Etiologies can be categorized under the 3 main volume statuses. Mannitol hyponatremia this makes elegant sense because the whole point of mannitol therapy is to attract water out of the intracellular compartment, so as to reduce the oedema in brain tissue. Fortunately, it is a disorder in which diagnosis and treatment rest firmly on physiologic principles. Hyponatremia s effects can be insidious, particularly in patients with heart failure, cirrhosis, and pneumonia. Pathophysiologic approach to hyponatremia jama internal.
Pathophysiology, diagnosis and management of hyponatremia. An algorithm for investigations and treatment is provided at the end of this article. Not graded estimates of the serum sodium concentration corrected for the presence of. As siadh remains a diagnosis of exclusion other potential causes. Clinical practice guideline on diagnosis and treatment of. This complication can be serious, with delirium, seizure, or even death. Investigators from the department of pediatrics at the university of udine school of medicine, udine, italy, conducted a prospective, observational study to determine the incidence and risk factors for hyponatremia in children with communityacquired pneumonia. Hyponatremia without hypotonicity can occur in patients with hyperglycemia, in patients who have accumulated exogenous effective osmoles, and in patients with pseudohyponatremia caused by extreme hyperlipidemia or hyperproteinemia. Most other causes of hyponatremia also result in hypoosmolality, and the manifestations attributed to low serum sodium concentrations cannot be separated from those occurring. Hyponatremia and hypernatremia symptom to diagnosis. Although childhood cases can occur in the ambulatory setting, most occur among inpatients, with the condition affecting approximately 25% of hospitalized children. Medications are often the cause of acute or chronic hyponatremia. Despite similar serum sodium concentrations, clinical manifestations can range.
Proper interpretation of the various laboratory tests helps to differentiate the various types of hyponatremia. Hyponatremia occurs when the concentration of sodium in your blood is abnormally low. Judicious use of vaptans may help in treatment of hyponatremia. Hypotonic hyponatremia has multiple etiologies, but only two general mechanisms of development, defective water excretion, usually. Water homeostasis is regulated mainly by two organs. Hyponatremia in children with pneumonia american academy. Hyponatremia is common in both inpatients and outpatients. In summary, in symptomatic chronic hyponatremia of siadh i. Hyponatremia has complex pathophysiology, is frequent and has potentially severe clinical manifestations, and its treatment is associated with high risks. Drinking too much water or receiving too much fluid through an iv. Pathophysiology, diagnosis and clinical management.
Hyponatremia due to heart failure is usually chronic and is not a lifethreatening process. Treatment varies with the nature of onset acute or chronic, severity and symptoms. Severe hyponatremia is a rare complication of preeclampsia. The reason that hyponatremia requires treatment is that the relative excess. Intense and prolonged exercise that causes excessive sweating.
Pathophysiology, impact, and management of hyponatremia. Treatment of severe hyponatremia american society of. Diagnosis and treatment of hyponatremia american journal. Syndrome of inappropriate secretion of antidiuretic. This material may not otherwise be downloaded, copied, printed, stored, transmitted or. Irrespective of the type, early diagnosis and treatment are of the utmost importance. Many medical illnesses, such as congestive heart failure, liver failure, renal failure, or pneumonia, may be associated with hyponatremia. What are the risk factors, symptoms and pathophysiology of thiazideinduced hyponatremia. A hospital incidence of 1520% is common, while only 35% of patients who are hospitalized have a serum sodium level of less than meq l. It is generally defined as plasma sodium of less than 5 mmoll. Hyponatremia, a serum sodium concentration less than 5 meql is one of the most common electrolyte disorders encountered in clinical medicine. Hyponatremia as a prognostic and predictive factor in cancer patients. Describe the major causes of hyponatremia in children. Hyponatremia is defined as a serum sodium level of less than 5 mmoll.
Hyponatremia happens when too much sodium leaves your body, or when more water than sodium stays in your blood. If the level of sodium in the fluids outside the cells goes down, the fluids enter the cells causing the cells to swell. Measuring the serum osmolality, urine sodium concentration and urine osmolality will help differentiate among the possible causes. Sodium is an electrolyte, and it helps regulate the amount of water thats in and around your cells.
Hyponatremia typically happens for the first few hours in a person with normal kidneys. Apply clinical tests to identify children with hyponatremia to determine the underlying condition. Any of the following conditions can lead to hyponatremia. The varied etiologies of hyponatremia and the multiple formulae for its correction make it a nightmare for the students and physicians alike. Pathophysiology in siadh, receptors are overridden with the production and secretion of adh that is not appropriate for. Downloaded free from on friday, december 19, 2014, ip. When a euvolemic patient receiving a thiazide manifests hyponatremia, it should be termed thiazideassociated hyponatremia tah. Hyponatremia can be hypertonic, isotonic or hypotonic. Hyponatremia is one of the most commonly encountered electrolyte disorders among both adults and children. Within minutes after the development of hypotonicity, water gain causes swelling of the brain and a decrease in osmolality of the brain. After discussing the pathophysiology of shock, engage your learners to identify 4 primary categories of shock. Laboratory data and a physical exam will help assess patients volume status. The volume status will help determine the etiology of the.
Hyponatremia is a common, multifactorial clinical condition. Normal saline forms the mainstay of treatment for hypovolemic hyponatremia while 3% nacl and fluid restriction are important for euvolemic. Causes of hyponatremia poor oraliv intake over hydration paraneoplastic syndrome from malignancy medications or street drugs adrenal insufficiency. Sodium homeostasis is essential for maintaining intravascular volume and is tightly linked to water balance. Vasopressin dysregulation and hyponatremia in hospitalized patients. The thiazide may be directly responsible, termed thiazideinduced hyponatremia by the hyponatremia registry, which encompasses more than 5,000 patients with serum sodium levels.
