Transcript Nutrition-lecture

Nutrition
. . . and the surgical patient
Nutrition
ENERGY SOURCES
 Carbohydrates
 Fats
 Proteins
Nutrition

Carbohydrates
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Limited strorage capacity, needed for CNS
(glucose) function
Yields 3.4 kcal/gm
Pitfall: too much = lipogenesis and increased
CO2 production
Nutrition
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Fats
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Major endogenous fuel source in healthy
adults
Yields 9 kcal/gm
Pitfall: too little=essential fatty acid (linoleic
acid) deficiency—dermatitis and increased
risk of infections
Nutrition
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Proteins
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Needed to maintain anabolic state (match
catabolism)
Yields 4 kcal/gm
Pitfall: must adjust in patients with renal and
hepatic failure
Nutrition
Non-protein
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Calories
Protein
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Calories
Fats
Carbohydrates
Proteins
Nutrition
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Requirements
HEALTHLY 70 kg MALE
• Caloric intake=35 kcal/kg/day
(max=2500/day)
• Protein intake=0.8-1gm/kg/day
(max=150gm/day)
• Fluid intake=30 ml/kg/day
Nutrition
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Requirements
? SURGICAL PATIENT ?
Nutrition
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Special considerations
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Stress
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Injury or disease
Surgery
Prehospital/presurgical
nutrition
Nutrition
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The surgical patient . . . .
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Extraordinary stressors (hypovolemia,
bacteremia, medications)
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Wound healing
 Anabolic state, appropriate vitamins (A, C, Zinc)
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Poor nutrition=poor outcomes
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For every gm deficit of untreated hypoalbuminemia
there is ~ 30% increase in mortality
Nutrition
HEALTHLY 70 kg MALE
Caloric intake
35 kcal/kg/day
(max=2500/day)
Protein intake
0.8-1gm/kg/day
(max=150gm/day)
Fluid intake
30 ml/kg/day
SURGERY PATIENT
Caloric intake
*Mild stres, inpatient
20-25 kcal/kg/day
*Moderate stress, ICU patient
25-30kcal/kg/day
*Severe stress, burn patient
30-40 kcal/kg/day
Protein intake
1-1.8gm/kg/day
Fluid intake
INDIVIDUALIZE
Nutrition
Non-protein

Calories
Protein
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Calories
30%
70%
CHO
Fats
Proteins
Nutrition

