Hyperglycinuria: diagnosis in middle age

Isolated hyperglycinuria is a rare disorder that is associated with osteoporosis and renal calculi. We report findings in a middle-aged, black woman who presented for renal function evaluation with a history of transient hypobicarbonataemia associated with topiramate therapy. She displayed the full triad of high urinary glycine, early-onset osteopenia despite normal reproductive hormones, and renal calculus with high urinary oxalate, phosphate and uric acid. Parathyroid hormone and fibroblast growth factor 23 were both normal. Formal genetic testing did not reveal mutations in SLC6A20, SLC6A18, SLC6A19, SLC36A2, the known genes associated with glycinuria; however, black individuals are poorly represented in the genetic databases. It may well be that otherwise unidentified mutations may be present or that topiramate may result in a lingering proximal tubule defect even after cessation of the drug.

Use of Venous Excess UltraSound (VExUS) score in hyponatraemia management in critically ill patient

Hyponatraemia is the most prevalent electrolyte disorder in the neurocritical care setting and is associated with a significant morbimortality. Cerebral salt wasting and inappropriate antidiuretic hormone secretion syndrome have been classically described as the two most frequent entities responsible for hyponatraemia in neurocritical care patients. An accurate aetiological diagnosis of hypotonic hyponatraemia requires a proper volume status assessment. Nevertheless, determination of volume status based on physical examination, laboratory findings and imaging modalities have several limitations and can lead to improperly diagnosis and hyponatraemia mismanagement. Point-of-care ultrasound (POCUS), specifically Venous Excess UltraSound (VExUS) score, is a fast and valuable tool to evaluate venous congestion at the bedside and identify hypervolaemia, helping the physicians in therapeutic decision making in a patient with hyponatraemia. We report a case where the use of POCUS, and more specifically VExUS, can be helpful in volume status assessment, complementing the complex management of multifactorial hyponatraemia in a neurocritical patient.

Successful living kidney donation from a patient with a Gitelman's syndrome

Living kidney donation from Gitelman's syndrome (GS) patients remains very rare. Long-term renal prognosis of donor and recipient patients remains unknown. We report a 67-year-old man with GS, harbouring a mutation of the SLC12A3 gene, who donated his kidney for transplant. Five years post-transplantation, his clinical condition and biochemical parameters remained stable with close monitoring and follow-up. Patients with non-complicated GS can be considered eligible to donate their kidney for transplant.

Refractory familial hypokalaemic periodic paralysis leading to cardiovascular compromise

Familial hypokalaemic periodic paralysis (FHPP) is a rare neuromuscular disorder that is classified under periodic paralysis (PP), which is characterised by episodes of muscle weakness. Common triggers include intense exercise, fasting or consumption of carbohydrate-rich meals. Hypokalaemic PP has an incidence of 1 in 100 000; despite the temporal association, cardiac manifestations are exceedingly rare. We present a case of FHPP, a channelopathy presenting with severe refractory hypokalaemia. The challenges with our patient were maintaining potassium levels within normal ranges and initiating a close follow-up plan. Due to the lack of clinical guidance in our case, many aspects of care, including surveillance, medications and genetic testing, remain unaddressed. Medical management includes aggressive correction with supplements, potassium-sparing diuretics and carbonic anhydrase inhibitors. Severe cases of dysrhythmias, especially ventricular fibrillation, require electrophysiology evaluation and possible implantation of a defibrillator to prevent sudden cardiac death.

Diagnostic and management considerations in pseudohypoaldosteronism type 1b

Pseudohypoaldosteronism type 1B is a rare autosomal recessive disorder caused by dysfunction of amiloride-sensitive epithelial sodium channels (ENaCs). We present the case of a neonate with cardiogenic shock after cardiac arrest due to profound hyperkalaemia. Genetic testing revealed a novel homozygous variant in SCNNIA We review diagnostic considerations including the molecular mechanisms of disease, discuss treatment approaches and highlight the possible significance of the diversity of pulmonary ENaCs.

Topiramate-induced severe electrolyte abnormalities and hypernatremia leading to central pontine myelinolysis

Central pontine myelinolysis (CPM) develops due to acute hypernatremia from a normal baseline serum sodium in the setting of electrolyte abnormalities induced by topiramate use. Topiramate is a commonly used medication with several indications including migraines, myoclonic jerks and seizures. It has been reported to cause renal tubular acidosis and severe electrolyte abnormalities, which in turn predispose patients to neuropathology via renal concentration defects and osmotic shifts. Our patient is a 55-year-old woman with a history of multiple sclerosis and myoclonus on topiramate for several years who presented with weakness and was found to be profoundly hypokalemic. She went on to develop changes in mental status, motor deficits and evidence of CPM on MRI during her hospitalisation. Surprisingly, the patient never had hyponatremia; however, she had an acute rise in serum sodium from a normal baseline after fluid resuscitation with normal saline for hypotension during her admission.

