FeNa: (Urine Na/Cr)/(Plasma Na/Cr) best test for azotemia

  • Pre-renal Azotemia:
    • FeNa: < 1%, Urine Na < 20, BUN/CR > 20, urine osmolality >500 mOsm

K concentrations:

  • Saliva has highest K concentration (20 mEq),
  • Then gastric (10 mEq)
  • Then pancreatic/duodenal (5 mEq)

Branched chain amino acids: (leucine, isoleucine, valine)

  • Are metabolized in muscle
  • All are essential

Vit D:

  • Made in skin è liver for (25-OH) è kidney (1-OH) è active
  • Vit D increase calcium binding protein to increase intestinal absorption of Ca++

Vit A: Systemic or topical reverses adverse effects of steroids on wound healing


  • Infant highest (80%)
  • Men (60%)
  • Women (50%).
  • 10% less if obese (less H2O in fat)
  • Water distribution: if TBW is 60%, then 40% is cellular, 15% is intestinal, and 5% in plasma

Carbs have 3.4 kcal/g

Protein has 4 kcal/g

Fat has 9 kcal/g

Basal calorie expenditure:

25 kcal/kg/day (~1g protein/kg/day needed)

Respiratory quotient:

  • Ratio of CO2 produced to O2 consumed during the oxidation of a given substrate.
  • >1 Lipogenesis è overfeeding
  • CO2 accumulation è inability to wean from ventilator.
  • 1 Pure Carbohydrate metabolism
  • 0.8 Protein Metabolism
  • 0.7 Fat Metabolism
  • 0.7 Ketogenesis = starvation

6.25 g of protein: contains 1 g of Nitrogen.

  • N balance: N in - N out = (Protein/6.25) - (24 hours urine N + 4 g)

Short chain fatty acids:

  • Acetate, propionate, butyrate
  • Butyrate is the preferred fuel of the colonocyte
  • Stimulate mucosal proliferation

Glutamine: preferred fuel of the small bowel

  • #1 amino acid in bloodstream
  • Stress decreases levels of glutamine as glutamine goes to kidney to form ammonium to help acidosis.
  • Shown to decrease translocation, increase mucosal health with chemo or RT to bowel

Fat digestion: Micelles è enterocytes è chylomicrons è lymphatics (è jxn LIJ/SCV)

Only Medium and Short Chain Triglycerides: go to portal system with AA's and carbs.

LCTG+Bile (pancreatic lipase): Mono+2FA W bile salts è Micelles brush border (enterocyte) absorption, by esterification èTG these TG + protein carrier èChylomicron which transported by Lymphatic system


  • Acute electrolyte derangements
  • Notably hypophosphatemia
  • Occurs when previously malnourished patients are fed with high carbohydrate loads.
  • The result is a rapid fall in phosphate, magnesium and potassium, along with an increasing ECF volume and cardiac dysfunction.
  • Prevention: start a low rate (10-15 Kcal/Kg/day)


  • Chromium: Hyperglycemia (relative diabetes), neuropathy
  • Zinc: Perioral rash, hair loss, poor healing, change in taste
  • Phosphate: Weakness (respiratory), encephalopathy (needed for ATP)
  • Copper: Hypochromic anemia refractory to Iron treatment, neutropenia
  • Linoleic acid: (essential fatty acid) Dermatitis, hair loss, change in vision
  • Vitamin A: can decrease vitamin C stores

Cori cycle: From muscle glucose to lactate è in liver lactate to glucose


  • Brain begins using ketones from fatty acids
  • (Normally brain and RBCs are glucose dependent)

Late starvation:

  • Gluconeogenesis shifts from liver to kidney as liver is depleted of alanine







Normal Saline



Lactated ringer's






Alkalosis: Causes hypokalemia by driving K into cells and into urine (exchange for H+)


  • (Peaked T wave, wide QRS)
  • Tx: 'C Big K die':
  • Calcium gluconate to protect heart, Bicarb/insulin/glucose, kayexalate, dialysis

Na deficit: ((0.6 x kg)(140-Na))

  • Replace no more than 1 mEq/hr to avoid CPM


  • Lowers Na
  • For every 100 glucose over 100, add 2 to the measured Na

'Hypocalcemia and hypomagnesemia:

  • Both have hyperexcitability
  • Low Calcium:
    • Increase reflexes (Chvostek's C of chick!)
    • Tetany
  • Low Mg:
    • Inhibits PTH so replace Mg if difficulty correcting a patient's Cacium

Anion gap acidosis: (MUDPILES)

  • Methanol, Uremia, DKA, Paraldehyde, Iron/INH, Lactic acidosis, Ethylene glycol, Salicylates
  • Anion gap = Na - (HCO3 + Cl) Normal < 12

All items (1)