1. . . . and the surgical patient Carli Schwartz, RD,LDN
Nutrition
. . . and the surgical patient
Carli Schwartz, RD,LDN

2. Nutrition and Surgery
Malnutrition may compound the severity of complications related to a surgical procedure
A well-nourished patient usually tolerates major surgery better than a severely malnourished patient
Malnutrition is associated with a high incidence of operative complications and death.

3. Normal Nutrition (EatRight.org)

4. The Newest Food Guide Pyramid
Balancing Calories   ● Enjoy your food, but eat less.   ● Avoid oversized portions.    
Foods to Increase   ● Make half your plate fruits and vegetables.   ● Make at least half your grains whole grains.   ● Switch to fat-free or low-fat (1%) milk.    
Foods to Reduce   ● Compare sodium in foods like soup, bread, and frozen meals ― and choose the foods with lower numbers.   ● Drink water instead of sugary drinks.   
          
Website:
Includes interactive tools including a personalized daily food plan and food tracker

5. Macronutrients Carbohydrates
Main sources include grains, fruits and beans
Limited storage capacity, needed for CNS (glucose) function
Yields 3.4 kcal/gm
Recommended 45-65% total daily calories.
Fats
Main sources include oil, nuts, butter, milk and cheese
Major endogenous fuel source in healthy adults
Yields 9 kcal/gm
Too little can lead to essential fatty acid (linoleic acid) deficiency and increased risk of infections
Recommended 20-30% of total caloric intake
Protein
Main sources include fish, beef, poultry and dairy products
Needed to maintain anabolic state (match catabolism)
Yields 4 kcal/gm
Must adjust in patients with renal and hepatic failure
Recommended 10-35% of total caloric intake.

6. Normal Nutrition Requirements HEALTHLY male/female
(weight maintenance)
Caloric intake=25-30 kcal/kg/day
Protein intake=0.8-1gm/kg/day (max=150gm/day)
Fluid intake=~ 30 ml/kg/day

7. Nutritional Needs for the Surgery Patient

8. Comparison of Protein/Energy Demands
HEALTHLY 70 kg MALE
Caloric intake
25-30 kcal/kg/day
Protein intake
0.8-1gm/kg/day (max=150gm/day)
Fluid intake
30 ml/kg/day
SURGERY PATIENT
Caloric intake
*Mild stress, inpatient
25-30 kcal/kg/day
*Moderate stress, ICU patient
30-35 kcal/kg/day
*Severe stress, burn patient
30-40 kcal/kg/day
Protein intake
1-2 gm/kg/day
Fluid intake
INDIVIDUALIZED

9. The surgical patient . . . . Increased risk of malnutrition due to:
Nutrient depletion occurs in the surgical patient due to decreased intake, increased metabolic expenditure and altered nutrient use.
Increased risk of malnutrition due to:
Inadequate nutritional intake
Metabolic response (hypermetabolism from long term inflammation or infectious conditions)
Nutrient losses without proper replenishment
Protein /energy store depletion
Diminished nutrient intake (pre/post operative)
Prevalence of GI obstruction, anorexia, malabsorption
Extraordinary stressors (surgical stress, hypovolemia, sepsis, bacteremia, medications)
Wound healing
Anabolic state, higher demand for nutrients (amino acids, zinc, vitamin A & C, arginine)

10. Perioperative Nutritional Assessment
Individuals are generally classified as well nourished or mildly, moderately, or severely malnourished
1: well nourished: no significant weight change; preoperative serum albumin > 3.5 g/dL
2. Mildly malnourished: <10% wt loss; preoperative serum albumin g/dL
3. Moderately malnourished: 10-20% wt loss; preoperative serum albumin g/dL
4. Severely malnourished: >20% wt loss; preoperative serum albumin < 2.5 g/dL
Nutritional assessment parameters also include a complete medical history, surgical history, social history, diet history, physical exam, anthropometric and laboratory evaluations.

11. Visceral Proteins Albumin Normal range: 3.5-5 g/dL.
Synthesized in and catabolized by the liver
Pro: often ranked as the strongest predictor of surgical outcomes- inverse relationship between postoperative morbidity and mortality compared with preoperative serum albumin levels
Con: lack of specificity due to long half-life (approximately 20 days). Not accurate in pt’s with liver disease or during inflammatory response

12. Visceral proteins
Prealbumin (transthyretin) - transport protein for thyroid hormone, synthesized by the liver and partly catabolized by the kidneys.
Normal range:16 to 40 mg/dL; values of <16 mg/dL are associated with malnutrition.
Pro: Shorter half life (two to three days) making it a more favorable marker of acute change in nutritional status. A baseline prealbumin is useful as part of the initial nutritional assessment if routine monitoring is planned.
Cons: More expensive than albumin. Levels may be increased in the setting of renal dysfunction, corticosteroid therapy, or dehydration, whereas physiological stress, infection, liver dysfunction, and over-hydration can decrease prealbumin levels.

