thera fluid & electrolyte

  1. Normal sodium level
    135-145 mEq/L
  2. normal plasma osmolality
    275 - 290 mOsm/kg
  3. distribution of total body water
    • IC - 60%
    • EC - 40%
    •    interstitial - 75%
    •    intravascular - 25%
  4. Crystalloid distribution
    • EC - 100%
    •   interstitial - 75%
    •   intravascular - 25%
  5. D5W distribution
    • IC - 60%
    • EC - 40%
    •   interstitial - 75%
    •   intravascular - 25%
  6. S/S of hypovolemia
    • increased BUN/Cr ratio > 10:1
    • tachycardia > 100bpm
    • hypotension SBP < 80 mmHg
    • orthostatic changes in HR or BP
    • dry mucous membranes
    • decreased skin turgor
    • reduced urine output
    • dizziness
  7. 3 issues to consider with Tx of hypovolemia
    • rate of fluid replacement
    • type of fluid infused
    • role for buffer therapy
  8. rate of fluid replacement for hypovolemia
    • 1-2 L of 0.9% NaCl administer as rapidly as possible
    • 500-1000mL bolus then reevaluate patient
  9. maintenance IV fluid dosing
    1500 mL + 20 mL/kg for every kg over 20 kg
  10. what is the typical maintenance fluid
    D5W with 0.045% NaCl + 20 - 40 mEq of KCl
  11. Tx for severe symptomatic hyponatremia
    • prompt correction with
    •   free water restriction &
    •   IV administration of hypertonic saline (3%)
    •   may need to add a loop diuretic
  12. definition and Tx rate for acute symptomatic hyponatremia
    • change in serum Na concentration > 0.5 mEq/L/hr or onset in less than 48 hours
    • 1-2 mEq/L/hr
  13. definition and Tx rate for chronic symptomatic hyponatremia
    • develops over more than 2-3 days
    • 0.5 mEq/L/hr
  14. maximum recommended increase in serum sodium concentration and what happens if exceeded
    • 8-12 mEq/L per 24 hours
    • neurologic complications - myelinolysis
  15. Tx of hypovolemic hypotonic hyponatremia
    0.9% NaCl or LR
  16. causes of hypovolemic hypotonic hypnatremia
    • renal - thiazides
    • nonrenal - GI losses (vomiting, diarrhea)
  17. Tx of isovolemic hypotonic hyponatremia
    • water restriction
    • mild diuresis with a loop
  18. most common cause of isovolemic hypotonic hyponatremia
    SIADH
  19. Tx of chronic SIADH
    demeclocyline HCl - caution may have negative effects on renal function
  20. Tx of primary acute SIADH
    • correct underlying disorder
    • water restriction
  21. meds that can cause SIADH
    • carbamazapine
    • sertraline & possibly fluoxetine
  22. Tx of hypervolemic hypotonic hyponatremia
    • optimizing underlying cause
    • Na & fluid restriction: 1000-1500 mL daily
    • diuresis with loop
  23. cause of isotonic hyponatremia
    hyperlipidemia
  24. cause of hypertonic hyponatremia
    hyperglycemia
  25. cause of hypovolemic hypotonic hyponatremia
    • thiazide diuretics
    • GI losses
  26. causes of hypervolemic hypotonic hyponatremia
    • CHF
    • cirrhosis
    • renal failure
  27. S/S of hypernatremia
    • lethargy
    • irritability
    • restlessness
    • thirst muscle irritability & spasticity
    • hyperreflexia
    • seizure
    • coma
    • death
  28. Tx of hypernatremia
    0.225% NaCl and D5W
  29. Na correction rate for acute hypernatremia
    • no faster than 1-2 mEq/L/hr
    • acute is occurring in less than 48 hours
  30. Na correction rate for chronic hypernatremia
    • 0.5 mEq/L/hr
    • chronic occurs in more than 2-3 days
  31. formula for water deficit
    total body water (TBW) x [(serum sodium conc./140)]-1 and multiply by dosing factor
  32. replacement of water deficit
    • half should be replace over the first 24 hours
    • remainder replaced over following 24 - 72 hours
  33. maximum rate of Na decrease in hypernatremia
    10-12 mEq/L per 24 hours
  34. Tx of hypovolemic hypernatremia and hemodynamically unstable
    0.9% NaCl of LR
  35. Tx of hypovolemic hypernatremia and hemodynamically stable
    • hypotonic: 0.45% NaCl or 0.225% NaCl + D5W
    • NEVER use sterile water
  36. Tx of isovolemic hypernatremia
    sodium restriction
  37. when is isovolemic hpernatremia seen
    • diabetes insipidus
    • central - inablility to produce ADH
    • nephrogenic - inability of kidney to respond to ADH
  38. causes of NDI
    • hypokalemia
    • hypercalcemia
    • lithium
  39. Tx of hypervolemic hypernatremia
    • removal of sodium products
    • sodium restriction
    • diuretics
  40. normal potassium level
    3.5 - 5 mEq/L
  41. S/S of hypokalemia
    • changes in muscle and cardiovascular function
    • N/V
    • weakness
    • constipation
    • paralysis
    • respiratory compromise
    • Rhabdo
  42. causes of hypokalemia - intracellular shifts
    • metabolic alkalosis
    • beta adrenergic agonist (albuterol)
    • insulin
    • theophylline
    • caffeine
  43. causes of hypokalemia
    • K sparring diuretics
    • sodium polystyrene sulfonate
