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Therapeutics 4 - Week 13 - Nutrition

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tylerwise's version from 2015-04-20 02:38

Assessment of Nutrition Status

ClassificationABW vs. IBW
Severe malnutritionABW < 70% IBW
Moderate malnutritionABW 70-79% IBW
Mild malnutritionABW 80-89% IBW
Normal statusABW 90-120% IBW
OverweightABW 121-149% IBW
ObeseABW 150-199% IBW
Morbidly obeseABW > 200% IBW
When to use Actual Body WeightIBW < ABW < 130% IBW
When to use Ideal Body WeightABW < IBW
When to use Adjusted Body WeightABW > 130% IBW
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Nutrient Requirements

Question Answer
Healthy, normal nutrition status
Population estimate
20-25 kcal/kg/day
Illness, metabolic stress (BMI < 30kg/m^2)
Population estimate
25-30 kcal/kg/day
Illness, metabolic stress (BMI > 30kg/m^2)
Population estimate
11-14 kcal/kg/day (ABW)
-or-
22-25 kcal/kg/day (IBW)
Severe stress, major burn injury
Population estimate
>30 kcal/kg/day
Stress Factor
Bed rest
1.2
Stress Factor
Ambulatory
1.3
Stress Factor
Mild to moderate stress
1.4-1.5
Stress Factor
Severe stress or trauma
1.5-2.0
Fluid volume requirements
Holliday-Segar method
1500 mL for first 20 kg
20 mL/kg for each addition 'kg'
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Indications for Parenteral Nutrition Support

Question Answer
Consider initiating after...
Adults
7-14 days
Adult indicationsInability to absorb nutrients via the GI tract
Cancer
Pancreatitis (depends on severity)
Critical care (burns, organ failure)
Perioperative
Hyperemesis gravidarum
Eating disorders
Consider initiating after...
Premature infants and pediatrics
Premies: 24-48 hours
Pediatric patients: 5-7 days
Pediatric indicationsGI tract is not functional or cannot be assessed
Pediatric patients requiring extracorporeal membrane oxygenation (ECMO)
Organ failure when EN is contraindicated
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Components of Parenteral Nutrition

Question Answer
MacronutrientsFluid
Amino acids (protein)
IV fat emulsion (lipids)
Dextrose
MicronutrientsVitamins
Trace elements
Electrolytes
Amino acid conversion factor1 gram = 4 kcal
Dextrose conversion factor1 gram = 3.4 kcal
IV fat emulsion conversion factors1 gram = 9 kcal
Dextrose standard concentration70% (70g/100mL)
IV fat emulsion standard concentrations10% = 1.1 kcal/mL
20% = 2 kcal/mL
30% = 3 kcal/mL
Maximum dextrose infusion ratesInfants: 14-18 mg/kg/min
Adults: 4-7 mg/kg/min
Estimated volume of Vitamins + Trace Elements + Electrolytes150 mL
Corrected Calcium Concentration EquationUtilize when [albumin] is low
4 - ([Albumin] * 0.8) + [Ca]
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Designing a Parenteral Nutrition Regimen

Question Answer
Two-in-one contentsDextrose
Amino acids
Micronutrients
Three-in-one contentsDextrose
Amino acids
Fat emulsion
Micronutrients
Time considerations for Peripheral PNGI tract function expected to return in 10-14 days
Time considerations for Central PNPN required for > 7-14 days
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Initiating and Advancing the Parenteral Nutrition Infusion

Question Answer
Dextrose rate considerations
Stable patients
Abrupt initiation and discontinuation are generally fine
Dextrose rate considerations
With comorbidities
Consider tapered initiation and cessation to avoid hyperglycemia and rebound hypoglycemia
Increase gradually over 12-24 hours
Decrease by 50% for 1 hour prior to discontinuation
Fat emulsion rate considerationsInfuse over 12-24 hours to promote clearance and minimize negative effects (including hypersensitivity reactions)
Continuous infusion considerationsPreferred for patients with unstable fluid balance or glucose control
Cyclic infusion considerationsGenerally given over 12-18 hours
Useful when venous access is limited
May prevent or treat hepatotoxicities associated with long-term PN
Accommodates "normal" lifestyle for patients at home
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Evaluation of Therapeutic Outcomes (PN)

FrequencyLab/Value to Test
Every ShiftPOC blood glucose
DailyBMP
Magnesium
Phosphorus
Weight
I/Os
WeeklyPrealbumin
LFTs
As NeededLipid panel
UUN
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Complications of Parenteral Nutrition

