Fluid and Electrolytes-Na+

How do you treat Diabetes insipidus?

Allow access to free water!! Central-give ADH (vasopressin/ desmopressin) nephrogenic DI- treat underlying cause, dietary sodium restriciton

A person with CHF presents as what fluid/electrolyte disorder? What is the treatment?

CHF: Hypervolemic hypotonic hyponatremia Tx: Sodium and water restriction and treat symptoms of the underlying cause with diuretics

When is hypertonic saline (i.e. NS 3% or NS 5%) most commonly indicated?

Commonly used in severe hyponatremia (Na+<110mEq/L) with symptoms of hypotonicity such as mental status changes!

Which IV solution is "free water"

D5W

What is diabetes insipidus?

Diabetes insipidus (DI) is the complete or partial failure of ADH secretion (central) or response (nephrogenic) Patients present with polyuria and polydipsia, and low urine osmolality (dilute urine) Note: most patients maintain near normal Na levels because they drink lots of fluid

How do you treat hypervolemic hypertonic hypernatremia (remember this is unusual)

Diuretics to eliminate sodium and free water to bring down Na

What are some potential causes of SIADH, that can further progress to a state of isovolemic hypotonic hyponatremia?

Drugs that can cause SIADH: chlorpropamide, carbamazepine, NSAIDS, CTX, vincristine, SSRIs Carcinomas: Lung, pancreas, pulmonary disorders, and many CNS disorders

For hyperglycemia (hypertonic hyponatremia), what is the relationship for the increase in glucose over the normal glucose level of "x" to the decrease in Na+?

Each 100 mg/dL INCrease in glucose over the normal glucose level of 100 mg/dL, there is a decrease of 1.6 mEq/Na/L

What is hyperglycemia

Hypertonic Hyponatremia

What is hypertonic hyponatremia classified as? (note: this is the only hypertonic hyponatremia fluid/electrolyte disorder

Hypertonic hyponatremia = hyperglycemia -Hypertonicity is due to the osmotic activity of GLUCOSE -->hyperglycemia causes increased osmotic activity that draws water from intracellular space, which in turn dilutes serum Na+ thus producing the hyponatermia Hypertonic Osmoles>290 mOsm/kg

Lithium causes:

Hypertonic isovolemic HYPERnatremia

What is hypervolemia, and what are some signs and symptoms by physical examination

Hypervolemia is ECF excess fluid Signs of hypervolemia: Distended veins in hands and neck and edema. -due to fluid overload, can experience increased BP, S3 gallop with heart failure, and weight gain (CHF and fluid overload would be hypervolemic

What can hyponatremia further be sub classified as? Which of these subclasses if further subdivided? into which subclassifications?

Hyponatremia --> can be hypertonic or hypotonic Furthermore, hypotonic hyponatremia can be hypervolemic, hypovolemic, or isovolemic

What is SIADH

Hypotonic Isovolemic Hyponatremia

What is CHF/ cirrhosis

Hypotonic hypervolemic hyponatremia

what is hypotonic hyponatremia defined as? what are the further subclassifications based on?

Hypotonic hyponatremia (<290 mosm/kg) There are 3 types based on VOLUME STATUS: 1) hypervolemic hypotonic hyponatremia 2) hypovolemic hypotonic hyponatremia 3) isovolemic hypotonic hyponatremia

What is hypovolemia defined as? what are some indications of hypovolemia by physical examination?

Hypovolemia aka ECF depletion or "volume depletion" is the loss of fluid and solutes from the body Signs of hypovolemia: Poor skin turgor, dry mucous membranes, flat neck veins, tachycardia, postural hypotension, decreased urine output, increased Scr, weight loss

What is hypovolemic hypertonic hypernatremia classified as? What are some losses that can contribute to this fluid state?

Hypovolemic hypertonic hypernatremia is a deficit in both water and sodium but loss of H2O> loss of sodium (Don't confuse! So hypovolemic Hyoptonic hyponatremia is a deficit in both Na and water however in this case, Na loss is greater than H20. Insensible fluids are hypo osmotic to plasma and can result in hypernatremia -GI and renal losses of hypotonic fluid (vomiting, diarrhea, osmotic diuretics) can result in hypernatremia *With this..Don't Forget!! Most patients who would otherwise become hypernatremic will want to drink and likely correct or prevent this in the first place.....

What is the treatment for hypovolemic hypotonic hyponatremia? What if the patient is symptomatic hypotonic state displaying signs and symptoms of mental status changes?