13. Visceral proteins
Transferrin: acute-phase reactant and a transport protein for iron
normal range: 200 to 360 mg/dL.
Medium half-life (8-10 days)
Smaller body pool than albumin, reflects more acute changes.
influenced by several factors, including liver disease, fluid status, inflammation, iron status and illness.
Cons: not studied extensively as albumin and pre-albumin in relation to nutritional status, may indicator more about iron metabolism
Levels decrease in the setting of severe malnutrition, however unreliable in the assessment of mild malnutrition

14. Other measures of nutrition status
Nitrogen balance: the relationship between the amount of nitrogen taken into the body, usually as food, and that excreted from the body in urine and feces. Most of the body's nitrogen is incorporated into protein.
Protein ~ 16% nitrogen
Protein intake (gm)/ (UUN +4)= balance in grams
Positive value: found during periods of growth, tissue repair or pregnancy. This means that the intake of nitrogen into the body is greater than the loss of nitrogen from the body, so there is an increase in the total body pool of protein.
Negative value: can be associated with burns, fevers, wasting diseases and other serious injuries and during periods of fasting. This means that the amount of nitrogen excreted from the body is greater than the amount of nitrogen ingested.
Healthy Humans= Nitrogen Equilibrium
Cons: Complex determination of balance, measures of losses difficult and limited utility in clinical setting

15. Feeding the patient: Post-operative Nutrient Provision

16. Traditional Method: Diet advancement
Introduction of solid food depends on the condition of the GI tract.
Oral feeding delayed for hours after surgery
Wait for return of bowel sounds or passage of flatus.
Start clear liquids when signs of bowel function returns
Rationale
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

17. Things to Consider…
For liquid diets, patients must have adequate swallowing functions
Even patients with mild dysphagia often require thickened liquids.
Must be specific in writing liquid diet orders for patients with dysphagia
There is no physiological reason for solid foods not to be introduced as soon as the GI tract is functioning and a few liquids are being tolerated. Multiple studies show patients can be fed a regular solid-food diet after surgery without initiation of liquid diets.

18. Diet Advancement
Advance diet to full liquids followed by solid foods, depending on patient’s tolerance.
Consider the patient’s disease state and any complications that may have come about since surgery.
Ex: steroid-induced diabetes in a post-kidney transplant patient.

19. Patients who cannot eat . . . ?
Consider Nutrition Support!

20. Perioperative Nutritional Support
Length of time a patient can remain NPO after surgery without complications is unknown, however depends on:
Severity of operative stress
Patient’s preexisting nutritional status
Nature and severity of illness
“In uncomplicated cases, well nourished patients tolerate up to 10 days of starvation with no medical complications. Moderately or severely malnourished patients usually require nutritional support earlier.” (A.S.P.E.N Nutrition Support Practice Manual 2nd Ed)

21. Goals of perioperative Nutrition Support
Decrease surgical mortality
Decrease surgical complications and infection
Reduce the catabolic state and restore anabolism
Support the depleted patient throughout the catabolic phase of recovery
Decrease hospital LOS
Speed the healing/recovery process
Ensure the prompt return of GI function to resume standard oral intake as soon as possible

22. Perioperative Nutrition Support Guidelines
The American Society for Parenteral and Enteral Nutrition evidence-based practice guidelines
1. preoperative specialized nutrition support should be administered for 7-14 days to moderately or severely malnourished pts undergoing major surgery
2. PN should not be routinely given in the immediate post-op period to pts undergoing major GI procedures
3. Postoperative nutrition support should be administered to patients who are expected to be unable to meet their nutrient needs orally for 7-10 days

23. Nutrition support: Clinical Decision Algorithm
AAFP.org

24. Nutrition Support Enteral Nutrition Support
Parenteral Nutrition support

25. What is enteral nutrition?
Also called "tube feeding," enteral nutrition is a liquid mixture of all the needed nutrients.
Consistency is sometimes similar to a milkshake.
It is given through a tube in the stomach or small intestine.
If oral feeding is not possible, or an extended NPO period is anticipated, an access devise for enteral feeding should be inserted at the time of surgery.
Feeds can meet 100% of patient’s needs or can be used to supplement poor po intake.

