What is the best way to diagnose pseudohyponatremia?
What is pseudohyponatremia?
What is the first step in the evaluation of pseudohyponatremia?
What is the normal serum sodium concentration for pseudohyponatremia?
What is the definition of hyponatremia?
How is serum sodium measured?
Does pseudohyponatremia require a diagnosis?
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What is the most common cause of Pseudohyponatremia?
The most common cause of pseudohyponatremia is due to severely elevated levels of cholesterol. [2] In serum blood samples taken from patients with severe hypertriglyceridemia, the sample may appear overtly lipemic, hyper viscous, or discolored from the overwhelming presence of insoluble triglycerides.
How can Pseudohyponatremia be prevented?
The following measures may help you prevent hyponatremia:Treat associated conditions. ... Educate yourself. ... Take precautions during high-intensity activities. ... Consider drinking sports beverages during demanding activities. ... Drink water in moderation.
How do you fix mild hyponatremia?
Options include:Intravenous fluids. Your doctor may recommend IV sodium solution to slowly raise the sodium levels in your blood. ... Medications. You may take medications to manage the signs and symptoms of hyponatremia, such as headaches, nausea and seizures.
How long does it take to correct sodium levels?
The rate of sodium correction should be 6 to 12 mEq per L in the first 24 hours and 18 mEq per L or less in 48 hours.
Should Pseudohyponatremia be treated?
No treatment may be appropriate, but for those that do require treatment, the options include intravenous administration of isotonic or hypotonic saline solutions, fluid restriction or diuretic therapy [3]. Withdrawal of diuretic drugs may be necessary.
What causes Pseudohyponatremia in hyperglycemia?
Hyperglycemia is associated with a decrease in serum sodium concentration. Water moves from the intracellular space to the extracellular space along the osmotic gradient, subsequently causing a reduction in the serum sodium level. Therefore, hyperglycemic patients are mostly mildly hyponatremic.
Will eating salt help hyponatremia?
In elderly patients with a diet poor in protein and sodium, hyponatremia may be worsened by their low solute intake. The kidney's need to excrete solutes aids in water excretion. An increase in dietary protein and salt can help improve water excretion.
Which organ is most affected by hyponatremia?
Hyponatremia occurs when your blood sodium level goes below 135 mEq/L. When the sodium level in your blood is too low, extra water goes into your cells and makes them swell. This swelling can be dangerous especially in the brain, since the brain cannot expand past the skull.
What to drink to get sodium levels up?
Here are 8 electrolyte-rich beverages you may want to add to your health and wellness tool kit.Coconut water. Coconut water, or coconut juice, is the clear liquid found inside of a coconut. ... Milk. ... Watermelon water (and other fruit juices) ... Smoothies. ... Electrolyte-infused waters. ... Electrolyte tablets. ... Sports drinks. ... Pedialyte.
What foods to avoid if you have hyponatremia?
High-Sodium FoodsSmoked, cured, salted or canned meat, fish or poultry including bacon, cold cuts, ham, frankfurters, sausage, sardines, caviar and anchovies.Frozen breaded meats and dinners, such as burritos and pizza.Canned entrees, such as ravioli, spam and chili.Salted nuts.Beans canned with salt added.
How long is hospital stay for low sodium?
Patients with hyponatremia had a hospital stay of 7.6 days compared with 5.6 days for those with normonatremia, a significant difference between the groups.
Can drinking salt water increase sodium level?
Whether you're swimming in the ocean or drinking salt water as part of a fad diet, swallowing too much of the liquid can have serious health consequences. The human body was built to handle just small amounts of sodium, and salt overload can cause levels to skyrocket.
Does alcohol cause pseudohyponatremia?
Excessive consumption of beer in particular, which has a low solute content (sodium concentration, 1.8 mEq/L and potassium concentration, 7.2 mEq/L), to the exclusion of other solute intake may result in severe hyponatremia.
Why do lipids cause pseudohyponatremia?
This is pseudohyponatremia. One known cause of pseudohyponatremia is extreme elevations in triglycerides in the blood. When lipids replace the water within the serum, a low sodium number will be recorded but will not be accurate. We describe a case of pseudohyponatremia in the setting of severe hypertriglyceridemia.
