Materiały źródłowe

• #1 Hyponatremia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK470386/

  Hyponatremia is defined as a serum sodium concentration of less than 135 mEq/L but can vary to a small extent in different laboratories. Hyponatremia is a common electrolyte abnormality caused by an excess of total body water when compared to total body sodium content. […] This activity explains when this condition should be considered on differential diagnosis, articulates how to properly evaluate for this condition, and highlights the role of the interprofessional team in caring for patients with this condition. […] The following steps may be performed while evaluating a patient with suspected hyponatremia: Step 1: Plasma Osmolality (275 mOsm to 290 mOsm/kg). It can help differentiate between hypertonic, isotonic, and hypotonic hyponatremia. True hyponatremic patients are hypotonic. If the patient is hypotonic, then go to step 2. […] Step 2: Urine Osmolality. Urine osmolality less than 100 mOsm/kg indicates primary polydipsia or reset osmostat. Urine osmolality greater than 100 mOsm/kg usually indicates a high ADH state; go to step 3.

• #1 Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia | AAFP

  https://www.aafp.org/pubs/afp/issues/2015/0301/p299.html

  Hyponatremia and hypernatremia are common findings in the inpatient and outpatient settings. Sodium disorders are diagnosed by findings from the history, physical examination, laboratory studies, and evaluation of volume status. […] Hyponatremia is a common electrolyte disorder defined as a serum sodium level of less than 135 mEq per L. […] The diagnostic workup should include a history and physical examination with specific attention to cardiac, cancer, pulmonary, surgical, endocrine, gastrointestinal, neurologic, and renal histories. […] Laboratory tests include a complete metabolic panel and urinary sodium and creatinine levels. […] The diagnosis of reset osmostat may be aided using fractional excretion of urate in nonedematous patients who have hyponatremia that does not respond to usual treatment. […] The treatment of hypernatremia involves treating the underlying cause and correcting the water deficit.

• #1 Hyponatraemia: Symptoms and Treatment | Doctor

  https://patient.info/doctor/hyponatraemia-pro

  Hyponatraemia is the most common electrolyte abnormality encountered in clinical practice. […] Hyponatraemia is associated with multiple poor clinical outcomes and is often managed suboptimally because of inadequate assessment and investigation. […] Clinical examination should be focused on fluid status, including blood pressure (BP), postural deficit, heart rate, peripheral oedema and central venous filling, as well as chest and heart examination. […] Clinical assessment should identify potential causes, establish the severity of hyponatraemia and determine if the patient is hypovolaemic, euvolaemic, or hypervolaemic. […] SIADH needs to be confirmed by results of paired serum and urine samples: serum hypo-osmolality is 275 mOsm/kg, and urine osmolality 100 mOsm/kg and sodium 30 mmol/L, in the absence of hypovolaemia, hypervolaemia, adrenal or thyroid dysfunction and use of diuretics.

• #1 Hyponatremia – Symptoms, diagnosis and treatment | BMJ Best Practice US

  https://bestpractice.bmj.com/topics/en-us/1214

  1st tests to order include serum sodium concentration, serum electrolytes, BUN, creatinine, and glucose, serum osmolality, urine sodium concentration, urine osmolality, urine electrolytes, urine flow rate, electrolyte-free water excretion, fractional excretion of sodium, thyroid-stimulating hormone, serum cortisol level and/or adrenocorticotropic hormone test, and serum lipids and serum protein electrophoresis. […] Tests to consider include CT brain, chest, abdomen/pelvis and other tests targeted at evaluating the underlying cause.

• #1 Hyponatremia made easy—a simple diagnostic algorithm | Medmastery

  https://www.medmastery.com/magazine/hyponatremia-made-easya-simple-diagnostic-algorithm?srsltid=AfmBOoqUL0PIwb_K8DnD4qPsVx9BVm01jqhYIm4p4XQlzdzw-JhmvBE-

  Hyponatremia diagnosis. So, the diagnosis of hyponatremia is really trivial. All you need to do is find a blood test with a sodium less than 135 and then you have your diagnosis of hyponatremia. But usually what people are talking about when they say what’s the diagnosis is what is the etiology? What is driving that low sodium? What’s the diagnosis behind the low sodium? And so, we can use an algorithmic approach to get that answer. […] And so, if once you have a sodium of 135, you have a diagnosis of hyponatremia then you want to check the serum osmolality, okay. So, that serum osmolality is low then you have true hyponatremia. If it’s normal, you have pseudohyponatremia. This is the lab error, due to high fats or high proteins in the blood. And if you have a high osmolality, we have what we were calling a factitious hyponatremia where the sodium is truly low but it doesn’t have the same implications as the true hyponatremia.

• #1 Hyponatremia; Current Diagnosis and Treatment

  https://turkjnephrol.org/en/hyponatremia-current-diagnosis-and-treatment-135913

  Hyponatremia is the most common electrolyte abnormality encountered in clinical practice. The symptoms of hyponatraemia are largely dependent on the rapidity of the development of hyponatraemia. Acute symptomatic hyponatremia is a serious clinical situation. The pathogenesis of hyponatremia has been found to occur secondary to the nonosmotic secretion of ADH in over 95% of cases. In other words, hyponatremia caused by more water imbalance than sodium imbalance in the majority of cases. Pseudohyponatremia(elevation of lipids or proteins in plasma causing artifactual decrease in serum sodium concentration) and translocational hyponatremia(the additional solutes in plasma such as glucose, mannitol and radiographic contrast agent causing osmotic shift of water from intracellular fluid to extracellular fluid) that are not associated excess are excluded on the first step in the differential diagnosis of hyponatraemia. While only fluid restriction is sufficient for treatment of asymptomatic patients, emergency treatment should be given in symptomatic patients. Recently ADH receptor antagonists have been used as an alternative treatment of saline infusion in the treatment of euvolemic and hypervolemic hyponatremia. Correction rate of sodium should be 0,5-1mEq/L/h in the treatment of hyponatremia. Rapidly correction should be avoided in hyponatraemia, because it can lead to celebral hemorrhage and central pontine myelinolysis.

• #1 Hyponatremia made easy—a simple diagnostic algorithm | Medmastery

  https://www.medmastery.com/magazine/hyponatremia-made-easya-simple-diagnostic-algorithm?srsltid=AfmBOoqUL0PIwb_K8DnD4qPsVx9BVm01jqhYIm4p4XQlzdzw-JhmvBE-

  Driving down into true hyponatremia, the next step is to check the urine osmolality or the urine specific gravity. And what we’re trying to do is we’re trying to determine if there is much ADH activity going on. You can think of urine osmolality as being an ADH dipstick. If there is low urine osmolality, the lower the more accurate this is, you’re going to have ADH independent disease, okay. […] These are due to low solute diets and they really respond quite briskly to IV fluids. […] The renal failure patients, these are the patients that are on dialysis or very, very low urine outputs. They will have the urine osmolality as close to 300. These are kidneys that are so sick, they’re not able to concentrate or dilute urine. […] Moving to the other side of the fence, we have the ADH dependent hyponatremias. These patients will have high osmolalities and again, the higher the osmolality that you measure in the urine, the more accurate this diagnosis is going to be.

