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.