An atypical presentation of high potassium renal secretion rate in a patient with thyrotoxic periodic paralysis: a case report.

BACKGROUND: Hypokalemia is one of the most common clinical electrolyte imbalance problems, and thyrotoxic periodic paralysis (TPP) is a leading cause of presentation to the emergency department. Low renal potassium secretion rates, a normal acid-base balance in the blood, and hyperthyroidism are the hallmarks of suspected TPP. CASE PRESENTATION: Here we report the case of a 36-year-old man who presented to the emergency department with a sudden onset of acute muscle weakness at 5 h prior to admission. Biochemistry tests revealed hypokalemia with hyperthyroidism and renal potassium wasting. TPP was initially not favored due to the presence of renal potassium wasting. However, his serum potassium level rebounded rapidly within several hours after potassium supplementation, indicating that the intracellular shifting of potassium ions was the main etiology for his hypokalemia. The early stage of TPP development may have contributed to this paradox. CONCLUSION: Therefore, it is premature to rule out TPP based on the presentation of high renal potassium secretion rates alone. This finding may result in an incorrect impression being made in the early stage of TTP and may consequently lead to an inappropriate potassium supplementation policy.

Normotensive hypokalemic primary hyperaldosteronism mimicking clinical features of anorexia nervosa in a young patient: A case report.

RATIONALE: The typical clinical presentations of patients with primary aldosteronism (PA) include generalized weakness, fatigue, high blood pressure, and potassium deficiency. However, normotensive PA is rare. Therefore, an atypical presentation of normal blood pressure is a challenge for the diagnosis and treatment of PA. PATIENT CONCERNS: A 43-year-old, thin, and tall woman (body mass index, 18.6 kg/m) with generalized weakness for 1 day presented to our emergency department, where hypokalemia was a significant finding. The initial diagnosis was anorexia nervosa with the evidence of renal potassium wasting with low urinary sodium and chloride levels, metabolic alkalosis, normal blood pressure, and low body mass index. However, neither vomiting features nor other specific induced vomiting features were noted. DIAGNOSES: The laboratory examination revealed high plasma aldosterone level, low plasma renin activity, and extremely high aldosterone-to-renin ratio indicating the diagnosis of PA, confirmed via adrenal computed tomography. INTERVENTIONS: Surgical adrenalectomy was performed. Pathological diagnosis was a benign cortical adenoma. OUTCOMES: Patient's serum potassium level and hormonal status became normalized after surgical removal of adrenal adenoma. She fully recovered without any further sequelae. LESSONS: It is too early to rule out PA based on the presence of normal blood pressure in a patient with metabolic alkalosis and renal wasting hypokalemia. Moreover, PA should be considered in a normotensive patient with an unknown hypokalemic etiology to avoid delayed diagnosis and treatment.