Nutrition and GI Flashcards
Pepsinogen produced and stimulated by?
Pepsinogen —> pepsin by acid
Produced by chief cells
Stimulated by vagus nerve, histamine, gastrin
Intragastric protein digestion doesnt occur for first 5-8 days because of high stomach pH
Stomach acid produced by?
Parietal cells
Stimulated by vagus nerve, histamine, gastrin
Gastrin stimulated by?
Presence of food and stimulates enzyme pepsin and gastic acid secretion
Chymotrypsinogen and trypsinogen conversion
To chymotrypsin and trypsin by enterokinase in the intestinal mucosa
Glucoamylase
Carb digestion
Intestinal brush border enzyme
Removes glucose from end of starch
Disaccharidases maturation levels
Maltase, isomaltase, sucrase at adult levels by 28 weeks
Lactase not until 36 weeks
Role of CCK
Hormone that triggers release of pancreatic juice and bile
Decreases gastrin secretion
Secretin role
Hormone that stimulates pancreas to release bicarbonate which slows gastric emptying
GIP
Gastrin inhibitory peptide
Hormone that is stimulated by protein and fat
Slows gastric emptying
Decreases gastrin
Motilin role
Hormone that increases gastric emptying
Erythromycin is a motilin agonist
Benefits of early enteral feeding
^intestinal BF
^gut barrier defense (earlier intestinal closure)
^enzyme maturation
^motility
Earlier attainment of full enteral feedings
Common diagnoses with pancreatic insufficiency
Schwachman-Diamond syndrome: pancreatic insufficiency, BM dysfunction (neutropenia), short stature, normal bicarb secretion
CF: increased Cl in sweat (>50meq/L) but sweat test not reliable until >2kg
Conjugated hyperbilirubinemia ddx
Infectious (viral, toxo, syphilis, tb, listeriosis)
Toxin mediated (sepsis, drugs, PN)
Metabolic (galactosemia, GSD, tyrosinemia, A1AT deficiency, hypopit, hypothyroid, CF, Zellweger)
Genetic (Turner, T21)
Vascular (vascular anomalies, Budd chiari)
Neonatal leukemia, HLH, lupus
Intrahepatic duct disease (neonatal idiopathic hepatitis, Alagille)
Extrahepatic duct obstruction (biliary atresia, sclerosing cholangitis, bile duct stenosis, choledochal cyst, bile plug syndrome)
Colostrum whey to casein ratio
80 (whey) : 20 (casein)
Mature milk whey to casein ratio
55:45
Predominantly casein formulas whey to casein ratio
20:80
Predominantly whey formulas whey to casein ratio
80:20 or 60:40
Preterm formulas whey to casein ratio
Greater protein content and whey >casein
Enfamil preterm formula 80 whey : 20 casein
AA that are glucose precursors
Alanine
Glutamate
Aspartate
Essential AA
Branched (valine, leucine, isoleucine) Histidine Lysine Methionine Phenylalanine Threonine Tryptophan
Percentage of total kilocalories protein should account for in parenteral nutrition
7-15%
1g protein = 1g AA = 0.16g nitrogen
Protein starting dose for PN
1.5-3g/kg with daily increments to max of 4g/kg
Enteral protein goal
- 5-4.5g/kg/day
3. 2-4.1 per 100kcal
Essential FA
Linoleic acid
Alpha linolenic acid
Essential fatty acids deficiency
Scaly dermatitis, alopecia, thrombocytopenia, susceptibility to bacterial infections, FTT
Prevention 0.5-1g/kg/day IL
Diagnosis of essential FA deficiency
Increased triene:tetraene ratio (>0.2)
Also called the Holman index
Kcal fat should provide in daily calories
30-50%
20% lipid solution: 1mL is 20% fat and fat has 9kcal/g so 1mL has 1.8kcal
How much glucose should be provided per gram of protein and why?
6g of glucose per g of protein for positive nitrogen balance
%kcal glucose should provide
35-45% of total kcal
GIR
(%dextrose x TF) / 144
(Rate x %dextrose) / (weight x 6)
(g dextrose x 1000) / wt / 1440
mg/kg/min
Vitamin E deficiency
Alpha tocopherol
Thrombocytopenia, anemia, reticulocytosis, acanthocytosis, neurologic deficits
Increased sensitivity to hemolysis
Vitamin K deficiency
Required for carboxylation of prothrombin to thrombin
Hemorrhagic disease of the newborn
Vitamin A deficiency
Retinol
Important in pulmonary epithelia growth
Photophobia, conjunctivitis, abn bone and teeth, scaling, FTT
Vitamin B1 deficiency
Thiamine Beriberi (fatigue, irritability, constipation, cardiac failure) A/c maple syrup urine disease and pyruvate dehydrogenase complex deficiency
Vitamin B2 deficiency
Riboflavin
FTT, photophobia, blurry vision, dermatitis, mucositis
A/c glutaric aciduria type 1
Vitamin B6 deficiency
Pyridoxine
Dermatitis, mucositis, anemia, seizures
A/c homocystinuria
Biotin deficiency
Alopecia, dermatitis, scaling, seborrhea
Zinc deficiency
Acrodermatitis enteropathica
FTT, alopecia, diarrhea, dermatitis
Calcium to phosphorous ratio in TPN
Ca:P
1.3:1 to 1.7:1
<1:1 are not recommended
PN cholestasis TPN adjustments
Decrease manganese and copper
Increase zinc
Renal insufficiency PN adjustments
Decrease chromium and selenium
PN cholestasis and lipids
IL can decrease to 1gkd
Smof for high risk of developing PN cholestasis
Onegaven for reversing established PN cholestasis
Nitrogen balance calculation
Balance = intake - lost
Nitrogen intake = protein intake (g/d) x 0.16 (because each gram of protein is 16% nitrogen)
Nitrogen lost = urine [urea] + estimated stool losses (4g)
Calorie calculations
Dextrose: %dextrose x mkd x 3.4
Protein: gkd x 4kc/g
Fat: gkd x 10kc/g
Or for fat: [(ml/d) x 2kc/ml] / wt
