D J Hirsch1, K K Jindal, P Wong, A D Fraser. 1. Department of Medicine, Queen Elizabeth II Health Sciences Centre, Dalhousie University, 5820 University Avenue, Halifax, Nova Scotia B3H 1V8, Canada.
Abstract
BACKGROUND: Conventional dialysis management of ethylene glycol and methanol poisoning includes frequent intradialytic determinations of serum toxin concentration. Dialysis is continued until a target toxin concentration is reached. Initially, the required dialysis duration is unknown, making planning difficult. We devised a simple method to estimate the duration of dialysis required and avoid quantitation of multiple toxin samples. METHODS: Using the assumption that toxic alcohols would have a dialysis clearance similar to urea, we proposed that required dialysis time (hours) to reach a 5 mmol/L toxin concentration target would be: [-V ln(5/A)]/0.06k, where V (liters) is the Watson estimate of total body water, A is the initial toxin concentration (mmol/L), and k is 80% of the manufacturer-specified dialyzer urea clearance (mL/min) at the initial observed blood flow rate. Directly measured dialysis and renal toxin clearance, and true dialysis requirement by conventional treatment protocol were compared with our estimate in two methanol and three ethylene glycol poisonings treated with Fresenius F8 dialyzers. RESULTS: There were no clinically or statistically significant differences between predicted dialysis duration (7.6 +/- 1.9 hours, +/-SD) and that actually provided using hourly toxin concentration sampling (7.4 +/- 1.9 hours). Renal toxin clearance was negligible compared to that of dialysis, and predicted dialysis clearance did not differ significantly from that observed. CONCLUSIONS: The simple estimate method is sufficiently valid to guide the prescription of dialysis for toxic alcohol poisoning. Data required at dialysis start include only the initial toxin concentration, dialyzer manufacturer's specified urea clearance at initial observed blood pump speed, and patient demographics to estimate total body water. This approach allows for planned dialysis therapy, without the need for additional toxin concentration measurements until dialysis is completed.
BACKGROUND: Conventional dialysis management of ethylene glycol and methanolpoisoning includes frequent intradialytic determinations of serum toxin concentration. Dialysis is continued until a target toxin concentration is reached. Initially, the required dialysis duration is unknown, making planning difficult. We devised a simple method to estimate the duration of dialysis required and avoid quantitation of multiple toxin samples. METHODS: Using the assumption that toxic alcohols would have a dialysis clearance similar to urea, we proposed that required dialysis time (hours) to reach a 5 mmol/L toxin concentration target would be: [-V ln(5/A)]/0.06k, where V (liters) is the Watson estimate of total body water, A is the initial toxin concentration (mmol/L), and k is 80% of the manufacturer-specified dialyzer urea clearance (mL/min) at the initial observed blood flow rate. Directly measured dialysis and renal toxin clearance, and true dialysis requirement by conventional treatment protocol were compared with our estimate in two methanol and three ethylene glycol poisonings treated with Fresenius F8 dialyzers. RESULTS: There were no clinically or statistically significant differences between predicted dialysis duration (7.6 +/- 1.9 hours, +/-SD) and that actually provided using hourly toxin concentration sampling (7.4 +/- 1.9 hours). Renal toxin clearance was negligible compared to that of dialysis, and predicted dialysis clearance did not differ significantly from that observed. CONCLUSIONS: The simple estimate method is sufficiently valid to guide the prescription of dialysis for toxic alcohol poisoning. Data required at dialysis start include only the initial toxin concentration, dialyzer manufacturer's specified urea clearance at initial observed blood pump speed, and patient demographics to estimate total body water. This approach allows for planned dialysis therapy, without the need for additional toxin concentration measurements until dialysis is completed.
Authors: Rupesh Raina; Manpreet K Grewal; Martha Blackford; Jordan M Symons; Michael J G Somers; Christoph Licht; Rajit K Basu; Sidharth Kumar Sethi; Deepa Chand; Gaurav Kapur; Mignon McCulloch; Arvind Bagga; Vinod Krishnappa; Hui-Kim Yap; Marcelo de Sousa Tavares; Timothy E Bunchman; Michelle Bestic; Bradley A Warady; Maria Díaz-González de Ferris Journal: Pediatr Nephrol Date: 2019-08-24 Impact factor: 3.714
Authors: Philippe Lachance; Fabrice Mac-Way; Simon Desmeules; Sacha A De Serres; Anne-Sophie Julien; Pierre Douville; Marc Ghannoum; Mohsen Agharazii Journal: Kidney Int Date: 2015-08-05 Impact factor: 10.612