Severe refeeding syndrome after human chorionic gonadotropin diet: a potentially lethal complication

We present the case of a young male patient who presented with paralysing muscle weakness due to severe hypokalaemia and hypophosphataemia. The initial patient history evaluations could not establish the aetiology. Only after we reviewed the patient's history did he reveal that he had been following a severe calorie-restricted regime, the human chorionic gonadotropin diet, which had ended 2 days prior to developing symptoms. This information then allowed us to diagnose severe refeeding syndrome. As a further complication, the patient developed rhabdomyolysis. After correction of serum electrolytes, symptoms resolved completely. This case emphasises the potential harm of severely calorie-restricted diets, often recommended by online 'experts'. Furthermore, we underline the importance of thorough history taking.

MELAS syndrome: an acute stroke-like episode complicated by renal tubular acidosis

MELAS, a mitochondrially inherited multisystem disorder, can present with acute stroke-like episodes. The literature thus far supports the use of L-arginine therapy in acute MELAS flares to alleviate and shorten the duration of symptoms. This is the case of a patient who presented with ataxia and worsening confusion on a background of genetically confirmed MELAS syndrome. In this instance, intravenous L-arginine therapy, along with corticosteroids, was administered in keeping with best practice. However, in a metabolically vulnerable patient, L-arginine therapy resulted in a further deterioration in his clinical status and the development of a non-anion gap metabolic acidosis.

Antenatal Bartter syndrome: a new compound heterozygous mutation in exon 2 of KCNJ1 gene

A 30+6/7-week infant was born by vaginal delivery to a 21-year-old primigravida with pregnancy complicated by polyhydramnios. The infant developed polyuria and significant weight loss in the first 2 weeks of life despite appropriate fluid management. He developed hyponatraemia, hypochloraemia, transient hyperkalaemia and prerenal azotaemia with metabolic acidosis. On further evaluation, he had elevated plasma renin and aldosterone levels. Bartter syndrome was considered in the differential diagnosis. Bartter syndrome gene panel revealed a rare compound heterozygous mutation in exon 2 of the KCNJ1 gene (Lys186Glu/Thr71Met), suggesting antenatal Bartter syndrome (type 2). The infant developed late-onset hypokalaemia and metabolic alkalosis by week 4 of life. He regained birth weight by week 3 of life but failed to thrive (10-20 g/kg/day) despite high caloric intake (140 kcal/kg/day). His electrolyte abnormalities gradually improved, and he was discharged home without the need for electrolyte supplements or medications.

Refractory hypokalaemia and hypertension with metabolic alkalosis: an acute presentation of Cushing's disease secondary to a pituitary macroadenoma

A 68-year-old woman presented with right arm cellulitis, not responsive to oral antibiotics. Intravenous antibiotics were commenced, and an ultrasound scan confirmed a collection that was surgically drained. She developed refractory hypokalaemia with normal magnesium, no gastrointestinal losses and no iatrogenic cause. She was hypertensive, hyperglycaemic, alkalotic, clinically obese with proximal myopathy and skin bruising. These clinical findings and refractory hypokalaemic hypertension with metabolic alkalosis raised a suspicion of Cushing's syndrome (CS). 24-hour urinary free cortisol (24 hours) was grossly raised on two occasions. The adrenocorticotropic hormone (ACTH) was significantly raised at 154 ng/L, confirming ACTH-dependant CS. A CT scan of the thorax, abdomen and pelvis excluded an ectopic source of hypercortisolaemia. MRI pituitary revealed an invasive macroadenoma. Treatment with endoscopic debulking resulted in the resolution of hypokalaemia and metabolic alkalosis with significant improvement in hyperglycaemia and hypertension.

Management of hyponatraemia in pre-eclampsia with severe features

Pre-eclampsia is a common pregnancy complication with many associated maternal and fetal risks, yet its pathophysiology remains poorly understood. Hyponatraemia is a rarely described finding in pre-eclampsia that has been associated with both maternal and fetal complications and medically indicated delivery. We present a case of hyponatraemia in a patient admitted for induction of labour for gestational hypertension, which developed into pre-eclampsia with severe features requiring magnesium sulfate therapy for seizure prophylaxis. The patient's hyponatraemia resolved with delivery, fluid restriction and serial sodium monitoring. Adjustment to the components of the patient's magnesium sulfate infusion was made to reduce free water intake and avoid further exacerbation of her hyponatraemia. While there is currently no recommendation to routinely monitor sodium levels in hypertensive disorders of pregnancy, careful consideration of this potential finding in cases of pre-eclampsia should be given due to the overlap between symptoms of hyponatraemia and cerebral symptoms of pre-eclampsia.

Pituitary microadenoma with hypopituitarism presenting as hyponatremia

The incidence of pituitary adenoma has been increasing these days. Majority of the cases are incidental findings on imaging; and these patients may be asymptomatic without any laboratory abnormalities. However, a non-functional sellar mass can initially present with hypopituitarism. The patient being described is an elderly female who presented with severe hyponatraemia. She has history of recurrent admissions for hyponatraemia in the past. Her biochemical evaluation revealed hypopituitarism and magnetic resonance imaging of brain showed pituitary microadenoma. Hyponatraemia as a presenting feature of hypopituitarism due to pituitary microadenoma is an uncommon scenario.

