Exam 1 Flashcards
IBW (males)
50kg + (2.3 x in>60)
IBW (women)
45kgs + (2.3 x in>60)
Normal body weight (NBW)
IBW + 0.25(TBW - IBW)
ADH changes
Decrease diuresis
Increase H2O retention
RAAS changes
Increase renin secretion
Na / H2O regulation
ANP
Decrease ADH release
Counteract RAAS
Isotonic range
275-290 mOsm/L
Hypotonic range
< 275 mOsm/L
Fluid moves into cell and increases volume
Hypertonic range
> 290 mOsm/L
Fluid pulled into blood out of cells
Osmolarity calculation
IV solution osm + electrolyte osm added
Convert electrolyte osm mEq -> mOsm
Hypertonic solutions
> 600 mOsm/L
Administered in small volumes < 500mL via central line
Clinical estimate MIVF
30-40 mg/kg/day
100-150 mL/h = normal rate
Ideal fluid properties
Predictable effects
No AEs
Sustained increased IV volume
No tissue accumulation
Cost effective
Stable when stored
Readily available
Easy to administer
Crystalloids
Normal saline (NS)
1/2 Normal solution (NS)
Dextrose 5% (D5W)
Lactated ringers (LR)
Balanced salt solutions
Colloids
Albumin
Hetastarch
Tetrastarch
Blood
Plasmate
Normal saline (NS)
0.9% NaCl
Used for IV replacement
NOT a maintenance fluid
1/2 Normal saline (1/2 NS)
0.45% NaCl
Used for maintenance as a combo
Lactated ringers (LR)
Used to replace blood loss
Approximated human plasma
Dextrose 5% (D5W)
Used for free H2O replacement
No Na or Cl
NOT resuscitative fluid
NOT used for MIVF by itself
Balanced salt solutions
Crystalloids with physiological levels of Cl and buffer solutions
Ex. LR, normosol-R, plasma-lyte
NaCl composition
154 mEq/L of Na and Cl each
Colloid use in therapy
Plasma expanders
Increase MW and half-life
Increase plasma oncotic pressure
Albumin
Indications:
Volume expansion, shock, burn, ARDS
AEs:
Hypervolemia, azotemia
Use 5% to increase volume
Use 25% to increase protein
Starches (synthetic colloids)
High association with bleeding
Longer half-life -> more side effects and toxicities
Not commonly used
Blood / packed RBCs
Used for acute blood loss or if low Hb
Hb < 7 def use, Hb < 8 can use
1 unit RBC increases Hb 1g/dL
Most common MIVF
D5W + 1/2 NS + 20mEq KCl / L
Used to increase plasma oncotic pressure
Signs of dehydration
Look dry on physical and cellular levels
Tachycardia and hypotension
BUN / SCr > 20
Na normal range
135-145 mEq/L
Hyponatremia
Osmolality 275-290 mOsm/L
Osmolality calculations
(2 x Na) + (BUN / 2.8) + (Glucose / 18)
Psuedohyponatremia
Na appears low but is actually displaced
Hypertonic hyponatremia
> 290 mOsm/L
Hypotonic hyponatremia
< 275 mOsm/L
Hypovolemic hypotonic hyponatremia
↓TBW
↓↓Na
Tx:
3% NaCl if symptoms
0.9% NaCl if asymptomatic
Isovolemic hypotonic hyponatremia
↑TBW
= Na
Tx:
Furosemide and judicious 3% NaCl if symptoms
Furosemide if asymptomatic
Acute hyponatremia
< 48 hrs
Brain swells -> cerebral edema -> death
Tx:
↑ Serum Na 1-2 mEq/L/hr until sx resolve
Max 8-12 mEq/L in first 24 hrs
Chronic hyponatremia
≥ 48 hrs
Minimal brain swell
Mild neurological sx
Rule of 8’s
Replace 1/2 of Na in first 8 hrs
Replace remaining within 8-16 hrs
Hypernatremia
> 145 mEq/L
Associated with hypertonicity
Impaired thirst response
Hypovolemic hypernatremia
↓H2O
↓↓TBW
↓Na
Associated with renal and GI disease
Isovolemic hypernatremia
↓H2O
↓TBW
= Na
Associated with diabetes
Hypervolemic hypernatremia
↑H2O
↑TBW
↑↑Na
Associated with Na overload
Free H2O deficit calculations
TBW x [(serum Na / 140) - 1]
K normal range
3.5-5 mEq/L
K levels affected by
Na/K ATPase pump
Kidneys
Arterial pH
Hypokalemia causes
Diuretic loss
B-agonist medications (Albuterol)
Mg depletion
IV K rates
10 mEq/hr without cardiac monitoring
20 mEq/hr with cardiac monitoring
Hyperkalemia
Mild: 5.5-6 mEq/L
Moderate: 6.1-6.9 mEq/L
Severe: ≥ 7 mEq/L
Hyperkalemia treatment
C A BIG K DROP
Calcium
Albuterol
Bicarbonate
Insulin + Glucose
Kayexalate / Lokelma
Diuretics
Dialysis
Chronic hyperkalemia treatment
Patiromer (Valtassa)
Mg normal range
1.5-2.5 mg/dL
Hypomagnesemia causes
Loop diuretics and thiazides
Hypomagnesemia treatment
IV if symptomatic
