NCA623 Module 2: Nutrition, Fluid, Electrolyte
Imbalances
1. How much total body water do men and females have?: Men 60%, females 50% - based on muscle/mass
-Decreases w age
2. What is the gold standard for assessment of renal electrolyte management?-
: 24-hour urine electrolyte collection (to see urine electrolyte concentration)
3. What is a normal serum osmolality?: How much WATER is in the blood vs solutes in blood
-285-295 mOsm/L (270-295 depending on place)
**Remember by doubling normal sodium range***
4. What is a normal urine osmolality range?: Assessment of water balance and urine concentration
-300-900 mOsm/kg
*More exact measurement of urine concentration than urine specific gravity
5. What is the most common electrolyte disorder found in an inpatient?: hy- ponatremia
6. What does hyponatremia result from?: an excess of total body water
7. What are the 3 types of hyponatremia and how are they differentiated?: Dif- ferentiated by serum osmolality
1. Hypotonic hyponatremia (hypo/hypervolemic/euvolemic) - serum osmo < 285
2. Hypertonic hyponatremia
3. Isotonic hyponatremia
8. What is hypovolemic hypotonic hyponatremia? What is it caused by, symp- toms, and treatment?: -Caused by
volume loss (free water AND sodium loss) - commonly by diuretic overuse
-Symptoms - signs of dehydration
-Treatment - correct underlying cause, sodium replacement Hold diuretics
*Random urine sodium is useful in identifying the source of the loss ( (normal random urine sodium is 10-20 mEq/L)
9. What is hypervolemic hypotonic hyponatremia What is it caused by, symp- toms, and treatment?: -Caused by
fluid retention (common in cardiac, hepatic, and renal failure)
-Signs of fluid overload (pitting edema, abd girth, etc)
-Treatment - treat underlying cause, diuresis (loop diuretics), free water restriction
10.What is euvolemic hypotonic hyponatremia? What is it caused by, symp- toms, and treatment? What test will
you need to order to help diagnose?: -Nor- mal body sodium level, but increased total body water
, NCA623 Module 2: Nutrition, Fluid, Electrolyte
Imbalances
-Signs - hypotension, fatigue, weight gain
-Treatment - treat underlying cause, free water restriction (<1L/day)
*Need to know urine osmo to treat this
-If urine osmo > 100 - consider hypothyroidism or glucocorticoid deficiency as the cause
< 100 - consider polydipsia
-Causes: SIADH, Addison's, Hypothyroidism, polydipsia, desmopressin, NSAIDs
11.What is a normal random urine sodium?: 10-20 mEq/L
<10 = losing water and sodium extra-renaly (common cause - profuse sweating, vomiting, third spacing)
> 20 = losing water and sodium through kidney
12. You are seeing a patient in the ER with evidence of heart failure. His sodium is 125 mq/dL. His O2
saturation is 90%. All of the following are treatment options, EXCEPT
-Furosemide
-1L fluid restriction
-3% NS at 100cc/hr
-2L per NC: -3% NS (HYPERtonic) at 100cc/hr
13.A patient comes in hyperglycemic with a sodium level of 125 and serum osmolality of 300. What is the
electrolyte imbalance called?: Hypertonic hy- ponatremia
14.What is hypertonic hyponatremia? What are 2 causes?: -Sodium < 135
-Serum osmolality > 295 (hyperosmolality)
-Causes: hyperglycemia and mannitol
*Can lead to cerebral edema d/t extracellular fluid shift
-Treatment: treat underlying causes and may need sodium replacement
15.What is isotonic hyponatremia?: <135mEq/L Na AND normal serum osmo (285-295)
AKA pseudohyponatremia
-Chronic, asymptomatic usually
-NO risk for fluid shift; treat underlying cause (sodium replacement isn't usually helpful)
, NCA623 Module 2: Nutrition, Fluid, Electrolyte
Imbalances
-Causes: Hyperglycemia, hyperproteinemia (most common cause - hyperlipidemia), IVIG
