Endo Sodium Potassium

Front 1

How many cc's of water loss is attributed to urine:

At rest?
During exercise?
On a hot day?

Back 1

At rest: 1000-1500

Exercise: 4000-5000

On a hot day: 500-1200

Front 2

How many cc's of total water loss occurs:

At rest?
During exercise?
On a hot day?

Back 2

At rest: 2300

Exercise: 6600

Hot day: 4200

Front 3

Blood volume in plasma?

Blood volume in red cells?

Back 3

Plasma: 3 liters

RBCs: 2 liters

Front 4

Extracellular volume of fluid?

Intracellular volume?

Total volume in 70 kg person?

Back 4

14 liters

28 liters

42 liters

Front 5

How do you calculate blood volume in 70k person for male vs female?

Back 5

Male: 70kg x 0.6 = 42 liters

Female: 70kg x 0.5 = 35 liters

Front 6

What is the normal narrow limit of body fluid osmolality?

Back 6

285-295 mOsmo/kg

Front 7

What primarily determines the distribution of body water?

Back 7

Osmotic forces

Front 8

What are 4 things that contribute to water balance?

Back 8

Access to water and intact thirst mechanism.

Extrarenal water losses.

Approp renal excretion of solutes/ water.

Intact ADH biosynth, release and response.

Front 9

What percentage of water reabsorbtion occurs in the PROXIMAL TUBULE?

Back 9

75%

Front 10

What occurs in the COLLECTING DUCT in regards to water reabsorbtion?

Back 10

Presence of ADH results in water reabsorbtion by opening aquaporin channels.

Absence of ADH results in water loss.

Front 11

What is osmolality?

What is the formula for it?

Back 11

# of osmoles per kg of solvent.

2 x Na + (gluc/18) + (BUN/2.8) + X

Front 12

Hypernatremia and osmolality?

Hyponatremia and osmolality?

Back 12

Hypernatremia ALWAY = hyperosmo

Hyponatremia may be low, normal or high osmo

Front 13

What does a change in serum sodium generally mean?

Back 13

There has been a change in water balance.

Front 14

What is the correlation between ECV (volume - blood pressure) and serum sodium vs total body sodium?

Back 14

Changes in total sodium alters blood pressure.

No correlation with serum sodium and renal sodium excretion or bp.

Front 15

What senses a change in potassium?

What compensatory mechanisms are triggered by changes in potassium?

Back 15

Sensed by osmoreceptors in hypothalamus.

--> change in thirst: regulate water intake.

-->affect ADH release from posterior lobe of pituitary: regulates water excretion by affecting water permeability of collecting tubule.

Front 16

2 compensatory mechanisms to correct potassium in the case of an increase in Na+ or loss of water?

Back 16

Thirst --> increased H2O intake --> decrease K.

Increased ADH --> decrease H2O excretion --> decrease K

Front 17

2 compensatory mechanisms to correct potassium in the case of a decrease in Na+ or increased water?

Back 17

Decreased thirst --> increased H2O intake --> increase K

Decrease ADH --> increased H2O excretion --> increase K

Front 18

2 causes of disruption of normal regulation of potassium?

Back 18

Renal disorder: impairs concentration or diluting ability.

Non-osmolar stimulus to ADH release: volume depletion, n/v, pain, ectopic production, meds

Front 19

What are two cases of hypoosmolality not caused by hyponatremia?

Back 19

Pseudohyponatremia: marked elevation of plasma lipids or proteins.

High concentration of effective solutes other than sodium (glucose, mannitol)

Front 20

Effects of acute hyponatremia?

Back 20

Cerebral edema and intracranial hypertension:
- HA
- irritability
- lethargy
- confusion
- n/v
- ataxia
- delirium
- seizure

Front 21

What are the symptoms of chronic hyponatremia?

Back 21

Often asymptomatic.

Front 22

How would you correct the sodium upward or downward for high glucose?

Back 22

For every 100 mg/dL of glucose over 100, multiply by 1.6. Take that value and either add to or subtract from the sodium result.

Front 23

What value constitutes hypo-osmolar serum?

Back 23

<280

Front 24

What value constitutes hyper-osmolar serum?

Back 24

>295

Front 25

3 states that can cause enhanced water reabsorbtion in the proximal tubule, leading to hyponatremia?

