Fluid & Electrolytes

Question 1

Urine Sodium Levels

Answer 1

Normal: 20 mEq/L
Low: <20 is from kidney conserving Na d/t dehydration/hypovolemia
High: >20 is d/t high Na intake, diuretics, adrenal insufficiency.

Question 2

Serum osmolality

Answer 2

Normal: 275-295.
Low: over hydration, hyponatremia, SIADH
High: dehydration, hypernatremia, DKA, DI, reduced kidney function

Question 3

Holliday-Segar Method

Answer 3

2-10 Kg: 100 ml/kg
11-20 kg: 1000 ml + 50 ml/kg for ea kg from 11-20 kg.
21-70 kg: 1500 ml + 20 ml/kg for ea kg from 21-70 kg
Calculate total volume for 24H then divide by 24 for hourly rate.

Question 4

4-2-1 Method

Answer 4

1st 10 kg: 4 ml/kg.
2nd 10 kg: 2 ml/kg + 1st 4ml/kg.
Over 20kg: 1 ml/hr + 1st & 2nd ml/kg

Question 5

BSA Calculation ml/m2/day

Answer 5

BSA= wt kg x ht cm / 3600 then squared.

Question 6

Fluid-Deficit Calculation

Answer 6

Fluid deficit=Pre-illness wt-illness wt
% dehydration= (pre-illness wt-illness wt) / illness wt x 100%
Then subtract fluid boluses given

Question 7

Na deficit calculation

Answer 7

Na deficit = (135 - Na level mEq/L x 100/ L

Question 8

Na replacement calculation

Answer 8

0.6 x wt x (target Na-measured Na)

Question 9

Hypernatremia

Answer 9

Na > 150
from excess free water loss: diarrhea, DI, inadequate BF. renal tubular disorders, inappropriate formula concentrations, increased Na intake.
Infants & Cognitive impaired at risk.

Question 10

Hypernatremia S/S

Answer 10

Weakness, lethargy, dec DTR’s, fever, high-pitch cry, irritability, muscle cramps, rnhabdomylosis, renal failure, AMS, sz’s, doughy skin, coma,

Question 11

Hypernatremia Management

Answer 11

Dec Na no more than 15mEq/L in 24Hrs or 0.5-1 mEq/L/hr

Question 12

Hypernatremia duration of correction

Answer 12

150 - 170 = correct over 48H
>170 = correct over 72H
>200 = consider dialysis
>170 should be managed in ICU setting for electrolyte, cardiac and neuro monitoring

Question 13

Hypovolemic hyponatremia

Answer 13

Na < 135 with loss of Na in excess of water
Osmotic diuresis, diarrhea, vomiting, burns, pancreatitis.

Question 14

Euvolemic hyponatremia

Answer 14

Na 135-145 with Na lost in proportion to water loss
CSW, meningitis, CF, Diuretic use

Question 15

Hypervolemic hyponatremia

Answer 15

Na > 145 net loss of water in excess of solute.
CHF, renal failure, Nephrotic syndrome, water intoxication, cirrhosis.

Question 16

Hyponatremia S/S

Answer 16

irritability, poor feeding, nausea, lethargy, sz’s, coma, cerebral edema.

Question 17

Hyponatremia Management

Answer 17

treat cause
restore intravascular volume
restore Na slowly

Question 18

Hyponatremia duration of correction

Answer 18

2-4 mEQ /L every 4 H or
10-20 mEQ/ L in 24 H

Question 19

Electrolyte imbalances that cause seizures

Answer 19

Hyponatremia
Hypernatremia
Hypophosphatemia
Hypochloremia
Hypercalcemia

Question 20

Hypocalcemia

Answer 20

Ca < 9; ica < 1.1
Ica binding to RBC’s, malabsorption, hypoparathyroidism, renal failure, sepsis, TLS, pancreatitis, DiGeorge syndrome, hyperphosphatemia & hypomagnesemia

Question 21

Hypocalcemia S/S

Answer 21

NM irritability, confusion, irritability, muscle cramps, numbness/tingling, paresthesias/weakness, sz’s. tetany.
Chvostek sigh +: facial nerve twitching when tapped.
Trousseau sign +: involuntary carpopedal spasm when BP cuff inflated.
myocardial irritability, hypotension, bradycardia

Question 22

Hypocalcemia Management

Answer 22

Acute replacement
CaCl 10-20 mg/kg/dose CL
Cagluc 100/mg/dose
Chronic: Cacarb, Cacitrate, Cagluconate. Vit D.
in refractory states, make sure Mg is normal.