What can cause false low sodium?
Conditions that can lead to falsely low sodium measurements include high blood protein levels such as in multiple myeloma, high blood fat levels, and high blood sugar. Treatment is based on the underlying cause. Correcting hyponatremia too quickly can lead to complications.
Why does DKA cause pseudohyponatremia?
The causes of hypernatremia in DKA could potentially be explained by excessive water losses relative to the osmotic loss of sodium through the urine. Additionally, recurrent vomiting, which is classically seen in patients with DKA, can exacerbate the excessive volume loss.
What is pseudohyponatremia? | AACC.org
February 15. AACC Academy Scientific Short: If one were to compile a list of terms that ought to be eliminated from the laboratory medicine lexicon, “pseudohyponatremia” (PHN) would certainly be on it (and, by the way, such a list would be very long!). The problem with the term PHN is that it is used in reference to two completely different phenomena, and it misleadingly implies that ...
Pseudohyponatremia - acute care testing
The adult human body contains around 3500 mmol (80 g) of sodium. Just under 30 % is contained in a non-exchangeable state in bones. The remaining (exchangeable) sodium is divided unevenly between extracellular fluid (ECF), which includes blood plasma, and intracellular fluid (ICF).
Guest post: Understanding pseudohyponatremia | ACDIS
by Howard Rodenberg, MD, MPH, CCDS A few years ago, there was a change of attitude within seizure medicine that manifested itself as new terminology.
Pseudohyponatremia - PubMed
Pseudohyponatremia should be distinguished from true hyponatremia lest injudicious therapy be instituted. Pseudohyponatremia is caused by a displacement of serum water by elevated concentrations of serum lipids or proteins. Only two (flame photometry and indirect potentiometry) of the three current …
Pseudohyponatremia - PubMed
Pseudohyponatremia is an uncommonly encountered laboratory abnormality defined by a serum sodium concentration of less than 135 mEq/L in the setting of a normal serum osmolality (280 to 300 mOsm/kg). Conversely, true hyponatremia is associated with low serum osmolality and should prompt evaluation f …
What is the treatment for hyponatremia?
Crucially, treatment of hyponatremia depends on the severity and a clear understanding of the mechanism of hyponatremia in each case. No treatment may be appropriate, but for those that do require treatment, the options include intravenous administration of isotonic or hypotonic saline solutions, fluid restriction or diuretic therapy [3]. Withdrawal of diuretic drugs may be necessary. Inappropriate choice of treatment can have serious effects and may contribute to fatal outcome [4].
What is hyponatremia associated with?
Depending on its cause, hyponatremia can be associated with a normal total amount of sodium, sodium deficit or even sodium excess. All cases of hyponatremia can be assigned to one of three groups, depending on the clinically assessed fluid status of the affected hyponatremic patient [2]. These three groups are:
How is sodium measured?
The technique [5] involves aspirating a fine (atomized) spray of a diluted plasma or serum sample into a flame, thereby changing the color of the flame. The intensity of the emitted light at the wavelength characteristic of sodium (539 nm) is measured. This measured emission intensity is directly proportional to the number of sodium atoms in solution. By comparing the measured intensity of the sample with that of standard solutions of a known concentration, the sodium concentration of the plasma sample can be computed. Although it remains a reference method, FES has been largely replaced by the alternative, more convenient ISE methodology. Only a small minority of laboratories still use FES.
What is the energy dependent sodium pump?
The energy-dependent sodium pump, present in the membrane of all cells, which effectively pumps sodium out of cells in exchange for potassium, ensures the large differential in sodium concentration between the ICF (5-10 mmol/L) and ECF (135-145 mmol/L) concentration.
How many groups of hyponatremia are there?
All cases of hyponatremia can be assigned to one of three groups, depending on the clinically assessed fluid status of the affected hyponatremic patient [2]. These three groups are:
What is the sodium concentration in the blood?