Back 25

CHF

Ascites

Dehydration

Front 26

5 states that can cause potentially high ADH states in the collecting ducts?

Back 26

Adrenal insufficiency,

Hypothyroid,

CHF,

SAIDH,

Volume depletion

Front 27

Urine sodium and Urine osmo values that indicate hypovolemia?

causes of this?

Back 27

<20 mEq/L urine sodium, >400 urine osmo.
-Nonrenal Na loss.
-GI loss.
-Skin loss.
-Sequestration.

Or:
>20 mEq/L / <400
-Renal Na loss
-Diuretics
-Salt-wasting states
-osmotic diuresis
-bicarbonaturia

Front 28

Urine sodium and Urine osmo that indicate hypervolemia?

Causes of this?

Back 28

<20 mEq/L, Urine osmo: >350
-Edematous states
-cirrhosis
-nephrotic syndrome
-CHF

>20 mEq/L and <350
-renal failure

Front 29

Urine sodium and Osomos that indicate euvolemia?

Causes?

Back 29

>20 una, high usomo
-SIADH
-Hypothyroidism
-Adrenal insuff
-stress

Variable una, <100 uosmo
-primary polydipsia
-reset osmostat

Front 30

What is fractional excretion of water equasion (FeNa)?

Back 30

Urine sodium x serum creat/ SNa x urine creat

Front 31

What is <1 FeNa and <10 urine sodium consistent with?

Back 31

Increased proximal tubule function

Front 32

What is >2 FeNa and >20 urine sodium consistent with?

Back 32

good hydration, diuretics in proximal tubule

Front 33

What is >300 urine osmo consistent with?

Back 33

ADH effect

Front 34

What is <100 urine osmo consistent with?

Back 34

no ADH

Front 35

What are 3 lab tests you should perform with hyponatremia and to rule out what conditions? (3)

Back 35

Renal function to exclude renal failure

Adrenal function to exclude Addison's disease

Thyroid function to exclude hypothyroid

Front 36

Treatment for hypovolemic hyponatremia?

Back 36

Isotonic IV fluids or colloids.

Reverse underlying process.

Front 37

What is the greatest risk in acute euvolemic hyponatremia (<48 hrs)?

Back 37

Neuro complications

Front 38

What are the risks in chronic euvolemic hyponatremia (>48 hrs)?

Back 38

Little risk from hyponatremia, but can have problems following rapid correction.

Front 39

Treatments for hypervolemic hyponatremia?

Back 39

Fluid restriction,

Sodium restriction,

LOOP diuretics,

Tx of underlying disease,

Rarely require therapy to increase K acutely.

Front 40

4 risk factors of developing cerebral demyelinating disease?

Back 40

More than a 12 mEq/L increase in first 24 hrs.

Overcorrection > 140 mEq/L w/in first 2 days.

Hypoxic or anoxic episodes prior to therapy.

Malnutretion or chronic ETOH.

Front 41

Treatment of severe hyponatremia that's asymptomatic?

Back 41

Fluid restriction 800-1000 mL/day.
Change nec IV meds to be in isotonic fluids.
May need LIMITED IV saline WITH lasix.
NO maintenance IV fluids.
Frequent monitoring of serum sodium.
Slow correction.

Front 42

Treatment of severe hyponatremia that IS symptomatic?

Back 42

Admit to ICU.
Use 3% NaCl (+/- lasix).
Calculate the sodium deficit to bring serum sodium to 120 mEq/L.

Front 43

In severe hyponatremia, if symptoms are mild, what should your serum sodium aim be?

Back 43

Increase serum sodium by 0.5 mEq/L/hr until 120 mEq/L

Front 44

In severe hyponatremia, if symptoms are severe, what should serum sodium goals be?

Back 44

Can increase rate of correction to 1-2 mEq/L/hr for first 5-10 mEq/L elevation in SNa, but still no more than 12 mEq/L/day

Front 45

Treatment for hypernatremia?

Back 45

If deficit is only water, replace water.

If deficit is both water, salt and hypovolemia, replace w/ hypotonic salt solution AND depending on severity of SNa, may treat w// normal saline, 1/2 normal saline or 1/4 normal saline.

Front 46

What should you do to determine treatment for hypernatremia?

Back 46

Calculate free water deficit.

