Nutrition

. . . and the surgical patient

Carli Schwartz, RD,LDN

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.

Normal Nutrition (EatRight.org)

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: http://www.choosemyplate.gov/

Includes interactive tools including a personalized daily food plan and food tracker

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.

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

Nutritional Needs for the Surgery Patient

Comparison of Protein/Energy Demands

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

HEALTHLY 70 kg MALE

Caloric intake25-30 kcal/kg/day

Protein intake0.8-1gm/kg/day

(max=150gm/day)

Fluid intake30 ml/kg/day

The surgical patient . . . . 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)

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 3.2-3.5 g/dL

3. Moderately malnourished: 10-20% wt loss; preoperative serum albumin 2.5-32 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.

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

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.

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

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)/6.25 - (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

Feeding the patient: Post-operative Nutrient Provision

Traditional Method: Diet advancement

Introduction of solid food depends on the condition of the GI tract.

Oral feeding delayed for 24-48 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

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.

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.

Patients who cannot eat . . . ?

Consider Nutrition Support!

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)

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

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

Nutrition support: Clinical Decision Algorithm

AAFP.org

Nutrition Support

Enteral Nutrition Support

Parenteral Nutrition support

What is enteral nutrition? 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.

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

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

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

1) Can the patient be fed into the stomach, or is small bowel access required?

2) How long will the patient need tube feedings?

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

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

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

Tulane Enteral Nutrition Product Formulary

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.

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

Determining Your 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 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” IBW: 120# +/- 10% Weight: 130# / 59kg 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)

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." 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.

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 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

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. Determine total volume of formulation based on individual patient fluid needs

2. Determine amino acid (protein) contentAdequate to meet patient’s estimated needs

3. Determine dextrose (carbohydrate) content~70-80% of non-protein calories or ~50% calorie needs

4. Determine lipid (fat) content~20-30% non-protein calories

5. Determine electrolyte needs6. Determine acid/base status based on chloride and co2

levels7. Check to make sure desired formulation will fit in the total

volume indicated

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

Tulane Daily Parenteral Nutrition Order Form

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 >250-400 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 18-35 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

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 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

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” IBW: 178# +/- 10% Weight: 155# / 70kg 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 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

Benefits of Enteral Nutritionover 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

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 25-30 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).

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

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

Questions

Contact Information:

Carli Schwartz, RD,LDNClinical Dietitian, Tulane Abdominal Transplant Institute(504) 988-1176Carli.Schwartz@hcahealthcare.com

References

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.

Krause’s Food, Nutrition & Diet Therapy, 11th Ed. Mahan, K., Stump, S. Saunders, 2004.

American Society for Parenteral and Enteral Nutrition. The Science and Practice of Nutrition Support. 2001.