In health, sodium concentration is maintained between 135 and 145 mmol/L, so that hyponatremia (reduction in plasma sodium) is diagnosed if the concentration falls below 135 mmol/L. Effective, safe correction of plasma sodium depends on establishing the cause.
How severe is hyponatremia?
Severity of signs and symptoms due to hyponatremia depend on the degree of hyponatremia and the speed of onset. Those with mild hyponatremia (plasma sodium 130-135 mmol/L) almost invariably suffer no symptoms. Moderate hyponatremia (plasma sodium 125-130 mmol/L) may be associated with non-specific symptoms including headache, nausea and muscle cramps. More severe neurological symptoms including confusion, disorientation and hallucinations become progressively more likely as sodium falls below 125 mmol/L. The most severe presentation occurs in those with acute onset (within 48 hours of plasma sodium <115 mmol/L). These patients may suffer seizures and lapse into coma. The risk of a fatal outcome increases as sodium falls below 115 mmol/L.
What is pseudohyponatremia?
The finding of pseudohyponatremia is an artifact that results from the way a blood sample is processed for serum sodium measurement. Some sources cite the presence of osmotically-active solutes, such as mannitol or hyperglycemia, as an additional etiology of pseudohyponatremia.
What is the normal serum sodium concentration for pseudohyponatremia?
Pseudohyponatremia is an uncommonly encountered laboratory abnormality defined by a serum sodium concentration of less than 135 mEq/L in the setting of a normal serum osmolality (280 to 300 mOsm/kg). Conversely, true hyponatremia is associated with low serum osmolality and should prompt evaluation f …
What is the osmolality of pseudohyponatremia?
Pseudohyponatremia is an uncommonly encountered laboratory abnormality define d by a serum sodium concentration of less than 135 mEq/L in the setting of a normal serum osmolality (280 to 300 mOsm/kg). Conversely, true hyponatremia is associated with low serum osmolality and should prompt evaluation for the presence of an additional abnormal solute that may be affecting the laboratory assessment. The finding of pseudohyponatremia is an artifact that results from the way a blood sample is processed for serum sodium measurement.
Is pseudo-sodium more appropriate?
In this case, “pseudo-“ is more appropriate, since the measured sodium concentration (except by direct potentiometry) does not reflect the true sodium concentration in the aqueous phase, which is the physiologically relevant parameter.
Is hyponatremia a benign condition?
The hyponatremia may be clinically benign, but the measurement is accurate. In 1973, Katz reported a formula that increases sodium by 1.6 mmol/L for every 100 mg/dL glucose concentration above 100 mg/dL ( e.g., for a patient with a glucose of 200 mg/dL, the sodium would be adjusted upward by 1.6 mmol/L.
What do you do when there's evidence for pseudohyponatremia but the clinician wrote a nonspecific?
What do you do when there’s evidence for pseudohyponatremia but the clinician wrote a nonspecific “hyponatremia?” The best way to address this would be through a clinical validation query, and it might be useful to put the selected terms in some kind of frame of reference. One might list choices such as “pseudohyponatremia (often associated with hyperglycemia)” or “hypotonic hyponatremia (related to dehydration, diuretic use, or GU fluid loss)” in an effort to provide a clinical context for the atypical terms.
How to understand pseudohyponatremia?
To understand pseudohyponatremia, you need to go all the way back to high school biology and the processes of diffusion and osmosis. As you may recall, solutions on either side of a membrane want to be in balance with each other.
What is the term for a decrease in the tonicity of the serum?
Hyponatremia—a decreased level of serum sodium—comes in several flavors. The most common is what we might call hypotonic hyponatremia. (The term “hypotonic” here refers to a true decrease in the tonicity of the serum, or the concentration of solutes—ions and molecules—within that fluid space. Sodium and sodium salts are the principal solutes within extracellular fluid.) This form of hyponatremia usually results from volume loss, such as with dehydration, vomiting or diarrhea; medical conditions such as heart failure and cirrhosis; and use of diuretic agents that inhibit the reabsorption of sodium within the kidney. Less common causes include the Syndrome of Inappropriate Anti-Diuretic Hormone Secretion (SIADH), advanced renal disease, and psychotic polydipsia with water intoxication,
How much does serum sodium drop?
