GI Lecture #1: Enteral Nutrition & Adult Parenteral Nutrition

Labs used to determine malnutrition

1. Serum proteins (albumin and pre-albumin)

2. nitrogen balance (if not enough food, protein breaks down into nitrogen containing amino acids )

Underlying disease states leading to undernutrition

Hypermetabolic stress (trauma, burns, sepsis)

Digestive/absorptive diseases (N/V/D/C)

Medications

Which medications can lead to malnutrition?

Corticosteroids

Immunosupresives

Radiation / Chemotherapy

General appearance signs of malnutrition

Ascites (protein deficiency)

Dehydration: Poor skin turgor, sunken eyes, orthostasis, and dry mucous membranes.

Recommended percentage of adult dietary carbohydrates

45% to 65% of total consumption.

Recommended percentage of adult dietary fats

20% to 35% of total consumption.

Recommended percentage of adult dietary protein

10% to 35% of total consumption.

What is the percentage of macromolecules required in an adult diet?

Carbohydrates = 45-65%

Fats = 20-35%

Protein = 10-35%

Components of daily energy expenditure in adults? Is this the same for peds?

Basal energy expenditure. (BEE), diet-induced thermogenesis, and physical activity energy.

NOT same for peds

Most common way to measure energy expenditure in adults?

What are other methods to measure adult energy expidenture?

Population estimate is most common using ACTUAL body weight.

Also can use

- Harris- Benedict Equation

- Indirect calorimetry (measures carbon dioxide output)

**Population-based energy estimate for healthy adults **

20 to 25 Kcal per kg of actual body weight per day.

**Protein requirement for healthy adults based on population estimates**

0.8 g/kg/day.

Protein requirement for elderly adults (61+)

1.0 to 1.5 g/kg/day

More than healthy 0.8

Protein requirement for burn patients

2.3 to 3.0 g/kg/day.

more than healthy 0.8

protein requirements for critical illness vs pregnancy/lactation

critical illness = 1.2-2

pregnancy/ lactation = 1.1

Clinical assessment tool for protein intake

Nitrogen balance.

Constant ratio of nitrogen in protein

How many grams of protein are in ONE gram of nitrogen

1g of nitrogen per 6.25g of protein.

This may vary for enternal and parenteral feeding

Nitrogen Out:

Increased stress = increased protein __________ = increased urinary ________ excretion

stress = increased protein CATABOLISM = incrased urinary NITROGEN excretion

Approximation of nitrogen output per day

24-hour urine urea nitrogen (UUN) plus 4

(4 is a factor representing usual skin, fecal, and respiratory nitrogen losses)

In healthy individuals UUN = 80-90% of total urine nitrogen (TUN) excreted

55 year old male no PMH who weighs 165 pounds and not in stress.

What is his caloric requirements and protein requirements?

total calories = 20-25 kcal/kg/day

Protein = 0.8g/kg/day

Why are vitamins and trace elements needed in minuscule amounts?

What causes deficiencies?

enzymes, hormones, and other essential substances

Deficiencies result in

- altered metabolism

- cell dysfunction

- interferance w/ metabolic processes necessary for nutritional repletion

The following are signs of deficiency in which vitamin/trace element?

- microcytic hypochromic anemia

- fatigue

- weakness

- pallor

Iron deficiency

The following are signs of deficiency in which vitamin/trace element?

- Dermatitis

- Altered Taste

Zinc deficiency

The following are signs of deficiency in which vitamin/trace element?

- HypOthyroid goiter

Iodine deficiency

The following are signs of deficiency in which vitamin/trace element?

- lactic acidosis

- encephalopathy (Wernikes)

Thiamine (B1) deficiency

The following are signs of deficiency in which vitamin/trace element?

- Pernicious anemia

Cobalamin (Vitamin B12) deficiency

The following are signs of deficiency in which vitamin/trace element?

- rickets

- osteomalacia

Vitamin D deficiency

Which medications would lead to antibiotics deficiency

Vitamin K deficiency bc/ usually produced by gut microbiome which has been killed off by antibiotics

Which medications would lead to vitamins ADEK and B-Carotene malabsorption?

Cholestyramine

Which medications could lead to B12 malabsorption?

H2RA and PPI bc/ reduced acid results in impaired release of B12 from food

Which medication causes deficiencies in

- vitamin B6

- niacin

Isoniazid

Vitamin ____ inhibits the effect of Warfarin and Vitamines ___ ____ and _____ may effect prothrombin time

k ihibits effect

ACE effect prothrombin time

What are some risk factors (causes)for metabolic complications of feeding?

Prolonged Fasting

Massive weight loss in obese patients (gastric bypass)

Chronic alcoholism/anorexia

Prolonged IV fluid repletion

Malnourishment due to chemotherapy

Elderly

Refeeding syndrome cause

Administration of excessive TPN after starvation, shifting electrolytes intracellularly.