Hypovolemic hypotonic hyponatremia Tx: Give NS replacement over 6-12 hours *If very low serum Na+ with s/sx of hypotonicity (i.e. mental status changes) then the patient should receive HYPERTONIC saline (NS 3% or NS 5%) and monitor closely

What is the most common type of hypernatremia? What are some subclassifications? (Hint: include diabetes insipidus)

Isovolemic hypertonic hypernatremia-most common; pure water loss Caused by: insensible loss of fluids (skin respiration or increased loss due to fever, resp. infections, burns) and diabetes insipidus Diabetes insipidus (DI) . There is also Central DI and Nephtogenic DI

What is the definintion of Euvolemic (aka isovolemic) hypotonic hyponatremia? w what is this condition commonly caused by?

Isovolemic hypotonic hyponatremia is defined as a normal total body Na+ with an excess in total body water Common causes: SIADH, water intoxication, and kidney disease

Ringers Lactate should be avoided in what populations?

Liver failure

For the treatment of SIADH, is demeclocycline used in emergency situations?

NO!!!! Demeclocylcine is NOT used in emergency situations. Dmeclocylcine antagonizes the effect of ADH in renal tubules, so it takes 3-6 days to see effect, so not used for acute/ emergency treatment situations!

Is NS hyper or hypotonic?

NS is hypotonic to patient

Comment on the distribution of Na+

Na+ is an EXTRACELLULAR cation -Balance of sodium in the body is maintained by intake and renal excretion -Sodium creates an OSMOTIC gradient between intracellular and extracellular fluid, which is the main determinant of osmolality ****Alterations in sodium levels cause water shifts between body compartments Normal: 135-145 mEq/L so 140 is a normal sodium level

What are the normal defenses against hypernatremia and hyperosmolality? Hypernatremia is most often seen in which populations?

Normal body defenses include thirst and stimulation of ADH -hypernatremia is most often seen in infants, the elderly, and unconscious people who can't communicate thirst

In hyponatremia, fluid moves into cells by:

Osmosis

Osmotic adaptation can occur with chronic hypernatremia. What is the major concern? In this process, there are idiogenic osmoles that are formed? why are they important?

Over time, the osmotic adaptation is when the brain tries to protect volume by generating idiogenic osmoles -->MC question: idiogenic osmoles protect the brain during long periods of dehydration -Important in treatment since quick reversal of chronic hypernatremia can result in cerebral edema

What is general treatment outline for the reversal of hypernatremia?

Reverse SLOWLY (over 2-3 days) NOT ABRUPTLY!! *Need to prevent cerebral edema Rate: 0.5mEq/L/h. Can calculate a water deficit and replace 1/2 of that deficit over 12-24 hours

What are signs and symptoms of hypernatremia (most commonly seen when Na+ > xxmEq/L

S/sx often observed when Na+ > 160 mEq/L *Major problem is CNS dysfunction from brain cell shrinkage First s/sx see thirst, dry mucous membranes, weakness, and mental status changes more severe hypernatremia can present as hallucinations, coma, seizures

What is SIADH? What does it commonly contribute to/ cause?

SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion) is an ELEVATION of ADH (water retention) without identifiable osmotic or volume stimuli SIADH often is culprit for establishing Isovolemic hypotonic hyponatremia

What is hypervolemic hypertonic hypernatremia classified as? Is this a common condition?

This is unusual. but hyer hyper hyper is solute gain (sod. bicarb, hypertonic saline, NaCl ingestion) in excess of H2O *CKD *mostly occurs with medical errors--giving too much sodium/fluid

Which symptoms are associated with disorders of volume? -Hypotension -Poor skin turgor -tachycardia Edema Seizure Confusion

Volume related: hypotension tachycardia -edema -poor skin turgor

How is volume status assessed? What can it be helpful to assess?

Volume status assessed by physical exam!! --> can be used as an assessment of sodium and water disorders

What is the definition of HYPOnatremia? At what point do signs and symptoms begin to appear?

hypo Na+--Serum sodium <136mEq/L *most common electrolyte disorder in inpatient medicine -indicative of excess water relative to sodium (H20>Na+) -signs and symptoms don't appear until Na+ <120mEq/L and those include: agitation, irritability, fatigue, cramps, nausea, headache (HA)

What may thiazide diuretics cause?

hypotonic hypovolemic hyponatremia

The SSRIs like fluoxetine, paroxetine can cause:

hypotonic isovolemic hyponatremia (listed with SIADH, potential cause of that)

What is hypovolemic hypotonic hyponatremia classified as? How is it defined by PE? what cause it?

hypovolemic hypotonic hyponatremia--deficit in both Na+ and water, but a deficit of sodium greater than water PE to detect hypovolemia: poor skin turgor, tachycardia, orthostatic hypotension, oliguria (production of abnormally small amounts of urine) Causes of hypovolemia: fluid loss (GI, skin, lung), 3rd spacing (Third-spacing occurs when too much fluid moves from the intravascular space (blood vessels) into the interstitial or "third" space-the nonfunctional area between cells. This can cause potentially serious problems such as edema, reduced cardiac output, and hypotension), renal losses (diuretics!!!)

