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33 Cards in this Set
- Front
- Back
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Conditions that increase/decrease fluid maintenance requirements
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Burns
Third spacing -Ascites -Bowel obstruction WATCH – patients with CHF, RF require LESS fluids! Overzealous replacement may lead to pulmonary edema, increased JVD, hepatojugular reflex, etc. Monitor weights in these patients!!! |
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Loop diuretic safe for use in sulfonamide allergy
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Ethacrynic acid (Edecrin®)
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Drugs for hyperkalemia
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Albuterol
Calcium Furosemide Sodium Polystyrene Sulfonate Insulin and dextrose |
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Fluid Maintenance – How Much?
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Each day:
100ml/kg for first 10 kg 50ml/kg for next 10 kg 20ml/kg for anything over 20kg 133 Lb = appx 60kg: 10 kg = 1000ml + next 10 kg = 500ml = 1500ml for first 20kg 20ml/kg (40kg) = 800ml 1500ml + 800ml = 2300ml over 24 hours 100ml/hr close enough – we don’t drink exact amounts every day – in normal renal/cardiac function, fluid load not critical… |
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What if hypovolemia is due to blood loss (most common scenario of isotonic loss)?
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1. Crystalloids (0.9% NaCl, LR)
2. Packed Red Blood Cells – typed and cross matched Each unit will increase Hgb by appx 1g/dL Each unit contains appx 200mg Fe IRON OVERLOAD A POSSIBILITY Citrate may lead to hypocalcemia if replacement excessive!!! Calcium in LR content may cause clotting unless blood: LR > 2:1 3. Colloids |
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Colloids
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E.g., dextran, albumin, hetastarch, Plasmanate®
Increase oncotic pressure to pull fluid from interstitial to intravascular Used for volume expansion during extreme situations (hemorrhage, 3rd spacing) Watch!! Capillary leak syndrome – will INCREASE 3rd spacing making ascites or respiratory symptoms worse |
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Comparison of Colloids
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Albumin
5% for volume expansion (500ml) 25% to increase oncotic pressure (50 ml) Risks: overload, allergy, infections (pooled human product) Hetastarch and Dextrans Variable molecular weight polysaccharides Risk: overload, anaphylaxis, hemodilution and increased bleeding (consider FFP, platelets), renal failure Plasmanate – contains human plasma proteins Risk: overload, blood borne infections, anaphylaxis |
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Chronic/mild hyponatremia
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(Na >125mEq/L) Sx usually overlooked: inattention, posture/gait disturbance, falls
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Moderate and severe hyponatremia
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Moderate (Na 115-125) severe (Na<115) or rapidly developing hyponatremia
Nausea, malaise Headache, lethargy, restlessness, disorientation Seizures, coma, brainstem herniation, death! |
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Euvolemic hyponatremia
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SIADH
Oat cell carcinoma of lung CNS: trauma, stroke, meningitis Pulmonary disease Drugs as cause DDAVP Carbamazepine (Tegretol®) Cyclophosphamide (Cytoxan®) NSAIDs SSRI, tricyclic antidepressants, phenothiazines Opiates Ecstasy |
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Treatments for SIADH
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-d/c causative agent
-AVP antagonists tolVAPTAN, coniVAPTAN -demeclocycline |
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Treatment of hyponatremia
1. Is the patient obtunded or having seizures?? |
If yes, start Tx STAT – 0.9% NaCl or 3% NaCL
If no, fluid restriction (<800ml/day or so) while you work out underlying cause 2. Consider all sources of excess free water IVPB, fluid intake, etc |
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Hypernatremia
Presentation |
Weakness, lethargy, restlessness, confusion, twitching, seizures, coma
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Hypernatremia
ECF volume Low Uvol <3L/d Uosm > 450 TX |
Sx hypovolemia: Tx with 0.9% NaCl
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Hypernatremia
normal or high Uosm < 250 |
Respond to AVP: Central DI
No response AVP: NDI |
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Hypernatremia
ECF volume Low Uvol >3L/d Uosm < 100 |
No sx ↓vol: Tx D5W
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Hypernatremia
normal or high Uosm>300 |
Post obstruction: D5W
Na overload: loop + D5 |
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Hypovolemic hypernatremia
TX |
a. Correct hypovolemia with NS at 200-300ml/Hr until Sx improve.
b. Water deficit - use 0.45NS or D5; do not lower Na> 10mEq/L/day (initially 0.5-1 mEq/L/hr reduction) c. c. Monitor Na q 2-3 hours until Na<148, then q 6-12 hrs x 24 hours. Assess fluid status frequently |
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Isovolemic or Hypervolemic: Diabetes Insipidus
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DDAVP (central DI)
HCTZ, Amiloride (central/nephrogenic) Carbamazepine has been used for both Amiloride is generally preferred for lithium induced DI where Li++ cannot be discontinued Monitor fluid status, serum and urine Na and Osm frequently during initial tx, then q 2 months at onset of chronic tx |
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Na overload
TX |
Loop diuretics
What would you do if patient has serious sulfa allergy? Intravenous D5W at rate to decrease serum Na by appx 0.5mEq/L/hr Monitor Na q 2-3 hours until Na<148, then q 6-12 hrs x 24 hours. Assess fluid status frequently |
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Reduced ADH effect including drug induced NDI
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Ethanol
Lithium Demeclocycline Foscarnet Clozapine Conivaptan/tolvaptan Amphotericin B Cidofovir |
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Increased ADH effect including drug induced SIADH
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Indomethacin > Ibuprofen
Carbamazepine Chlorpropamide Selective serotonin reuptake inhibitors Tricyclic antidepressants Haloperidol and phenothiazines Vincristine and vinblastine |
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Drugs that ↑renal excretion
of K |
Diuretics
High dose penicillins Mineralocorticoids Nephrotoxic drugs Aminoglycosides, amphotericin, cisplatin |
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Drugs that can cause hypokalemia
Transcellular shift: |
Beta 2 agonists, theophylline, caffeine, insulin
Alkalosis, excessive HCO3 cause hypokalemia |
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Drugs that ↑ fecal elimination
of K |
Sodium polystyrene sulfonate, laxatives
cause hypokalemia |
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Hyperkalemia
Causes |
Renal failure
Excess intake (salt substitutes!!) Acidosis Adrenal insufficiency Hemolysis (including in sample tube) |
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Magnesium replacement
Oral Forms |
Forms
Milk of magnesia MagOx 400mg = 84 mg Mg++ Slow mag 64 mg Mg++ ADE: diarrhea, accumulation in renal failure |
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Magnesium replacement
IV |
Slower infusion rates allow for tissue distribution
Be aware of slow tissue distribution! |
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Hypermagnesemia
causes |
Renal insufficiency
Excess intake Pre-eclampsia use of Mg Hypothyroidism Lithium therapy |
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Sx: hypotension, bradycardia, confusion, coma, respiratory depression, “floppy baby”
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Hypermagnesemia
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Hypermagnesemia
Sx |
hypotension, bradycardia, confusion, coma, respiratory depression, “floppy baby”
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Hypermagnesemia
TX |
Correct cause
Consider pacing Calcium Gluconate, Calcium Chloride NS or 0.45% NaCl Furosemide Dialysis |
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Calcium
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Decreases membrane excitability in hyperkalemia, but does NOT reduce serum K
Antidote for Mg toxicity Antidote for CCB toxicity When given IV, usually diluted in IVPB of at least 50-100ml More on calcium in endocrine, CKD, and nutrition |