Severe metabolic derangement: a case of concomitant diabetic ketoacidosis and beer potomania

Diabetic ketoacidosis (DKA) and hyponatraemia associated with beer potomania are severe diagnoses warranting intensive care level management. Our patient, a middle-aged man, with a history of chronic alcohol abuse and insulin non-compliance, presents with severe DKA and severe hyponatraemia. Correcting sodium and metabolic derangements in each disorder require significant attention to fluid and electrolyte levels. Combined they prove challenging and require an individualised approach to prevent the overcorrection of sodium. Furthermore, management of these conditions lends to the importance of understanding the pathophysiology behind their hormonal and osmotic basis.

Cyclical haematological changes in a case of hypopituitarism

A 40-year-old woman presented to our emergency department in an altered state following a generalised tonic-clonic seizure. On regaining consciousness, she gave a history of bleeding tendencies and menorrhagia, fatigue, nausea, vomiting and appetite loss for a long time. She had received multiple blood transfusions in the last 10 years. Investigations revealed severe hyponatraemia, transaminitis and pancytopenia, which showed cyclical fluctuations in the hospital. Hyponatraemia was attributed to a central cause owing to secondary hypothyroidism and hypocortisolism on evaluation. A diagnosis of cyclical thrombocytopenia was made by logging the trends of blood cell lines and applying the Lomb-Scargle test. Liver biopsy showed features of transfusion hemosiderosis explaining transaminitis. All of the haematological abnormalities and clinical symptoms resolved on thyroxine and corticosteroid replacement, suggesting causal association hypopituitarism with cyclical thrombocytopenia.

Management of severe hyponatremia with low-dose continuous kidney replacement therapy and peripheral D5W in an infant with acute kidney injury

We report a 7-month-old female infant who presented with anuric acute kidney injury and severe hyponatremia (serum sodium 110 mEq/L). The patient was treated with low-dose continuous kidney replacement therapy (CKRT), that is, 85% of total clearance dose divided equally between normonatric (Na 140 mEq/L) replacement and dialysate fluids. The remaining 15% of the clearance was provided by peripheral infusion of dextrose 5% (D5W). The patient's sodium was maintained between 119 mEq/L and 121 mEq/L for the first 24 hours of CKRT. Over the next 2 days, the rate of D5W infusion was slowly decreased while replacement and dialysis flow rates were proportionately increased. Serum sodium was normalised by day 2 of the therapy. The patient had no neurologic sequelae associated with this therapy.

Late diagnosis of chronic hypocalcemia due to autoimmune hypoparathyroidism

Hypoparathyroidism is most often the result of postsurgical damage to the parathyroid glands but may occasionally be autoimmune hypoparathyroidism. In the latter context, activating antibodies directed against the calcium-sensing receptor (CaSR) have been described. We hereby present the case of a patient suffering from chronic recurrent muscle cramps and paresthesia, presenting for a seizure due to hypocalcaemia. After eliminating the possibility of a genetic disorder, we searched for autoimmune hypoparathyroidism as there was no obvious cause of hypoparathyroidism. The search for anti-CaSR antibodies was positive. There was no argument for autoimmune polyendocrine syndrome type 1 so we concluded that it was isolated autoimmune hypoparathyroidism caused by activating antibodies to the CaSR. The patient was treated with vitamin D and calcium supplementation. The search for complications of hypoparathyroidism and hypercalciuria revealed basal ganglia calcification. The patient's hypocalcaemia is now being kept under control with oral supplementation.

Severe hypercalcaemia from ectopic intact parathyroid hormone secretion treated with continuous renal replacement therapy in a patient with two malignancies

We present a 61-year-old Caucasian woman with endometroid carcinoma as well as a poorly differentiated adenocarcinoma who developed severe hypercalcaemia in the setting of an elevated intact parathyroid hormone. The patient was hospitalised twice for her condition. During her first hospitalisation, she was diagnosed with an endometroid carcinoma and hypercalcaemia. With medical management, she had a normal calcium level on discharge. She presented 3 weeks later with hypercalcaemia and encephalopathy. This time her hypercalcaemia was refractory to medical management, and required continuous renal replacement therapy (CRRT) to normalise her serum calcium. Lung biopsy revealed a poorly differentiated adenocarcinoma, suspicious for pancreatic primary. Due to her poor prognosis, rapid elevation of calcium with each attempt to discontinue CRRT, and the poor options for treatment of her cancers, she elected to pursue hospice care.

Hypermagnesaemia causing mesenteric ischaemia and small bowel infarction

We present a case of mesenteric ischaemia caused by hypermagnesaemia after ingestion of a large oral dose of magnesium citrate, which resulted in smooth muscle relaxation, hypotension and bowel infarction. The patient had a history of chronic bowel dysmotility and renal impairment. On operative exploration, the bowel was noted to have a distinct pattern of ischaemia along its antimesenteric border. Small bowel resection was performed, and the patient was left in discontinuity, with definitive repair and anastomosis performed 24 hours later. The patient's magnesium level was 8.39 mg/dL, which was treated with intermittent haemodialysis and eventually normalised over several sessions. Our patient recovered and was discharged after a month-long hospitalisation. She returned shortly after with respiratory failure and died. On review of the literature, we identified similar cases and present a pathophysiological mechanism of hypermagnesaemia causing mesenteric ischaemia, consistent between our cases and those already reported.