Diabetes insipidus presents as:

isovolemic hypertonic hypernatremia

With severe hyponatremia (defined by what sodium level?) can present with the following symptoms

severe hyponatremia Na+<110mEq/L Can experience: confusion, seizures, stupor/coma, respiratory arrest

What are the "VAPTANS" ? What are the Vaptans used to treat, and which condition should they be avoided in?

"VAPTANS" = Vasopressin Receptor Antagonists so they antagonize the effects of ADH so they promote water elimination rather than retention. Free water excretion is increased in the kidney Vaptans include: Conivaptan (Vaprisol) and Tolvaptan. "Vaptan is in the name! Tx for: mild (non-symptomatic) isolvolemic hypotonic hyponatremia and hypervolemix hypotonic hyponatremia **NOT FOR hypovolemia. These pts are already fluid deficit, do not want to promote further excretion of any fluids they may have left. AVOID in hypovolemic hypotonic hyponatremia

What is the treatment for isovolemic hypotonic hyponatremia (SIADH treatment basically)

-If drug induced, remove offending agent TX for SIADH nonsymptomatic: water restriction to <1L/day Long term tx: can use demeclocycline -can also give NaCl tablets and/or loop diuretics if needed --"Vaptans" (Vasopressin (ADH) Receptor Antagonists) are a new option If mental status changes (i.e. symptomatic isovolemic hypotonic)-->give hypertonic saline and monitor closely!!

Which IV solution is isotonic? -0.45% NaCl -0.9% NaCl -3% NaCl -D5W

0.9% NaCl is isotonic

When assessing alterations in plasma sodium levels, what are two things you need to think of?

1) Osmolality 2) Volume Status

broad review of hypernatremia, of which all are hypertonic. What are the causes of each 1) hypovolemic hypertonic hypernatremia 2) Isovolemic hypertonic hypernatremia 3)hypervolemic hypertonic hypernatremia

1) hypovolemic hypertonuc hypernatremia: loss of water>loss of sodium. Renal, adrenal insufficiency, GI loss, insensible loss 2) isovolemic hypertonic hypernatremia: Diabetes insipidis (DI) 3) hypervolemic hypertonic hypernatremia: sodium overload; mineralcorticoid excess

How much does 1 L of water weigh?

1L= 1kg

A pt with low serum sodium has a low total body sodium (t/F)

False

what is the treatment for Hyperglycemia?

Hyperglycemia (hypertonic hyponatremia) Tx: Treat hyperglycemia with INSULIN and the serum sodium will normalize

What is hypernatemia always indicative of?

Hypernatremia (serum Na+ >145mEq/L) is always indicative of a deficit in body water relative to sodium (loss of hyptotonic fluid) in conjunction with a disturbance in water intake *All hypernatremia is hypertonic*

Infusion of hypertonic saline may result in:

Hypertonic Hypervolemic hypernatremia *remember this is rare, but often caused by medical error of giving too much Na+ and fluid

What us hypervolemic hypotonic hyponatremia classified as? i.e. what fluid/electrolyte imbalance?

Hypervolemic hypotonic hyponatremia: Due to EXCESS Na and water with WATER excess predominating -this is evident as edema!!! Remember patients are volume overloaded to capacity Examples of hypervolemic hypotonic hyponatremia: -CHF -cirrhosis -nephrotic syndrome

What is the treatment for hypovolemic hypertonic hypernatremia?

Hypo Hyper Hyper--Replace volume first with NS and then replace free water loss NOTE: NS is hypertonic to patients so serum sodium serum will fall

Increased serum sodium levels cause....

Thirst and increased ADH secretion

What is the contraindication associated with Tolvaptan?

Tolvaptan C/I with cirrhosis and liver disease -Tolvaptan may cause increases in liver functions, thus avoid in pts. with liver disease including cirrhosis

Vincristine causes which fluid imbalance?

Vincristine--> Hypotonic isovolemic hyponatremia (listed as a potential offending agent of SIADH)

In the setting of water intoxication and hyponatremia, which of the following will occur? -cellular swelling will occur -the thirst response will be blunted (reduced) -ADH levels will fall -A concentrated urine output will occur

water intoxication--this would be isovolemic hypotonic hyponatremia. This would cause: -cellular swelling -thirst response reduced -ADH levels will fall