Transcript Nutrition

SURGICAL NUTRITION
Awadh Alqahtani MD,MSc,FRCSC(surgery)FRCSC(oncology)
FISC
Surgical oncologist and laparoscopic Bariatric surgeon
22/9/2014
LECTURE OUTLINE
Energy Sources
Nutrition Requirements
Diet Advancement
Micronutrients for wound healing
Enteral versus Parenteral Nutrition
• Case studies
ENERGY SOURCES
Carbohydrates
• Limited storage capacity, needed for CNS function
• Yields 3.4 kcal/gram
• Pitfall: too much=lipogenesis and increased CO2 production
Fats
• 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
Protein
• Needed to maintain anabolic state (match catabolism)
• Yields: 4 kcal/gm
• Pitfall: must adjust in patient with renal and hepatic failure
• Elevated creatinine, BUN, and/or ammonia
NUTRITION
REQUIREMENTS
Healthy Adults
• Calories: 25-35 kcals/kg
• Protein: 0.8-1 gm/kg
• Fluids: 30 mls/kg
Requirement Change for the Surgical Patient
Special Considerations
• Stress
• Injury or disease
• Surgery
Pre-hospital/pre-surgical nutrition
NUTRITION
The surgical patient…
• Extraordinary stressors (hypovolemia, hypervolemia, bacteremia,
medications)
• Wound Healing
• Anabolic state, appropriate vitamins (A, C, Zinc), and adequate
kcals/protein.
Poor Nutrition=Poor Outcomes
• For every gram deficit of untreated hypoalbuminemia there is ~30%
increase in mortality
POST-OPERATIVE
NUTRITION REQUIREMENTS
Calories:
• Increase to 30-40 kcals/kg
• Patient on ventilator usually require less
calories ~20-25 kcal/kg
Protein:
• Increase to 1-1.8 grams/kg
Fluids:
• Individualized
DIET ADVANCEMENT
Traditional Method:
• Start clear liquids when signs of bowel function returns.
• Rationale: Clear liquid diets supply fluid and electrolytes in a form
that require minimal digestion and little stimulation of the GI tract.
• Clear liquids are intended for short-term use due to inadequacy
DIET ADVANCEMENT
Recent Evidence:
• Suggests that liquid diets and slow diet progression may not be warranted!!
Clinical study:
• Looked at early post-operative feeding using regular diets or very fast
progression vs. traditional methods of NPO until bowel function with slow
diet progression and found no difference in post-operative
complications. (emesis, distention, NGT reinsertion, LOS,)
MICRONUTRIENTS IN
WOUND HEALING
Vitamin Supplementation to promote healing has been somewhat
disputed.
Some studies show no significant effect unless there is a clinical
vitamin deficiency
Serum vitamin levels are not always accurate; therefore, must use
subjective diet history and clinical judgment to determine deficiency.
KEY NUTRIENTS FOR
WOUND HEALING
Vitamin A:
• Cellular differentiation, proliferation, epithelialization,
collagen synthesis, counteract catabolic effect of steroids.
• RDA=3333 International Units
• Appropriate dose=25,000 IU per day x 10 days in setting of high dose
steroids or deficiency.
• Avoid long term supplementation due to high risk of toxicity with fatsoluble vitamins.
No vitamin A with renal failure due to greater potent ional for
toxicity. (Can exceed the binding capacity of retinol binding
protein leading to elevated circulating levels.)
KEY NUTRIENTS FOR
WOUND HEALING
Vitamin C:
• Collagen synthesis
• RDA=50-90 mg/day
• Low levels are common in high risk population (elderly,
smokers, cancer, liver disease).
• Appropriate dose: 500 mg x 10 days
• No vitamin C with renal failure due to risk for renal oxalate stone
formation.
KEY NUTRIENTS FOR
WOUND
HEALING
Zinc:
• Protein synthesis, cellular replication, collagen formation; large
wounds, chest tubes, and wound drains contribute to further zinc
loses.
• Appropriate dose: 220 mg per day of Zinc Sulfate or
50 mg of elemental Zinc x 10 days.
• Prolonged Zinc supplementation interferes with copper absorption
and can lead to copper deficiency which delays wound healing by
impairing collagen synthesis.
MVI with minerals:
• 1 tablet daily to compensate for any general micronutrient losses.
WHAT IS NUTRITION
SUPPORT?
An alternate means of providing nutrients to people who cannot eat
any or enough food
When is it needed?
