Hyponatraemia – diagnostic difficulties in 2.5-year-old boy with nephrogenic syndrome of inappropriate antidiuresis. Case report (original) (raw)
Related papers
Journal of Maternal-Fetal and Neonatal Medicine, 2009
Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a recently described genetic cause of hyponatremia in male infants. Whether this X-linked condition could be detected in the adult or also could affect women is unknown. A large five-generation family was identified in which the recently described arginine-vasopressin receptor type 2 (AVPR2) mutation that is responsible for NSIAD was segregated. The proband was a 74-yr-old patient who had a syndrome of inappropriate antidiuresis and whose hyponatremia resisted administration of two AVPR2 antagonists. The phenotype of family members who carry the mutation was investigated. Patients with normal serum sodium were subjected to a water-load test. The previously reported activating missense R137C mutation in the AVPR2 gene in three hemizygous male and four heterozygous female individuals was identified. Except in one woman, spontaneous episodes of hyponatremia or abnormal water-load test were identified in all patients with the mutation, whether male or female. Skewed X inactivation was evidenced in the blood of the asymptomatic woman, which is compatible with preferential inactivation of her mutated allele. NSIAD is not limited to male infants. The diagnosis also should be considered in both male and female adults.
Difficulties in diagnosing the cause of hyponatraemia in an extremely premature boy
Pediatria Polska, 2018
We present the history of a nine-month-old male infant born prematurely with extremely low birth weight, who was admitted to the paediatric nephrology department with dehydration, acute kidney injury, hyponatraemia, hyperkalaemia, and metabolic acidosis. While the crucial first step in the diagnosis of hyponatraemia includes the assessment of the patient's fluid status, we focus in the discussion on the causes, diagnosis, and treatment of hypovolemic hyponatraemia. With the notable exception of congenital adrenal hyperplasia (CAH) and other primary adrenal diseases, in which there is a deficiency in aldosterone synthesis, many other salt-losing disorders share the common feature of inducing secondary hyperaldosteronism. In the presented case hyponatraemia was caused by NEC-related ileostomy with, typically, hyperkalaemia despite secondary hyperaldosteronism. The clinical picture can be very similar to pseudohypoaldosteronism type 1 (PH 1), with the renal handling of sodium being the key differentiating feature.
Hyponatremia and hypernatremia: disorders of water balance
The Journal of the Association of Physicians of India, 2009
Total body water and tonicity is tightly regulated by renal action of antidiuretic hormone (ADH), renin-angiotensinaldosterone system, norepinephrine and by the thirst mechanism. Abnormalities in water balance are manifested as sodium disturbances -hyponatremia and hypernatremia. Hyponatremia ([Na + <136meq/l]) is a common abnormality in hospitalized patients and is associated with increased morbidity and mortality. A common cause of hyponatremia is impaired renal water excretion either due to low extracellular fluid volume or inappropriate secretion of ADH. Clinical assessment of total body water and urine studies help in determining cause and guiding treatment of hyponatremia. Acute and severe hyponatremia cause neurological symptoms necessitating rapid correction with hypertonic saline. Careful administration and monitoring of serum [Na + ] is required to avoid overcorrection and complication of osmotic demyelination. Vasopressin receptor antagonists are being evaluated in management of euvolemic and hypervolemic hyponatremia. Hypernatremia ([Na + ]>145meq/l) is caused by primary water deficit (with or without Na + loss) and commonly occurs from inadequate access to water or impaired thirst mechanism. Assessment of the clinical circumstances and urine studies help determine the etiology, while management of hypernatremia involves fluid resuscitation and avoiding neurological complications from hypernatremia or its correction. Frequent monitoring of [Na + ] is of paramount importance in the treatment of sodium disorders that overcomes the limitations of prediction equations. ©
Neonatal onset of nephrogenic syndrome of inappropriate antidiuresis
Pediatric Nephrology, 2008
This paper describes the manifestaton in a child of a new syndrome characterized by unusual, severe, persistent hyponatremia associated with hyposmolarity, euvolemia, inappropriately concentrated urine and elevated natriuresis. This is the fourth case of this syndrome reported to date, and the first to be reported in a neonate. The clinical features resemble those typically observed in patients with inappropriate antidiuretic hormone secretion, although high arginine vasopressin (AVP) levels are lacking. The findings led the authors to hypothesise a nephrogenic syndrome of inappropriate antidiuresis (NSIAD). The previously described R137C gain-of-function mutation was detected by means of mutation analysis of the V2R gene. Our results indicate that NSIAD is already present during the neonatal period and that molecular analysis of the V2R receptor should therefore be carried out, in all newborns with prolonged euvolemic hyponatremia with hypo-osmolarity, high urinary sodium and normal/low or undetectable AVP levels.