• #1 Hyponatremia: Practice Essentials, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/242166-overview

  Three laboratory tests are essential in the evaluation of patients with hyponatremia: serum osmolality, urine osmolality, and urinary sodium concentration. Together with the history and the physical examination, those tests help to establish the primary underlying etiologic mechanism in an algorithmic fashion. […] Serum osmolality readily differentiates true hyponatremia (hypotonic hyponatremia) from pseudohyponatremia. […] Urine osmolality helps differentiate between conditions associated with the presence or absence of antidiuretic hormone (ADH), also called arginine vasopressin (AVP). […] Urinary sodium concentration helps to differentiate hyponatremia secondary to hypovolemia or ineffective intravascular volume status from syndrome of inappropriate antidiuretic hormone secretion (SIADH).

• #1 Diagnosis and Treatment of Hyponatremia: Compilation of the Guidelines

  https://pmc.ncbi.nlm.nih.gov/articles/PMC5407738/

  The initial differentiation in hypotonic and nonhypotonic hyponatremia is important, because management is different. […] The United States guideline subsequently divided hypotonic hyponatremia into hypovolemic, euvolemic, and hypervolemic hyponatremia. […] Two additional diagnostic tests for hyponatremia merit discussion, including a trial of volume expansion and the fractional uric acid excretion (FEUA). […] A trial of volume expansion with isotonic saline can be used to diagnose hypovolemic hyponatremia. […] The kidneys will respond to hypovolemia or a low effective arterial blood volume with sodium retention, UNa30 mmol/L can be used to identify both hypovolemic and hypervolemic hyponatremia. […] The European guideline committee proposed an algorithm that prioritizes UOsm and UNa over volume status.

• #1 Hyponatremia – Wikipedia

  https://en.wikipedia.org/wiki/Hyponatremia

  The history, physical exam, and laboratory testing are required to determine the underlying cause of hyponatremia. A blood test demonstrating a serum sodium less than 135 mmol/L is diagnostic for hyponatremia. […] The history and physical exam are necessary to help determine if the person is hypovolemic, euvolemic, or hypervolemic, which has important implications in determining the underlying cause. An assessment is also made to determine if the person is experiencing symptoms from their hyponatremia. These include assessments of alertness, concentration, and orientation. […] False hyponatremia, also known as spurious, pseudo, hypertonic, or artifactual hyponatremia is when the lab tests read low sodium levels but there is no hypotonicity. […] True hyponatremia, also known as hypotonic hyponatremia, is the most common type. It is often simply referred to as „hyponatremia.” Hypotonic hyponatremia is categorized in 3 ways based on the person’s blood volume status. Each category represents a different underlying reason for the increase in ADH that led to the water retention and thence hyponatremia.

• #1 Hyponatremia Workup: Laboratory Studies, Imaging Studies

  https://emedicine.medscape.com/article/242166-workup

  Serum uric acid levels can be important supportive information; they are typically reduced in SIADH and in salt wasting. […] Thyroid-stimulating hormone (TSH) and serum cortisol levels should be measured if hypothyroidism or hypoadrenalism is suspected. […] Head computed tomography (CT) scanning and chest radiography can be used to assess for an underlying etiology in select patients with suspected SIADH or cerebral salt wasting. […] A diffusion-weighted magnetic resonance imaging (MRI) scan can help evaluate patients suspected of osmotic demyelination syndrome (ODS).

• #1 Point-of-care ultrasound in Hyponatremia – NephroPOCUS

  https://nephropocus.com/2022/05/07/point-of-care-ultrasound-in-hyponatremia/

  Urine osmolality gives an idea about ADH activity. Beyond this, it is of not much help to distinguish between various causes. This is where physical examination (= POCUS) helps to objectively evaluate fluid status and narrows the differential. […] Basically, the most important thing that guides management is fluid status. The accuracy of conventional parameters such as weight, BNP, auscultation, checking for pedal edema, doctors feelings (I feel the patient is dry!) is limited. As POCUS is the new physical examination, lets see how we can use it to discern fluid status. […] Is there any evidence supporting POCUS use in hyponatremia? Yes, below is a table summarizing pertinent case reports published till date (May 2022). Click on the first author for the link. Is there any evidence, especially a randomized controlled trial demonstrating mortality benefit of using POCUS to evaluate hyponatremia? No, POCUS is only a diagnostic tool. Putting the probe on the body does not improve mortality, neither do auscultation nor touching the patient.

• #1 Diagnosis and Management of Hyponatremia | RECAPEM

  https://recapem.com/diagnosis-and-management-of-hyponatremia/

  Hyponatremia is a lab diagnosis and the level of serum sodium is diagnostic (i.e. 135 mmol/l). […] Traditional diagnostic algorithms often fail, because patients frequently have multifactorial hyponatremia (especially in critically ill patients). Therefore, patients have a tendency to break the rules and fall outside the boxes. Nonetheless, laboratory tests can often point us in the correct direction. Labs should always be combined with the history, medication evaluation, and physical examination. Obtaining following lab test are useful: […] Importantly SIADH is a diagnosis of exclusion. The originally proposed diagnostic criteria include: […] Effective serum osmolality 275mOsm/kg […] Urine osmolality 100mOsm/kg at some level of decreased effective osmolality […] Clinical euvolemia […] Urine sodium concentration 30mmol/l with normal dietary salt and water intake […] Absence of adrenal, thyroid, pituitary or renal insufficiency […] No recent use of diuretic agents.

• #1 The suspect – SIADH

  https://www.racgp.org.au/afp/2017/september/the-suspect-siadh

  Hyponatraemia is one of the most commonly encountered electrolyte abnormalities in general practice. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is an important but under-recognised cause. […] This article explores the presentation, investigation, diagnosis and management of SIADH. […] Diagnosis is made on the basis of clinical euvolaemic state with low serum sodium and osmolality, raised urine sodium and osmolality, and exclusion of pseudohyponatraemia and diuretic use. […] SIADH accounts for about one-third of all hyponatraemia presentations, yet remains commonly under-diagnosed and, therefore, under-managed. […] This article will focus on the diagnosis, investigation and management of hyponatraemia secondary to SIADH. […] Barrter and Schwartz describe the following criteria for the diagnosis of SIADH: decreased serum osmolality (275 mOsm/kg), increased urine osmolality (100 mOsm/kg), euvolaemia, increased urine sodium (20 mmol/L), no other cause for hyponatraemia (no diuretic use and no suspicion of hypothyroidism, cortisol deficiency, marked hyperproteinaemia, hyperlipidaemia or hyperglycaemia). […] Euvolaemic hyponatraemia with low serum sodium and osmolality, and raised urine osmolality in the absence of diuretic use or pseudohyponatraemia, are diagnostic of SIADH.