The traditional rule of thumb has been that for every 100 mg/dl that serum glucose rises over baseline, the serum sodium drops 1.6 meQ/l. Newer literature suggest the actual number may be higher, up to 2.4 mEq/L. If we split the difference at 2.0 mEq/L, a serum glucose of 600 mg/dl (5x a normal baseline of roughly 100 gm/dl) might drop the serum sodium by ten (from 135 to 125 mEq/L).
What is the difference between pseudoseizure and non-seizure?
The theory behind the change is that the term pseudoseizure implies that the patient is consciously faking the seizure, while the latter suggests that maybe the person can’t help it, that their non-seizure seizure is a result ...
Does osmosis cause hyponatremia?
As it does, the incoming water also dilutes the sodium concentration within the plasma, resulting in a relative, “false” hyponatremia.
Is pseudohyponatremia real?
Pseudohyponatremia, however, is something real, and something I’m seeing more often in my denials work. What usually happens is that a diabetic patient with profound hyperglycemia is also diagnosed with hyponatremia by the clinician, and the latter claim is rejected by the payer. As often as I think denials are justified with bogus reasons, this one I actually understand.
How many consecutive acute medical admission patients were hyponatremic?
Another [4] found that a remarkable 40 % of 469 consecutive acute medical-admission patients were hyponatremic; mild, moderate and severe hyponatremia being present in 25 %, 11 % and 3 % of this study cohort, respectively.
What is spuriously reduced sodium?
The focus of this first article is spuriously reduced sodium (pseudohyponatremia) due to increased plasma protein or lipid concentration, whilst the subject of the second [1] is spuriously increased sodium (pseudohypernatremia) due to decreased plasma protein. By way of introduction to the topic this first article will include discussion ...
What is the reference range for sodium?
Plasma sodium concentration is normally maintained within the approximate reference range of 135-145 mmol/L so that hyponatremia (reduced plasma sodium) is diagnosed if the result is <135 mmol/L, whilst hypernatremia (increased plasma sodium) is diagnosed if the result is >145mmol/L.
How long has sodium been measured?
For over 80 years plasma sodium concentration has been routinely measured using either one of two broad techniques:
Is hyponatremia a cause of death?
It remains unclear if the observed general association between hyponatremia and mortality means that hyponatremia has a causative role in the eventual death of patients or is merely a surrogate marker of other lethal risk factors associated with the underlying serious condition. This important unresolved aspect of hyponatremia is the subject of a recent review [9].
Does hyponatremia cause long term mortality?
There is an ever-growing body of evidence that hyponatremia even without accompanying encephalopathy is associated with long-term mortal ity for many patients groups (e.g. those in intensive care, those with heart failure, cirrhosis, and pulmonary embolus, etc.) so that even mild asymptomatic hyponatremia might be clinically significant for many patient groups.
Is mild hyponatremia asymptomatic?
Mild hyponatremia is usually asymptomatic and the principal clinical concern of hyponatremia is the encephalopathy associated with acute-onset severe hyponatremia and consequent cerebral edema.
ABSTRACT
Objective: To describe a case of pseudohyponatremia in the setting of hypercholesterolemia.
INTRODUCTION
The prevalence of hyponatremia in hospitalized patients is around 28 to 38% ( 1., 2., 3., 4. ). Hyponatremia is defined as a plasma sodium (P Na) level ≤135 mmol/L ( 5 ). Osmolality or tonicity refers to the concentration of a solute in a solution. Hyponatremia can be classified into 3 different categories based on the underlying etiology ( 3 ).
Case Report
A 69-year-old male was admitted for asymptomatic hyponatremia found on follow-up evaluation for drug-induced cholestatic hepatitis. He was initially diagnosed with immunoglobulin G4-related disease in 2011 after presenting with an orbital pseudotumor. He was treated with rituximab and prednisone that was eventually tapered off.
DISCUSSION
Pseudohyponatremia is the result of laboratory measurement artifact and depends on the method used to measure the P Na level. The ion-selective electrode (ISE) method was developed in the 1980s to measure plasma solute concentrations and remains the technique most widely used in laboratories across the United States today.
