Interactive medical case: wasting away

This interactive feature presents the case of a 40-year-old woman with pain, weakness, and poor oral intake. She had had a gradual onset of bilateral flank pain spreading to her lower back, abdomen, and extremities. Test your diagnostic and therapeutic skills at NEJM.org.

Bartter syndrome type 3 in an elderly complicated with adrenocorticotropin-deficiency

Bartter syndrome (BS) is a disorder with normotensive hypokalemic alkalosis and hyperreninemic hyperaldosteronemia. BS affects infants or early childhood. Patients with BS type 3 harbor mutation in CLCNKB, Cl channel Kb. Gitelman syndrome (GS) is a disorder in childhood, with mutation in SLC12A3. Isolated adrenocorticotropin deficiency (IAD) causes secondary adrenal insufficiency. Neither elderly cases, nor cases with IAD were previously reported in BS. A 72-year-old man was admitted with acute adrenal crisis. He had been treated for IAD for 19 years. He had no trouble during perinatal period, delivery, and growth. After the recovery from adrenal crisis, laboratory tests revealed hypokalemia; 3.0 mEq/L (normal: 3.5-4.5), impaired renal function: eGFR; 37.6 mL/min/1.73 m2, normomagnesemia; 2.1 mg/dL (1.7-2.3), hyperreninemia; 59.4 ng/mL/h (0.2-2.7), hyperaldosteronemia; 23.5 ng/dL (3.0-15.9), and normal urinary ratio of calcium/creatinine. In diuretic tests, he showed a fine response to furosemide, and a mild response to thiazide. In genetic tests, no mutation of SLC12A3 was found and homozygous mutation: c.1830 G > A in CLCNKB was shown. Thus he was diagnosed as BS type 3. Current case presented with unusual features as BS type 3, 1) his late and mild clinical manifestation suggested GS rather than BS, 2) laboratory data and diuretics tests did not show typical features as BS, and 3) IAD and chronic renal failure altered electrolyte metabolism. In conclusion, current case implies that BS type 3 should be considered even in elderly cases with normotensive hypokalemia, and highlights importance of endocrinological and genetic examinations.

Gender and magnetic resonance imaging classification-related differences in clinical and biochemical characteristics of Cushing's disease: a single-centre study

BACKGROUND

Cushing's disease (CD) presents a remarkable preponderance in female gender, and a significant minority of patients with CD presented with negative magnetic resonance imaging (MRI) findings. The aim of this study was to evaluate gender-related and MRI classification-related differences in clinical and biochemical characteristics of CD.

METHODS

We retrospectively studied 169 patients with CD, comprising 132 females and 37 males, and 33 patients had no visible adenoma on MRI.

RESULTS

We observed that male and MRI-positive patients presented with high adrenocorticotropic hormone (ACTH) values (P < 0.05). Female patients presented with higher prevalence of hirsutism and hyperpigmentation and lower prevalence of purple striae (P < 0.05). The prevalence of buffalo-hump and hypertension was greater in MRI-negative patients (P < 0.05). In addition, male patients with CD presented at a younger age compared with females (P < 0.05). Patients with fatigue and hypokalaemia presented significantly higher urinary-free cortisol, ACTH and cortisol levels compared with patients without these symptoms (P < 0.05). The prevalence of LH reduction, hyper total cholesterol (TC) and hyper low-density lipoprotein was more frequent in MRI-positive patients (P < 0.05). Hyper-TC levels and PRL reduction were more frequent in males (P < 0.05). T3, T4 and FT3 levels negatively correlated with age at diagnosis (r = -0.310, P < 0.01; r = -0.191, P < 0.05; r = -0.216, P < 0.05). T3, T4, FT3 and FT4 levels significantly negatively correlated with 8-am plasma cortisol levels (r = -0.328, P < 0.01; r = -0.195, P < 0.05; r = -0.333, P < 0.01; r = -0.180, P < 0.05). Females presented higher total protein level (P < 0.01) and lower blood urea nitrogen and serum creatinine levels (P < 0.01), compared with male patients.