• #1 Evaluation of hyponatremia – Differential diagnosis of symptoms | BMJ Best Practice US

  https://bestpractice.bmj.com/topics/en-us/57

  In most cases, hyponatremia reflects hypotonicity or low effective osmolality. It is often iatrogenic and avoidable. […] Common causes of hyponatremia include true volume depletion, effective arterial volume depletion (e.g., congestive heart failure, cirrhosis), and medication-induced hyponatremia due to thiazide diuretics or antidepressants. […] Hyponatremia can also be classified according to its rate of onset. […] Acute hyponatremia is defined as hyponatremia with a duration of 48 hours. Chronic hyponatremia is defined as hyponatremia with a duration of at least 48 hours. Chronic hyponatremia is much more common than acute, and cases where the duration of hyponatremia is unclear should be considered to be chronic unless there is clinical evidence suggesting otherwise. […] Failure to correct hyponatremia can lead to permanent neurologic damage, as can correcting sodium levels too rapidly. […] When hyponatremia is chronic and the serum sodium concentration increases too rapidly, osmotic demyelination syndrome (ODS; also known as central pontine myelinolysis) may develop. ODS is characterized by altered mental status, reduced motor functioning, and/or abnormalities of balance.

• #1 Hyponatremia | Diagnosis & Disease Information – Renal and Urology News

  https://www.renalandurologynews.com/ddi/hyponatremia/

  Conditions related to sodium loss include the use of thiazide diuretics or infusion of saline in the presence of ADH. […] Water retention may due to the following conditions: Primary polydipsia; Late-stage renal failure; Congestive heart failure; Ascites; Nephrotic syndrome; Deficiency of aldosterone; Hypothyroidism; and SIADH. […] Many conditions are associated with inappropriate ADH secretion and thus can result in hyponatremia. […] How hyponatremia is treated depends on the underlying diagnosis and severity of symptoms. […] In general, sodium levels should be increased gradually to avoid osmotic demyelination syndrome. […] Acute hyponatremia with severe neurologic symptoms can be treated with a sodium infusion of 4 to 6 mmol/L over 4 to 6 hours. […] The total increase in sodium concentration should not exceed 6 to 12 mmol/L within 24 hours or 18 mmol/L within 48 hours.

• #1 Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia | AAFP

  https://www.aafp.org/pubs/afp/issues/2023/1100/sodium-disorders-hyponatremia-hypernatremia.html

  Hyponatremia and hypernatremia are electrolyte disorders that can be associated with poor outcomes. Hyponatremia is considered mild when the sodium concentration is 130 to 134 mEq per L, moderate when 125 to 129 mEq per L, and severe when less than 125 mEq per L. […] Physicians should identify the cause of a patient’s hyponatremia, if possible; however, treatment should not be delayed while a diagnosis is pursued. […] Management to correct sodium concentration is based on whether the patient is hypovolemic, euvolemic, or hypervolemic. […] Treating euvolemic hyponatremia includes restricting free water consumption or using salt tablets or intravenous vaptans. […] Hypervolemic hyponatremia is treated primarily by managing the underlying cause (e.g., heart failure, cirrhosis) and free water restriction.

• #1 Hyponatremia – Wikipedia

  https://en.wikipedia.org/wiki/Hyponatremia

  Chronic hyponatremia is when sodium levels drop gradually over several days or weeks and symptoms and complications are typically moderate. […] Acute hyponatremia is when sodium levels drop rapidly, resulting in potentially dangerous effects, such as rapid brain swelling, which can result in coma and death.

• #1 Hyponatremia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK470386/

  Treatment of hyponatremia depends upon the degree of hyponatremia, duration of hyponatremia, severity of symptoms, and volume status. […] The goal of correction: Correct sodium by no more than 10 mEq/L to 12 mEq/L in any 24-hour period. […] Symptoms depend upon the degree and chronicity of hyponatremia. Patients with mild-to-moderate hyponatremia (greater than 120 mEq/L) or a gradual decrease in sodium (greater than 48 hours) have minimal symptoms. […] Patients with severe hyponatremia (less than 120 mEq/L) or rapid decrease in sodium levels have multiple varied symptoms.

• #1 Hyponatremia – Diagnosis and Treatment : Emergency Care BC

  https://emergencycarebc.ca/clinical_resource/clinical-summary/hyponatremia-diagnosis-and-treatment/

  Hyponatremia is the most common electrolyte disorder in adults. 3-6% of patients presenting to the ED are hyponatremic. […] Lab investigations include electrolytes, glucose, creatinine/GFR, urea, urine osmolality, and urine sodium. LFT’s and BNP if clinically indicated. […] Acute hyponatremia = hyponatremia occurring in <48hrs. [...] If the acuity cannot be determined assume chronic. [...] Severity of symptoms reflects both rapidity of change and sodium level. [...] Treatment based on patient’s volume status (eg. orthostatic hypotension assessment, moisture of mucus membranes, peripheral edema, JVP, POCUS of IVC diameter, and collapsibility). [...] Mild to moderate: headache, nausea, vomiting, muscle cramps. [...] Severe symptoms: seizure, coma, delirium, altered level of consciousness.

• #1 Hyponatremia – Knowledge @ AMBOSS

  https://www.amboss.com/us/knowledge/hyponatremia/

  Hyponatremia is defined as a serum sodium concentration below 135 mEq/L. […] The cause of hyponatremia is determined by assessing the patient’s volume status and ability to retain sodium. […] Treatment involves careful correction of the sodium deficit and/or fluid imbalance. […] A rapid increase in the serum sodium concentration can have damaging osmotic effects (i.e., osmotic demyelination syndrome). […] Confirm hyponatremia: Repeat BMP. […] Exclude hyperglycemia: Check serum glucose. […] Check the serum osmolality (SOsm): first step in the evaluation of confirmed hyponatremia. […] Serum osmolality measurement is the first step in the evaluation of verified hyponatremia. […] Consider additional focused diagnostic evaluation to identify the underlying cause. […] In patients taking diuretics, urinary sodium concentrations should be interpreted with caution.