Question 23

Hypercalcemia

Answer 23

Williams syndrome, excessive intake, hyperparathyroidism, immobility, malignancy, thiazide diurectics.

Question 24

Hypercalcemia S/S

Answer 24

asymptomatic
GI: nausea, anorexia, constipation, anxiety, depression, HA, lethargy, hypotonia, sz’s, coma.
Short QT interval, bradycardia, 1st degree heart block, vent tachycardia
polyuria, renal calculi, renal tubular dysfunction

Question 25

Hypocalcemia Evaluation

Answer 25

Serum & ica, pth, pH, 25-hydroxy Vit D, 1,25-dihydroxy Vit D Urine Ca, phos, creatinine ankle & wrist xrays EKG

Question 26

Hypercalcemia Evaluation

Answer 26

serum Ca & ica , PTH, pH, Vit D levels, urine electrolytes, EKG, KUB, renal US

Question 27

Hypercalcemia Management

Answer 27

treat underlying cause NS at 2-3x maintenance. Loop directs glucocorticoids biphosphonates hemodialysis

Question 28

Hyperphosphatemia

Answer 28

phosphorus > 4.5 hypoparathyroidism, TLS, rhabdomyolysis, renal failure

Question 29

hyperphosphatemia S/S

Answer 29

AMS, sz's, tetany, weakness, parethesias, fatigue, cramping, layrngospasm, NM irritability, arrhythmia, Ca deposits in soft tissue

Question 30

Hypophosphatemia

Answer 30

phosphorus < 2.5 malnutrition/starvation DKA, steroid use, diuretic use, Vit D deficiency, chronic use of antacids, extensive burns, hyperparathyroidism

Question 31

Hypophosphatemia S/S

Answer 31

confusion, irritability, coma, muscle weakness, sz;s, apnea, hypoxia, hemolytic anemia, thrombocytopenia, myocardial depression, impaired granulocyte activity

Question 32

Hypophosphatemia Management

Answer 32

replace with K phos or Na phos.

Question 33

Hyperphoshatemia Management

Answer 33

protein restriction sevelamer hydrochloride, Ca carbonate or aluminum hydroxide as phos binders. Vitamin C supplements diuresis with normal Renal function or dialysis.

Question 34

Hyperkalemia

Answer 34

acidosis, Addison dx, aldosterone insensitivity, ACE inhibitors, angiotensin blockers, theophylline, NSAIDS, CAH, crush injuries, rhabdomyolysis, renal impairment, excessive supplementation

Question 35

Hypokalemia

Answer 35

amphotericin, diuretics, decongestant, dopamine, dobutamine, bronchodilators, Barter syndrome, Cushing syndrome, leukemia, diarrhea, laxatives, vomiting, increased insulin, DKA, metabolic alkalosis

Question 36

Hypokalemia S/S

Answer 36

HTN, arrhythmias, flattened T waves (delayed polarization) Long QT, U waves. cramping, decreased perfusion, fatigue, ileum, impaired insulin release. paralysis, polyuria

Question 37

Hyperkalemia S/S

Answer 37

Peaked T waves, prolonged PR & QRS interval, ST changes, AV block, V-tac, V-fib, merging of QRS T wave, systole, muscle weakness, parethesias, tetany.

Question 38

Hypokalemia Management

Answer 38

replace with KCl at 0.5-1 mEq/kg/dose for acute.

