Persistent severe hypokalemia: Gitelman syndrome and differential diagnosis.

The main causes of hypokalemia are usually evident in the clinical history of patients, with previous episodes of vomiting, diarrhea or diuretic use. However, in some patients the cause of hypokalemia can become a challenge. In such cases, two major components of the investigation must be performed: assessment of urinary excretion potassium and the acid-base status. This article presents a case report of a patient with severe persistent hypokalemia, complementary laboratory tests indicated that's it was hypomagnesaemia and hypocalciuria associated with metabolic alkalosis, and increase of thyroid hormones. Thyrotoxic periodic paralysis was included in the differential diagnosis, but evolved into euthyroid state, persisting with severe hypokalemia, which led to be diagnosed as Gitelman syndrome.

Persistent severe hypokalemia: Gitelman syndrome and differential diagnosis / Hipocalemia grave persistente: Síndrome de Gitelman e diagnósticos diferenciais

Abstract The main causes of hypokalemia are usually evident in the clinical history of patients, with previous episodes of vomiting, diarrhea or diuretic use. However, in some patients the cause of hypokalemia can become a challenge. In such cases, two major components of the investigation must be performed: assessment of urinary excretion potassium and the acid-base status. This article presents a case report of a patient with severe persistent hypokalemia, complementary laboratory tests indicated that's it was hypomagnesaemia and hypocalciuria associated with metabolic alkalosis, and increase of thyroid hormones. Thyrotoxic periodic paralysis was included in the differential diagnosis, but evolved into euthyroid state, persisting with severe hypokalemia, which led to be diagnosed as Gitelman syndrome.

Resumo As principais causas de hipocalemia normalmente são evidentes na história clínica dos pacientes em investigação etiológica, com episódios prévios de vômitos, diarréia ou uso de diuréticos. Entretanto, em alguns pacientes, a causa da hipocalemia pode se tornar um desafio. Em tais casos, dois principais componentes da investigação devem ser realizados: avaliação da excreção do potássio urinário e do "status" ácido-básico. Este artigo traz um relato de caso de uma paciente portadora de hipocalemia grave persistente, com investigação laboratorial complementar caracterizada por hipomagnesemia e hipocalciúria, associada à alcalose metabólica e elevação dos hormômios tireoideanos. A apresen- tação inicial do quadro incluiu paralisia periódica tireotóxica como um dos principais diagnósticos diferenciais, porém, a paciente evoluiu para um es- tado eutireoideo e persistiu com grave hipocalemia, sendo, por fim, realizado diagnóstico clínico de Síndrome de Gitelman.