D-lactic acidosis presenting as metabolic encephalopathy in a patient with short bowel syndrome

We present a case of D-lactic acidosis presenting as a metabolic encephalopathy secondary to small intestinal bacterial overgrowth. This patient had a known history of short bowel syndrome. Of note, this case required the alteration of treatment to promote a sustained clinical and biochemical improvement. We discuss the pathophysiological mechanisms thought to be involved. We also review the current therapies as well as potential future strategies. This case highlights the importance of the prompt clinical recognition of signs and symptoms as well as the rapid initiation of management strategies to ameliorate this condition.

A rare case of hypokalaemia and hypophosphataemia secondary to geophagia

We report a case of severe hypokalaemia and moderate hypophosphataemia from clay ingestion. A 60-year-old woman presented with flaccid paralysis. Investigations revealed a serum potassium level of 1.8 mmol/L, phosphate level of 0.56 mmol/L and creatine kinase level of 30 747 IU/L. She had marked proximal and distal muscle weakness due to severe hypokalaemia and concurrent hypophosphataemia, which likely contributed to the onset of rhabdomyolysis. The patient subsequently admitted to significant pica, most likely secondary to an associated iron deficiency. We conclude that the ingested clay acted as a potassium and phosphate binder. Although we did not investigate the content of the clay in this case, it has been reported that clay can bind potassium in vitro and is rich in minerals such as aluminium that could play a role in the binding of phosphate, although the exact mechanism remains unclear. The patient recovered fully and outpatient follow-up at 6 months and again at 40 months confirmed no electrolyte abnormality, myopathy nor any further geophagia.

Diagnosis and outpatient management of Gitelman syndrome from the first trimester of pregnancy

A 32-year-old woman presented with an incidental finding of hypokalaemia on routine bloods at 9 weeks of a second pregnancy, on a background of lifelong salt craving. Her previous pregnancy was uncomplicated. She had no previous significant medical or family history. Venous blood gases showed a hypokalaemic, normochloraemic metabolic alkalosis. Urinary potassium was elevated. Escalating doses of oral supplementation of potassium, magnesium, sodium and potassium-sparing diuretics were required through the course of pregnancy, in response to regular electrolyte monitoring. These were later weaned and completely stopped post partum. Delivery was uneventful with no maternal or neonatal complications. Genetic testing performed post partum showed heterogenous mutation of SCL12A3 gene.

Acute life-threatening hyperkalaemia in a patient with giant hydronephrosis: a case report

A 52-year-old man with a history of urolithiasis presents to the emergency department with a sudden, sharp, continuous right flank colicky pain. Laboratory workup demonstrates acute kidney injury with a mild hyperkalaemia. During the observation period, the patient develops an atypical broad complex sinus bradycardia and eventually short asystolic periods. This was caused by a severe therapy-resistant hyperkalaemia, wherefore emergency haemodialysis was necessary. Radiographic results showed a giant hydronephrosis with a blowout of the right kidney and an obstructing calculi of 21 mm in the distal ureter. We will discuss the mechanism of reversed intraperitoneal dialysis causing the refractory hyperkalaemia and the need of close ECG monitoring in patients where kidney blowout is considered.

Type 3 antenatal Bartter syndrome presenting with mild polyuria

Bartter syndrome (BS) is a well-recognised inherited tubular dysfunction that causes polyuria, metabolic alkalosis and hypokalaemia. Among BS cases, antenatal/neonatal BS (ABS) usually shows distinct polyhydramnios prenatally and presents features of BS in the early neonatal period. We encountered a premature infant with type 3 ABS presenting with mild polyuria and discuss the pathogenesis of mild polyuria in type 3 ABS. A male infant was born at 31 weeks' gestation. His mother received amniocentesis because of polyhydramnios. Hyponatraemia and hypokalaemia appeared within 3 days after birth. Metabolic alkalosis, hyperreninaemia and hyperaldosteronism were also identified. Temporary polyuria developed at 1 month after birth; however, the mean urine output during hospitalisation was within the normal range. CLCNKB compound heterozygous mutations were confirmed. Polyuria of type 3 ABS may be less severe than in other types of ABS. Lower urine sodium loss may be a characteristic feature of type 3 ABS.

Nearly fatal hypokalaemia due to non-hypertensive primary hyperaldosteronism in the post partum

A previously healthy postpartum 33-year-old woman was admitted at the emergency department after two episodes of syncope. In the waiting room, she collapsed, ventricular fibrillation was detected, and she was reanimated by electric cardioversion. At admission, she was conscient, with blood pressure of 102/74 mm Hg and heart rate of 78 bpm. In the laboratory workup, severe hypokalaemia was found (K⁺ 1.77 mEq/L). Abdominopelvic CT revealed a 27 mm nodule in the right adrenal gland. High aldosterone and low plasma renin levels were detected, and the diagnosis of primary hyperaldosteronism was made, although she never had hypertension. Posteriorly, a cosecretion of aldosterone and cortisol was found. Two months after admission, the patient remained stable with normal K⁺ levels under spironolactone and a right adrenalectomy was performed. The cure of primary hyperaldosteronism and a partial adrenal insufficiency were confirmed. K⁺ levels and blood pressure remained normal without treatment and 10 months after surgery hydrocortisone was suspended.