Then calculate rate to correct water deficit at the rate of no faster than 0.5 mEq/hr.

This formula may underestimate water deficit in pts w/ hypotonic fluid loss. Doesn't acct for ongoing insensible and free water losses.

Front 47

Medication treatments for hyponatremia (2)?

Back 47

Conivaptan: PO or IV. Promotes aquaresis and reduces vasomotor tone. Potent inhibitor of CYP3A4.

Tolvaptan (Satavapan, lixivaptan): PO.
Thirst increases and may limit rise in serum sodium.
Potential for overcorrection. Costly.

Front 48

Practical approach to treating hyponatremia? (3)

Back 48

1. exclude elevated gluc or trigs.

2. exclude endo causes: hypothyroid, adrenal insuff, ADH tumor.

3. Look at renal causes: renal failure, increased prox tubular absorption. (CHF, ascites, dehydration, increased ADH)

Front 49

Hyponatremia pearl: treat hypovolemia with: ________

Back 49

isotonic IVF

Front 50

If euvolemic or hypervolemic and stable: ______________ while evaluatation of hyponatremia in process?

Back 50

HEP lock IVF

Front 51

At what rate should you correct hyponatremia?

Back 51

The tempo at which is developed.

Front 52

Why should you not aim for a normal SNa in hyponatremia?

Back 52

Overcorrection may occur.

Front 53

In ICU setting, what should you be cautious about using because of risk of fluctuation of sodium?

Back 53

Cautious use of 3% NaCl w/ freq monitoring of SNa.

Front 54

Labs to check in hyponatremia?

Back 54

Glucose,

Urine Sodium (will tell you about volume),

Urine osmolarity (to check for ADH)

Calculate serum osmo: 2Na + gluc/18 + BUN/2.8

Front 55

What does hypernatremia represent?

Back 55

Water deficit in relation to body's sodium stores.

Most commonly seen in extremes of life

Usually a manifestation of severe dehydration (rarely due to increased sodium). Almost always net water losses from body coupled w/ inadequate water intake.

Front 56

What is normal defense against hypernatremia?

Back 56

ADH and thirst.

Front 57

Clinical manifestations of hypernatremia? (6)

Back 57

Confusion/ irritability/ weakness.
Neuromuscular irritability.
Seizure.
Coma.
CNS hemorrhage.
Venous sinus thrombosis.

Front 58

3 renal losses causes of hypovolemic hypernatremia?

Back 58

Osmotic or loop diuretics.

Postobstruction.

Intrinsic renal disease.

Front 59

4 extrarenal losses causes of hypovolemic hypernatremia?

Back 59

Excessive sweating.

Burns.

Diarrhea.

Fistulas.

Front 60

5 causes of hypervolemia hypernatremia (sodium gains)?

Back 60

Primary hyperaldosteronism.

Cushings.

Hypertonic dialysis.

Hypertonic sodium solutions.

Sodium ingestion.

Front 61

Extrarenal water losses in euvolemic hypernatremia?

Back 61

Insensible losses: respiratory, dermal

Front 62

Renal losses in euvolemic hypernatremia?

Back 62

Diabetes insipidus,

Osmotic diuresis,

Hypodipsia

Front 63

4 management strategies of hypernatremia?

Back 63

Discontinue offending agents if hypervolemic hypernatremia and use diuretics as needed.
Correct existing volume deficit w/ isotonic IVF/ colloids if hemodynamic comrpomise.
Correct underlying prob if poss.
Administer hypotonic fluids to correct water deficit.

Front 64

Calculation of free water deficit?

Back 64

Total body water x [(SNa/140)] - TBW

Front 65

In hypernatremia, after calculating the free water deficit, how do you apply that?

Back 65

Replete half the deficit during first 24 hrs and the remainder over next 24 hrs.

May underestimate deficit in pts w/ hypotonic fluid loss.

Front 66

How do you want to manage hypernatremia?

Back 66

Correct at tempo at which it developed.

Too rapid correction --> cerebral edema!

Try to use oral route or feeding tube.

Watch gluc concentration w/ D5W used.

Front 67

If hypernatremia is not acute or unknown, correction?

Back 67

Maximal rate of 0.5 mEq/L/hr

Front 68

What do you need to be aware of when using equations to calculate water depletion?

