Nutritional support is important for surgical patients to prevent complications. Three key aspects of nutritional support discussed are: 1) Enteral nutrition is preferred over parenteral nutrition when possible, with a hierarchy of feeding methods from oral to tube feeding to be followed. 2) Malnutrition increases surgical risk, so nutritional screening and optimization of intake, including supplementation, is important pre-and post-operatively. 3) Close monitoring of caloric and protein intake as well as electrolytes and glucose is needed for patients receiving enteral or parenteral nutrition support.

1. NUTRITIONAL SUPPORT
OF SURGICAL PATIENT.
BY
DR RUTAYISIRE FRANÇOIS XAVIER

2. NUTRITION THERAPY
• Nutrition therapy is the provision of nutrition or nutrients either orally (regular diet,
therapeutic diet, e.g. fortified food, oral nutritional supplements) or via enteral
nutrition (EN) or parenteral nutrition (PN) to prevent or treat malnutrition.
• “Medical nutrition therapy is a term that encompasses oral nutritional
supplements, enteral tube feeding (enteral nutrition) and parenteral nutrition”
• Nutrition therapies are individualized and targeted nutrition care measures using
diet or medical nutrition therapy.
• Dietary advice or nutritional counselling can be part of a nutrition therapy.

3. • Malnourished patients make poor surgical candidates.
• Surgery causes physiological stress with a resultant hyper-metabolic state and
catabolic response, which is not favored in the malnourished patient.
• A proportion of surgical patients will have a degree of malnutrition owing to their
underlying disease process thus reducing their nutritional reserves in the post-
operative period. Malnourished patients are at increased risk of post-operative
complications, such as reduced wound healing, increased infection rates, and skin
breakdown.
• Clearly it is important that any patient undergoing elective or semi-elective surgery
should be assessed for evidence of malnutrition and where possible this should be
corrected or nutrition supported both pre- and post-operatively.

5. • 80% of surgeons agree that nutrition decreases
complications, but only 20% implement any interventions

6. CON;T
• If malnutrition is identified then nutritional support may be appropriate as this improves
surgical outcomes. The decision when and how to deliver nutritional support, and the timing of
subsequent surgery, should be decided on a case-by-case basis.
• An appropriate schedule for nutritional support should be given with the assistance and under
the direction of a registered dietitian. The type of nutritional support that can be offered will
depend largely on the pathology present.
• As a general principle, it is always best to give enteral nutrition via the oral route wherever
possible (this applies to both pre- and post-operative nutrition). However for many patients it
may not be possible to administer sufficient calories via this route and alternative nutrition
support strategies will need to be considered.
• There is a simple hierarchy of feeding methods that should be followed and applied
appropriately.

7. CON”T

8. SYSTEMATIC NUTRITIONAL RISK
SCREENING (NRS)
• The items of the NRS comprise BMI <20.5 kg/m2, weight loss >5%
within 3 months, diminished food intake, and severity of the
disease.
• In order to improve oral intake documentation of food intake is
necessary and nutritional counselling should be provided as
needed. Oral nutritional supplements (ONS) and EN (tube feeding)
as well as PN offer the possibility to increase or to ensure nutrient
intake in case of insufficient oral food intake.

9. • The introduction of Enhanced Recovery After Surgery (ERAS) was revolutionary engendering
real change and is now an established part of surgical practice. The basic tenets behind ERAS
consist of:
• Reduction in ‘Nil By Mouth’ times (clear fluids up to 2 hours pre-surgery)
• Pre-operative carbohydrate loading
• Minimally invasive surgery
• Minimizing the use of drains and nasogastric tubes
• Rapid reintroduction of feeding post-operatively
• Early mobilization

10. • There is good evidence that early post-operative feeding reduces post-operative
complications and the Enhanced Recovery After Surgery (ERAS) protocol is
designed to start post-operative feeding as soon as possible (coupled with early
mobilisation to reduce muscle loss).
• It is now recognized that most surgical patients can safely tolerate an enteral
diet within 24 hours of uncomplicated gastrointestinal surgery without increasing
the risk of post-operative complications.

11. CON;T
• ESPEN has recently defined diagnostic criteria for malnutrition according to two options
option 1: BMI <18.5 kg/m2
option 2: combined: weight loss >10% or >5% over 3 months and reduced BMI.
• Reduced BMI is <20 or <22 kg/m2 in patients younger and older than 70 years, respectively.
• Preoperative serum albumin is a prognostic factor for complications after surgery and also associated with
impaired nutritional status. Therefore, albumin may also be considered to define surgical patients at severe
nutritional risk by the presence of at least one of the following criteria:
weight loss >10-15% within 6 months
BMI <18.5 kg/m2
preoperative serum albumin <30 g/l (with no evidence of hepatic or renal dysfunction).