Therapeutic hypothermia and outcome in hyponatraemic encephalopathy secondary to maternal water intoxication

Misguided encouragement to consume large volumes of water during labour for pain relief results in dilutional hyponatraemia in mothers and their babies presenting with neurological dysfunction. We report three babies who were encephalopathic with seizures in the background of hyponatraemia secondary to maternal ingestion of large volumes of water and mild perinatal asphyxia. All babies underwent therapeutic hypothermia in addition to sodium supplementation with fluid restriction. Their neurodevelopment was appropriate for age. This case series highlights the dilemma that could arise with hyponatraemic encephalopathy and mild perinatal asphyxia in the first 6 hours of life, which is the window of opportunity for therapeutic hypothermia for hypoxic-ischaemic encephalopathy. It is important to educate pregnant mothers in labour on the adverse effects of excessive fluid ingestion.

Multifactorial diabetes insipidus during pregnancy: a challenging diagnosis

Diabetes insipidus (DI) is characterised by thirst and polydipsia with hypotonic polyuria. Several forms exist, namely, central or pituitary, nephrogenic and gestational and must be differentiated for adequate treatment. We describe the case of a 41-year-old woman chronically infected with HIV who had been recently medicated with a tenofovir-based antiretroviral treatment and who, at 22 weeks of pregnancy, presented with transient gestational DI. Obstetric ultrasound revealed oligohydramnios and foetal growth restriction that did not improve despite serum sodium correction. The severity of the case suggested the presence of an underlying disorder and elevated copeptin levels indicated that an underlying subclinical form of nephrogenic DI, possibly induced by HIV-related nephropathy or tenofovir use, was present and rendered clinically overt during pregnancy.

Patient with Bartter syndrome in whom chronic potassium depletion was considered one of the causes of hyponatremia

A 53-year-old man was admitted to our hospital because of general fatigue and disorientation. He had been diagnosed with Bartter syndrome in his teens and had been taking potassium preparations since then. However, his serum potassium concentration (K⁺ _s) remained persistently low. Ten days before admission, he developed fever. He was diagnosed as having bronchitis and was treated with antibiotics. Although his fever subsided, general fatigue worsened. Laboratory examination showed hyponatraemia (127 mEq/L), while K⁺ _s was 2.3 mEq/L. C reactive protein was negative. On admission, laboratory examination revealed deterioration of hyponatraemia (125 mEq/L). Although his serum sodium concentration (Na⁺ _s) was refractory to electrolyte replacement, the level increased towards normal after spironolactone administration, following normalisation of K⁺ _s, suggesting that hyponatraemia was caused by K⁺ depletion. Physicians should be aware of the importance of the effects of exchangeable K⁺ (K⁺ _e) on Na⁺ _s.

Distinguishing cerebral salt wasting syndrome and syndrome of inappropriate ADH in a patient with traumatic brain injury

A previously healthy 48-year-old woman was referred to our intensive care unit (ICU) from a neurosurgical ward due to deterioration of her conscious level. She had a road traffic accident 6 days earlier. On admission to the hospital, a brain CT demonstrated subarachnoid haemorrhage which was considered not amenable to surgical intervention. A second CT brain performed shortly after admission to ICU showed no change in comparison to the initial CT. Serum sodium level on ICU admission was 108 mEq/L; serum and urine osmolalities were 223 mOsm/kg and 438 mOsm/kg, respectively. Her hyponatraemia was initially attributed to syndrome of inappropriate antidiuretic hormone. However, a clinical impression of low volume status raised the suspicion of cerebral salt wasting syndrome. She was managed by infusion of hypertonic saline and fluids for 5 days and discharged from ICU after improvement of her conscious level and normalisation of serum sodium.

Rare but serious cause for hypokalaemia and hypertension

Adrenocortical carcinoma is a rare tumour but hypertension conversely is very common. We present the case of a woman in her 30s, with poorly controlled hypertension on four antihypertensive agents. She was referred to the accident and emergency department with hypokalaemia. For a year, she had experienced oedema, weight gain, acne, hirsutism and oligomenorrhea. She had a classic Cushingoid appearance and marked striae. Cushing's syndrome was confirmed biochemically with an abnormal overnight dexamethasone suppression test. She was diagnosed with metastatic adrenocortical carcinoma following CT imaging. This was resected via a right adrenalectomy, nephrectomy and cholecystectomy. She also received mitotane. Unfortunately, she has a terminal prognosis having experienced a recurrence. This case demonstrates the value of a thorough clinical assessment. More importantly, it highlights the need to refer earlier patients under 40 with resistant hypertension to a specialist. Finally, it encourages clinicians to investigate hypokalaemia in the context of hypertension.