Psychotropicinduced hyponatremia mdedge psychiatry. Plasma osmolality has a role in the pathophysiology of hyponatremia. In hyponatremia, one or more factors ranging from an underlying medical condition to drinking too much water cause the sodium in your body to become. Hyponatremia results from the inability of the kidney to excrete a water load or excess water intake. Most common disorder of electrolytes encountered in clinical practice, occurring in 22% of hospitalized patients. Pathophysiology, impact, and management of hyponatremia zachary v. Challenge your learners to list different causes within each category of shock and the impact on cvppreload, co and svr. Antidepressants and hyponatremia the american journal of. Download fulltext pdf download fulltext pdf pathophysiology of hyponatremia in children article pdf available in frontiers in pediatrics 5 october 2017 with 645 reads. Hyponatremia in the physical states of extracellular fluid ecf volume contraction and expansion can be easy to. Sodium in the body fluid is used to maintain electrolyte balance, blood pressure and for the working of muscles and nerves. Prognostic and predictive role of hyponatremia in cancer.
Plasma water volume is regulated mainly by the secretion of an antidiuretic hormone adh and by the thirst mechanism. Hyponatremia take home messages hypona results from adhinduced retention of ingested or infused water. Principles of management of severe hyponatremia journal. Unfortunately, as is true of all electrolyte disturbances, there are no randomized trials to guide the treatment of this challenging. Identify children at risk for syndrome of inappropriate secretion of antidiuretic hormone siadh and modify fluid management to avoid development of hyponatremia. Effects of hyponatremia on the brain and adaptive responses. The reason that hyponatremia requires treatment is that the relative excess of water lowers serum osmolality of. Electrolyte disturbances pathophysiology, diagnosis and clinical management hyponatremia hypernatremia bert bammens uz leuven ku leuven 1. Hyponatremia is a water balance disorder in which the ratio between sodium and water is disturbed.
The treatment for hyponatremia is chosen on the basis of duration and symptoms. Hyponatremia has been reported in up to 30% of elderly patients in nursing homes 30% of depressed patients on ssri common causes include diuretic use, diarrhea, heart failure, and renal disease. Hyponatremia is an important and common clinical problem. Treatment should always respect the how long hypona took to develop and the pathophysiology of the diseases. Hyponatremia is defined as a serum sodium level of less than 5 meql and is considered severe when the serum level is below 125 meql. The pattern of urinary chemistries low sodium concentration and high osmolality is indistinguishable between hypovolemic hyponatremia from extrarenal causes and hypervolemic hyponatremia.
Proper understanding of the pathophysiology of hyponatremic states is essential for establishing the correct diagnosis and. Hyponatremia and hypernatremia are classified based on volume status hypovolemia, euvolemia, and hypervolemia. Thirst is sensed by osmoreceptors located in the hypothalamus and leads to the release of antidiuretic hormone vasopressin from the posterior pituitary. Hyponatremia is defined as serum sodium concentration hyponatremia is long but the diagnostic approach can be easily framed in a few simple steps. Causes of hypernatremia involve a net gain of sodium or a loss of free water. Treatment of hypotonic hyponatremia often challenges clinicians on many counts. This disorder may be present on admission to the intensive care setting or develop during hospitalization as a result of treatment or multiple comorbidities. The management of hyponatremia norbert lameire, 2015. Hypotonic hyponatremia has multiple etiologies, but only two general mechanisms of development, defective water excretion, usually because of elevated serum vasopressin levels, or. The causes of hyponatremia without hypotonicity are. The guidelines for management of hyponatremia have been revised recently and, in addition new agents vaptans have become available in market for. It is well known that antidepressants can cause hyponatremia, particularly in elderly patients. Hyponatremia and hypernatremia may result from changes in water balance in the body and sodium levels in the blood.
Hyponatremia is usually defined as a plasma sodium level hyponatremia results from the inability of the kidney to excrete a sufficient amount of fluid, or is due to excessive fluid intake. Pathogenesis and treatment of hyponatremia electrolytes. Pdf hyponatremia is a common electrolyte disorder in children. In the classic study by fabian et al,1 paroxetine, a selective serotonin reuptake inhibitors ssri, was found to induce hyponatremia in 12% of elderly patients within a mean duration of 9 days.
Pdf pathophysiology of hyponatremia in children researchgate. Pdf hyponatremia is an important and common clinical problem. Rather, there is usually a fairly stable sodium of 1205 mm. Hyponatraemia with a measured osmolality causes of nonhypotonic hyponatraemia as listed in table 3. Hypona is a bad actor, especially when associated with a chronic disease. Most of the individual causes of hyponatremia are discussed manifestations of hyponatremia and hypernatremia in adults view in chinese patients with acute hyponatremia generally reflects the severity of cerebral overhydration, which is related to the degree of hyponatremia. Hyponatremia and hypernatremia are classified based on volume. Of 8 cases reported in the literature, the postulated mechanism was hypervolemic hyponatremia in 5 and syndrome of inappropriate secretion of antidiuretic hormone siadh in the remaining 3. Frontiers pathophysiology of hyponatremia in children. Hyponatremia is a common electrolyte disorder in children. Pathophysiology and management of preeclampsiaassociated. Hyponatremia is the most frequently occurring electrolyte abnormality and can lead to lifethreatening complications. Hyponatremia, the most common electrolyte disorder encountered, is associated with increased morbidity and mortality even in its milder forms. Hyponatremia may be euvolemic, hypovolemic or hypervolemic.
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