Fluid, Electrolytes and Acid Base Disorders Flashcards
Normal urine output for adults
.5 to 1.0 mL/kg/hour
Low urine output could be a sign of volume depletion
Daily weights may be more accurate
Normal saline indications
dehydration or lost blood
D51/2NS indications
Standard maintenance fluid often with 20 mEq of KCl/L of fluid
Dextrose added to inhibit muscle breakdown
D5W indication
Sometimes used for hypernatremia
Lactated Ringer’s solution indications
Replacement of intravascular volume used for trauma resuscitation
Not used in hyperkalemia
Hypovolemia diagnosis and treatment
Diagnosis: Monitor urine output and daily weights
Critically ill (cardiac or renal dysfunction)-consider placing Swan Ganz catheter to measure CVP and PCWP
Elevated serum sodium, low urine sodium, and BUN/Cr ratio>20:1
Increased hematocrit
Treatment: use bolus to achieve euvolemia: normal saline or ringer’s solution
Maintain urine output at .5-1 ml/kg/hr
Replace blood loss with crystalloid at a 3:1 ratio
Maintenance fluid: D51/2NS with 20 mEq KCl/L
Hypervolemia diagnosis and treatment
Diagnosis: elevated CVP and PCWP, pulmonary rales
Low hematocrit and albumin concentration
Treatment: diuretics
Fluid restriction
Monitor urine output and daily weighs, consider Swan Ganz catheter
Hypotonic hyponatremia-hypovolemic causes and diagnosis
Low urine sodium less than 10-increaed sodium retention by kidneys to compensate for extrarenal losses
Diarrhea, vomiting, dipahoresis, burns, pancreatitis
High urine sodium: renal salt loss
Diuretics, Ace inhibs, ATN
Treatment: Na=120-130: restrict free water
Na=110-120: loop diuretics with saline
Na=less than 110 and symptomatic: hypertonic saline
Do not increase more than 8 mmol/L during first 24 hours
Hypotonic hyponatremia-euvolemic causes and diagnosis
SIADH, polydipisa, hypothyroidism, haloperidol, cyclophosphamide,
Urinary excretion of Na increased
Treatment: Na=120-130: restrict free water
Na=110-120: loop diuretics with saline
Na=less than 110 and symptomatic: hypertonic saline
Do not increase more than 8 mmol/L during first 24 hours
Hypotonic hyponatremia-hypervolemic causes and diagnosis
CHF, nephrotic syndrome, liver disease-urinary excretion of sodium decreased
RF: sodium urinary excretion increased
Treatment: Na=120-130: restrict free water
Na=110-120: loop diuretics with saline
Na=less than 110 and symptomatic: hypertonic saline
Do not increase more than 8 mmol/L during first 24 hours
Isotonic hyponatremia
An increase in plasma solids lowers the plasma sodium concentration but sodium in plasma is normal
elevated protein or lipid levels
Diagnosis: nromal (280-295) osmolality
Treatment: treat underlying disorder
Hypertonic (shrink) hyponatremia
osmotic shift of water out of the cell
Hyperglycemia, mannitol, glycerol, raidiocontrast agents
Diagnosis: high serum osmolality (>295)
Treatment: treat underlying disorder
Hypovolemic hypernatremia
Sodium decrease but water loss more
Renal loss: diutrics, osmotic diuresis (glycosuria), renal failure
Extrearenal loss: diarrhea, diaphoresis, respiratory losses
Diagnosis: low urine volume
urine osmolarity>800
Treatment: isotonic NaCl, hemodynamically stable then free water replacement
Isovolemic hypernatremia
Sodium stores normal, water loss
Diabetes insipidus, tachypnea
Diagnosis: low urine volume
urine osmolarity>800
Treatment: DI=vasopressin
oral fluids or D5W if they cannot drink
Hypervolemic hypernatremia
Iatrogenic
Exogenous glucocorticoids, cushigns, hyperaldosteronism
Diagnosis: low urine volume
urine osmolarity>800
Treatment: diuretics (furosemide), D5W to remove excess sodium
Dialyze if renal failure
Hypocalcemia treatment
Symptomatic: IV calcium gluconate
Long term management: oral calcium supplements (calcium carbonate) and Vitamin D
PTH deficiency: replacement therapy with Vitamin D plus high oral calcium intake
Thiazide diuretics
Correct hypomagnsemia
Hypercalcemia treatment
Initial treatment is IV normal saline
Diuretics: furosemide
Inhibit bone resorption in osteoclastic-bisphosphonates, Calcitonin
Glucocorticoids if Vitamin D related mechanisms and multiple myeloma