Question Answer
Mechanical/TechnicalMalfunctions in the system used for IV delivery of solution
Problems with administration sets or tubing
Problems with the catheter
InfectiousSkin organisms at the catheter insertion site
Contamination of catheter hub
Hematogenous seeding of the catheter from a distant site
Metabolic/NutritionalPN-associated liver disease
Hypertriglyceridemia
Hyperglycemia
Refeeding syndrome
Complications associated with long-term deficiencies
Essential fatty acid deficiency
Metabolic bone disease
Trace elements and vitamin complications
Refeeding syndromeSevere and rapid declines in serum phosphate, potassium, and magnesium concentrations
Fluid retention
Other micronutrient deficiencies
People at risk include severely malnourished with significant weight loss who receive aggressive nutritional supplementation
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Indications for Enteral Nutrition

Question Answer
Indications for ENFunctional GI tract!!!!!
Inability to eat a sufficient amount to meet nutritional requirements
Contraindications for ENIntestinal obstruction
Necrotizing enterocolitis
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Enteral Access

RouteConsiderations
Short-term options< 4-6 weeks
Easier to initiate, less invasive, less costly
Nasogastric (NG)
Orogastric (OG)
Nasoduodenal (ND)
Nasojejunal (NJ)
Long-term options> 4-6 weeks
More comfortable, more reliable, fewer long-term complications
Gastronomy (G-tube)
Percutaneous endoscopic gastronomy (PEG)
Jejunostomy (J-tube)
Pharyngostomy/Esophagostomy
Nasogastric (NG)/Orogastric (OG)Least expensive
Least labor-intensive
Not well-tolerated in patients with impaired gastric motility
Nasoduodenal (ND)/Nasojejunal (NJ)More challenging to place
Beneficial in patients unable to tolerate gastric feeding
Not appropriate for bolus/intermittent feedings!
Gastronomy (G-tube)/Percutaneous endoscopic gastronomy (PEG)Most common
Relatively easy to place
Large-bore = less risk of clogging
Jejunostomy (J-tube)Better for patients at high risk of aspiration or GERD
Appropriate for patients unable to tolerate gastric feeding
Smaller bore = easier to clog
Not appropriate for bolus/intermittent feedings!
Pharyngostomy/EsophagostomyHigh complication rates
Rarely used
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Administration Methods (EN)

MethodConsiderations
ContinuousVolume given evenly over 24 hours
Better tolerated than bolus or intermittent
Inconvenient for ambulatory patients
CyclicVolume given only at night
More convenient for ambulatory patients
BolusVolume given over 5-10 minutes four to six times daily
Poorly tolerated in duodenal/jejunal access
Avoid in delayed gastric emptying or high risk of aspiration
IntermittentVolume given over 20-60 minutes four to six times daily
Option for those unable to tolerate faster bolus administration
Most consistent physiologically with normal eating patterns
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Initiation and Advancement Protocol (EN)

Question Answer
Continuous
Adults
Start at 20-50 mL/hour
Increase 10-25 mL/hour every 4-8 hours until goal rate
Bolus/Intermittent
Adults
Start at 120 mL every 4 hours
Increase 30-60 mL every 8-12 hours until goal rate
Continuous
Pediatrics
Start at 1-2 mL/kg/hour (no more than 25-30 mL/hour)
Increase by similar amount every 4-24 hours
Bolus/Intermittent
Pediatrics
Start at 2-4 mL/kg per bolus (no more than 30-90 mL/bolus)
Increase by similar amount every 4-24 hours
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Complications and Monitoring (EN)

Question Answer
Monitoring patternDaily: weight, I/Os
Weekly: prealbumin, LFTs, BMP
As needed: lipid panel, UUN
Metabolic complicationsHyperglycemia
Issues with hydration and electrolyte imbalances
GI complicationsDiarrhea
Nausea
Vomiting
Abdominal distension
Cramping
Aspiration
Constipation
Mechanical complicationsTube occlusion (e.g., kinking)
Tube malposition
Nasopulmonary intubation
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Drug Delivery Via Feeding Tube (EN)

Question Answer
Dosage forms to avoid via feeding tubeSublingual forms
Sustained-release capsules or tablets
Enteric-coated tablets
Drugs with special considerations with ENPhenytoin
Fluoroquinolones
Tetracyclines
Warfarin
Omeprazole
Lansoprazole
Issues with PhenytoinReduced bioavailability in the presence of tube feedings due to protein binding
Issues with FluoroquinolonesPotential reduced bioavailability due to complexation of the drug
Issues with TetracyclinesPotential reduced bioavailability due to complexation of the drug
Issues with WarfarinReduced bioavailability and absorption due to protein binding
Antagonism by vitamin K present in tube feedings
Issues with OmeprazoleAbsorption complicated by acid-labile medications (or PN) within delayed-release, base-labile granules
Issues with LansoprazoleAbsorption complicated by acid-labile medications (or PN) within delayed-release, base-labile granules
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