• Illness resulting in inability to take in adequate nutrients by mouth
• Illness or surgery that results in malfunctioning gastrointestinal
tract
Two types:
• Enteral nutrition
• Parenteral nutrition
INDICATIONS FOR
ENTERAL NUTRITION
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
Adaptive phase of short bowel syndrome
Following severe trauma or burns
CONTRAINDICATIONS TO ENTERAL
NUTRITION SUPPORT
Malnourished patient expected to eat within 5-7 days
Severe acute pancreatitis
High output enteric fistula distal to feeding tube
Inability to gain access
Intractable vomiting or diarrhea
Aggressive therapy not warranted
Expected need less than 5-7 days if malnourished or
7-9 days if normally nourished
ENTERAL ACCESS
DEVICES
Nasogastric
Nasoenteric
Gastrostomy
• PEG (percutaneous endoscopic gastrostomy)
• Surgical or open gastrostomy
Jejunostomy
• PEJ (percutaneous endoscopic jejunostomy)
• Surgical or open jejunostomy
Transgastric Jejunostomy
• PEG-J (percutaneous endoscopic gastro-jejunostomy)
• Surgical or open gastro-jejunostomy
FEEDING TUBE
SELECTION
Can the patient be fed into the stomach, or is small bowel access
required?
How long will the patient need tube feedings?
GASTRIC VS. SMALL
BOWEL ACCESS
“If the stomach empties, use it.”
Indications to consider small bowel access:
• Gastroparesis / gastric ileus
• Recent abdominal surgery
• Sepsis
• Significant gastroesophageal reflux
• Pancreatitis
• Aspiration
• Ileus
• Proximal enteric fistula or obstruction
SHORT-TERM VS. LONGTERM
TUBE FEEDING ACCESS
No standard of care for cut-off time between short-term and long-term
access
However, if patient is expected to require nutrition support longer than 68 weeks, long-term access should be considered
CHOOSING APPROPRIATE
FORMULAS
Categories of enteral formulas:
• Polymeric (Jevity)
• Whole protein nitrogen source, for use in patients with normal
or near normal GI function
• Monomeric or elemental (Perative, Optimental)
• Predigested nutrients; most have a low fat content or high % of
MCT oil (medium-chain triglycerides); for use in patients with
severely impaired GI function
• Disease specific (Nepro, Nutrahep, Glucerna)
• Formulas designed for feeding patients with specific disease
states
• Formulas are available for respiratory disease, diabetes, renal
failure, hepatic failure, and immune compromise
*well-designed clinical trials may or may not be available
ENTERAL NUTRITION
PRESCRIPTION GUIDELINES
Gastric feeding
• Continuous feeding:
• Start at rate 30 mL/hour
• Advance in increments of 20 mL q 8 hours to goal
• Check gastric residuals q 4 hours
• Bolus feeding:
• Start with 100-120 mL bolus
• Increase by 60 mL q bolus to goal volume
• Typical bolus frequency every 3-8 hours
Small bowel feeding
• Continuous feeding only; do not bolus due to risk of dumping
syndrome
• Start at rate 20 mL/hour
• Advance in increments of 20 mL q 8 hours to goal
• Do not check gastric residuals
ASPIRATION
PRECAUTIONS
To prevent aspiration of tube feeding, keep HOB > 30° at all times
Do not use methylene blue to test for aspiration; regular blue food
dye OK but not proven effective method of detecting aspiration
COMPLICATIONS OF ENTERAL
NUTRITION SUPPORT
Nausea and vomiting / delayed gastric emptying
Malabsorption
• Common manifestations include unexplained weight loss, steatorrhea,
diarrhea
• Potential causes include gluten sensitive enteropathy, Crohn’s disease,
radiation enteritis, HIV/AIDS-related enteropathy, pancreatic insufficiency,
short gut syndrome
ENTERAL NUTRITION
CASE STUDY
78-year-old woman admitted with new CVA
Significant aspiration detected on bedside swallow
evaluation and confirmed with modified barium
swallow study; speech language pathologist
recommended strict NPO with alternate means of
nutrition
PEG placed for long-term feeding access
Plan of care is to stabilize the patient and transfer
her to a long-term care facility for rehabilitation
ENTERAL NUTRITION
CASE STUDY (CONTINUED)
Height: 5’4”
Weight: 130# / 59kg
IBW: 120# +/- 10%
100% IBW
BMI: 22
Usual weight: ~130#
no weight change
Estimated needs:
• 1475-1770 kcal (25-30 kcal/kg)
• 59-71g protein (1-1.2 g/kg)
• 1770 mL fluid (30 mL/kg)
STEPS TO DETERMINE THE
ENTERAL NUTRITION
PRESCRIPTION
1.