• #1 Hyponatremia: Causes, Symptoms, Diagnosis & Treatment

  https://my.clevelandclinic.org/health/diseases/17762-hyponatremia

  Healthcare providers use blood tests and urine (pee) tests to diagnose hyponatremia. Theyll check the levels of sodium, potassium, hormones and other substances in your body. Theyll also check how well your kidneys and liver are working. Depending on your symptoms, your provider might get imaging, like a CT scan or chest X-ray. […] Knowing which type of hyponatremia you have helps your healthcare provider diagnose the cause and determine treatment. […] Treatment for hyponatremia depends on the cause and what kind of hyponatremia you have. Treatments could include: Water intake restrictions, Adjustments to your medications (like stopping them or taking a different dosage), IV fluids, Medication that treat low sodium levels, like tolvaptan or conivaptan. […] Healthcare providers are careful not to overcorrect when treating hyponatremia. Increasing sodium levels in your body too quickly can cause life-threatening side effects, like central pontine myelinolysis or osmotic demyelination syndrome. These are types of brain damage. This is why its important to see a healthcare provider right away if you think you have hyponatremia.

• #1 Diagnosis and Treatment of Hyponatremia: Compilation of the Guidelines

  https://pmc.ncbi.nlm.nih.gov/articles/PMC5407738/

  Although the literature on this approach is limited, it offers a rational approach to prevent a rapid rise in SNa that may occur once hypovolemia has been corrected. […] Fenske et al. found that FEUA12% had the highest sensitivity and specificity to diagnose SIAD with or without diuretic use. […] Although both guidelines only briefly discuss copeptin, emerging data justify a brief discussion on the diagnostic utility of this novel marker. […] The two guidelines diverge in their recommendations regarding pharmacologic therapy for SIAD and hypervolemic hyponatremia. […] The United States guideline lists vaptans as one of the pharmacologic options, if fluid restriction has failed. […] The European guideline did not recommend vaptans in moderate hyponatremia. […] The average rise in SNa after 24 hours was 9.03.9 mmol/L. Excessive correction of hyponatremia (12 mmol/L per day) was observed in 23% of patients (all with profound hyponatremia), although none of them developed signs of ODS. […] Both guidelines recommend frequent monitoring of SNa during the active correction phase (i.e., all treatments except fluid restriction).

• #1 Hyponatremia – Knowledge @ AMBOSS

  https://www.amboss.com/us/knowledge/hyponatremia/

  The distinction between hypovolemia and euvolemia is usually difficult to make on examination alone; examination findings have low sensitivity and specificity. […] Monitor urine output closely (e.g., every hour). […] Measure serum sodium frequently (at least every 46 hours until 125 mEq/L). […] Sodium concentration should be increased by 46 mEq/L within 12 hours for patients with severe or moderately severe symptoms or acute hyponatremia.

• #1 Hyponatremia – Diagnosis and Treatment : Emergency Care BC

  https://emergencycarebc.ca/clinical_resource/clinical-summary/hyponatremia-diagnosis-and-treatment/

  Overcorrection = rise > 10mEq/L in the first 24hrs or 8mEq/L if the patient has chronic hyponatremia or sodium was initially <120mEq/L. [...] When overcorrection occurs: Discontinue treatment immediately. [...] Consult nephrologist, endocrinologist. [...] Consider desmopressin. [...] 2-4 micrograms every 8 hours IV. [...] Monitor sodium every hour.

• #1 Hyponatremia – Symptoms, diagnosis and treatment | BMJ Best Practice US

  https://bestpractice.bmj.com/topics/en-us/1214

  Hyponatremia is the most common electrolyte disorder encountered in clinical practice. […] Serum osmolality, urine osmolality, and urine sodium concentration help to determine the underlying cause. […] Hyponatremia is defined as a serum sodium concentration of 135 mEq/L (normal serum sodium concentration is in the range of 135-145 mEq/L). […] Hyponatremia is generally caused by an increase in renal water reabsorption due to release of vasopressin (arginine vasopressin also known as antidiuretic hormone) along with water intake, and can occur in situations of volume depletion, volume overload, or normal volume. […] This topic principally focuses on hypotonic (hypo-osmolar) hyponatremia, the most common type of hyponatremia. […] Key diagnostic factors include high fluid intake, fluid losses, history of diabetes mellitus, history of cirrhosis, nephrosis, congestive heart failure, nausea/vomiting, mild cognitive symptoms, altered mental status, seizures, coma, low urine output, weight changes, orthostatic hypotension, abnormal jugular venous pressure, poor skin turgor, dry mucus membranes, absence of axillary sweat, edema, rales or crackles on lung auscultation, and polyuria.

• #2 Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia | AAFP

  https://www.aafp.org/pubs/afp/issues/2015/0301/p299.html

  Hyponatremia and hypernatremia are common findings in the inpatient and outpatient settings. Sodium disorders are diagnosed by findings from the history, physical examination, laboratory studies, and evaluation of volume status. […] Hyponatremia is a common electrolyte disorder defined as a serum sodium level of less than 135 mEq per L. […] The diagnostic workup should include a history and physical examination with specific attention to cardiac, cancer, pulmonary, surgical, endocrine, gastrointestinal, neurologic, and renal histories. […] Laboratory tests include a complete metabolic panel and urinary sodium and creatinine levels. […] The diagnosis of reset osmostat may be aided using fractional excretion of urate in nonedematous patients who have hyponatremia that does not respond to usual treatment. […] The treatment of hypernatremia involves treating the underlying cause and correcting the water deficit.

• #2 Hyponatremia – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/hyponatremia/diagnosis-treatment/drc-20373715

  Your doctor will start by asking about your medical history and doing a physical examination. […] However, because the signs and symptoms of hyponatremia occur in many conditions, it’s impossible to diagnose the condition based on a physical exam alone. To confirm low blood sodium, your doctor will order blood tests and urine tests.

• #2 Diagnosis and Treatment of Hyponatremia: Compilation of the Guidelines

  https://pmc.ncbi.nlm.nih.gov/articles/PMC5407738/

  Hyponatremia is a common water balance disorder that often poses a diagnostic or therapeutic challenge. […] Diagnostically, the initial step is to differentiate hypotonic from nonhypotonic hyponatremia. Hypotonic hyponatremia is further differentiated on the basis of urine osmolality, urine sodium level, and volume status. […] Recently identified parameters, including fractional uric acid excretion and plasma copeptin concentration, may further improve the diagnostic approach. […] The United States guideline refrained from using a quality-of-evidence scoring system due to the limited evidence. Instead, the guideline was on the basis of expert panel recommendations, which relied on a critical evaluation of relevant literature by the panel members. The European guideline did perform systematic reviews of the available evidence using the Grading of Recommendations Assessment Development and Evaluation scoring system.

• #2 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Hyponatremia-Diagnosis-and-Tests.aspx

  The diagnosis of hyponatremia involves assessing levels of sodium in the blood. A healthy sodium level is between 135 and 145 mmol/l and a person is considered to be hyponatremic if the level falls to below 135 mmol/l. The hyponatremia is considered severe if this level falls to below 125 mmol/l. […] While evaluating a patient, a doctor will also try to establish the type of hyponatremia. Osmolality and urine sodium tests are performed to help diagnose the underlying cause of the condition. […] There are several biochemical tests that can help distinguish between these two types of hyponatremia. Serum potassium, urea and albumin levels are often reduced in dilutional hyponatremia and the blood pressure is often normal or high. In cases of depletional hyponatremia, the blood pressure is often low.