Blood electrolyte drops seen in refeeding syndrome

Hypokalemia, hypomagnesemia, hypophosphatememia, and thiamine deificiency

REFEEDING SYNDROME:

When starved→

increased _______ + ____________ + protein ________ →

Protein, fat, mineral, electrolyte, and vitamin depletion (salt + water intolerance)

REFEEDING (switch to anabolism) → fluid, salt, nutrients (CHO major energy source) →

Increase _________ Secretion →

Increase glucose, K+, Mg2+, PO42- uptake + utilization of thiamine +

protein and glycogen synthesis →

NOW bc/ they are in the cells → levels are low IN THE BLOOD :

HYPOkalemia

HYPOmagesemia

HYPOphosphatemia

Thiamine deficiency (thiamine utilized in Krebs cycle as response to insulin)

Salt + water retention (oedema)

gluconeogenesis + glycogenolysis _+ protein catabolism

when refed too quickly --> insulin secretion --> nutrients uptook in the CELLS

-->

potassium, magnesium, phosphate, thiamine now low in the blood

+ water + salt retained

Prevention method for refeeding syndrome

Provide less than 50% of goal calories within the first 24 hours and slowly titrate.

Definition of enteral nutrition

Any feeding method using the GI tract to deliver caloric requirements. (ex. oral diet + tube feeds)

When is enteral feeding preferred over parenteral?

Whenever the GI tract is functional, to avoid IV risks.

Three main GI functions

1. Digestion

Conversion of complex

chemical + physical nutrients into a form absorbable by the intestinal mucosa (can't get complex nutrients parenterally)

2. Absorption:

Transfer of nutrients across cell membranes (underutilization leads to atrophy of the gut)

3. Defence:

Prevents the spread of intraluminal bacteria and endotoxins to systemic organs/tissues (wouldn't get this additional protection from parenteral)

What are the benefits of enteral nutrition?

1. Bowel mucosa serve as first line defence against pathogenic organisms

2. Prevents bowel atrophy (bc/ we are using gut)

3. Prevents translocation of gut bacteria

4. Provide complex nutrients such as fiber (will break it down)

what are the two ABSOLUTE contraindications for enteral nutrition

you CANNOT use enteral must be parenteral

Mechanical intestinal obstruction

Necrotizing enterocolitis

What are some relative contraindications of enteral nutrition? (can use if necessary)

GI surgery

Severe pancreatitis

Severe inflammatory disease

Short bowel syndrome

Hemodynamic instability

Intractable diarrhea

GI bleeding

Obstruction/ ileus

Is the absence of bowel sounds an enteral contraindication?

No, it is not a contraindication.

Short-term NONSURGICAL enteral feeding routes

Nasogastric + Orogastric (stomach)

Nasoduodenal + Nasojejunal (intestinal)

Long-term SURGICAL enteral feeding routes

Gastrostomy

PEG

jejunostomy tubes

Both Neogastric/Orgogastric and Nasoduodenal/ Nasojejunal are for SHORT TERM nonsurgical, but when would you use one over the other?

Neogastric/ Orgogastric =

Normal gastric emptying

Nasoduodenal/Nasojejunal = IMPAIRED gastric emptying + pt has high risk of aspiration

Both Gastrostomy (GT)/ Percutaneous endoscopic gastronomy (PEG) and Jejunostomy are for LONG TERM surgical, but when would you use one over the other?

Gastrostomy (GT)/ Percutaneous endoscopic gastrostomy (PEG) = normal gastric emptying

Jejunostomy = for patients who have normal gastric emptying AND have HIGH RISK OF ASPIRATION

What are some specific disease states in which we would have to adjust enteral feeding?

Renal

Hepatic

Diabetic

Pulmonary

Trauma + Burn

enteral route for impaired gastric emptying and aspiration risk

Nasoduodenal or nasojejunal tubes.

Enteral formula adjustment for renal disease (Nepro / Novasource Renal)

HIGH calories

LOW Protein and electrolytes (especially K)

Hepatic enteral formula adjustment

(Nutrihep - only for hepatic encephalopathy)

HIGH branched-chain amino acids LOW aromatic amino acids (to prevent encephalopathy)

Diabetic enteral formula adjustment

(Glucerna / Diabetsource)

HIGH fat

LOW carbohydrates.

Pulmonary enteral formula adjustment

HIGH fat

LOW carbohydrates to prevent excess CO2

Trauma + Burn enteral formula adjustment

(Impact 1.5 / Peptamen)

HIGH hydrolyzed glutamine, arginine, nucleotides, and/or omega-3 fatty acids

Most serious enteral tube feeding complication

Aspiration pneumonia.

How can we prevent Aspiration Pneumonia?

Providing appropriate mouth hygiene (have good flora take out the bad)

What are some medication administration considerations to keep in mind with enteral tube feeding?

1. Placement of tube

2. PK/PD (can you crush tablets before going into tube?)

3. Dose form

AVOID sublingual + ER + enteric coated + do not crush

Liquid forms may contain sorbitol or high osmolality

4. Medications SHOULD NOT BE directly mixed with Enteral Nutrition (must dissolve in water FIRST)

5. Consider drug-drug and drug-food interactions w/ continuous feeding

Premixed TPNs utility

Useful for off-hours, but unsuitable for

- fluid-overloaded

- highly catabolic (AKI)

- highly metabolic (critically ill)

- Pediatric

Which medications should be AVOIDED when giving ENTERAL nutrition?

1. Floroquinolones

2. Tetracyclines

3.Phenytoin

4. Lansoprazole

5. Omeprazole

6. Warfarin

F This Phenytoin LOW