Hyponatraemia due to hypothyroidism: a rare side effect from pomalidomide

Pomalidomide is an immunomodulatory drug used for relapsed and refractory multiple myeloma (RRMM). Hypothyroidism is an uncommon side effect of pomalidomide. We present a 70-year-old male patient with RRMM on daratumumab, pomalidomide and dexamethasone, who presented with 2 weeks of fatigue. Laboratory values showed sodium of 120 mEq/L, plasma osmolarity of 256 mOsm/kg, urine osmolarity of 648 mOsm/kg and urine sodium of 93 mEq/L. Adrenocorticotropic hormone (ACTH) stimulation test was within normal limits. Thyroid-stimulating hormone (TSH) was 88.6 IU/mL (0.380-4.700 IU/mL), total triiodothyronine (TT3) <21 ng/mL (0.8-2 ng/mL), free thyroxine (fT4) 0.10 ng/dL (0.93-1.70 ng/dL) and free triiodothyronine (fT3) <0.5 pg/mL (2.3-4.2 pg/mL). Antithyroid peroxidase antibody was 726 IU/mL (<9 IU/mL). TSH 1 year ago was 2.88 IU/mL and TT3 was 1.06 ng/mL. He was started on levothyroxine with improvement in his symptoms, sodium level and thyroid functions. The most likely culprit was pomalidomide. Checking thyroid functions before and periodically while on pomalidomide is important in screening for this possible side effect.

Presentation of mixed diabetic ketoacidosis and metabolic acidosis due to ileal neobladder reconstruction

Diabetic ketoacidosis (DKA) is one of the most serious acute metabolic complications of diabetes mellitus. It is characterised by the biochemical triad of hyperglycaemia, ketonemia/ketonuria, and an increased anion gap metabolic acidosis. In this case, a 40-year-old male patient presented to the emergency department, with vomiting, nausea, polydipsia, polyuria and weight loss. He was found to have an elevated plasma glucose, despite having no known history of diabetes mellitus. His medical history was significant for spina bifida and ileal neobladder reconstruction. The plasma glucose level was 38 mmol/L. Blood gas analysis showed normal anion gap metabolic acidosis with high chloride and low bicarbonate. His plasma ketone level was 4.5 mmol/L. No significant reason for hyperchloraemia was identified. On initiation of DKA regimen, his condition improved and serum ketones normalised. Due to persistent hyperchloraemic metabolic acidosis, bicarbonate infusion was administered and his metabolic acidosis resolved.

Type-5 Bartter syndrome presenting with metabolic seizure in adulthood

Bartter syndrome is a very rare and heterogeneous disease with variable age of onset and symptom severity. Genotypically they have inherited disorders of the thick ascending limb in the renal tubular system, which manifest phenotypically as electrolyte imbalance due to loss of sodium, chloride and potassium. Gain of function mutations in the calcium-sensing receptor has been described in some patients with Bartter's syndrome (type-5 Bartter syndrome or autosomal dominant hypocalcaemia with Bartter syndrome) associated with hypocalcaemia and hypercalciuria differentiating it from Gitelman syndrome. This phenotype has been reported to present in adulthood with metabolic abnormalities. We present a case of a middle-aged woman who presented with metabolic seizures and on evaluation was found to have profound electrolyte abnormalities which were corrected with supplements and led to the resolution of symptoms.

New onset adrenal insufficiency in a patient with COVID-19

SARS-CoV-2 is the cause of COVID-19. Since the outbreak and rapid spread of COVID-19, it has been apparent that the disease is having multi-organ system involvement. Still its effect in the endocrine system is not fully clear and data on cortisol dynamics in patients with COVID-19 are not yet available. SARS-CoV-2 can knock down the host’s cortisol stress response. Here we present a case of a 51-year-old man vomiting for 10 days after having confirmed COVID-19 infection. He had hypotension and significant hyponatraemia. Work-up was done including adrenocorticotropic hormone stimulation test. He was diagnosed as suffering from adrenal insufficiency and started on steroids with subsequent improvement in both blood pressure and sodium level. COVID-19 can cause adrenal insufficiency. Clinicians must be vigilant about the possibility of an underlying relative cortisol deficiency in patients with COVID-19.

Novel SLC12A3 mutation in Gitelman syndrome

Gitelman syndrome (GS) is an autosomal recessive disease characterised by the presence of hypokalaemic metabolic alkalosis with hypomagnesaemia and hypocalciuria. The prevalence of this disease is 1-10/40 000. GS is usually associated with mild and non-specific symptoms and many patients are only diagnosed in adulthood. The disease is caused by mutations in the SLC12A3 gene. We present the case of a 49-year-old man referred to a nephrology appointment due to persistent hypokalaemia and hypomagnesaemia. Complementary evaluation revealed hypokalaemia, hypomagnesaemia, metabolic alkalosis, hyperreninaemia, increased chloride and sodium urinary excretion, and reduced urinary calcium excretion. Renal function, remainder serum and urinary ionogram, and renal ultrasound were normal. A diagnosis of GS was established and confirmed with genetic testing which revealed a novel mutation in SLC12A3 (c.1072del, p.(Ala358Profs*12)). This novel mutation extends the spectrum of known SLC12A3 gene mutations and further supports the allelic heterogeneity of GS.