• #2 Hyponatremia | Diagnosis & Disease Information – Renal and Urology News

  https://www.renalandurologynews.com/ddi/hyponatremia/

  Hyponatremia Workup and Differential Diagnosis Hyponatremia Management Monitoring […] When evaluating suspected hyponatremia, laboratory testing should include the following: Plasma sodium (if possible, compare with past results); Blood urea nitrogen (BUN); Plasma electrolytes; Blood glucose; Osmolality; Liver function tests; Plasma creatinine; Uric acid; Thyroid-stimulating hormone; and Cortisol. […] If BUN and creatinine levels are symmetrically elevated, then intrinsic renal disease may be the cause of hyponatremia. […] If BUN is increased more than creatinine, then the patients hyponatremia may be due to hypovolemia with prerenal azotemia. […] Low BUN and uric acid levels may indicate SIADH or cerebral salt-wasting syndrome. […] Underlying conditions to consider in cases of suspected hyponatremia can be categorized as those related to loss of sodium and those related to water retention.

• #2 Pseudohyponatremia: Mechanism, Diagnosis, Clinical Associations and Management

  https://www.mdpi.com/2077-0383/12/12/4076

  Pseudohyponatremia remains a problem for clinical laboratories. In this study, we analyzed the mechanisms, diagnosis, clinical consequences, and conditions associated with pseudohyponatremia, and future developments for its elimination. […] The early identification of pseudohyponatremia can prevent initiating measures that are directed towards correcting a falsely low [Na]S. This review aims to explain the underlying mechanisms, diagnosis and conditions associated with pseudohyponatremia, plus future developments aiming to eliminate it. […] One approach used to calculate the [Na]SW, and consequently to diagnose pseudohyponatremia, consists of dividing the [Na]S reported by a method using pre-measurement dilution by the SWC. […] We suggest that pseudohyponatremia should be considered in all low [Na]S values measured using an indirect ISE. Pseudohyponatremia is diagnosed directly in this case by measuring the [Na]S with a direct ISE.

• #2 Hyponatremia – WikEM

  https://wikem.org/wiki/Hyponatremia

  Defined as sodium concentration 135meq/L. […] Patients often not symptomatic until 120meq/L, although this level varies by patients and may be higher if the change occurred abruptly. […] True serum sodium (corrected) based on serum glucose. […] Algorithm for hyponatremia diagnosis: Correct for glucose, determine volume status, calculated osm (in true hyponatremia the osm is reduced). […] Hypertonic Hyponatremia defined as osmolarity 295mmol/L with the following causes: Hyperglycemia, Sodium decreases by 2.4mEq/L for each 100mg/dL increase in glucose over 100mg/dL, Mannitol excess. […] Isotonic (pseudo) hyponatremia defined as osmolarity 275-295mmol/L. […] Hypotonic Hyponatremia defined as an osmolarity 275 mmol/L and categorized as hypovolemic, hypervolemic or euvolemic. […] Must have sufficient confidence that the symptoms are caused by hyponatraemia; see Clinical Features for definition of categories.

• #2 Hyponatremia: Practice Essentials, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/242166-overview

  Three laboratory tests are essential in the evaluation of patients with hyponatremia: serum osmolality, urine osmolality, and urinary sodium concentration. Together with the history and the physical examination, those tests help to establish the primary underlying etiologic mechanism in an algorithmic fashion. […] Serum osmolality readily differentiates true hyponatremia (hypotonic hyponatremia) from pseudohyponatremia. […] Urine osmolality helps differentiate between conditions associated with the presence or absence of antidiuretic hormone (ADH), also called arginine vasopressin (AVP). […] Urinary sodium concentration helps to differentiate hyponatremia secondary to hypovolemia or ineffective intravascular volume status from syndrome of inappropriate antidiuretic hormone secretion (SIADH).

• #2 #96: Saltshakers and Stethoscopes: A Practical Approach to Hyponatremia – The Curbsiders

  https://thecurbsiders.com/cribsiders-podcast/96

  Renowned pediatric nephrologist, Michelle Starr, returns to the podcast to help unravel and simplify the approach to pediatric hyponatremia, providing valuable insights into diagnosis and treatment strategies. […] Before working up hyponatremia, one should first confirm a patient is truly hyponatremic by sending a serum sodium and serum osm. […] To narrow the differential diagnosis, look at the urine osm to determine whether ADH is active or inactive. Urine osm < 200 points towards an ADH inactive state, while > 250 is consistent with active ADH. […] In order to do this, you must first consider whether you’re dealing with a true hyponatremia or pseudohyponatremia. In order to differentiate between these two entities, it’s helpful to re-order a serum sodium along with a serum osm. […] If normal osm with low serum sodium, this is not a true hyponatremia. Rather, this is a lab error as the machine measures sodium per plasma volume, but reports the value as sodium per plasma water.

• #2 Hyponatremia made easy—a simple diagnostic algorithm | Medmastery

  https://www.medmastery.com/magazine/hyponatremia-made-easya-simple-diagnostic-algorithm?srsltid=AfmBOoqUL0PIwb_K8DnD4qPsVx9BVm01jqhYIm4p4XQlzdzw-JhmvBE-

  We have hypervolemic patients with heart failure, cirrhosis, and nephrotic syndrome. We have hypovolemic patients with GI losses, renal losses, and other losses. And we have euvolemic patients, hypothyroidism, adrenal insufficiency, and SIADH, syndrome of inappropriate antidiuretic hormone. […] Essentially, it’s just a coin toss whether you can accurately determine the volume status. […] The hypervolemic patients, they’re going to have a urine sodium less than 20 and a high uric acid. Now, it may not be frankly high but it’s going to be towards the upper range of normal. The hypovolemic patients will also have a urine sodium less than 20 and a high uric acid or a high normal uric acid. And finally, the euvolemic patients will have a urine sodium greater than 20 and a low uric acid. […] Some other things to caution you about, the urine sodium is not going to be accurate in patients that have recently received diuretics, which is probably 100% of patients in heart failure. They could have an artificially elevated urine sodium, due to the diuretic effect.

• #2 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Hyponatremia-Diagnosis-and-Tests.aspx

  Some of the tests that may be run to help determine which form of hyponatremia a person has include: Blood urea, potassium, calcium, magnesium and phosphate; Plasma and urine osmolality. In dilutional hyponatremia, the plasma osmolality is lower than normal; Blood glucose, which may be raised in cases of hyponatremia; Thyroid function tests; Urine sodium level; Cardiac investigations may be performed to check for heart failure. […] In order to check whether hyponatremia may be caused by SIADH, a person is assessed for the following features of the syndrome: Normal blood volume; Normal kidney, adrenal and thyroid function; Raised urine sodium; Urine osmolality of less than 100; The patient is not taking any medication that could cause hyponatremia such as diuretics.