Question 39

Hyperkalemia Management

Answer 39

Stabilize the myocardium: CaCl or Cagluc for membrane stabilizations. IV insulin & glucose. Enhance movement of K+ into cells: IV NaHCO3 or inhaled albuterol, glucose & insulin 0.1-0.3 u/kg Remove K from patient: Kayexelate 1g/kg diuretics if normal renal or beta-agonists. remove all K sources. hemodialysis

Question 40

Dehydration assessment

Answer 40

Assess level of hydration * mild (5%) * moderate (10%) * severe (15%) Symptoms: * Mild (5%) - fatigue, may refuse PO, normal vitals * Moderate (10%) - thirsty, restless, irritable, mild change in vitals, decreased tears, dry oral mucosa * Severe (15%) - Lethargy, alteration in all vitals, cool, mottled, minimal output, deep breathing

Question 41

Hypoglycemia (glucose < 50)

Answer 41

Neonatal: diabetic mom, adrenocortical deficiency, inborn errors, hypopituitarism. Can be transient, immature fasting, lack of supply * Childhood: inborn errors, growth hormone deficiency, stress, hepatic dysfunction, ingestion(beta-blockers), infection, uncontrolled diabetes

Question 42

Hypoglycemia sx's

Answer 42

jittery, irritable, seizures, vomiting, headache

Question 43

Hypoglycemia evaluation & management

Answer 43

Need to send critical labs while hypoglycemic (free fatty acid (FFA), insulin, beta- hydroxybutyrate (BHOB), cortisol, acylcarnitine, lactate, pyruvate, NH4, GH, urine ketones). Endocrine consult. ** Glucose replacement – 10% or 25% glucose – 0.5 – 1g/kg

Question 44

Expected Anion Gap Calculation

Answer 44

Cations – Anions OR Na - (Cl + HCO3) Normal range = 12 + 2 mEq/L

Question 45

Non-Gap Acidosis

Answer 45

Diarrhea, Renal Tubular Acidosis, Adrenal Insufficiency, Chronic Kidney Disease, Intestinal, pancreatic, biliary fistula, Hypoaldosteronism, Spironolactone, prostaglandin inhibitors, triamterene, amiloride, trimethoprim, pentamidine, cyclosporin

Question 46

Gap Acidosis: CAT MUDPILES

Question 47

Which of the following electrolyte imbalances is MOST likely associated with seizures? 1. glucose, sodium and phosphorus 2. sodium, calcium and phosphorus 3. glucose, sodium and calcium 4.calcium, sodium and magnesium

Answer 47

3. glucose, sodium and calcium

Question 48

A lethargic breastfed infant delivered at a birthing center without a newborn screen presents to the ER with poor muscle tone, hoarse cry, normal pH, and hypothermia. Which of the following is the MOST likely cause of these symptoms? 1.Botulism 2.Metabolic disease 3.Hypernatremia 4.Hypothyroidism

Answer 48

4.Hypothyroidism

Question 49

A 2-month-old with vomiting presents with dry mucous membranes, a weak cry, and cool extremities. Which of the following interventions is FIRST? 1.Fluid bolus of D5NS and re-assess 2.Check glucose and administer NS bolus 3.Administer NS bolus and D25W 2mL/kg 4.Warm, check glucose, and bolus D5NS

Answer 49

2.Check glucose and administer NS bolus

Question 50

A child is admitted with Acute Kidney Injury (AKI). The labs at presentation are: Na 142, Cl 110, HCO3 14. What is the anion gap? 1. 14 2. 18 3.13 4.17

Answer 50

2. 18

Question 51

What kcal/kg/day is a 5 kg infant receiving who took in 500 mL of Similac 27 kcal/oz? 1.75 2.90 3.100 4.110

Answer 51

2.90

Question 52

Question 8 Which of the following are expected responses during critical illness? 1.Hypermagnesemia, low cortisol 2.Hyperglycemia, hypoalbuminemia 3.Hypercalcemia, high cortisol 4.Hypokalemia, hyperalbumunemia

Answer 52

2.Hyperglycemia, hypoalbuminemia