26. Indications for Enteral Nutrition
When the GI tract is functional or partially functional and…..
Patient has inability to consume or absorb adequate nutrients.
Patient is not meeting > 75% of needs with po intake.
Malnourished patient expected to be unable to eat adequately for > 5-7 days
Adequately nourished patient expected to be unable to eat > 10 days

27. Contraindications to Enteral Nutrition Support
Expected need less than 5-7 days if malnourished or 7-9 days if normally nourished
Severe acute pancreatitis
Small bowel obstruction, ileus or high output enteric fistula distal to feeding tube
Inability to gain access
Hemodynamic instability
Need for high dose pressors/vasoactives
MAP consistently < 60 mmHg
Intractable vomiting or diarrhea
Those requiring massive fluid resuscitation

28. 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

29. Feeding Tube Selection
Can the patient be fed into the stomach, or is small bowel access required?
2) How long will the patient need tube feedings?

30. Gastric vs. Small Bowel Access
Gastric 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

31. Short-Term vs. Long-Term 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 6-8 weeks, long-term access should be considered

32. Choosing Appropriate Formulas
Categories of enteral formulas:
Polymeric
Whole protein nitrogen source, for use in patients with normal or near normal GI function. Examples include Ensure and Jevity.
Monomeric or elemental
Predigested nutrients; most have a low fat content or high % of MCT; for use in patients with severely impaired GI function. Examples include Peptamen and Optimental
Disease specific
Formulas designed for feeding patients with specific disease states
Formulas are available for respiratory disease, diabetes, renal failure, hepatic failure, and immune compromise. Examples include Glucerna and Nepro
*well-designed clinical trials may or may not be available

33. Tulane Enteral Nutrition Product Formulary

34. Complications of Enteral Nutrition Support
Issues with access, administration, GI complications, metabolic complications. These include:
Nausea, vomitting, diarrhea, constipation, delayed gastric emptying, malabsorption, refeeding syndrome, hyponatremia, microbial contamination, tube obstruction, leakage from ostomy/stoma site, micronutrient deficiencies.

35. Implementation of Enteral Nutrition
Gastric feeding
Pump assisted: Continuous feeding and cyclic feeding
Allows for max nutrient absoroption and improved tolerance
best in sicker/hospitalized patients
Start at rate 30 mL/hour and advance in increments of 20 mL q 8 hours to goal. Check gastric residuals q 4 hours for tolerance
Gravity Controlled: Bolus feeding
Infusion of a predetermined volume of formula at specified intervals. Example: 1 can Glucerna (240 ml) via PEG tube q 4 hours.
Easiest, least expensive, more physiologic (mimic normal eating pattern)
Small bowel feeding
Continuous feeding only; do not bolus due to risk of dumping syndrome
Start at low volume to assess tolerance (20 mL/hour)
Advance in increments of 20 mL q 8 hours to goal
Do not check gastric residuals

36. Determining Your Enteral Nutrition Prescription
Estimate energy, protein, and fluid needs
Select most appropriate enteral formula
Determine continuous vs. bolus feeding
Determine goal rate to meet estimated needs
Write/recommend the enteral nutrition prescription

37. 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

38. Enteral Nutrition Case Study (continued)
Height: 5’4” IBW: 120# +/- 10%
Weight: 130# / 59kg % IBW
BMI: 22
Usual weight: ~130# no weight change
Estimated needs:
kcal (25-30 kcal/kg)
59-71g protein (1-1.2 g/kg)
1770 mL fluid (30 mL/kg)

39. 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

40. What is parenteral nutrition?
also called "total parenteral nutrition," "TPN," or "hyperalimentation."
Defined as nutrients provided intravenously.
Components of a PN mixture include:
Protein (Amino Acids) , carboydrates (dextrose) , Fats (Long-chain fatty acids), sterile water, electrolytes, vitamins and trace minerals
For use in nutritionally compromised patients when enteral nutrition is contra-indicated.