PO if asymptomatic
Ca normal range
8.5-10.5 mg/dL
Ca metabolism by…
Bones, kidneys, intestines
Hypocalcemia causes
Mg deficiency
Increased volume of blood products
Hypoalbuminemia
Corrected Ca calculations
Measured Ca + [(4 - measured albumin) x 0.8]
Acute hypocalcemia treatment
100-300mg elemental Ca IV over 5-10 minutes
Ca gluconate preferred for PIV administration
Chronic hypocalcemia treatment
1-3g elemental Ca / day
PO4 normal range
2.5-4.5 mg/dL
Hypophosphetemia
Mild to mod: 1-2mg/dL
Severe: < 1mg/dL
Hypophosphetemia treatment
Mild to mod: oral phosphorus
Severe: KPhos (<4) or NaPhos (≥4)
NEVER push phosphate
in ICU values
K > 4
PO4 > 3
Mg > 2
Physiological function of kidney
BP control
pH balance
Drug metabolism and excretion
Endocrine -> hormones
AKI causes
Sepsis
Ischemia
Nephrotoxins
CKD progression
Increase glomerular pressure ->
Proteinuria ->
Glomerulosclerosis
Nephritic disease
Inflammation disrupting basement membrane
Nephrotic disease
Podocyte damage -> disrupt charge barrier
Pyelonephritis
Caused by bacteria traveling into the kidney
Antibiotic causes of interstitial nephritis
Penicillin
Anticonvulsant
Diuretics
NSAIDs
Don’t use NSAIDs with
AKI, CKD, heart failure
Classes of diuretics
CA-I’s
Osmotic diuretics
Na/K/Cl symport inhibitors
Na/Cl symport inhibitors
Renal epithelial Na channel inhibitors
Mineralocorticoid receptor antagonists
OAT mediated transporters
Furosemide
Thiazide
Penicillin
NSAIDs
Active secretion in proximal tubule
OCT mediated transporters
Digoxen
Metformin
Morphine
Vancomycin
CA-I
Block NaHCO3 reabsorption
Weak diuretic
Ex. acetazolamide
Osmotic diuretics
Inhibit H2O reabsorption
2 sites of action: PCT, descending loop
Ex. mannitol, isosorbide, glucose, glycerin, urea
PO osmotic diuretics
Isosorbide, glucose, glycerin
IV osmotic diuretics
Mannitol, urea
Na/K/Cl inhibitors (loop diuretics)
Most active and potent
Ex. furosemide, bumetanide, ethacrynic acid, torsemide
Na/Cl inhibitors (thiazides)
Increase potency of CA-I
2 sites of action: DCT, PCT
Thiazides -> unsaturated
Hydrothiazides -> saturated
Na channel inhibitors (K sparing)
Act at late distal tubule and collecting duct
Relatively weak
Ex. Amiloride, triamterene
Contraindicated: ACE inhibitors, K supplements
Mineralcorticoid receptor antagonists (MRA)
Only diuretic that doesn’t act in tubular lumen
Always combo therapyi
Contraindicated: ACE inhibitors, K supplements
Breaking phenomenon
Prolonged use of loop diuretics leads to stabilizing at lower levels showing desensitization
CKD causes
Diabetes
HTN
CKD and GFR
Normal: < 60mL/min
G3a: 45-59
G3b: 30-44
G4: 15-29
G5: <15
EGFR use
Nephrologists use to stage KD
CrCl use
RPh use to dose medications
Cockroft and Gault formula
CrCl / kidney function
Men: [(140 - age) x IBW] / (SCr x 72)
Women: (CrCl) x 0.85
MDRD formula
More accurate
Less used clinically
Uremia effects
Urine breath
Metallic taste
Uremic frost
Edema treatment
If CrCl < 30 mL/min use loop diuretics
If CrCl ≥ 30 mL/min use thiazides
Ethacrynic acid
No risk of sulfa allergy reaction
Hyperphosphetemia treatment
Ca phosphate binders
Non-Ca phosphate binders
Ca phosphate binders
Ca carbonate (Tums)
Ca acetate (PhosLo)
Non-Ca phosphate binders
Sevelamer carbonate (Renvela)
Lanthanum carbonate (Fosrenol)
Sucroferric oxyhydrox (Velphoro)
Auryxia (Ferric citrate)
Aluminum hydroxide (Amphojel)
Mg carbonate (Mag-Carb)
Nicotinic acid and nicotinamide
Activated Vit. D forms
Calcitriol
Pericalcitriol
Doxercalciterol
Unactivated Vit. D forms
Ergocalciferol (Calciferol)
Cholecalciferol (Vit. D3)
Calcimimetics
Cinacalcet (Sensipar) -> PO
Etelcalcetide (Parsabiv) -> IV
Contraindicated: hypocalcemia
Anemia MCV
↑MCV = Vit. B12 deficiency
↓MCV = Fe deficiency
Normal MCV = 80-96 mcm^3
Anemia treatment
Iron therapy (oral, heme, IV)
ESAs -> don’t push Hb > 11.5
ESAs
Recombinant human erythropoietin
Darbepoetin alfa (Aranesp)
Methoxy polyethylene glycol (Micera)
HIF-PHIs
New tx for anemia with CKD
Daprodustat (Jesduvroq)
Easier dosage form -> ↑ adherence