous kidney replacement therapy (CKRT) and slow low efficiency dialysis (SLED), ecological-based endpoints are not frequently evaluated. Literature in critical care concerning the environmental impact of these techniques is scarce. We aimed to determine the waste production, water and energy consumption in SLED and CKRT and identify the technique with higher environmental impact. Method We conducted a cross-sectional, observational, single-center study in patients with acute kidney injury requiring kidney replacement therapy admitted to an intensive care unit (ICU). We analyzed the waste weight of each dialysis technique (Fresenius Medical Care 5008 for SLED and Baxter Prismaflex for CKRT) before and after the treatment. We estimated the water consumption of a SLED session with a Qd of 300 ml/min for 8 hours and 12 hours sessions, considering a Reverse Osmosis (RO) system with a 50% rate water rejection and a CKRT session for an 80Kg patient, with a Qd of 1300 mL/h and a reposition solution flow of 500 mL/h. Both techniques included a disinfection volume of 14 L. Results A SLED session produced 1600 g of waste (1200 g was hazardous and 400 g was non-hazardous waste). A CKRT session produced 2700 g of waste, not considering the substitution solution volume, which can vary up to a maximum of 15000 g/treatment. Waste consumables for each technique are discriminated in Table 1. The unpurified water consume of 8-hours and 12-hours SLED treatment was 237 L and 345 L, respectively. For CKRT, we estimated a consume of 43.2 L a day and 129.6 L for a 72-hour treatment. SLED had an energy consumption of 5.71 kW and 8.43 kW, for 8-hours and 12 hours treatment, respectively. The CKRT consumed about 12 to 14.4 kW per day. Conclusion Our study highlights the quantity of waste produced, water and power consumption of dialysis techniques in the critical patient. CKRT produces more hazardous waste, that generates a larger carbon footprint. Hazardous waste cannot be recyclable and implies specific management and disposal, which is more expensive and laborious than non-hazardous. CKRT has also a higher power consumption due to treatment duration and technology used to generate electricity. SLED has higher water consumption, nevertheless, current strategies used in hemodialysis units could also be implemented in UCI to minimize this effect. For example, the rejected water can be reused to agriculture and toilet flushing; more efficient water purification system with a lower proportion of rejected water can also reduce water consumption. SLED has unequivocal clinical benefits in the critical patient and, from an ecological perspective, seems to be a more sustainable option.