    • corticosteroids
    • aminoglycosides
    • magnesium depletion
    • hemodialysis
    • GI losses
  44. Tx of mild - moderate hypokalemia
    20-40 mEq K - IV or oral
  45. Tx of severe hypokalemia
    40-80 mEq K - oral or IV
  46. value of mild-moderate hypokalemia
    2.5-3.4 mEq/L
  47. value of severe hypokalemia
    <2.5 mEq/L
  48. impaired renal function and Tx of hypokalemia
    50% initial K dose
  49. what coexists with hypokalemia
    hypomagnesemia
  50. S/S of hyperkalemia
    • arrhythmias
    • muscle twitching
    • cramping weakness
    • ascending paralysis
    • ECG changes
  51. what drugs or condition can cause hyperkalemia
    • renal insufficiency
    • K sparring diuretics
    • ACEIs
    • NSAIDS
    • hypoaldosteronism
  52. causes of hyperkalemia extracellular shifts
    • metabolic acidosis
    • succinylcholine
    • beta blockers
    • digoxin overdose
    • muscular injury
  53. symptomatic ECG changes; Tx of hyperkalemia antagonizing affect
    • IV calcium gluconate
    • then increase K elimination by
    •   potassium-wasting diuretic
    •   sodium polystyrene sulfonate
    •   renal replacement therapy
  54. rapid correction of hyperkalemia
    • insulin & dextrose
    • sodium bicarbonate
    • albuterol
  55. normal phosphorus level
    2.7-4.5 mg/dL
  56. causes of hypophosphatemia
    • malnutrition
    • carb loads - refeeding syndrome
    • insulin, diuretics, antacids, sucralfate
  57. Tx of asymptomatic mild hypophosphatemia
    PO phosphate supplementation if GI tract is functional
  58. Tx of symptomatic mild-severe hypophosphatemia
    • 2.3-2.7 mg/dL - 0.08-0.16 mmol/kg/dose
    • 1.5-2.2 mg/dL - 0.16-0.32 mmol/kg/dose
    • <1.5 mg/dL - 0.32-0.64 mmol/kg/dose
  59. most common clinical manifestation of hyperphosphatemia
    hypocalcemia
  60. causes of hyperphosphatemia
    • renal insufficiency
    • respiratory & metabolic acidosis
    • hemolysis
    • rhabdo
    • hypoparathyroidism
    • vit D toxicity
  61. one of the main goals of hyperphosphatemia
    maintaining serum (calcium x phosphorus) < 55-60mg2/dL2
  62. Tx of hyperphosphatemia
    • calcium salts - preferred in chronic renal damage
    • aluminum salts - increase constipation
    • magnesium salts - increase diarrhea
  63. Tx of hyperphosphatemia if hypercalcemia and chronic renal failure
    sevelamer
  64. normal range of calcium
    8.6-10.2 mg/dL
  65. what do you do if a pt is hypoalbuminemia with regard to calcium
    • corrected calculation
    • serum Ca conc. + (0.8 x [4-serum albumin con])
  66. hallmark sign of severe acute hypocalcemia
    tetany
  67. S/S of chronic hypocalemia
    • skin manifestations
    • hair loss
    • dermatitis
    • eczema
  68. rapid Tx of hypocalcemia
    • calcium chloride - 3x more Ca
    • calcium gluconate - preferred because if you mess up the dose you are actually underdosing
  69. Tx of asymptomatic hypocalcemia due to hypoalbuminemia
    no therapy required
  70. Tx of severe hypocalcemia
    • prompt correction with IV calcium
    • 1000 mg Ca or
    • 3g calcium gluconate given over 10 minutes
  71. Tx of severe hypercalcemia when not in an acute setting
    bisphosphonates
  72. Tx of severe hypercalcemia
    • IV hydration - 0.95 NaCl 200-300 mL/hr
    • IV furosemide - 40-100 Q 1-4hrs
    • Adding the two together will reduce the serum calcium by 2-3 mg/dL within the first 48 hours
  73. normal magnesium levels
    1.5-2.4 mg/dL
  74. what other condition can hypomagnesemia cause
    hypokalemia and hypocalcemia
  75. what is severe hypocalcemia and what can it cause
    • < 1.0 mg/dL
    • arrhythmias (torsades)
    • seizurescomadeath
  76. meds that cause hypomagnesemia
    • thaizide
    • aminoglycosides
    • digoxin
  77. causes of hypomagnesemia
    • excessive GI losses
    • renal losses
    • surgery
    • trauma
    • infection or sepsis
    • burns
    • starvation
    • alcoholism
  78. Tx goal of mild - moderate hypomagnesemia
    • 1.0-1.5 mg/dL
    • 8-32 mEq Mg IV
    •   1-4 g Mg sulfate
  79. Tx of severe hypomagnesemia
    • 32-64 mEq Mg IV/dose
    •   4-8 Mg sulfate
  80. renal threshold for Tx of asymptomatic hypomagnesemia
    total dose should not exceed 12 g of Mg sulfate over 12 hours
  81. Tx of severe symptomatic hypomagnesemia
    • 32-64 mEq Mg IV/dos
    • doses up to 4 g Mg sulfate over 4-5 minutes
  82. what signifies severe symptomatic hypomagnesemia
    torsades
  83. Tx of asymptomatic hypermagnesemia
    discontinue exogenous Mg administration
  84. Tx of severe symptomatic hypermagnesemia
    IV calcium
  85. what 3 electrolyte conditions do you reduce the dose by 50% in renal impairment
    • hypomagnesemia
    • hypophosphatemia
    • hypokalemia
Author
coal
ID
241313
Card Set
thera fluid & electrolyte
Description
thera fluid & electrolyte
Updated