Nutrition . . . and the surgical patient
Nutrition
ENERGY SOURCES Carbohydrates Fats Proteins
Nutrition
Carbohydrates Limited strorage capacity, needed for CNS
(glucose) function Yields 3.4 kcal/gm Pitfall: too much = lipogenesis and increased
CO2 production
Nutrition
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
Nutrition
Proteins Needed to maintain anabolic state (match
catabolism) Yields 4 kcal/gm Pitfall: must adjust in patients with renal and
hepatic failure
Nutrition
ProteinsProtein
Calories
Non-protein
CaloriesCarbohydrates
Fats
Nutrition 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
Requirements? SURGICAL PATIENT ?
Nutrition
Special considerations Stress
Injury or disease Surgery
Prehospital/presurgical nutrition
Nutrition The surgical patient . . . .
Extraordinary stressors (hypovolemia, bacteremia, medications)
Wound healing Anabolic state, appropriate vitamins (A, C, Zinc)
Poor nutrition=poor outcomes For every gm deficit of untreated hypoalbuminemia
there is ~ 30% increase in mortality
NutritionSURGERY 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
HEALTHLY 70 kg MALE
Caloric intake35 kcal/kg/day
(max=2500/day)
Protein intake0.8-1gm/kg/day
(max=150gm/day)
Fluid intake30 ml/kg/day
Nutrition
CHOFats
ProteinsProtein
Calories
Non-protein
Calories
70%
30%
Nutrition Measures of success
Serum markers Retinol binding protein, prealbumin, transferrin,
albumin
Nutrition Measures of success
Nitrogen balance Protein ~ 16% nitrogen Protein intake (gm)/6.25 - (UUN +4)= balance in
grams Metabolic cart (indirect calorimetry)
ICU patient, measure of exchange of O2 and CO2 Respiratory quotient =1
Nutrition What route to feed?
GUT, GUT, GUT
TPN
When to feed? EARLY, EARLY, EARLY
Diet Advancement Traditional Method
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
Diet Advancement Recent Evidence
Liquid diets and slow diet progression may not be warranted!!
Clinical study Early post-operative feeding with regular diets vs.
traditional methods demonstrated no difference in post-operative complications Emesis, distention, NGT reinsertion, and Length of stay
Pitfalls… 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
Patients who cannot eat . . . ?
Two types of nutritional support Enteral Parenteral
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 Following severe trauma or burns
Enteral Access Devices 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
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 Abdominal surgery Significant gastroesophageal reflux Pancreatitis Aspiration Proximal enteric fistula or obstruction
Enteral Nutrition Case Study 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? Parenteral Nutrition
AKA total parenteral nutrition TPN hyperalimentation
Liquid mixture of nutrients given via the blood through a catheter in a vein Mixture contains all the protein, carbohydrates, fats,
vitamins, minerals, and other nutrients needed to maintain nutrition balance
Indications for Parenteral Nutrition 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 Paralytic ileus, mesenteric ischemia, small bowel
obstruction, enteric fistula distal to enteral access sites
TPN vs. PPN TPN
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) 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 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)
Complications of Parenteral Feeds
Hepatic steatosis 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 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 What route to feed?
TPNVS
Nutrition What route to feed?
TPNTPN
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)
Sequelae may include EKG changes, hypotension, arrhythmia, cardiac arrest Weakness, paralysis Respiratory depression Ketoacidosis / metabolic acidosis
Refeeding Syndrome 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
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
Risks associated with under-feeding Depressed ventilatory drive Decreased respiratory muscle function Impaired immune function Increased infection
Life is not measured by the number of breaths we take, but by the moments that take our breath away.
TPN
Food for Thought (that is . . . nutrition for your brain)
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.