Hyponatremia in pregnancy
Nadia Barghouthi, Jessica Perini in Endocrine Diseases in Pregnancy and the Postpartum Period, 2021
Mild hyponatremia is a common finding in pregnancy. Both serum osmolality and sodium levels drop by a predictable amount due to hormonal, renal, and vascular effects leading to a reset osmostat. Mild, euvolemic hyponatremia is common in pregnancy secondary to a reset osmostat, which is a change in the set point of anti-diuretic hormone (ADH) release and stimulation of thirst. The syndrome of inappropriate ADH can occur in pregnancy, typically associated with nonosmotic stimuli such as hypovolemia, nausea, and pain, promoting the release of ADH. Under nonpregnant conditions, serum osmolality is maintained within a narrow range of 275–295 mOsm/L. Hyponatremia during labor is now thought to be primarily associated with overdrinking. Increased free water intake either due to stress or social encouragement may overcome the kidney’s ability to excrete the water load.
Hyponatraemia
Sherif Gonem, Ian Pavord in Diagnosis in Acute Medicine, 2017
Hypotonic hyponatraemia should be considered a disorder primarily of water balance rather than of sodium balance. The majority of cases of hyponatraemia are caused by an excess of total body water relative to total body sodium. This excess water is distributed equally throughout all of the body compartments, lowering the concentration of all solutes and resulting in hyponatraemia with a low serum osmolality. The independence of sodium and water balance is highlighted by the fact that they are regulated by two separate endocrine control mechanisms. Sodium balance, and thus extracellular volume, is controlled by the renin–angiotensin system, whereas water balance, and thus body fluid osmolality, is controlled by the antidiuretic hormone– thirst axis. A pure excess of free water without derangement of sodium balance may occur as a result of a primary increase in water intake.
Central nervous system lesions
E Glucksman in MCQs in Neurology and Neurosurgery for Medical Students, 2022
Central pontine myelinolysis is a fatal complication that is due to rapid correction of hyponatraemia. An acute onset of paralysis, dysarthria, dysphagia, diplopia and eventual loss of consciousness may occur following correction. Clinical vasospasm can present with a reduced Glasgow Coma scale score or delayed ischaemic neurological deficit (stroke) and is considered to occur as a result of irritation of the blood vessels by the subarachnoid blood. If the mass enlarges further, it exceeds the critical level and the Intracranial Pressure (ICP) then increases very rapidly as auto-regulation fails. In these patients, mannitol (a diuretic) can be used to reduce the ICP prior to more definitive neurosurgical intervention. If the mass enlarges further, it exceeds the critical level and the ICP then increases very rapidly as auto-regulation fails. In these patients, mannitol (a diuretic) can be used to reduce the ICP prior to more definitive neurosurgical intervention.
Treatment of hyponatremia: the role of lixivaptan
Published in Expert Review of Clinical Pharmacology, 2014
George Liamis, Theodosios D Filippatos, Moses S Elisaf
Hyponatremia is the most common electrolyte disorder and is associated with serious neurologic sequelae and increased mortality. Conventional treatment options for hyponatremia, such as fluid restriction, hypertonic saline, loop diuretics, demeclocycline or urea, are ineffective in the long-term. The present review considers the role of vasopressin receptor inhibitors (vaptans), focusing on lixivaptan, in the treatment of patients with euvolemic or hypervolemic hyponatremia. Lixivaptan is an oral selective V2 receptor inhibitor, which produces a significantly greater increase of serum sodium levels compared with placebo. These effects seem promising, but more trials are needed to examine whether the beneficial effect of lixivaptan on serum sodium concentration translates into clinical benefit in these patient populations.
Hyponatremia induced by antiepileptic drugs in patients with epilepsy
Published in Expert Opinion on Drug Safety, 2017
Introduction: Hyponatremia induced by antiepileptic drugs (AEDs) has not received sufficient attention in patients with epilepsy. Areas covered: We reviewed articles between 1966 and 2015 about hyponatremia as an adverse effect of AEDs in patients with epilepsy. The incidence, clinical symptoms, onset times of AEDs-induced hyponatremia are discussed in detail, as are the risk factors associated with AEDs-induced hyponatremia and mechanisms underlying its development. We also briefly describe strategies for treating AED-induced hyponatremia. Expert opinion: Carbamazepine and oxcarbazepine are the most common AEDs which induce hyponatremia in patients with epilepsy. Recently, other AEDs, such as eslicarbazepine, sodium valproate, lamotrigine, levetiracetam and gabapentin have also been reported to cause hyponatremia. Understanding the risk associated with AED-induced hyponatremia and taking effective measures to combat serum sodium imbalance induced by AED therapy are necessary.
Maternal and neonatal hyponatremia during labor: a case series
Published in The Journal of Maternal-Fetal & Neonatal Medicine, 2019
Neta Solomon, Ariel Many, Rotem Orbach, Dror Mandel, Shiri Shinar
Background: Hyponatremia during labor and delivery may result in severe maternal and neonatal sequelae. Our aim was to describe the direct effect of hyponatremia in labor on pregnancy outcome. Methods: A case series of parturients diagnosed with hyponatremia during labor and their neonates. Clinical presentation, laboratory workup, and maternal and neonatal outcomes are presented. Results: Four parturients and their corresponding six neonates were diagnosed with hyponatremia. Of these, two cases were caused by water intoxication and two were preeclampsia induced. While two were identified due to maternal or neonatal symptoms, two were diagnosed by routine laboratory testing. In all cases, low maternal sodium resulted in similarly low neonatal sodium. Neonatal symptoms included respiratory distress syndrome (RDS), lethargy, and jaundice. Conclusion: Psychogenic drinking during labor and preeclampsia may predispose to maternal hyponatremia, resulting in neonatal hyponatremia. Early recognition and treatment can prevent further maternal deterioration and adverse neonatal sequelae.
Related Knowledge Centers
- Electrolyte Balance
- Homeostasis
- Blood Plasma
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- Water
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