References & formulas

SODIUM PREDICTION: Prediction of plasma sodium after the prescribed CRRT, considering anthropometric values, therapy duration, effluent volume, and the sodium concentration in CRRT fluids.

[Na] meq/L prediction =   plasma [Na]  + (1- [e (-Kt/V)] x (plasma [Na] - Net [Na] in CRRT ))

The net sodium in CRRT is the  concentration obtained after accounting for the different volumes and sodium concentrations of CRRT solutions, post-filter infusion, and citrate.

Net [Na] in CRRT: [([Na] 1 x Vol 1) + ([Na] 2 x Vol 2) +( [Na 3 ] x Vol 3) ] / Vol 1 + Vol 2 + Vol 3 

Citrate infusion and post-filter infusion should be considered part of the total effluent input.

Yessayan LT, Szamosfalvi B, Rosner MH. Management of dysnatremias with continuous renal replacement therapy. Semin Dial. 2021 Nov;34(6):472-479. 

PMID: 34218456.

Yessayan L, Yee J, Frinak S, Szamosfalvi B. Treatment of severe hyponatremia in patients with kidney failure: role of continuous venovenous hemofiltration with low-sodium replacement fluid. Am J Kidney Dis. 2014 Aug;64(2):305-10. 

PMID: 24792353.

Yessayan L, Yee J, Frinak S, Szamosfalvi B. Continuous Renal Replacement Therapy for the Management of Acid-Base and Electrolyte Imbalances in Acute Kidney Injury. Adv Chronic Kidney Dis. 2016 May;23(3):203-10. 

PMID: 27113697.

Rosner MH, Connor MJ Jr. Management of Severe Hyponatremia with Continuous Renal Replacement Therapies. Clin J Am Soc Nephrol. 2018 May 7;13(5):787-789. 

 PMID: 29463598; 

Neyra JA, Ortiz-Soriano VM, Ali D, Morris PE, Johnston CM. A Multidisciplinary Approach for the Management of Severe Hyponatremia in Patients Requiring Continuous Renal Replacement Therapy. Kidney Int Rep. 2018 Sep 13;4(1):59-66. 

PMID: 30596169;