Review Article of Global Journal of Urology and Nephrology
A Practical Approach for Pathophysiological Diagnosis of Refractory Hypokalemia
Mohamed Foda Hendi, Zeyad Faoor Alrais, Hesham El Kholy
Department of Intensive Care Medicine, Rashid Hospital, Dubai health Authority, Dubai, United Arab Emirates
Hypokalemia is a common finding in hospitalized patients. In most cases the cause will be obvious. However, in a subgroup of patients the cause is occasionally uncertain and establishing the diagnosis may present difficulties and can become a challenge.
In such cases, measurement of urinary indices e.g. trans-tubular potassium gradient [TTKG] and random urine potassium/creatinine concentrations along with blood acid/base parameters and assessment of urinary excretion of potassium, chloride, calcium and creatinine have been employed in the differential diagnosis.
TTKG and urine potassium/creatinine ratio are used as a rapid appropriate index of potassium excretion and to establish a proper diagnosis and management in this medical emergency. It helps to differentiate between hypokalemia caused by redistribution or renal potassium wasting.
Urinary chloride excretion and urinary calcium/creatinine ratio in conjunction with plasma acid/base values, aldosterone, renin and cortisol values are used for narrowing the differential diagnosis of refractory hypokalemia.
Conclusions: Calculating the trans-tubular potassium concentration gradient, urinary potassium/creatinine ratio, urinary chloride excretion and urinary calcium/creatinine ratio in conjunction with plasma acid/base values provided simple and reliable tests for differential diagnosis of causes of refractory hypokalemia and to provide a proper management in the intensive care unit and in the emergency until advanced further tests to be done.
Keywords: Refractory Hypokalaemia, Trans-tubular Potassium Concentration Gradient, Urinary Potassium-creatinine Ratio, Urinary Calcium-Creatinine Ratio, Bartter Syndrome, Gitelman Syndrome.
How to cite this article:
Mohamed Foda Hendi, Zeyad Faoor Alrais, Hesham El Kholy.A Practical Approach for Pathophysiological Diagnosis of Refractory Hypokalemia. Global Journal of Urology and Nephrology, 2018, 1:6. DOI:10.28933/gjun-2018-10-1508
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