16. Which of the following is a common cause of isotonic hyponatremia?
-Hypothyroidism
-Hyperglycemia
-Hyperlipidemia
-Heart failure: Hyperlipidemia
Hypothyroidism - euvolemic hypotonic hyponatremia Heart failure -
hypervolemic hypotonic hyponatremia Hyperglycemia - hypertonic
hyponatremia
17.What is SIADH?: high antidiuretic hormone production leads to water retention
increased total body water DILUTIONAL
HYPONATREMIA
-will see signs of fluid volume overload, changes in loc, weight gain w/o edema, hypertension, tachycardia
**seizure precautions d/t possibility for cerebral edema "SOAKED INSIDE"
-Treatment - restrict water (< 100mL/day), loop diuretics and salt tablets
18.What are the first signs of hyponatremia?: Nausea and malaise (120-125)
<110 = nausea, seizures, coma
19.What is the treatment of severely symptomatic hyponatremia with seizure and coma?: 3% Hypertonic saline
solution
-usually started at 100mL/hr
(Run slow, if develop more symptoms - immediately slow down or stop)
20.Why is sodium replacement done slowly?: To prevent central pontine myeli- nolysis - demyelination of central
pons leading to permanent neurologic damage (paraparesis, dysphagia, coma)
-Asymptomatic chronic hyponatremia - correct at a rate of mEq/L/hr or less (Na recheck q 2hrs) **Do not exceed 6
mEq/L/day**
-Acutely symptomatic - correct at a rate of 2 mEq/L/hr in first 2 hours until symptoms resolve **do not exceed 8
mEq/L/day**
21.What is overcorrection of sodium treated with?: D5W and dDAVP
Imbalances
1. How much total body water do men and females have?: Men 60%, females 50% - based on muscle/mass
-Decreases w age
2. What is the gold standard for assessment of renal electrolyte management?-
: 24-hour urine electrolyte collection (to see urine electrolyte concentration)
3. What is a normal serum osmolality?: How much WATER is in the blood vs solutes in blood
-285-295 mOsm/L (270-295 depending on place)
**Remember by doubling normal sodium range***
4. What is a normal urine osmolality range?: Assessment of water balance and urine concentration
-300-900 mOsm/kg
*More exact measurement of urine concentration than urine specific gravity
5. What is the most common electrolyte disorder found in an inpatient?: hy- ponatremia
6. What does hyponatremia result from?: an excess of total body water
7. What are the 3 types of hyponatremia and how are they differentiated?: Dif- ferentiated by serum osmolality
1. Hypotonic hyponatremia (hypo/hypervolemic/euvolemic) - serum osmo < 285
2. Hypertonic hyponatremia
3. Isotonic hyponatremia
8. What is hypovolemic hypotonic hyponatremia? What is it caused by, symp- toms, and treatment?: -Caused by
volume loss (free water AND sodium loss) - commonly by diuretic overuse
-Symptoms - signs of dehydration
-Treatment - correct underlying cause, sodium replacement Hold diuretics
*Random urine sodium is useful in identifying the source of the loss ( (normal random urine sodium is 10-20 mEq/L)
9. What is hypervolemic hypotonic hyponatremia What is it caused by, symp- toms, and treatment?: -Caused by
fluid retention (common in cardiac, hepatic, and renal failure)
-Signs of fluid overload (pitting edema, abd girth, etc)
-Treatment - treat underlying cause, diuresis (loop diuretics), free water restriction
10.What is euvolemic hypotonic hyponatremia? What is it caused by, symp- toms, and treatment? What test will
you need to order to help diagnose?: -Nor- mal body sodium level, but increased total body water
, NCA623 Module 2: Nutrition, Fluid, Electrolyte
Imbalances
-Signs - hypotension, fatigue, weight gain
-Treatment - treat underlying cause, free water restriction (<1L/day)
*Need to know urine osmo to treat this
-If urine osmo > 100 - consider hypothyroidism or glucocorticoid deficiency as the cause
< 100 - consider polydipsia
-Causes: SIADH, Addison's, Hypothyroidism, polydipsia, desmopressin, NSAIDs
11.What is a normal random urine sodium?: 10-20 mEq/L
<10 = losing water and sodium extra-renaly (common cause - profuse sweating, vomiting, third spacing)
> 20 = losing water and sodium through kidney
12. You are seeing a patient in the ER with evidence of heart failure. His sodium is 125 mq/dL. His O2
saturation is 90%. All of the following are treatment options, EXCEPT
-Furosemide
-1L fluid restriction
-3% NS at 100cc/hr
-2L per NC: -3% NS (HYPERtonic) at 100cc/hr
13.A patient comes in hyperglycemic with a sodium level of 125 and serum osmolality of 300. What is the
electrolyte imbalance called?: Hypertonic hy- ponatremia
14.What is hypertonic hyponatremia? What are 2 causes?: -Sodium < 135
-Serum osmolality > 295 (hyperosmolality)
-Causes: hyperglycemia and mannitol
*Can lead to cerebral edema d/t extracellular fluid shift
-Treatment: treat underlying causes and may need sodium replacement
15.What is isotonic hyponatremia?: <135mEq/L Na AND normal serum osmo (285-295)
AKA pseudohyponatremia
-Chronic, asymptomatic usually
-NO risk for fluid shift; treat underlying cause (sodium replacement isn't usually helpful)
, NCA623 Module 2: Nutrition, Fluid, Electrolyte
Imbalances
-Causes: Hyperglycemia, hyperproteinemia (most common cause - hyperlipidemia), IVIG
16. Which of the following is a common cause of isotonic hyponatremia?
-Hypothyroidism
-Hyperglycemia
-Hyperlipidemia
-Heart failure: Hyperlipidemia
Hypothyroidism - euvolemic hypotonic hyponatremia Heart failure -
hypervolemic hypotonic hyponatremia Hyperglycemia - hypertonic
hyponatremia
17.What is SIADH?: high antidiuretic hormone production leads to water retention
increased total body water DILUTIONAL
HYPONATREMIA
-will see signs of fluid volume overload, changes in loc, weight gain w/o edema, hypertension, tachycardia
**seizure precautions d/t possibility for cerebral edema "SOAKED INSIDE"
-Treatment - restrict water (< 100mL/day), loop diuretics and salt tablets
18.What are the first signs of hyponatremia?: Nausea and malaise (120-125)
<110 = nausea, seizures, coma
19.What is the treatment of severely symptomatic hyponatremia with seizure and coma?: 3% Hypertonic saline
solution
-usually started at 100mL/hr
(Run slow, if develop more symptoms - immediately slow down or stop)
20.Why is sodium replacement done slowly?: To prevent central pontine myeli- nolysis - demyelination of central
pons leading to permanent neurologic damage (paraparesis, dysphagia, coma)
-Asymptomatic chronic hyponatremia - correct at a rate of mEq/L/hr or less (Na recheck q 2hrs) **Do not exceed 6
mEq/L/day**
-Acutely symptomatic - correct at a rate of 2 mEq/L/hr in first 2 hours until symptoms resolve **do not exceed 8
mEq/L/day**
21.What is overcorrection of sodium treated with?: D5W and dDAVP