CONCLUSIONS

Carefulness and caution are required in all patients with CD, because of the complexity of clinical and biochemical characteristics in CD patients of different gender and MRI classification, particularly male patients and MRI-negative patients.

Primary aldosteronism: emerging trends

Primary aldosteronism (PA) is the most common etiology of endocrine hypertension (HTN), and recent prevalence studies suggest that it may be under-diagnosed. Indications for screening have been expanded with recognition that many patients with PA do not have hypokalemia and that the disease may be familial. The aldosterone:renin ratio (ARR) is the preferred screening test for PA. The ARR can be interpreted in patients on most anti-hypertensive agents, and can be used to guide medical therapy of HTN even in patients without PA. Once PA is confirmed, adrenal venous sampling (AVS) should be performed to determine if PA is due to bilateral disease or a unilateral adenoma, if surgery is being considered. Targeted medical or surgical therapy improves patient outcomes.

Multiple electrolyte disorders in a neurosurgical patient: solving the rebus

BACKGROUND

It is important to ensure an adequate sodium and volume balance in neurosurgical patients in order to avoid the worsening of brain injury.Indeed, hyponatremia and polyuria, that are frequent in this patient population, are potentially harmful, especially if not promptly recognized.Differential diagnosis is often challenging, including disorders, which, in view of similar clinical pictures, present very different pathophysiological bases, such as syndrome of inappropriate antidiuresis, cerebral/renal salt wasting syndrome and diabetes insipidus.

CASE PRESENTATION

Here we present the clinical report of a 67-year-old man with a recent episode of acute subarachnoid haemorrhage, admitted to our ward because of severe hyponatremia, hypokalemia and huge polyuria.We performed a complete workup to identify the underlying causes of these alterations and found a complex picture of salt wasting syndrome associated to primary polydipsia. The appropriate diagnosis allowed us to correct the patient hydro-electrolyte balance.

CONCLUSION

The comprehension of the pathophysiological mechanisms is essential to adequately recognize and treat hydro-electrolyte disorders, also solving the most complex clinical problems.

Hypokalaemic paralysis in an adult case of Plasmodium vivax malaria

Hypokalaemia and its subsequent complications are more often seen in children rather than in adults and are more common with falciparum malaria. This is a case of a 26-year-old male with Plasmodium vivax malaria who had developed paraparesis secondary to hypokalaemia. His treatment involved correction of the potassium level as well as the treatment of malaria. Such an atypical manifestation of malaria in an adult has not been previously documented.

Utility of F-18 FDG-PET in detecting primary aldosteronism in patients with bilateral adrenal incidentalomas

In patients with primary aldosteronism who have bilateral adrenal incidentalomas, it is important to identify which adrenal gland is secreting excess aldosterone. Traditionally, adrenal vein sampling (AVS) has been performed for lateralization despite its invasiveness. Here we report a case of bilateral adrenal incidentaloma in which 18-Fluorodeoxyglucose (FDG)-positron emission tomography (PET) was used to identify the functional adrenal mass. A 53-yr-old man was referred to our clinic due to bilateral adrenal incidentalomas (right: 1 cm, left: 2.5 cm) on computed tomography (CT). Given his history of colon cancer, FDG-PET/CT scanning was used to rule out metastasis. Although there was focal hot uptake lesion in the right adrenal gland, the patient was suspected primary aldosteronism clinically more than metastasis because of the patient's underlying hypertension with hypokalemia. It was consistent with the results of AVS. Based on these findings, we propose that FDG-PET/CT can be used instead of AVS to identify the source of primary aldosteronism between two bilateral adrenal incidentalomas.