Measures of success
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Serum markers
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Retinol binding protein, prealbumin, transferrin,
albumin
Nutrition
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Measures of success
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Nitrogen balance
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Protein ~ 16% nitrogen
Protein intake (gm)/6.25 - (UUN +4)= balance in
grams
Metabolic cart (indirect calorimetry)
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ICU patient, measure of exchange of O2 and CO2
Respiratory quotient =1
Nutrition
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What route to feed?
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GUT, GUT, GUT
When to feed?
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EARLY, EARLY, EARLY
TPN
Diet Advancement
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Traditional Method
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Start clear liquids when signs of bowel function
returns
Rationale
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Clear liquid diets supply fluid and electrolytes that
require minimal digestion and little stimulation of the
GI tract
Clear liquids are intended for short-term use due
to inadequacy
Diet Advancement
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Recent Evidence
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Liquid diets and slow diet progression may not be
warranted!!
Clinical study
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Early post-operative feeding with regular diets vs.
traditional methods demonstrated no difference in
post-operative complications
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Emesis, distention, NGT reinsertion, and Length of stay
Pitfalls…
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For liquid diets, patients must have adequate
swallowing functions
Even patients with mild dysphagia often
require thickened liquids.
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Must be specific in writing liquid diet orders for
patients with dysphagia
Patients who cannot eat . . . ?
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Two types of nutritional support
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Enteral
Parenteral
Indications for Enteral Nutrition
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Malnourished patient expected to be unable
to eat adequately for > 5-7 days
Adequately nourished patient expected to be
unable to eat > 7-9 days
Following severe trauma or burns
Enteral Access Devices
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Nasogastric/nasoenteric (temporary)
Gastrostomy (long-term)
 Percutaneous endoscopic gastrostomy (PEG)
 Open gastrostomy
Jejunostomy
 Percutaneous endoscopic jejunostomy (PEJ)
 Open jejunostomy
Transgastric Jejunostomy
 Percutaneous endoscopic gastro-jejunostomy (G-J)
 Open gastro-jejunostomy
Feeding Tube Selection
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Can the patient be fed into the stomach, or is
small bowel access required?
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How long will the patient need tube feedings?
Gastric vs. Small Bowel Access
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“If the stomach empties, use it.”
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Indications to consider small bowel access
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Gastroparesis/gastric ileus
Abdominal surgery
Significant gastroesophageal reflux
Pancreatitis
Aspiration
Proximal enteric fistula or obstruction
Enteral Nutrition Case Study
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78-year-old woman admitted with new CVA
Significant aspiration detected on bedside swallow
evaluation, confirmed on modified barium swallow
study
 Speech language pathologist recommended strict
NPO with alternate means of nutrition
What is parenteral nutrition?
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Parenteral Nutrition
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AKA
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total parenteral nutrition
TPN
hyperalimentation
Liquid mixture of nutrients given via the blood
through a catheter in a vein
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Mixture contains all the protein, carbohydrates, fats,
vitamins, minerals, and other nutrients needed to
maintain nutrition balance
Indications for Parenteral Nutrition
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Malnourished patient expected to be unable
to eat > 5-7 days AND enteral nutrition is
contraindicated
Patient failed enteral nutrition trial with
appropriate tube placement (post-pyloric)
Severe GI dysfunction is present
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Paralytic ileus, mesenteric ischemia, small bowel
obstruction, enteric fistula distal to enteral access
sites
TPN vs. PPN
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TPN
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High glucose concentration (15%-25% final dextrose
concentration)
Provides a hyperosmolar formulation (1300-1800
mOsm/L)
Must be delivered into a large-diameter vein through
central line
Peripheral parenteral nutrition (PPN)
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Similar nutrient components as TPN, but lower
concentration (5%-10% final dextrose concentration)
Osmolarity < 900 mOsm/L (maximum tolerated by a
peripheral vein)
Because of lower concentration, large fluid volumes are
needed to provide a comparable calorie and protein
dose as TPN
Parenteral Access Devices
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Peripheral venous access
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Catheter placed percutaneously into a peripheral
vessel
Central venous access (catheter tip in SVC)
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Percutaneous jugular, femoral, or subclavian
catheter
Implanted ports (surgically placed)
PICC (peripherally inserted central catheter)
Complications of
Parenteral Feeds
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Hepatic steatosis
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May occur within 1-2 weeks after starting TPN
May be associated with fatty liver infiltration
Usually is benign, transient, and reversible in
patients on short-term TPN—typically resolves in
10-15 days
Limiting fat content and cycle feeds over 12 hours
to control steatosis in patients on long-term TPN
Parenteral Nutrition Case Study
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55-year-old male admitted with small bowel
obstruction
History of complicated cholecystecomy 1
month ago. Since then patient has had poor
appetite and 20-pound weight loss
Patient has been NPO for 3 days since admit
Right subclavian central line was placed and
plan noted to start TPN since patient is
expected to be NPO for at least 1-2 weeks
Nutrition
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What route to feed?
VS
TPN
Nutrition
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What route to feed?
TPN
TPN
Benefits of Enteral Nutrition
(Over Parenteral Nutrition)
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Cost
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Maintains integrity of the gut
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Tube feeding cost ~ $10-20 per day
TPN costs up to $1000 or more per day!
Tube feeding preserves intestinal function; it is more
physiologic
TPN may be associated with gut atrophy
Less infection
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Enteral feeding—very small risk of infection and
may prevent bacterial translocation across the gut
wall
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TPN—high risk/incidence of infection and sepsis
Refeeding Syndrome
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“The metabolic and physiologic consequences of
depletion, repletion, compartmental shifts, and
interrelationships of phosphorus, potassium, and
magnesium…”
Severe drop in serum electrolyte levels resulting
from intracellular electrolyte movement when
energy is provided after a period of starvation
(usually > 7-10 days)
Sequelae may include
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EKG changes, hypotension, arrhythmia, cardiac arrest
Weakness, paralysis
Respiratory depression
Ketoacidosis / metabolic acidosis
Refeeding Syndrome
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Prevention and Therapy
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Correct electrolyte abnormalities before starting
nutrition support
Continue to monitor serum electrolytes after
nutrition support begins and replete aggressively
Initiate nutrition support at low rate/concentration
(~ 50% of estimated needs) and advance to goal
slowly in patients who are at high risk
Over and Under Feeding
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Risks associated with over-feeding
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Hyperglycemia
Hepatic dysfunction from fatty infiltration
Respiratory acidosis from increased CO2 production
Difficulty weaning from the ventilator
Risks associated with under-feeding
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Depressed ventilatory drive
Decreased respiratory muscle function
Impaired immune function
Increased infection
Food for Thought
(that is . . . nutrition for your brain)
Life is not measured by the number of breaths we take,
but by the moments that take our breath away.
TPN
References
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American Society for Parenteral and Enteral Nutrition. The
Science and Practice of Nutrition Support. 2001.
Han-Geurts, I.J, Jeekel,J.,Tilanus H.W, Brouwer,K.J.,
Randomized clinical trial of patient-controlled versus fixed
regimen feeding after elective abdominal surgery. British
Journal of Surgery. 2001, Dec;88(12):1578-82
Jeffery K.M., Harkins B., Cresci, G.A., Marindale, R.G., The
clear liquid diet is no longer a necessity in the routine
postoperative management of surgical patients. American
Journal of Surgery.1996 Mar; 62(3):167-70
Reissman.P., Teoh, T.A., Cohen S.M., Weiss, E.G.,
Nogueras, J.J., Wexner, S.D. Is early oral feeding safe after
elective colorectal surgery? A prospective randomized trial.
Annals of Surgery. 1995 July;222(1):73-7.
Ross, R. Micronutrient recommendations for wound healing.
Support Line. 2004(4): 4.