Back 68

Don't account for ongoing solute and water losses.

Monitor lab studies CLOSELY.

Front 69

If hypernatremia shows contracted ECF volume, BP, HR, HX
AND
volume is low and urine osmo is high?

Back 69

Non-renal losses of H2O.
GI or skin

Front 70

If hypernatremia shows contracted ECF volume, BP, HR, Hx,
AND
volume is high and urine osmo is low?

Back 70

Renal H2O loss.
Central DI or nephro DI

Front 71

How long should you take to correct serum sodium from 160 to 140?

Back 71

40 hrs (rate of no more than 0.5 meq/L per hr)

Approximation b/c of any ongoing losses (diarrhea, fever, burns).
Measure sodium frequently to avoid too rapid correction.

Front 72

Labs to assess in hypernatremia?

Back 72

serum sodium, gluc, BUN, creat,
urine na, urine osmo

Front 73

What are the total body K+ stores in an adult?

Back 73

3000-4000 mEq

Front 74

How much of total body K+ is INTRACELLULAR?

Back 74

98%

Front 75

What is the concentration of K+ extracellularly (serum potassium)?

Back 75

3.5-5 mEq/L

Front 76

Major roll of K+?

Small changes in K+ can lead to what effects?

Back 76

Crucial role in cell metabolism and maintenance of resting membrane potential in excitable cells.

Disturbance effects on skeletal muscle, cardiac and neural cells

Front 77

Things that effect the distribution of potassium between cell and extracellular fluid?

Back 77

Na-K ATPase.
Catecholamines.
Insulin.
Exercise.
Inorganic metabolic acidosis.
Plasma K+ concentration.
Hyperosmolality.
Rate of cell breakdown (hemolysis, tumor lysis, rhabdo) and production.

Front 78

Things that regulate the daily K+ excretion which occurs in the kidney via secretion of K into lumen of distal nephron?

Back 78

Aldo,
Plasma K concentration,
Distal tubular flow rate,
Distal tubular Na delivery,
Extracellular pH,
ADH

Front 79

4 main causes of hypokalemia?

Back 79

Decreased net intake.
Increased cell entry.
Increased GI losses.
Increased urinary loss.

Front 80

Causes of increased cell entry of K leading to hypokalemia?

Back 80

Alkalemia,
Increased insulin,
B-adrenergic activity (caffeine, theo, decongestant),
Periodic paralysis,
Tx of anemia,
Hypothermia,
Hyperthyroidism

Front 81

Causes of increased urinary loss of K leading to hypkalemia?

Back 81

Diuretics,
Mineralcorticoid excess,
Increased distal nephron flow (salt-wasting; diuretics),
Amph B,
Hypomagnesemia,
Polyuria,
Na reabsorption w/ nonreabsorbably anion.

Front 82

5 main clinical manifestations of hypokalemia?

Back 82

Muscle weakness or paralysis,
Cardiac arrhythmias,
Rhabdomyolysis,
Hyperglycemia,
Renal dysfunction

Front 83

What can occur to muscles at K <2.5?

Back 83

Ascending muscle weakness, similar to that seen w/ hyperK.
Sometimes even respiratory paralysis occurs.

Front 84

5 forms of renal dysfunction due to hypokalemia?

Back 84

Impaired concentrating ability,
Increased ammonioagenesis,
Impaired urinary acidification,
Increased bicarb reabsorption,
Hypokalemic nephropathy

Front 85

Things to determine in order to determine treatment for hypokalemia?

Back 85

Assess physiologic effect of K deficit:
- ECG,
- muscle strength.

Approximate K deficit:
- is it cellular shift or K loss?

Front 86

What is the progression starting at normal in decreasing serum K on ECG?

Back 86

Flat T wave,

Prominent U wave,

Depressed ST segment

Front 87

Oral treatments for hypokalemia?

Back 87

KCl given.
(Alkaline salts reserved for pts w/ hypokalemia & metabolic acidosis).

Mild (3-3.4): give KCl as 20 mEq dose 1-3x/d

Severe or sx: give 40 mEq 3-4x/d

Front 88

In what conditions would you give IV KCl for hypokalemia?

Back 88

Pts unable to take PO

Life-threatening (paralysis, dig tox),

ECG abnormal

Front 89

What should you give in life threatening hypokalemia?

