Nutrition, Fluids, Electrolytes

• FeNa <1, Urine Na <20, Bun/Cr >30 all indicative of low volume, 'pre-renal'
• Saliva has highest K concentration (20mEq), then gastric (10), pancreatic/duodenal (5)
• Branched chain amino acids are metabolized in muscle (leucine, isoleucine, valine); all essential
• Vit D made in skin, to liver for (25-OH) then to kidney (1-OH); now active
• Vit D increases calcium binding protein to increase intestinal Ca absorption
• Vit A systemic or topical reverses adverse effects of steroids on wound healing
• TBW: infant highest (80%), then men (60%), then women (50%). 10% less is obese (less H2O in fat)
• Water distribution: if tbw 60%, then 40% is cellular, 15% is intestinal, 5% in plasma
• Carbs have 3.4 kcal/g, protein 4 kcal/g, fat 9 kcal/g
• Basal calorie expenditure = 25 kcal/kg/day (~1g protein/kg/day needed)
• Respiratory Quotient = ratio of CO2 produced to O2 consumed.  0.7 = fat used, 1.0 = carb used
• 6.25g of protein contains 1 gram of Nitrogen. Nitrogen balance = Nitrogen(in) - Nitrogen(out).  Nitrogen(in) = (protein/6.25) and Nitrogen(out) = (24 hr urine N + 4g)
• Short chain fatty acids: preferred fuel of the colon
• Glutamine: preferred fuel of the small bowel.  #1 amino acid in bloodstream, see decreased levels with stress 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 to enterocytes -> chylomicrons to lymphatics (to jxn LIJ/Subclavian). Only medium and short chain triglycerides go to portal system with amino acids and carbs
• Chromium deficiency: hyperglycemia (relative diabetes), neuropathy
• Zinc deficiency: perioral rash, hair loss, poor healing, change in taste
• Phosphate deficiency: weakness (respiratory), encephalopathy (needed for ATP)
• Copper deficiency: anemia, neutropenia
• Linoleic acid (essential fatty acid) deficiency: dermatitis, hair loss, change in vision
• Vit A deficiency: can decrease Vit C stores
• Cori cycle: glucose -> lactate, to the liver -> glucose
• Starvation: brain begins using ketones from fatty acids (normally brain and rbc's are dependant on glucose)
• Late starvation: gluconeogenesis shifts to kidney as liver is depleted of alanine
• IVF: Normal saline is 154mEq Na and Cl; LR is Na 130, K4, Ca 2.7, Cl 109, bicarb 28
• Alkalosis causes hypokalemia by driving K into cells and into urine (exchange for H+)
• Hyperkalemia (peaKed t wave, wide QRS): give Ca to protect heart, Bicarb/Insulin/Glucose, Kayexalate, Dialysis if severe; 'C Big K die'
• Na deficit = .6 (wt in kg)(140-Na); replace no more than 1 mEq/hr to avoid CPM
• Hyperglycemia lowers Na; for every 100 glucose over 100 add 2 to Na
• Hypocalcemia and hypomagnesemia both have hyperexcitability, increase reflexes (Chvostek's), tetany
• Anion gap acidosis with MUDPLES = methanol, uremia, dka, paraldehyde, lactic acidosis, ethylene glycol, salicylates. Anion gap = Na - (HCO3 + Cl). Normal less than 12.
• Low mag inhibits PTH so replace mag if difficulty correcting a patient's low Ca

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