41. 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

42. PPN vs. TPN TPN (total parenteral nutrition)
High glucose concentration (15%-25% final dextrose concentration)
Provides a hyperosmolar formulation ( mOsm/L)
Must be delivered into a large-diameter vein
PPN (peripheral parenteral nutrition)
Similar nutrient components as TPN, but lower glucose 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

43. 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)

44. Writing TPN prescriptions
Determine total volume of formulation based on individual patient fluid needs
Determine amino acid (protein) content
Adequate to meet patient’s estimated needs
Determine dextrose (carbohydrate) content
~70-80% of non-protein calories or ~50% calorie needs
Determine lipid (fat) content
~20-30% non-protein calories
Determine electrolyte needs
Determine acid/base status based on chloride and co2 levels
Check to make sure desired formulation will fit in the total volume indicated

45. Parenteral Nutrition Prescription
Important items to consider:
Glucose infusion rate should be < 5 mg/kg/minute (maximum tolerated by the liver) to prevent hepatic steatosis
Lipid infusion should be < 0.1 g/kg/hour (ideally < 0.4 g/kg/day to minimize/prevent TPN-induced liver dysfunction)
Initiate TPN at ~½ of goal rate/concentration and gradually increase to goal over 2-3 days to optimize serum glucose control

46. Tulane Daily Parenteral Nutrition Order Form

47. Parenteral Nutrition Monitoring
Electrolytes -adjust TPN/PPN electrolyte additives daily according to labs
Check accu-check glucose q 6 hours
Regular insulin may be added to TPN/PPN bag for glucose control as needed
Check triglyceride level within 24 hours of starting TPN/PPN
If TG > mg/dL, lipid infusion should be significantly reduced or discontinued
Daily addition of Carnitine to TPN/PPN may improve lipid metabolism
~100 grams fat per week is needed to prevent essential fatty acid deficiency
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 pre-albumin mg/dL
Adequate amino acids provided when there is an increase in pre-albumin of ~1 mg/dL per day
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

48. 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 days
Limiting fat content of PN and cycling PN over 12 hours is needed to control steatosis in long-term PN patients
Cholestasis
Occurs because there are no intestinal nutrients to stimulate hepatic bile flow
May occur 2-6 weeks after starting PN
Indicated by progressive increase in TBili and an elevated serum alkaline phosphatase
*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

49. 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

50. Parenteral Nutrition Case Study (continued)
Height: 6’0” IBW: 178# +/- 10%
Weight: 155# / 70kg % IBW
BMI: 21
Usual wt: 175# % wt loss x 1 mo.
Estimated needs:
kcal (30-35 kcal/kg)
84-98g protein ( g/kg)
mL fluid (30-35 mL/kg)

51. Parenteral Nutrition Prescription
TPN via right-SC line
2 L total volume x 24 hours
Amino acid 4.5% (or 45 g/liter)
Dextrose 17.5% (or 175 g/liter)
Lipid 20% 285 mL over 24 hours
Above will provide 2120 kcal, 90g protein, glucose infusion rate 3.5 mg/kg/minute, lipid 0.9 g/kg/day

52. Benefits of Enteral Nutrition over parenteral nutrition
Cost
Tube feeding cost ~ $10-20 per day
TPN cost ~ $100 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
Tube feeding—very small risk of infection and may prevent bacterial translocation across the gut wall
TPN—high risk/incidence of infection and sepsis

53. Transitional Feedings
Parenteral to enteral feedings
Introduce a minimal amount of enteral feeding at a low rate (30-40 ml/hr) to establish tolerance.
Decrease PN level slowly to keep nutrient levels at same prescribed amount
As enteral rate is increased by ml/hr increments every 8-24 hrs, parenteral can be reduced
Discontinue PN solution if 75% of nutrient needs met by enteral route.
Parenteral/Enteral to oral feedings
Ideally accomplished by monitoring oral intake and concomitantly decreasing rate of nutrition support until 75% of needs are met.
Oral supplements are useful if needs not met 100% by diet. Ex (Nepro, Glucerna, Boost, Ensure).

54. Dangers of Over and Under Feeding
Risks associated with over-feeding:
Hyperglycemia
Hepatic dysfunction from fatty infiltration
Respiratory acidosis from increased CO2 production
Difficulty weaning from the ventilator
Refeeding syndrome
Risks associated with under-feeding:
Depressed ventilatory drive
Decreased respiratory muscle function
Impaired immune function
Increased infection
Weight loss and malnutrition

55. 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

56. 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

57. Questions
Contact Information:
Carli Schwartz, RD,LDN
Clinical Dietitian, Tulane Abdominal Transplant Institute
(504)

58. References
American Society for Parenteral and Enteral Nutrition. The Science and Practice of Nutrition Support
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):
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 July;222(1):73-7.
Ross, R. Micronutrient recommendations for wound healing. Support Line. 2004(4): 4.
Krause’s Food, Nutrition & Diet Therapy, 11th Ed. Mahan, K., Stump, S. Saunders, 2004.