Unusual presentation of sarcoidosis, requiring a positron emission tomography/CT (PET/CT) for diagnosis

A 43-year-old man presented to hospital after routine laboratory tests showed an acute kidney injury and hypercalcaemia. He had no relevant medical history and normal physical examination, other than a 6-week history of lower back pain for which he had been taking naproxen. Low parathyroid hormone (PTH) levels indicated a PTH-independent hypercalcaemia. Investigations including CT of thorax, abdomen and pelvis and subsequent bone biopsy and renal biopsy were unremarkable. Positron emission tomography/CT (PET/CT) scan was ultimately considered as a diagnostic test and showed abnormalities in the right subpectoral and portacaval region with intense fluorodeoxyglucose F 18 uptake in local lymph nodes. A biopsy of the right subpectoral node showed granulomatous change consistent with sarcoidosis. PET/CT scanning can play an important role in the investigation of suspected malignancy, infection and inflammatory disease and in this case, was required to diagnose an atypical presentation of sarcoidosis.

Metformin-associated lactic acidosis: reinforcing learning points

Metformin-associated lactic acidosis (MALA) carries a high mortality rate. It is seen in patients with type 2 diabetes on metformin or patients who attempt suicide with metformin overdose. We present the case of a man in his early 20s with type 2 diabetes, hypertension and hypothyroidism who presented with agitation, abdominal pain and vomiting after ingesting 50-60 g of metformin; he developed severe lactic acidosis (blood pH 6.93, bicarbonate 7.8 mEq/L, lactate 28.0 mEq/L). He was managed with intravenous 8.4% bicarbonate infusion and continuous venovenous haemodiafiltration. He also developed acute renal failure (ARF) requiring intermittent haemodialysis and continuous haemodiafiltration. MALA is uncommon and causes changes in different vital organs and even death. The primary goals of therapy are restoration of acid-base status and removal of metformin. Early renal replacement therapy for ARF can result in rapid reversal of the acidosis and good recovery, even with levels of lactate normally considered to be incompatible with survival.

Deferasirox-induced liver injury and Fanconi syndrome in a beta-thalassemia major male

A 33-year-old male presenting with subacute abdominal pain was found to have hyperbilirubinaemia, hypokalaemia and hyponatraemia. This was in the setting of transitioning between deferasirox iron chelator formulations, from dispersible tablets to film-coated tablets for ongoing treatment of chronic iron overload secondary to transfusion requirement for beta-thalassemia major. A liver biopsy demonstrated acute cholestasis with patchy confluent hepatocellular necrosis and mild to moderate microvesicular steatosis. Based on the histological, biochemical and clinical findings, the diagnosis of hepatotoxicity and Fanconi-like syndrome was made. The patient improved clinically and biochemically with cessation of the deferasirox film-coated tablets and supportive management. To our knowledge, this is the first case report of hepatotoxicity and Fanconi-like syndrome occurring due to deferasirox film-coated tablets with previous tolerance of dispersible deferasirox tablets. It is important to raise clinical awareness of this potentially severe complication.

Omeprazole-induced hypomagnesaemia, causing renal tubular acidosis with hypokalaemia, hypocalcaemia, hyperlactacidaemia and hyperammonaemia

A 72-year-old Japanese man treated with omeprazole for 11 years was admitted due to loss of consciousness and muscle weakness. Wolff-Parkinson-White syndrome-induced tachycardia was considered as the cause of syncope. His blood examination revealed rhabdomyolysis, hypokalaemia, hypomagnesaemia, hypocalcaemia, hyperlactacidaemia, hyperammonaemia and high-anion-gap metabolic acidosis. Hypomagnesaemia could be caused by magnesium malabsorption due to omeprazole use. Hypocalcaemia might be caused by the inhibitory effect of hypomagnesemia on the parathyroid gland hormone secretion. Hyperammonaemia might be caused by two reasons: (1) renal ammonium production induced by hypokalaemia; (2) inhibition of ammonium secretion by omeprazole. Both hypocalcaemia and hypokalaemia might cause chronic elevation of serum creatinine phosphokinase which ended up with rhabdomyolysis. Correction of serum electrolytes rapidly improved his muscle weakness. Discontinuation of omeprazole no longer caused these abnormalities. A physician should be aware of unexplained signs and symptoms of patients using proton-pump inhibitors to avoid life-threatening electrolyte and physiologic disturbances.

Rare case of pseudohypoaldosteronism in a neonate secondary to congenital hydrometrocolpos

Pseudohypoaldosteronism (PHA) due to obstructive uropathy, urinary tract infections and congenital urogenital malformations has been reported in the literature; however, there are no reports of PHA associated with hydrometrocolpos due to a common urogenital tract. Hydrometrocolpos is a condition resulting in distension of the vagina and uterus due to accumulation of secretions (other than blood), caused by increased oestrogenic stimulation and vaginal outflow obstruction. We report on a neonatal case of PHA caused by recurrent hydrometrocolpos presenting with vomiting and poor weight gain. There was significant hyponatraemia, hyperkalaemia, and anaemia requiring medical stabilisation prior to surgery. The mechanism by which PHA occurs in obstruction involves renal tubular dysfunction due to pressure from hydronephrosis and the release of intrarenal cytokines. In addition, there is an immature or resistant renal tubular responsiveness to aldosterone during infancy. Clinicians should be aware of this uncommon but serious presentation.