• #2 Diagnosis and Treatment of Hyponatremia: Compilation of the Guidelines

  https://pmc.ncbi.nlm.nih.gov/articles/PMC5407738/

  Although the literature on this approach is limited, it offers a rational approach to prevent a rapid rise in SNa that may occur once hypovolemia has been corrected. […] Fenske et al. found that FEUA12% had the highest sensitivity and specificity to diagnose SIAD with or without diuretic use. […] Although both guidelines only briefly discuss copeptin, emerging data justify a brief discussion on the diagnostic utility of this novel marker. […] The two guidelines diverge in their recommendations regarding pharmacologic therapy for SIAD and hypervolemic hyponatremia. […] The United States guideline lists vaptans as one of the pharmacologic options, if fluid restriction has failed. […] The European guideline did not recommend vaptans in moderate hyponatremia. […] The average rise in SNa after 24 hours was 9.03.9 mmol/L. Excessive correction of hyponatremia (12 mmol/L per day) was observed in 23% of patients (all with profound hyponatremia), although none of them developed signs of ODS. […] Both guidelines recommend frequent monitoring of SNa during the active correction phase (i.e., all treatments except fluid restriction).

• #2 Hyponatremia Workup: Laboratory Studies, Imaging Studies

  https://emedicine.medscape.com/article/242166-workup

  Serum uric acid levels can be important supportive information; they are typically reduced in SIADH and in salt wasting. […] Thyroid-stimulating hormone (TSH) and serum cortisol levels should be measured if hypothyroidism or hypoadrenalism is suspected. […] Head computed tomography (CT) scanning and chest radiography can be used to assess for an underlying etiology in select patients with suspected SIADH or cerebral salt wasting. […] A diffusion-weighted magnetic resonance imaging (MRI) scan can help evaluate patients suspected of osmotic demyelination syndrome (ODS).

• #2 Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia | AAFP

  https://www.aafp.org/pubs/afp/issues/2023/1100/sodium-disorders-hyponatremia-hypernatremia.html

  Spasovski G, Vanholder R, Allolio B, et al.; Hyponatraemia Guideline Development Group. Clinical practice guideline on diagnosis and treatment of hyponatraemia. […] Braun MM, Barstow CH, Pyzocha NJ. Diagnosis and management of sodium disorders: hyponatremia and hypernatremia. […] Fenske W, Maier SKG, Blechschmidt A, et al. Utility and limitations of the traditional diagnostic approach to hyponatremia. […] Chung HM, Kluge R, Schrier RW, et al. Clinical assessment of extracellular fluid volume in hyponatremia. […] Bassi V, Fattoruso O. The role of fractional excretion of uric acid in the differential diagnosis of hypotonic hyponatraemia in patients with diuretic therapy. […] Chatterjee T, Koratala A. Point of care cardiac ultrasound in the management of hyponatremia. […] Samant S, Koratala A. Point-of-care Doppler ultrasound in the management of hyponatremia: another string to nephrologists’ bow.

• #2 The suspect – SIADH

  https://www.racgp.org.au/afp/2017/september/the-suspect-siadh

  Hyponatraemia is one of the most commonly encountered electrolyte abnormalities in general practice. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is an important but under-recognised cause. […] This article explores the presentation, investigation, diagnosis and management of SIADH. […] Diagnosis is made on the basis of clinical euvolaemic state with low serum sodium and osmolality, raised urine sodium and osmolality, and exclusion of pseudohyponatraemia and diuretic use. […] SIADH accounts for about one-third of all hyponatraemia presentations, yet remains commonly under-diagnosed and, therefore, under-managed. […] This article will focus on the diagnosis, investigation and management of hyponatraemia secondary to SIADH. […] Barrter and Schwartz describe the following criteria for the diagnosis of SIADH: decreased serum osmolality (275 mOsm/kg), increased urine osmolality (100 mOsm/kg), euvolaemia, increased urine sodium (20 mmol/L), no other cause for hyponatraemia (no diuretic use and no suspicion of hypothyroidism, cortisol deficiency, marked hyperproteinaemia, hyperlipidaemia or hyperglycaemia). […] Euvolaemic hyponatraemia with low serum sodium and osmolality, and raised urine osmolality in the absence of diuretic use or pseudohyponatraemia, are diagnostic of SIADH.

• #2 SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion)

  https://my.clevelandclinic.org/health/diseases/23976-siadh-syndrome-of-inappropriate-antidiuretic-hormone-secretion

  SIADH causes your body to retain too much water and commonly leads to hyponatremia, which is low levels of sodium in your blood. […] The main sign and consequence of ADH is hyponatremia, which is when you have low levels of sodium (salt) in your blood. […] Hyponatremia, the main medical consequence of SIADH, is the most common electrolyte imbalance found in people in the hospital, and SIADH is the most common cause of the condition. […] A low blood sodium level (hyponatremia) is the most common cause of symptoms of SIADH. […] If youre having symptoms of hyponatremia, your healthcare provider will perform a complete physical examination. […] Theres no single best test to diagnose SIADH. […] Because of this, your provider will likely order other tests to check for hyponatremia, including: Comprehensive metabolic panel (CMP), Osmolality blood test, Urine osmolality test, Urine sodium and potassium test, Toxicology screens for certain medications.

• #2 Hyponatremia | Diagnosis & Disease Information – Renal and Urology News

  https://www.renalandurologynews.com/ddi/hyponatremia/

  Conditions related to sodium loss include the use of thiazide diuretics or infusion of saline in the presence of ADH. […] Water retention may due to the following conditions: Primary polydipsia; Late-stage renal failure; Congestive heart failure; Ascites; Nephrotic syndrome; Deficiency of aldosterone; Hypothyroidism; and SIADH. […] Many conditions are associated with inappropriate ADH secretion and thus can result in hyponatremia. […] How hyponatremia is treated depends on the underlying diagnosis and severity of symptoms. […] In general, sodium levels should be increased gradually to avoid osmotic demyelination syndrome. […] Acute hyponatremia with severe neurologic symptoms can be treated with a sodium infusion of 4 to 6 mmol/L over 4 to 6 hours. […] The total increase in sodium concentration should not exceed 6 to 12 mmol/L within 24 hours or 18 mmol/L within 48 hours.