12. Energy Sources
Carbohydrates
Limited storage capacity, needed for CNS function
Yields 3.4 kcal/gram
Too much=lipogenesis and increased CO2 production
Fats
Major endogenous fuel source in healthy adults
Yields 9 kcal/gm
Too little=essential fatty acid (linoleic acid deficiency-dermatitis and
increased risk of infections
Protein
Needed to maintain anabolic state.
Yields: 4 kcal/gm
Must adjust in patient with renal and hepatic failure
Elevated creatinine, BUN, and/or ammonia

13. 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
• The surgical patient…
• Extraordinary stressors (hypovolemia,
hypervolemia, bacteremia, medications)

14. 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

15. Diet Advancement
• Initial phase:
• 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 Nutrition inadequacy

16. Immuno-Nutrition
• Immune nutrition involves feeding (enteral or TPN)
enriched with various pharmaconutrients (arginine,
glutamine, omega-3-fatty acids, nucleotides and anti-
oxidants: copper, selenium, zinc, vitamins B, C and
E) to improve immune responses and modulate
inflammatory responses
• ‘Immune modulating diets’ (IMD) are the complete
supplemented nutritional formulations used
• Wound Healing
• Anabolic state, appropriate vitamins & Minerals (A, C, Zinc), and
adequate kcals/protein.
• Poor Nutrition=Poor Outcomes
• For every gram deficit of untreated hypoalbuminemia there is ~30% increase in
mortality

17. 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

18. Indications for Enteral
Nutrition
• Patient must be hemodynamically stable
before starting 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

19. 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

20. 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
(celiac), Crohn’s disease (IBD), radiation enteritis,
HIV/AIDS-related enteropathy, pancreatic insufficiency,
short gut syndrome

21. Enteral Access Devices
Nasogastric
Nasoenteric
Passed proximally from the nose distally into the stomach
or small bowel. Orogastric: passed through the mouth.
Gastrostomy
PEG (percutaneous endoscopic gastrostomy)
Surgical or open gastrostomy
Jejunostomy
PEJ (percutaneous endoscopic Jejunostomy)
Surgical or open Jejunostomy
Trans gastric Jejunostomy
PEG-J (percutaneous endoscopic gastro-Jejunostomy)
Surgical or open gastro-Jejunostomy

22. 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 (Do not consider automatic cessation of EN
until a second high GRV is demonstrated at least four hours after the first).
• 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

23. 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

24. Choosing Appropriate Formulas
Categories of enteral formulas:
Polymeric (Jevity, Fresubin P.E drink)
Whole protein nitrogen source, for use in patients with normal
or near normal GI function
Monomeric or elemental (Perative, Optimental, Supportan
drink)
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, Diben drink)
Formulas designed for feeding patients with specific disease
states
Formulas are available for respiratory disease, diabetes, renal
failure, hepatic failure, and immune compromise

25. Inpatient care for surgical adult
px
• Malnutrition in adults is commonly associated with other
diseases and improper/delayed post-surgical feeding. These
include chronic and acute infections, intestinal
malabsorption, liver and endocrine disease, alcoholism and
other addictions as well as cancer and RVD. Even in times
of famine, these conditions may present as the first cause of
malnutrition. However, they may have been exacerbated by
weakness, immune depression and weight loss in a
malnourished patient, or be directly due to primary
malnutrition itself. In all cases, both the underlying disease
and malnutrition must be treated.

26. TherapeuticInpatient treatment:
Phase I (Stabilization):
F75 milk
Adolescents (12 to 17 years) 65 ml/kg/day (50 kcal/kg/day
)
Adults (18 to 50 years) 55 ml/kg/day (40 kcal/kg/day
)
Older persons (> 50 years
) 45 ml/kg/day (35 kcal/kg/day
Transition phase:
F100milk
Use the same amounts asfor F75 in phase I ( Increase progressively) alternating with other foods e.g. CSB (FBF)
Adolescents (12 to 17 years) 65 ml/kg/day(65kcal/kg/day
)
Adults (18 to 50 years) 55 ml/kg/day(55 kcal/kg/day
)
Older persons (> 50 years) 45 ml/kg/day(45 kcal/kg/day)
Phase II(Rehabilitation
/Rapid catch-up):
F100milk
Adolescents (12 to 17 years) 100ml/kg/day (100kcal/kg/day
)
Adults (18 to50 years) 80ml/kg/day(80kcal/kg/day
)
Older persons (> 50 years
) 70ml/kg/day (70kcal/kg/day
)

27. Gastric Residual Volume
• Clinically assess patient for:
– Abdominal distension/discomfort
– Bloating/Fullness
– Nausea/Vomiting
• Gradually switch to a more calorically
dense product to decrease the total volume
infused.
Aspiration Precautions
 To prevent aspiration of tube feeding, keep HOB > 30° at all
times.

28. 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.

29. 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

30. 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

31. 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)

32. Parenteral Nutrition Monitoring
Check daily electrolytes and adjust TPN/PPN electrolyte
additives accordingly
Check accu-chek 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
~100 grams fat per week is needed to prevent essential fatty acid
deficiency

33. Parenteral Nutrition administered
• Kabiven central vein
Vol: 2053 mL, Osmolality:1060 mosm/l, Total energy:
1900 Kcal
• Kabiven peripheral or central vein
Vol: 1440 mL, Osmolality: 750 mosm/l, Total energy:
1000 Kcal
• NuTRIflex (B-Braun) peri or central line
Vol 1875 mL, Osmolality:920 mosm/l, Total
energy:1435 Kcal

34. 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 pre-
albumin 18-35 mg/dL
• Adequate amino acids provided when there is an increase in
pre-albumin of ~1 mg/dL per day

35. 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

36. 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

37. 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

38. 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

39. 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

40. 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

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