Estimate energy, protein, and fluid needs
2.
Select most appropriate enteral formula
3.
Determine continuous vs. bolus feeding
4.
Determine goal rate to meet estimated needs
5.
Write/recommend the enteral nutrition prescription
ENTERAL NUTRITION
PRESCRIPTION
Tube feeding via PEG with full strength
Jevity 1.2
Initiate at 30 mL/hour, advance by 20 mL q 8 hours
to goal
Goal rate = 55 mL/hour continuous infusion
• Above goal will provide 1584 kcal, 73g protein, 1069 mL free
H2O
Give additional free H2O 175 mL QID to meet
hydration needs and keep tube patent
Check gastric residuals q 4 hours; hold feeds for
residual > 200 mL
Keep HOB > 30° at all times
WHAT IS PARENTERAL
NUTRITION?
Parenteral Nutrition
• also called "total parenteral nutrition," "TPN," or
"hyperalimentation."
• It is a special liquid mixture given into the blood via a catheter in a
vein.
• The mixture contains all the protein, carbohydrates, fat, vitamins,
minerals, and other nutrients needed.
INDICATIONS FOR PARENTERAL
NUTRITION SUPPORT
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)
Enteral nutrition is contraindicated or severe GI dysfunction is present
• Paralytic ileus, mesenteric ischemia, small bowel obstruction, enteric
fistula distal to enteral access sites
PPN VS. TPN
TPN (total parenteral nutrition)
• 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.
PPN (peripheral parenteral nutrition)
• Similar nutrient components as TPN, but lower concentration
(5%-10% final dextrose concentration)
• Osmolarity < 900 mOsm/L (maximum tolerated by a peripheral
vein)
• May be delivered into 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
Peripheral venous access
• Catheter placed percutaneously into a peripheral vessel
Central venous access (catheter
tip in SVC)
• Percutaneous jugular, femoral, or subclavian catheter
• Implanted ports (surgically placed)
• PICC (peripherally inserted central catheter)
WRITING TPN
PRESCRIPTIONS
1.
2.
Determine total volume of formulation based on
individual patient fluid needs
Determine amino acid (protein) content
Adequate to meet patient’s estimated needs
3.
Determine dextrose (carbohydrate) content
~70-80% of non-protein calories
4.
Determine lipid (fat) content
~20-30% non-protein calories
5.
6.
7.
Determine electrolyte needs
Determine acid/base status
Check to make sure desired formulation will fit in the
total volume indicated
PARENTERAL NUTRITION
MONITORING
Check daily electrolytes and adjust TPN/PPN electrolyte
additives accordingly
Check accu-check glucose q 6 hours (regular insulin may be added to
TPN/PPN bag for glucose control as needed)
• Non-diabetics or NIDDM: start with half of the previous day’s sliding
scale insulin requirement in TPN/PPN bag and increase daily in the same
manner until target glucose is reached
• IDDM: start with 0.1 units regular insulin per gram of dextrose in
TPN/PPN, then increase daily by half of the previous day’s sliding scale
insulin requirement
Check triglyceride level within 24 hours of starting TPN/PPN
• If TG >250-400 mg/dL, lipid infusion should be significantly reduced or
discontinued
• Consider adding carnitine 1 gram daily to TPN/PPN to improve lipid
metabolism
• ~100 grams fat per week is needed to prevent essential fatty acid
deficiency
PARENTERAL NUTRITION
MONITORING (CONTINUED)
Check LFT’s weekly
• If LFT’s significantly elevated as a result of TPN, then
minimize lipids to < 1 g/kd/day and cycle TPN/PPN over 12
hours to rest the liver
• If Bilirubin > 5-10 mg/dL due to hepatic dysfunction, then
discontinue trace elements due to potential for toxicity of
manganese and copper
Check pre-albumin weekly
• Adjust amino acid content of TPN/PPN to reach normal prealbumin 18-35 mg/dL
• Adequate amino acids provided when there is an increase in prealbumin of ~1 mg/dL per day
PARENTERAL NUTRITION
MONITORING
(CONTINUED)
Acid/base balance
• Adjust TPN/PPN anion concentration to maintain proper acid/base
balance
