BODY FLUIDS AND FLUID THERAPY

Question 1

• Principal determinant of extracellular osmolality
• Maintenance of intravascular volume
• > 40% in bones, <3% intracellular

Answer 1

Sodium

Question 2

most devastating consequence of hypernatremia

Answer 2

brain hemorrhage

Question 3

MC cx of hypovolemic hyponatremia

Answer 3

diarrhea d/t gastroenteritis

Question 4

CHF, nephritic syndrome, Renal Failure & cirrhosis

Answer 4

Hypervolemic hyponatremia

Question 5

Overly rapid correction of hyponatremia

Answer 5

Central pontine myelinolysis

Question 6

Hyponatremia w/ no evidence of volume overload/ volume depletion have euvolemic hyponatremia

Answer 6

SIADH

Question 7

• Principal hormone regulating secretion of potassium

Answer 7

aldosterone

Question 8

For contractility of cardiac, skeletal & smooth muscle

Answer 8

potassium

Question 9

• 1 of the most alarming electrolyte abnormalities d/t its potential lethal arrhythmias
• Caused by spurious laboratory value, ↑intake, transcellular shifts & ↓excretion

Answer 9

hyperkalemia

Question 10

ECG: peaking of the T waves, ↑PR interval, flattening of P wave, widening of QRS complex –> ventricular fibrillation

Answer 10

hyperkalemia

Question 11

tx of hyperkalemia

Answer 11

prevent arrhythmia – stabilize heart & remove K from body (Ca, insulin w/glucose, albulterol neb & Na polystyrene sulfonate/kayexalate)

Question 12

• Common in children, most cases related to gastroenteritis
• Caused by ↑WBC, transcellular shifts, ↓intake & renal & extrarenal losses
• Muscle weakness & cramps, polyuria & polydipsia
• ↑aldosterone: ↑urinary loss of K, metabolic alkalosis, hypokalemia, renal Na retention & ↑urinary Cl

Answer 12

hypokalemia

Question 13

level of K that causes paralysis & ileus

Answer 13

K <2.5meq/L

Question 14

• ECG: flat T wave, depressed ST segment, U wave

- SVT, VT, heart block

Answer 14

hypokalemia

Question 15

tx of hypokalemia

Answer 15

K 0.5-1meq/L x 1hr IV

Question 16

Hypercalciuria

Nephrocalcinosis

Answer 16

Barter Syndrome

Question 17

Low urinary Ca losses

Hypomagnesemia

Answer 17

Gittleman Syndrome

Question 18

• 4TH MC cation in body
• 3rd MC intracellular cation
• 50-60% in bones

Answer 18

Magnesium

Question 19

For membrane stabilization & nerve conduction

Answer 19

Magnesium

Question 20

normal value of magnesium

Answer 20

NV: 1.5-2.3mg/dL

Question 21

• Major cx: GI or renal losses
• Seizure, tetany, (+) Chvostek & trousseau sign
• Causes secondary hypocalcemia

Answer 21

hypomagnesemia

Question 22

tx of hypomagnesemia

Answer 22

MgSO4 25-50mg/kg

Question 23

• Almost always d/t excessive intake
• Inhibit acetylcholine at neuromuscular junction
• Hypotonia, hyporeflexia, weakness, paralysis, hypotension & flushing
• Symptoms appear if Mg >4.5mg/dL

Answer 23

hypermagnesemia

Question 24

hypermagnesemia is exacerbated by ___

Answer 24

aminoglycosides

Question 25

tx of hypermagnesemia

Answer 25

IVF & loop diuretics | o IV CaGluconate 100mg/kg (acute emergency)

Question 26

- Most is in bone/ is intracellular, w/ <1% in plasma - Most plentiful intracellular anion, although majority is part of a larger compound (ATP) - For skeletal maturation, cellular energy metabolism & nucleic acid synthesis

Answer 26

Phosphorus

Question 27

- Refeeding syndrome, hungry bone syndrome, Fanconi syndrome, Dent dse, tumor & antacids - Causes rickets, hemolysis, WBC dysfunction, proximal muscle weakness & atrophy

Answer 27

hypophosphatemia

Question 28

MC complication of hypophosphatemia

Answer 28

Rhabdomyolysis

Question 29

tx of hypophosphatemia

Answer 29

Na phosphate or K phosphate 0.08-0.16mmol/kg 6hr Oral maintenance: 2-3mmol/kg/day in divided doses

Question 30

MC cx of hyperphosphatemia

Answer 30

renal insufficiency

Question 31

principal consequences of hyperphosphatemia

Answer 31

hypocalcemia & systemic calcification

Question 32

- Conjunctiva: foreign body feeling, erythema & injection - Ominous manifestation: hypoxia (pulmonary calcification) & renal failure (nephrocalcinosis)

Answer 32

hyperphosphatemia

Question 33

tx of hyperphosphatemia

Answer 33

Ca carbonate, Ca acetate, Sevelamer HCl