Point-of-care ultrasound to evaluate volume status in severe hyponatremia

A 51-year-old man was hospitalised for severe hyponatremia. Initial history and physical examination suggested hypovolemia, and he was treated with normal saline at 100 mL/hour. After several days, his hyponatremia failed to improve, and then worsened without resolution of presenting ataxia and fatigue. He had no new complaints including no cough or orthopnea. He had no jugular venous distention or oedema, and his lungs were clear to auscultation. Point-of-care ultrasound was used, revealing a distended inferior vena cava, pulmonary oedema and pleural effusion, suggesting hypervolemia. Based on ultrasound findings, we treated with 60 mg oral torsemide two times per day. Hyponatremia resolved without complication within 48 hours. In this case, physical examination failed to recognise volume status change from hypovolemic to hypervolemic, increasing hospitalisation and morbidity. The point-of-care ultrasound proved to be an accurate tool for proper volume evaluation, and may be used as an adjunct to physical examination for hyponatremic patients.

Syndrome of inappropriate antidiuretic hormone associated with eosinophilic granulomatosis and polyangiitis

A 62-year-old man presented with classic signs and symptoms of eosinophilic granulomatosis and polyangiitis (EGPA, also known as Churg-Strauss syndrome)-mononeuritis multiplex, palpable purpura, hypereosinophilia, positive P-ANCA (perinuclear anti-neutrophil cytoplasmic antibodies) developed diffuse alveolar haemorrhage. The patient had longstanding mild hyponatraemia, but developed moderate and symptomatic hyponatraemia characteristic of the syndrome of inappropriate antidiuretic hormone. The patient's serum sodium returned to his baseline- mildly hyponatraemic, after initiation of treatment targeted towards EGPA.

BRASH syndrome

A 62-year-old woman with chronic kidney disease stage 4, sleep apnoea on continuous positive airway pressure and recent admission for acute-on-chronic diastolic heart failure presented to emergency room with weakness. She was hypotensive and had symptomatic bradycardia in the 30 s secondary to hyperkalaemia and beta-blockers, raising concern for BRASH syndrome. Antihypertensives were immediately held. Potassium-lowering agents (with calcium gluconate for cardiac stability) were begun, as were fluids and dopamine for vasopressor support. The patient was admitted to intensive care unit and electrophysiology was consulted. Over the next 2 days, the patient clinically improved: she remained off dopamine for over 24 hours; potassium levels and renal function improved; and heart rate stabilised in 60 s. The patient was eventually discharged and advised to avoid metolazone, bumetanide and carvedilol, with primary care provider and cardiology follow-up.

Colistin-induced acquired Bartter-like syndrome: an unusual cause of meltdown

Colistin-induced nephrotoxicity is commonly associated with elevation of serum creatinine level or a reduction of urine output. Uncommonly, tubulopathy associated with colistin has been reported. Here we present a unique case of a 46-year-old man who developed polyuria, hypokalaemia, hypocalcaemia, hypomagnesemia and metabolic alkalosis after 3 days of therapy with intravenous colistimethate sodium. After ruling out other causes, a diagnosis of colistin-induced acquired Bartter syndrome was made. The patient required daily aggressive intravenous repletion of fluids and electrolytes. However, polyuria and metabolic abnormalities abated only after drug discontinuation.

Ventricular arrhythmia and tachycardia-induced cardiomyopathy in Gitelman syndrome, hypokalaemia is not the only culpable

Gitelman syndrome (GS) is an autosomal recessive tubulopathy recently implicated in cases with ventricular arrhythmias (VAs), the latter being considered linked to electrolytes' imbalance. However, a direct causal relationship is considered to be an oversimplification for a complex molecular dysfunction. Recent work has suggested a degree of microvascular dysfunction in patients with GS that might be attributed as a mechanism of arrhythmia. We report a case of GS presenting with VAs complicated by cardiomyopathy. The high load of premature ventricular contractions that were attributed to the hypokalaemia has masked the presence of the left ventricular (LV) outflow tract tachycardia. Her LV systolic function recovered after successful electrophysiology ablation procedure. Atrioventricular nodal re-entry tachycardia was discovered incidentally during the study and was ablated successfully.

Concomitant presentation of IgG4-negative idiopathic retroperitoneal fibrosis and Addison's disease

We describe a patient who was admitted to our medical centre with acute renal failure, hyponatraemia and hyperkalaemia. CT of the abdomen and pelvis showed a retroperitoneal mass with bilateral ureteral obstruction. Biopsy revealed fibrosis with inflammatory infiltrate, but rare IgG₄-positive plasma cells. After placement of bilateral pigtail nephrostomy catheters, renal failure improved but metabolic derangements remained. Morning serum cortisol level was equivocal, but with blunted response on cosyntropin stimulation testing indicating adrenal insufficiency. Serology for 21-hydroxylase antibodies was strongly positive, supporting the diagnosis of Addison's disease. In addition to nephrostomy catheters for obstructive uropathy, idiopathic retroperitoneal fibrosis was treated with mycophenolate mofetil. Physiological doses of hydrocortisone and fludrocortisone for Addison's disease were also initiated. The patient continues to be monitored for regression of the mass. Based on review of the literature, this is the first reported case of IgG₄-negative idiopathic retroperitoneal fibrosis presenting with autoimmune primary adrenal insufficiency.