[Hypokalemic myopathy with severe constipation in a patient routinely administered sodium polystyrene sulfonate and the spherical carbon adsorbent]

66-year-old man was hospitalized because of severe abdominal pain. He had been treated for chronic renal failure. Sodium polystyrene sulfonate (SPS) and the spherical carbon adsorbent AST-120 were routinely administered to him. However, after several treatments, his pain did not resolve and his serum creatine kinase concentration was markedly elevated, so he was transferred to our hospital. Before admission to the previous hospital, muscular weakness was noted in his extremities and those symptoms persisted. His serum potassium concentration was 1.6 mEq/L, and he was administered potassium. A lower gastrointestinal endoscopy revealed normal mucosa and SPS powder-like brownish-yellow stool containing AST-120 granules in the colorectum. After massive stool discharge, the patient's pain improved and his serum potassium concentration gradually increased. The patient was diagnosed with hypokalemic myopathy thought to be mainly caused by accumulation of SPS in the colorectum.

[Unusual alcoholic weaning, complicated: do you check the blood phosphate?]

A 65 year old alcoholic man was hospitalized because he was tired, hypotonic, with postural tremor. The neurologic symptoms increased during the first two days despite an adequate therapy for alcoholic weaning with hydratation, benzodiazepines and vitamins. A severe hypophosphatemia is diagnosed, associated with hypovitaminosis D, mild hypomagnesemia, mild hypokaliemia and a refeeding syndrome. 24 hours after the normalisation of his phosphatemia, the neurologic symptoms are adjusted.

Supervised analysis of drug prescription sequences

Hospitals have at their disposal large databases that may be considered for reuse. The objective of this work is to evaluate the impact of a drug on a specific laboratory result by analyzing these data. This analysis first involves building a record of temporal patterns, including medical context, of drug prescriptions. Changes in outcome due to these patterns of drug prescription are assessed using short phases of the inpatient stay compared to monotonous changes in the laboratory result. To illustrate this technique, we investigated potassium chloride supplementation and its impact on kalemia. This method enables us to assess the impact of a drug (in its frequent context of prescription) on a laboratory result. This kind of analysis could play a role in post-marketing studies.

[Hypokalemia]

Hypokalemia, defined as a less than 3.5 mmol/I serum potassium, is probably the most common electrolyte abnormality in clinical practice. It is usually well tolerated but, if severe, it can be life-threatening. However, even mild or moderate hypokalemia increases the risks of morbidity and mortality in patients with cardiovascular disease. When hypokalemia is identified, the underlying cause should be established and the disorder immediately treated.

Hypokalemic paralysis as a presenting manifestation of primary Sjögren's syndrome accompanied by vitamin D deficiency

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by progressive lymphocyte infiltration of the exocrine glands. Overt or latent renal tubular acidosis (RTA) is a common extraglandular manifestation of pSS.Vitamin D deficiency is associated with autoimmune disorders; however, the potential correlation between pSS and vitamin D deficiency is rarely discussed. The current patient presented with distal RTA, hypocalcemia, and hypophosphatemia that were found to be secondary to both vitamin D deficiency and pSS. In patients diagnosed with both distal RTA and vitamin D deficiency, clinicians should consider autoimmune diseases such as pSS, as a possible underlying etiology.

Congenital adrenal hyperplasia masquerading as periodic paralysis in an adolescent girl

Congenital adrenal hyperplasia is an uncommon diagnosis in routine clinical practice. 21-hydroxylase deficiency, which is its most common subtype, may be diagnosed at birth in a female infant by virilisation or by features of salt wasting in both genders. However, other uncommon subtypes of this condition such as 17-alpha-hydroxylase deficiency, 11-beta-hydroxylase deficiency may present much later in adolescence or adulthood. A high index of suspicion is necessary when evaluating children with hypertension, hypokalaemia, metabolic alkalosis or sexual infantilism.