• Increase/decrease chloride content as needed
• Since bicarbonate is unstable in TPN/PPN preparations, the
precursor—acetate—is used; adjust acetate content as needed
COMPLICATIONS OF
PARENTERAL NUTRITION
Hepatic steatosis
• May occur within 1-2 weeks after starting PN
• May be associated with fatty liver infiltration
• Usually is benign, transient, and reversible in patients on short-term PN
and typically resolves in 10-15 days
• Limiting fat content of PN and cycling PN over 12 hours is needed to
control steatosis in long-term PN patients
COMPLICATIONS OF PARENTERAL
NUTRITION SUPPORT (CONTINUED)
Cholestasis
• May occur 2-6 weeks after starting PN
• Indicated by progressive increase in TBili and an elevated serum
alkaline phosphatase
• Occurs because there are no intestinal nutrients to stimulate
hepatic bile flow
• Trophic enteral feeding to stimulate the gallbladder can be helpful
in reducing/preventing cholestasis
Gastrointestinal atrophy
• Lack of enteral stimulation is associated with villus hypoplasia,
colonic mucosal atrophy, decreased gastric function, impaired GI
immunity, bacterial overgrowth, and bacterial translocation
• Trophic enteral feeding to minimize/prevent GI atrophy
PARENTERAL NUTRITION
CASE STUDY
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
PARENTERAL NUTRITION
CASE STUDY
(CONTINUED)
Height: 6’0”
Weight: 155# / 70kg
IBW: 178# +/- 10%
87% IBW
BMI: 21
Usual wt: 175#
11% wt loss x 1 mo.
Estimated needs:
• 2100-2450 kcal
(30-35 kcal/kg)
• 84-98g protein
(1.2-1.4 g/kg)
• 2100-2450 mL fluid (30-35 mL/kg)
PARENTERAL NUTRITION
PRESCRIPTION
TPN via right-SC line
2200 mL total volume x 24 hours
Amino acid: 45 g/liter=
• 45g x 2.2 L= 99 grams x 4 kcals/gram =369 kcals
Dextrose 175 g/liter=
• 175g x 2.2 L= 385 grams x 3.4 kcals/gram= 1309 kcals
Lipid 20% 285 mL over 24 hours
• 285 mls x 2= 570 kcals
Above will provide 2275 kcal, 99g protein,
DIR=(385 g dex/ 70 kg /1440 minute in a day)*1000=
3.8mg/kg/min
LIR= (285 mls lipid * 20%)/ 70 kg=0.8 g/kg/day
PARENTERAL NUTRITION
PRESCRIPTION
Important items to consider:
• Dextrose infusion rate should be < 4 mg/kg/minute (maximum tolerated
by the liver) to prevent hepatic steatosis
• Lipid infusion rate should be less than 1 g/kg/day to minimize/prevent
TPN-induced liver dysfunction
• You may need to adjust/eliminate lipids if patient is on propofol. (1 ml
propofol =1.1 kcal)
• Ex. Propofol @ 10 ml/hr would provide 264 kcals
(10 ml/hr x 1.1 kcal/ml, x 24 hrs)
• Initiate TPN at ~½ of goal rate/concentration and gradually increase to
goal over 2-3 days to optimize serum glucose control
BENEFITS OF ENTERAL
NUTRITION
OVER PARENTERAL NUTRITION
Cost
• Tube feeding cost ~ $10-20 per day
• TPN costs up to $1000 or more per day!
Maintains integrity of the gut
• Tube feeding preserves intestinal function; it is more physiologic
• TPN may be associated with gut atrophy
Less infection
• Enteral feeding—very small risk of infection and may
prevent bacterial translocation across the gut wall
• TPN—high risk/incidence of infection and sepsis
REFEEDING SYNDROME
“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)
Physiologic and metabolic sequelae may include:
• EKG changes, hypotension, arrhythmia, cardiac arrest
• Weakness, paralysis
• Respiratory depression
• Ketoacidosis / metabolic acidosis
REFEEDING SYNDROME
(CONTINUED)
Prevention and Therapy
• 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
CONSEQUENCES OF
OVER-FEEDING
Risks associated with over-feeding:
• Hyperglycemia
• Hepatic dysfunction from fatty infiltration
• Respiratory acidosis from increased CO2 production
• Difficulty weaning from the ventilator
Risks associated with under-feeding:
• Depressed ventilatory drive
• Decreased respiratory muscle function
• Impaired immune function
• Increased infection
QUESTIONS
Reference:
• 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 patientcontrolled 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.