• #2 Evaluation of hyponatremia – Differential diagnosis of symptoms | BMJ Best Practice US

  https://bestpractice.bmj.com/topics/en-us/57

  In most cases, hyponatremia reflects hypotonicity or low effective osmolality. It is often iatrogenic and avoidable. […] Common causes of hyponatremia include true volume depletion, effective arterial volume depletion (e.g., congestive heart failure, cirrhosis), and medication-induced hyponatremia due to thiazide diuretics or antidepressants. […] Hyponatremia can also be classified according to its rate of onset. […] Acute hyponatremia is defined as hyponatremia with a duration of 48 hours. Chronic hyponatremia is defined as hyponatremia with a duration of at least 48 hours. Chronic hyponatremia is much more common than acute, and cases where the duration of hyponatremia is unclear should be considered to be chronic unless there is clinical evidence suggesting otherwise. […] Failure to correct hyponatremia can lead to permanent neurologic damage, as can correcting sodium levels too rapidly. […] When hyponatremia is chronic and the serum sodium concentration increases too rapidly, osmotic demyelination syndrome (ODS; also known as central pontine myelinolysis) may develop. ODS is characterized by altered mental status, reduced motor functioning, and/or abnormalities of balance.

• #2 Hyponatremia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK470386/

  Treatment of hyponatremia depends upon the degree of hyponatremia, duration of hyponatremia, severity of symptoms, and volume status. […] The goal of correction: Correct sodium by no more than 10 mEq/L to 12 mEq/L in any 24-hour period. […] Symptoms depend upon the degree and chronicity of hyponatremia. Patients with mild-to-moderate hyponatremia (greater than 120 mEq/L) or a gradual decrease in sodium (greater than 48 hours) have minimal symptoms. […] Patients with severe hyponatremia (less than 120 mEq/L) or rapid decrease in sodium levels have multiple varied symptoms.

• #2 Hyponatremia – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/hyponatremia/symptoms-causes/syc-20373711

  Hyponatremia occurs when the concentration of sodium in your blood is abnormally low. […] Hyponatremia treatment is aimed at resolving the underlying condition. Depending on the cause of hyponatremia, you may simply need to cut back on how much you drink. […] A normal blood sodium level is between 135 and 145 milliequivalents per liter (mEq/L). Hyponatremia occurs when the sodium in your blood falls below 135 mEq/L. […] Seek emergency care for anyone who develops severe signs and symptoms of hyponatremia, such as nausea and vomiting, confusion, seizures, or lost consciousness. […] Call your doctor if you know you are at risk of hyponatremia and are experiencing nausea, headaches, cramping or weakness. Depending on the extent and duration of these signs and symptoms, your doctor may recommend seeking immediate medical care.

• #2 Hyponatremia – Diagnosis and Treatment : Emergency Care BC

  https://emergencycarebc.ca/clinical_resource/clinical-summary/hyponatremia-diagnosis-and-treatment/

  Hyponatremia is the most common electrolyte disorder in adults. 3-6% of patients presenting to the ED are hyponatremic. […] Lab investigations include electrolytes, glucose, creatinine/GFR, urea, urine osmolality, and urine sodium. LFT’s and BNP if clinically indicated. […] Acute hyponatremia = hyponatremia occurring in <48hrs. [...] If the acuity cannot be determined assume chronic. [...] Severity of symptoms reflects both rapidity of change and sodium level. [...] Treatment based on patient’s volume status (eg. orthostatic hypotension assessment, moisture of mucus membranes, peripheral edema, JVP, POCUS of IVC diameter, and collapsibility). [...] Mild to moderate: headache, nausea, vomiting, muscle cramps. [...] Severe symptoms: seizure, coma, delirium, altered level of consciousness.

• #2 Hyponatremia – Knowledge @ AMBOSS

  https://www.amboss.com/us/knowledge/hyponatremia/

  Hyponatremia is defined as a serum sodium concentration below 135 mEq/L. […] The cause of hyponatremia is determined by assessing the patient’s volume status and ability to retain sodium. […] Treatment involves careful correction of the sodium deficit and/or fluid imbalance. […] A rapid increase in the serum sodium concentration can have damaging osmotic effects (i.e., osmotic demyelination syndrome). […] Confirm hyponatremia: Repeat BMP. […] Exclude hyperglycemia: Check serum glucose. […] Check the serum osmolality (SOsm): first step in the evaluation of confirmed hyponatremia. […] Serum osmolality measurement is the first step in the evaluation of verified hyponatremia. […] Consider additional focused diagnostic evaluation to identify the underlying cause. […] In patients taking diuretics, urinary sodium concentrations should be interpreted with caution.

• #2 Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia | AAFP

  https://www.aafp.org/pubs/afp/issues/2023/1100/sodium-disorders-hyponatremia-hypernatremia.html

  Hyponatremia and hypernatremia are electrolyte disorders that can be associated with poor outcomes. Hyponatremia is considered mild when the sodium concentration is 130 to 134 mEq per L, moderate when 125 to 129 mEq per L, and severe when less than 125 mEq per L. […] Physicians should identify the cause of a patient’s hyponatremia, if possible; however, treatment should not be delayed while a diagnosis is pursued. […] Management to correct sodium concentration is based on whether the patient is hypovolemic, euvolemic, or hypervolemic. […] Treating euvolemic hyponatremia includes restricting free water consumption or using salt tablets or intravenous vaptans. […] Hypervolemic hyponatremia is treated primarily by managing the underlying cause (e.g., heart failure, cirrhosis) and free water restriction.

• #2 Hyponatremia – Diagnosis and Treatment : Emergency Care BC

  https://emergencycarebc.ca/clinical_resource/clinical-summary/hyponatremia-diagnosis-and-treatment/

  Overcorrection = rise > 10mEq/L in the first 24hrs or 8mEq/L if the patient has chronic hyponatremia or sodium was initially <120mEq/L. [...] When overcorrection occurs: Discontinue treatment immediately. [...] Consult nephrologist, endocrinologist. [...] Consider desmopressin. [...] 2-4 micrograms every 8 hours IV. [...] Monitor sodium every hour.

• #2 Hyponatremia: Causes, Symptoms, Diagnosis & Treatment

  https://my.clevelandclinic.org/health/diseases/17762-hyponatremia

  Healthcare providers use blood tests and urine (pee) tests to diagnose hyponatremia. Theyll check the levels of sodium, potassium, hormones and other substances in your body. Theyll also check how well your kidneys and liver are working. Depending on your symptoms, your provider might get imaging, like a CT scan or chest X-ray. […] Knowing which type of hyponatremia you have helps your healthcare provider diagnose the cause and determine treatment. […] Treatment for hyponatremia depends on the cause and what kind of hyponatremia you have. Treatments could include: Water intake restrictions, Adjustments to your medications (like stopping them or taking a different dosage), IV fluids, Medication that treat low sodium levels, like tolvaptan or conivaptan. […] Healthcare providers are careful not to overcorrect when treating hyponatremia. Increasing sodium levels in your body too quickly can cause life-threatening side effects, like central pontine myelinolysis or osmotic demyelination syndrome. These are types of brain damage. This is why its important to see a healthcare provider right away if you think you have hyponatremia.

