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 Proteins Protein  Calories Non-protein  Calories Carbohydrates 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

Nutrition SURGERY PATIENT Caloric intake *Mild stres, inpatient kcal/kg/day *Moderate stress, ICU patient 25-30kcal/kg/day *Severe stress, burn patient kcal/kg/day Protein intake 1-1.8gm/kg/day Fluid intake INDIVIDUALIZE 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 Proteins Protein  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)/ (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 ( 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 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? TPN VS

Nutrition What route to feed? TPN

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 CO 2 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 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): 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.