[Liquorice-induced hypertension and hypokalaemia]

Consumption of large amounts of liquorice can cause hypertension and hypokalaemia. Liquorice contains glycyrrhetinic acid, which inhibits the enzyme 11 beta-hydroxysteroid dehydrogenase type 2, and ultimately leads to an apparent mineralocorticoid excess syndrome. This case report describes a 50 year-old woman presenting with hypertension and hypokalaemia-induced limb paresis due to chronic liquorice ingestion. The patient was treated with potassium supplementation and spironolactone. Her blood pressure and electrolyte status normalised within a month after cessation of liquorice intake.

Advances in diagnosis and management of hypokalemic and hyperkalemic emergencies

With up to 56% of individuals taking diuretics likely to develop hypokalemia, and comorbid disease and many other types of medications having the potential to induce hyperkalemia, potassium abnormalities are some of the most commonly seen electrolyte abnormalities in the emergency department (ED). Unless recognized and treated appropriately, they can also be some of the most deadly. Symptoms accompanying potassium abnormalities are often vague, involving multiple organ systems. This evidence-based review discusses the etiology, differential diagnosis, and diagnostic studies for detecting hypokalemia and hyperkalemia, including managing laboratory errors that lead to factitious potassium findings. Recognition and treatment of life-threatening dysrhythmias in hypokalemia and hyperkalemia are key to managing these potassium abnormalities. Electrocardiogram (ECG) findings, treatment algorithms, and controversies on treating potassium abnormalities in the ED are discussed, with recommendations on criteria for disposition.

[To start eating again could be dangerous]

A 36-year-old woman with anorexia nervosa and resulting malnutrition decided to change her life and eat properly. One day after the refeeding start, instead of feeling better she felt much worse: fatigue, nausea and leg swelling occurred. She consulted our emergency department. A «refeeding syndrome» has been diagnosed. In this case report we discuss causes, clinical presentation and treatment of this illness. The aim is to make practitians aware about the existing of this disease even with oral refeeding. Warning signs have to be interpreted correctly in order to avoid dramatic consequences.

Distal renal tubular acidosis that became exacerbated by proton pump inhibitor use

Acid-base imbalances and electrolyte disorders induced by proton pump inhibitors (PPIs) are extremely rare. However, under certain conditions, PPIs may cause metabolic acidosis or hypokalemia, probably due to an inhibitory action on the proton pump that contributes to H(+) and K(+) homeostasis in the kidney. We herein present a case of marked hypokalemia accompanied by distal renal tubular acidosis in which a PPI appeared to contribute to the pathophysiology of metabolic acidosis.

[A case of hypomagnesemia linked to refractory hypokalemia and hypocalcemia with short bowel syndrome]

We report a case of a 59-year old Japanese woman with short bowel syndrome, whose hypokalemia and hypocalcemia were successfully treated with magnesium (Mg) supplementation. Two years previously, she underwent Mile's operation for advanced rectal cancer, which could have been the cause of subsequent extensive resection of the small intestine by strangulation. After serial resection, she gradually developed chronic diarrhea and anorexia. Three weeks before admission, she developed general fatigue and tetany, and was hospitalized at another hospital. On admission, her serum K and Ca were 2.5 mEq/L and 4.3 mg/dL, respectively, hence regular fluid therapy containing potassium (K) and calcium (Ca) was provided following admission. However, her hypokalemia and hypocalcemia persisted, and she also displayed renal dysfunction and thereafter was transferred to our department for further evaluation and treatment. Since the laboratory tests revealed severe hypomagnesemia (0.4 mg/dL), we started intravenous Mg supplementation together with fluid therapy containing K and Ca. After the combination therapy, her clinical symptoms and electrolyte disorders were remarkably improved within a week. As Mg is essential for PTH secretion in response to hypocalcemia and to inhibit the K channel activity that controls urinary K excretion, hypomagnesemia can cause hypocalcemia and hypokalemia, which is refractory to repletion therapy unless Mg is administered. Therefore, for patients who present with signs of Mg deficiency, early and accurate diagnosis of Mg deficiency should be made and corrected.