• #2 Hyponatremia – Knowledge @ AMBOSS

  https://www.amboss.com/us/knowledge/hyponatremia/

  The distinction between hypovolemia and euvolemia is usually difficult to make on examination alone; examination findings have low sensitivity and specificity. […] Monitor urine output closely (e.g., every hour). […] Measure serum sodium frequently (at least every 46 hours until 125 mEq/L). […] Sodium concentration should be increased by 46 mEq/L within 12 hours for patients with severe or moderately severe symptoms or acute hyponatremia.

• #2 Evaluation of hyponatremia – Differential diagnosis of symptoms | BMJ Best Practice US

  https://bestpractice.bmj.com/topics/en-us/57

  Hyponatremia is the most common electrolyte disorder encountered in clinical practice and is estimated to occur in up to 30% of hospital inpatients. […] It is defined as a serum sodium 135 mEq/L (normal serum sodium concentration is in the range of 135 to 145 mEq/L); severe hyponatremia is defined as a serum sodium 125 mEq/L. Patients with hyponatremia have increased morbidity and mortality compared with patients without hyponatremia. […] Mild hyponatremia is an independent risk factor for adverse outcome and mortality even in the general population. […] Hyponatremia is primarily a disorder of water balance. A low serum sodium concentration indicates dilute body fluids or an excess of water. […] The clinical manifestations of hyponatremia depend on the rate of decline of serum sodium. An acute fall in sodium over 24 to 48 hours produces severe cerebral edema, which can be fatal.

• #3 Hyponatremia; Current Diagnosis and Treatment

  https://turkjnephrol.org/en/hyponatremia-current-diagnosis-and-treatment-135913

  Hyponatremia is the most common electrolyte abnormality encountered in clinical practice. The symptoms of hyponatraemia are largely dependent on the rapidity of the development of hyponatraemia. Acute symptomatic hyponatremia is a serious clinical situation. The pathogenesis of hyponatremia has been found to occur secondary to the nonosmotic secretion of ADH in over 95% of cases. In other words, hyponatremia caused by more water imbalance than sodium imbalance in the majority of cases. Pseudohyponatremia(elevation of lipids or proteins in plasma causing artifactual decrease in serum sodium concentration) and translocational hyponatremia(the additional solutes in plasma such as glucose, mannitol and radiographic contrast agent causing osmotic shift of water from intracellular fluid to extracellular fluid) that are not associated excess are excluded on the first step in the differential diagnosis of hyponatraemia. While only fluid restriction is sufficient for treatment of asymptomatic patients, emergency treatment should be given in symptomatic patients. Recently ADH receptor antagonists have been used as an alternative treatment of saline infusion in the treatment of euvolemic and hypervolemic hyponatremia. Correction rate of sodium should be 0,5-1mEq/L/h in the treatment of hyponatremia. Rapidly correction should be avoided in hyponatraemia, because it can lead to celebral hemorrhage and central pontine myelinolysis.

• #3 Hyponatraemia: Symptoms and Treatment | Doctor

  https://patient.info/doctor/hyponatraemia-pro

  Hyponatraemia is the most common electrolyte abnormality encountered in clinical practice. […] Hyponatraemia is associated with multiple poor clinical outcomes and is often managed suboptimally because of inadequate assessment and investigation. […] Clinical examination should be focused on fluid status, including blood pressure (BP), postural deficit, heart rate, peripheral oedema and central venous filling, as well as chest and heart examination. […] Clinical assessment should identify potential causes, establish the severity of hyponatraemia and determine if the patient is hypovolaemic, euvolaemic, or hypervolaemic. […] SIADH needs to be confirmed by results of paired serum and urine samples: serum hypo-osmolality is 275 mOsm/kg, and urine osmolality 100 mOsm/kg and sodium 30 mmol/L, in the absence of hypovolaemia, hypervolaemia, adrenal or thyroid dysfunction and use of diuretics.

• #3 Hyponatremia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK470386/

  Hyponatremia is defined as a serum sodium concentration of less than 135 mEq/L but can vary to a small extent in different laboratories. Hyponatremia is a common electrolyte abnormality caused by an excess of total body water when compared to total body sodium content. […] This activity explains when this condition should be considered on differential diagnosis, articulates how to properly evaluate for this condition, and highlights the role of the interprofessional team in caring for patients with this condition. […] The following steps may be performed while evaluating a patient with suspected hyponatremia: Step 1: Plasma Osmolality (275 mOsm to 290 mOsm/kg). It can help differentiate between hypertonic, isotonic, and hypotonic hyponatremia. True hyponatremic patients are hypotonic. If the patient is hypotonic, then go to step 2. […] Step 2: Urine Osmolality. Urine osmolality less than 100 mOsm/kg indicates primary polydipsia or reset osmostat. Urine osmolality greater than 100 mOsm/kg usually indicates a high ADH state; go to step 3.

• #3 Hyponatremia: Practice Essentials, Pathophysiology, Etiology

  https://emedicine.medscape.com/article/242166-overview

  Three laboratory tests are essential in the evaluation of patients with hyponatremia: serum osmolality, urine osmolality, and urinary sodium concentration. Together with the history and the physical examination, those tests help to establish the primary underlying etiologic mechanism in an algorithmic fashion. […] Serum osmolality readily differentiates true hyponatremia (hypotonic hyponatremia) from pseudohyponatremia. […] Urine osmolality helps differentiate between conditions associated with the presence or absence of antidiuretic hormone (ADH), also called arginine vasopressin (AVP). […] Urinary sodium concentration helps to differentiate hyponatremia secondary to hypovolemia or ineffective intravascular volume status from syndrome of inappropriate antidiuretic hormone secretion (SIADH).

• #3

  https://link.springer.com/article/10.1007/s10157-025-02624-9

  In hypovolemic hyponatremia, a urine [Na+] of 30 mmol/L indicates extrarenal Na+ loss, such as diarrhea, vomiting, and sweating, whereas a urine [Na+] of 30 mmol/L indicates renal Na+ loss due to diuretics (natriuretics), salt-losing nephropathy, and primary adrenal insufficiency, among others. […] Diagnosis of SIAD is usually challenging because it is a diagnosis of exclusion; however, many reports have shown that serum uric acid (UA) concentration and fractional excretion of UA (FEUA) help differentiate SIAD from other causes of hyponatremia. […] Hyponatremia varies among patients and frequently exhibits a heterogeneous pathophysiology, posing difficulty in diagnosing the cause. When hyponatremia is identified, it is crucial to evaluate for urgency based on neurological symptoms caused by the hyponatremia.

Zobacz więcej