Fluid and Electrolytes Flashcards Preview

• 135-145
• Predominant cation of the ECF
• Primary electrolyte in establishing osmostic pressure between the ICF and ECF
• All body fluids are in osmotic equilibrium and changes in serum sodium concentration (Na) are associated with shifts of water in and out of body fluid compartements 
  • Adding Sodium in the intravascular compartment from the interstitial fluid and, ultimately from ICF

• Not be used as an index of sodium because it does not reflect total body sodium content, Na primarily reflects disturbances in TBW
• Without first assessing the body fluid status 
• Water disorder
• 80-120 meq/day 

• Agitation 
• Fatigue
• HA
• Muscle cramps 
• Nausea/anorexia

• Confusion 
• Seizures
• Coma 

hyperglycemia 

Treat the hyperglycemia na with return to normal 

Sodium deficit = (45 liters)(140 mEq/L - 123 mEq/L) = 765 mEq

STOPPED at HYPERNATREMIA 

1. Dehydration = loss of hypotonic fluid (respiratory, skin losses)
2. Decreased water intake
3. Osmotic diuresis
4. Diabetes insipidus (decreased ADH activity)
   1. May be induced by certain drugs (lithium, phenytoin)
5. Latrogenic- Admin of too mich hypertonic saline-uncommon

• Water def= Normal TBW - Present TBW
• Over 48-72 hours with solution hypotonic to pts serum 

• Rapid may lead to cerebral edema and death
• Hypertonicity
• Asymptomatic, 0.5 mEq/L/hour
• Replace half the calculated deficit with hypotonic solutions over 12 to 24 hours 

Water Def (L) = TBW x [(serum sodium/140)-1]

45 x 0.1 = 5 L

• 9-10.5 mg/dL
• Parathyroid hormone (Increased, increases calcium concentration
• Vit D
• Calcitonin increased, decreases calcium 

Maintenance- 800-1200

CC- accounts for a decrease in percent of protein binding due to decrease albumin concentration

CC= observed [Ca] + 0.8 (normal albumin*-observerd albumin)

Normal = 4 g/dL

• Apply a BP cuff to pts upper arm and inflate
• Pt will experience adducted thumb, flexed wrist and metacarpophalangeal joints
  • Carpopedal spasm=tetany

• Tap on pts focial nerve adjacent to the ear
• Brief contraction of upper lip, nose, or side of face indicated tetany 

Calcium gluconate- preferred less irritating

Calcium chloride- irritating to veins-->central line

Preparation given as slow push or added to 50 mL to 250 mL .9% NaCl, LR, D5W for slow infusion 

• Pt symptomatic (patesthesia, tetany, Chvostek sign)
• Clinically relevant hypocalcemia (serum Ca < 1 mmol/L)
• Massive blood transfusion (especially with preexisting cardiac disease)
• CCB overdose
• Receiving inotropic or vasopressor support
• Emergent hyperkalemia 

• 200-300 mg of elemental calcium IV and repeat until symptoms fully controlled 
  • 1 gram of calcium chloride or 2-3 grams of calcium gluconate
  • No faster then 30-60 mg of elemental calcium per minute
  • Caution if serum phosphate elevated or if on digoxin therapy 

• Consider if pt symptomatic and/or serum concentration > 12 mg/dL
• 0.9% NaCl +- furosemide
  • Infusion rate as high as 200-300 ml/hr may be needed
  • Only ass loop diuretic after initial ECF depletion has been corrected
  • Function kidney needed (hemodialysis alternative)
  • Monitor [K] and [Mg] Carefully 

• Because of polyuria, pt is usually dehydrated
• Normal saline 200-300 mL/hr, checking for continued dehydration or fluid overload. Goal: up tp 4 L on day one
• Once rehydrated, add furosemide (Block Ca reabsorption) 40-80 mg IV Q 1-4 hours until urine output = 200-250 mL/hour
• Monitor serum K and Mg 

• 3-4.5 mg/dL
• = amount in mg/ atomic moleculat wt
• 800-1200 mg/day (250 mg = 8 mmol)

• Mild 2-2.5
  • Eat
• Moderate 1-2.5 
  • Oral therapy
    • 1.5-2 grams/day divided into 3-4 doses
    • Diarrhea may be dose limiting
• Severe <1
  • Parenteral therapy indicated
    • .o8-.64 mmol/kg
    • Range 5-45 over 4-12 hours
    • Select replacement based on need for other electrolytes (Na vs. K)
    • Caution in pts with hypercalcemia, renal dysfunction, or evidence of tissue injury
    • Switch to oral supplement when level 2-2.5 mg/dL

• Dietary restriction of phosphate and protein
• If tetany (spasms) administer calcium salts IV (see hypocalciemia aboce)
• Diaylsis of caused by renal failure
• Oral phosphate binders
  • Mg hydroxide (milk of Mg)
    • Can cause diarrhea
  • Calcium carbonate
    • Inexpensive, tablen can be crushed 

1. Mg hydroxide (milk of Mg)
   1. Can cause diarrhea
2. Calcium carbonate (tums)
   1. inexpensive, tablets can be crushed
3. Calcium acetate 
   1. 2 tabs/each meal 
4. Sevelamer carbonate
   1. Cationic polyer, contains neither Ca ot Al
   2. 800-1600 mg/each meal
5. Lantanim carbonate
   1. Initial dose 250-500 mg PO 3 x daily to max 3750 mg/day
   2. most need 1500-3000 mg/day 

3.5-5 mEq/L

0.5-1 mEq/kg/day or 40-50 mEq/day