Nephrogenic syndrome of inappropriate antidiuresis
Nephrology Dialysis Transplantation, 2010
The nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a rare, recently recognized disorder in water balance affecting not only infants but also adults. A new molecular mechanism responsible for NSIAD has recently been identified: a gain of function of the arginine vasopressin (AVP) receptor type 2 (V2R), causing the constitutive activation of the receptor. Clinical presentation and laboratory findings of NSIAD resemble those of the syndrome of inappropriate secretion of antidiuretic hormone and consist of hyponatraemia, seizures and the lack of urinary dilution; however, the AVP levels in plasma are undetectable or very low. An elucidation of the pathophysiology of this syndrome will provide more insight into the action of AVP. An effective treatment of NSIAD is available. It consists of fluid restriction and administration of oral urea. Reported experience with furosemide treatment in NSIAD is still lacking.
Pediatric Nephrology, 2018
Nephrogenic syndrome of inappropriate antidiuresis (NSIAD), first described in 2005, is a rare genetic X-linked disease, presenting with hyponatremia, hyposmolarity, euvolemia, inappropriately concentrated urine, increased natriuresis, and undetectable or very low arginine-vasopressine (AVP) circulating levels. It can occur in neonates, infants, or later in life. NSIAD must be early recognized and treated to prevent severe hyponatremia, which can show a dangerous impact on neonatal outcome. In fact, it potentially leads to death or, in case of survival, neurologic sequelae. This review is an update of NSIAD 12 years after the first description, focusing on reported cases of neonatal and infantile onset. The different molecular patterns affecting the AVP receptor 2 (V2R) and determining its gain of function are reported in detail; moreover, we also provide a comparison between the different triggers involved in the development of hyponatremia, the evolution of the symptoms, and modality and efficacy of the different treatments available.
Hyponatremia and hypernatremia are disorders of water balance and are very common especially in hospitalized patients. Hyponatremia is defined as serum sodium < 135 mEq/l (mmol/l). Hypernatremia is defined as serum sodium > 145 mEq/l (mmol/l). Most of hyponatremia and hypernatremia cases are mild but they are clinically significant. Even mild hyponatremia is associated with many non-specific symptoms and may quickly evolve into severe hyponatremia. Quick and uncontrolled correction of chronic hyponatremia may lead to severe clinical consequences. Hypernatremia is associated with high mortality due to associated co-morbid conditions even after successful correction. The following review will cover the most salient aspects of hyponatremia and hypernatremia and provide the clinician with a practical guide to the diagnosis and treatment. Complex tables, flow charts and algorithms will be avoided. The review will conclude with clinical cases that apply the discussed principles in diagnosis and treatment.
Urine sodium composition in ambulatory healthy children: hypotonic or isotonic?
Pediatric Nephrology, 2008
A controversy exists in the literature as to the most appropriate sodium concentration for maintenance parenteral fluids. The purpose of this study was to evaluate urinary sodium composition in otherwise healthy children in order to help determine if 0.9% sodium chloride (NaCl) would be an appropriate parenteral fluid. The composition of urinary sodium was evaluated over 24 h in 100 otherwise healthy children aged 3-18 years referred to a pediatric nephrology outpatient clinic for hematuria or proteinuria. The average urine sodium concentration was 158±59 mEq/l, similar to that of 0.9% NaCl (154 mEq/l). Urine sodium excretion was 2.9± 1.3 mEq/kg per 24 hours, and urine flow rate was 0.9±0.4 ml/ kg per hour. It was concluded that healthy children generate free water via the excretion of a hypertonic urine. It is unlikely that 0.9% NaCl would result in hypernatremia when administered in parenteral fluids.