Hemodialysis in renal failure patients
Hypokalemia causes, diagnosis and treatment
Causes: vomiting and nasogastric drainage, diarrhea, laxatives
diuretics, excessive glucocorticoids, hyperaldosteronism, insulin, bactrim and amphotericn, epinephrine
Diagnosis: arrhytmias (Cause of death), flattened or inverted T waves, U waves, (exacerbates digitalis toxicity)
Treatment: Oral KCl safest IV KCL if less than 2.5 or arrhythmia (monitor cardiac rhythm) Max infusion 10 mEQ/hr if peripheral Max infusion 20 mEQ/hr if central Can use lidocaine to reduce pain
Treat hypomagnesemia
Hyperkalemia causes, diagnosis and treatment
Causes: renal failure, Addisons disease, Potassium sparing diuretics, hypoaldosteronism, ACe inhibs, blood transfusions, Acidosis, rhabdo, hemolysis, insulin deficiency, rapid administration of B blocker
Diagnosis: Arrhythmia : V fib of note
peaked T waves, prolonged QRS, PR interval prolongation, loss of P waves, sine wave pattern
Treatment: Hyperkalemia >7.0 or ECG changes present give IV calcium (watch in digoxin)-stabilizes cardiac membrane
Glucose and insulin
Sodium bicarbonate: emergency measure
Kayexalate: prevents reabsorption in GI tract
Hemodialysis: rapid and effective-reserved for intractable hyperkalemia or in renal failure
Diuretics: furoseide for moderate with saline infusion
B2 agonists
Hypomagnesium: clinical, causes, diagnosis and treatment
Causes: malabsorption (steatorrhea), prolonged fasting, receiving TPN, alcoholism, SIADH, diuretics, gentamicin, amphotericin B, cisplatin, renal transplantation, postparathyrodectomy, DKA, thyrotoxisis
Clinical: muscle twitching, weakness, tremors, hyperreflexia, seizures, mental status changes
Concomitant: hypocalcemia (inhibits PTH and decreases effect of PTH on bone), hypokalemia
Diagnosis: prolonged Qt (torsades), T wave flattening
Treatment: mild oral Mg (mg oxide)
Severe-parenteral Mg (Mg sulfate)’
oxide is oral, sulfate is stabbed
Hypermagnesium: clinical, causes, diagnosis and treatment
Causes: RF, early stage burns, massive trauma, surgical stress, severe acidosis, Adrenal insufficiency, rhabdo,
Clinical: Nausea, weakness, facial paresthesias,
progressive loss of deep tendon reflexes (first sign)
somlonence and coma-occur late
Death due to respiratory failure or cardiac arrest
Diagnosis: increased PR interval, widened QRS, elevated T waves
Treatment: IV calcium gluconate for emergent symptoms
Administer saline and furosemide
Dialysis for renal failure
Prepare to intubate
Hypophosphatemia: causes, clinical, diagnosis and treatment
Causes: alcohol abuse, Vit. D deficiency, excessive use of antacids, TPN, starvation
Excess PTH, hyperglycemia, ATN, hypokalemia, hypomagnesia
respiratory alkalosis, steroids, hyperthermia, DKA
Clinical: asymptomatic if mild
if Severe:
encephalopathy, seixures, paresthesia, hemolysis, RBC/WBC/platelets dysfunction, cardiomyopathy-low ATP (cardiac arrest), rhabdo, anorexia
Treatment: mild (>1 mg): oral supplementation: neutra Phos capsules, K-Phos tablets, milk
severe or NPO: parenteral supplementation
Hyperphosphatemia: causes, clinical, diagnosis and treatment
Causes: renal insufficiency, bisphosphonats, hypoparathyroidsm, Vit. D intoxication, rhabdo, cell lysis or acidosis
Clinical: metastatic calcification-tetany, neuromusclar irritability
Treatment: phosphate binding antacids containing aluminum hydroxide or carbonate-prevent its absorption
Hemodialysis
Saline responsive metabolic alkalosis
ECF contraction and hypokalemia
vomiting or nasogastric suction
Diuretics
laxative abuse
Give Saline with potassium
Saline resistant metabolic alkalosis
ECF expansion and hypertension, low Cl
Hyperaldosteronism, cushings, sever K deficiency, and diuretic abuse
Give spironolactone
Higher than what PaCO2 level implies superimposed respiratory acidosis on metabolic alkalosis
PaCO2 >50-55
Treatment of respiratory acidosis
if PaO2 less than 60=supplemental O2
Naloxone if morphine induced
Intubation: severe acidosis PaCO>60 or inability to increase O2 Deterioration of mental status Impending respiratory fatigue
