﻿ Equations
 Equations
 Anthropometrics Body mass index BMI = Wt(kg) / Ht (m)2   Body surface area Adults (age > 11 years) BSA = 0.007184 x  (Ht(cm) ^ 0.725)  x  (Wt(kg) ^ 0.425) Peds BSA = 0.024265 x  (Ht(cm) ^ 0.3964)  x  (Wt(kg) ^ 0.5378)   Ideal body weight Adults (age > 11 years) IBW = 45.5 + (2.3 x  (Ht(in) - 60)) If male then add 4.5 to above Peds IBW = (Ht(cm)2  x  1.76) / 1000       Modified body weight If Actual weight is greater than 125% of IBW then MBW = IBW + 0.2 x (ABW - IBW) If Actual weight is less than 80% of IBW then MBW = IBW + 0.2 x (IBW - ABW) Otherwise MBW = ABW   Mid arm muscle circumference MAMC = MAC -  (0.314 x  TSF)     Monitoring parameters Nitrogen balance N Bal = N in - N out where N in = Protein intake (g/d) / 6.25 N out = UUN + 4   Creatinine clearance Adults (age > 11 years) CrCl = (140 - Age) x Wt(kg) / (Cr * 72) If Female multiply above by 0.85 Peds     CrCl = (Ht * 0.55) / Cr   Corrected calcium Corrected Ca = Ca + (0.8  x   (4 - Albumin)   Plasma osmolality Plasma osmol = (2  x  Na) + (Glucose / 18) + (BUN / 2.8)   Bicarbonate deficit Bicarb def  = (24 - Bicarb) x  Wt(kg) x   0.5   Fluid deficit Fluid deficit = (1 - (140 / Na)) x  Wt(kg)  x  0.6   Sodium deficit Sodium deficit  = (140 - Na)  x  Wt(kg)  x   0.6     Nutritional needs assessment Basal energy expenditure Adults (age > 11 years) Male BEE = 66 + (13.7 x  Weight) + (5 x  Height) - (6.8  x   Age) Female BEE = 665 + (9.6  x  Weight) + (1.7  x  Height) - (4.7  x   Age) Age 3 to 11 years   Male BEE = (22.7 x  Weight) + 495 Female BEE = (22.5  x  Weight) + 499 Age 1 to 2 Male BEE = (60.9  x  Weight) - 54 Female BEE = (61  x   Weight) - 51   Estimated energy expenditure EEE = BEE x Stress/activity factor   Fluid requirements Fluid req = 1 to 1.5ml per Kcal   Protein requirements Adults (age  > 11 years) Protein req = Weight  x  (1.2 + (Activity  x   0.2)) Age 7 to 11 years Protein req = Weight  x   (1 + (Activity  x   0.2)) Age 4 to  6 years Protein req = Weight  x   (1.1 + (Activity  x   0.2)) Age 1 to 3 years Protein req = Weight  x   (1.2 + (Activity  x   0.2))     TPN evaluation parameters Calcium:Phosphate solubility product Ca:PO4 product = Ca(meq)  x  PO4(meq)   Osmolarity per liter 1.  Amino acid contribution AA mOsmol = 100 mOsmol/final % 2.  Dextrose contribution Dextrose mOsmol = 50 mOsmol/final % 3.  Lipid contribution Lipid mOsmol = 1.7 mOsmol/g 4.  Electrolyte contribution Total mEq of each constituent cation and anion 1 mOsmol = 1 mEq 5.  Add all contributions and divide by volume/1000 Osmolarity per liter = (AA mOsmol + Dext mOsmol + Lipid mOsmol + Lyte mOsmol)  /  (Total volume / 1000)   Nitrogen:Calorie ratio N:C ratio = Kcal/day / (Protein(g/day)  /  6.25)

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