CONCLUSION
Around two thirds of laboratories in the United States use indirect potentiometry for measurement ( 14 ). It is important to keep this in mind when evaluating patients with hyperlipoproteinemia and hyponatremia to prevent inappropriate management that can lead to increased morbidity and mortality. In such cases, direct potentiometry is recommended.
What is the best way to diagnose pseudohyponatremia?
A thorough history and physical examination are essential for suspected pseudohyponatremia. A comprehensive review of systems should be obtained, in addition to a careful review of the patient’s past medical history to search for a potential etiology. Symptoms that suggest true hyponatremia, such as fatigue, muscle cramps, altered mentation, headaches, and seizure, should be excluded before considering the spurious elevation of serum sodium. Comprehensive medication reconciliation is necessary at the initial encounter to exclude exogenous factors that may alter normal sodium homeostasis.
What is pseudohyponatremia?
Pseudohyponatremia is an uncommon laboratory artifact finding that can lead to severe morbidity and mortality if not recognized promptly. This activity reviews the evaluation and management of pseudohyponatremia and highlights the role of the interprofessional team in managing patients with this finding.
What is the first step in the evaluation of pseudohyponatremia?
The most important step in the initial evaluation of suspected pseudohyponatremia is to exclude true hyponatremia; failure to accurately diagnose true hyponatremia can result in severe iatrogenic complications and even death. [3][6][10] Evaluation of hyponatremia should always include a thorough history and physical examination, with specific attention to the history of present illness, past medical history, medications, and assessment of volume status. Serum osmolality should also be obtained, as true hyponatremia is more likely to be associated with low serum osmolality, which is defined as a value of less than 280 mOsm/kg.[11] Calculated serum osmolality should also be obtained, as a significant discrepancy between measured and calculated serum osmolality suggests confounding factors. Once a diagnosis of pseudohyponatremia is confirmed, the clinician should construct a differential diagnosis of potential etiologies—the likely etiologies under consideration direct further laboratory workup of pseudohyponatremia.
What is the normal serum sodium concentration for pseudohyponatremia?
Pseudohyponatremia is an uncommonly encountered laboratory abnormality defined by a serum sodium concentration of less than 135 mEq/L in the setting of a normal serum osmolality (280 to 300 mOsm/kg). Conversely, true hyponatremia is associated with low serum osmolality and should prompt evaluation for the presence of an additional abnormal solute that may be affecting the laboratory assessment.[1] The finding of pseudohyponatremia is an artifact that results from the way a blood sample is processed for serum sodium measurement.
What is the definition of hyponatremia?
Hyponatremia is defined as a serum sodium level of less than 135 mEq/L
How is serum sodium measured?
Flame Emission Spectrophotometry: In the early 1950s, serum sodium was measured by a process known as flame emission spectrophotometry (FES), in which a diluted sample of serum was sprayed across a flame. A spectrophotometer then measures the intensity of light generated at the specific wavelength corresponding to sodium. From this data, the serum sodium level is extrapolated with efficiency with the necessary application of a correction factor.
Does pseudohyponatremia require a diagnosis?
Most cases of pseudohyponatremia do not require the use of DISE to confirm the diagnosis, with few exceptions. In general, DISE merits consideration in situations where the diagnosis is uncertain, and confirmation of pseudohyponatremia is likely to change management significantly; in the absence of these criteria, DISE is likely to be of little diagnostic or prognostic value. If multiple confounders are present, particularly the presence of osmotically active solutes, one should consider DISE to discriminate between hyperosmolar hyponatremia and pseudohyponatremia. We recommend measuring a direct serum sodium level with DISE in the following circumstances[12][3][5]:
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- Crucially, treatment of hyponatremia depends on the severity and a clear understanding of the mechanism of hyponatremia in each case. No treatment may be appropriate, but for those that do require treatment, the options include intravenous administration of isotonic or hypotonic saline solutions, fluid restriction or diuretic therapy [3]. Withdrawa...
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