Back 89

KCl in non-dextrose containing fluids. "K-runs" at max rate of 10-20 mEq/hr.

Use central line and infusion pump.

Front 90

Hints toward diagnosis of hypokalemia in hx?

Back 90

Diarrhea,

Diuretics,

Diabetic on insulin

(3 Ds)

Front 91

Labs to obtain in hypokalemia?

Back 91

Serum K,
Renin,
Aldo,
Serum bicarb,
Osmo,
Urine K,
Urine osmo,

Front 92

What is TTKG and how is it measured?

Back 92

Trans Tubular Potassium Gradient.

U/P K divided by U/P osmo.

Front 93

Interpretation of TTKG?

Back 93

If <2: minimal urine K

If >4: increased urine K loss

Front 94

3 main causes of hyperkalemia?

Back 94

Increased intake

Movement out of cells

Decreased urine excretion

Front 95

Causes of movement of K out of cells?

Back 95

Metabolic acidosis,
Insulin def,
Tissue catabolism,
B-adrenergic blockade,
Severe exercise,
Digoxin OD,
Periodid paralysis,
Succinylcholine

Front 96

Causes of decreased urinary excretion?

Back 96

Renal failure,
Volume depletion,
Hypoaldosteronism,
Hyperkalemic renal tubular acidosis,
Drugs

Front 97

3 clinical manifestations of hyperkalemia?

Back 97

Impaired NM function (weakness to paralysis).

Decreased ammoniagenesis.

Decreased cardiac conduction and dysrhythmias.

Front 98

ECG progression from normal in increasing serum K?

*Progression of changes are UNPREDICTABLE

Back 98

Peaked T wave,

Wide QRS/ short QT/ long PR,

Further widening of QRS/ absent P,

Sine-wave morphology (v tach)

Front 99

Importance of elevated K?

Back 99

Life threatening! Requires immed eval and tx.

Front 100

What labs should you check in hyperkalemia?

Back 100

Serum and plasma K.

BUN and creat (determine renal function).

Urine K, Serum K, Uosmo and serum osmo to calc TTKG. If TTKG high: kidneys trying to get rid of K. If low, renal prob.

Serum aldo or cortisol to exclude adrenal insuf.

Front 101

Treatment goals of hyperkalemia?

Back 101

Discontinue K intake.

Stabilize: membrane antagonism.

Temporize: redistribution.

Enhance excretion.

Front 102

Treatmnet options for hyperkalemia?

Back 102

Calcium gluconate IV.
Sodium if hyponatremic.
Bicarb IV.
Resin exchange: kayexlate w/ sorbitol.
Insulin w/ gluc.
B agonist: albuterol neb.
Diuretics: loop.
Dialysis: CKD pts.

Front 103

How does calcium cause direct antagonism of membrane and is used for tx of hyperkalemia?
Dose, onset, druation, caution?

Back 103

Increases threshold potential.

10-20 mL of 10% calc gluc.
Onset: 1-3 min.
Duration 30-60 min.

Caution w/ digoxin

Front 104

sodium causes direct antagonism of membrane and is used for tx of hyperkalemia. Who should get this and in what form?

Back 104

Pt w/ hyponatremia.

Sodium bicarb.

Hypertonic saline

Front 105

Hx that should hint at hyperkalemia?

Back 105

Salt substitute,
Renal failure,
DM,
ACE/ARB therapy,
K sparing diuretic,
AIDS,
heparin

Front 106

What labs should be checked in hyperkalemia?

Back 106

BUN,
Creat,
Bicarb,
Urine lytes,
Renin,
Aldo,
TTKG calc,
ECG

Front 107

What does Normal saline (0.9%) contain? What is the osmolarity?

Back 107

Sodium

300

Front 108

What does 1/2 Normal saline contain?
Osmolarity?

Back 108

Sodium

150

Front 109

What does D51/2NS contain?
Osmolarity?

Back 109

Sodium, gluc

400

Front 110

WHat does D5W contain?
Osmo?

Back 110

Gluc

250

Front 111

What does lactated ringers contain?
Osmo?

Back 111

Sodium, K, lactate, Ca

275

Front 112

What does D5 lactated ring contain?
Osmo?

Back 112

Sodium, gluc, K, Lactate, Ca

525