<abstract xmlns="http://www.w3.org/1999/xhtml"><bold>Objective</bold>: To develop a more accurate, cost effective, non-invasive test to differentiate between pre-renal renal failure (PRA) and acute tubular necrosis (ATN) in acute kidney injury (AKI).<bold>Methods</bold>: Urine sodium/potassium (Na/K) ratios were compared with fractional excretion of sodium (FeNa) and renal failure index (RFI) as well as other commonly used indices to differentiate patients with PRA from ATN. Patients with a rise in serum creatinine > 0.5 mg/d identified from medical records for a six- to eighteen-month period, were reviewed and categorized either as PRA or ATN based on presenting findings, course in hospital or renal biopsy. All patients had urinary sodium and potassium, creatinine, and serum creatinine done.<bold>Results</bold>: The Na/K was &lt; 1 in PRA and > 1 in ATN, correctly identifying all 42 cases of PRA and all 28 patients with ATN. The FeNa was >1 and misdiagnosed 9 of 42 patients with PRA and was >1 and correctly diagnosed all patients with ATN. The RFI was >1 and misdiagnosed 11 of 42 patients with PRA but was >1 and correctly diagnosed all patients with ATN. The BUN/creatinine ratio, urine sodium concentration and U/P creatinine ratio all had a very poor correlation with the correct diagnosis.<bold>Conclusion</bold>: The Na/K ratio correctly diagnosed all 42 cases of PRA and all 28 cases of ATN. It is easy to do, is cost effective, non-invasive, and is useful for following patients with PRA to see if and when they develop ATN.</abstract>

Objective: To develop a more accurate, cost effective, non-invasive test to differentiate between pre-renal renal failure (PRA) and acute tubular necrosis (ATN) in acute kidney injury (AKI).Methods: Urine sodium/potassium (Na/K) ratios were compared with fractional excretion of sodium (FeNa) and renal failure index (RFI) as well as other commonly used indices to differentiate patients with PRA from ATN. Patients with a rise in serum creatinine > 0.5 mg/d identified from medical records for a six- to eighteen-month period, were reviewed and categorized either as PRA or ATN based on presenting findings, course in hospital or renal biopsy. All patients had urinary sodium and potassium, creatinine, and serum creatinine done.Results: The Na/K was < 1 in PRA and > 1 in ATN, correctly identifying all 42 cases of PRA and all 28 patients with ATN. The FeNa was >1 and misdiagnosed 9 of 42 patients with PRA and was >1 and correctly diagnosed all patients with ATN. The RFI was >1 and misdiagnosed 11 of 42 patients with PRA but was >1 and correctly diagnosed all patients with ATN. The BUN/creatinine ratio, urine sodium concentration and U/P creatinine ratio all had a very poor correlation with the correct diagnosis.Conclusion: The Na/K ratio correctly diagnosed all 42 cases of PRA and all 28 cases of ATN. It is easy to do, is cost effective, non-invasive, and is useful for following patients with PRA to see if and when they develop ATN.

Urinary Sodium/Potassium Ratio in Acute Kidney Injury Accurately Differentiates Prerenal Azotemia from Acute Tubular Necrosis

Acta Marisiensis - Seria Medica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Objective: To develop a more accurate, cost effective, non-invasive test to differentiate between pre-renal renal failure (PRA) and acute tubular necrosis (ATN) in acute kidney injury (AKI).Methods: Urine sodium/potassium (Na/K) ratios were compared with fractional excretion of sodium (FeNa) and renal failure index (RFI) as well as other commonly used indices to differentiate patients with PRA from ATN. Patients with a rise in serum creatinine > 0.5 mg/d identified from medical records for a six- to eighteen-month period, were reviewed and categorized either as PRA or ATN based on presenting findings, course in hospital or renal biopsy. All patients had urinary sodium and potassium, creatinine, and serum creatinine done.Results: The Na/K was  1 in ATN, correctly identifying all 42 cases of PRA and all 28 patients with ATN. The FeNa was >1 and misdiagnosed 9 of 42 patients with PRA and was >1 and correctly diagnosed all patients with ATN. The RFI was >1 and misdiagnosed 11 of 42 patients with PRA but was >1 and correctly diagnosed all patients with ATN. The BUN/creatinine ratio, urine sodium concentration and U/P creatinine ratio all had a very poor correlation with the correct diagnosis.Conclusion: The Na/K ratio correctly diagnosed all 42 cases of PRA and all 28 cases of ATN. It is easy to do, is cost effective, non-invasive, and is useful for following patients with PRA to see if and when they develop ATN.

Objective: To develop a more accurate, cost effective, non-invasive test to differentiate between pre-renal renal failure (PRA) and acute tubular necrosis...

Urinary Sodium/Potassium Ratio in Acute Kidney Injury Accurately Differentiates Prerenal Azotemia from Acute Tubular Necrosis

Published Online: Sep 26, 2019

Page range: 103 - 110

Received: Mar 12, 2019

Accepted: May 23, 2019

DOI: https://doi.org/10.2478/amma-2019-0011

Keywords
acute renal injury, prerenal azotemia, tubular necrosis

© 2019 Theodore Shankel et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Urinary Sodium/Potassium Ratio in Acute Kidney Injury Accurately Differentiates Prerenal Azotemia from Acute Tubular Necrosis

Published Online: Sep 26, 2019

Page range: 103 - 110

Received: Mar 12, 2019

Accepted: May 23, 2019

DOI: https://doi.org/10.2478/amma-2019-0011

Keywordsacute renal injury, prerenal azotemia, tubular necrosis

© 2019 Theodore Shankel et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
acute renal injury, prerenal azotemia, tubular necrosis