preoperative, perioperative and postoperative enteral and peranteral nutrition

1. Basics in Surgical Nutrition
Aditya yadav

2. •Patients with chronic malnutrition benefit from nutritional support.
•Enteral nutrition:
•Is preferred over parenteral nutrition in patients with a functional GI tract
•Should be initiated within 18 hours of injury in burn patients.
•Should be initiated within 24 hours of admission in the critically ill.
•Immunonutrition should be utilized in:
•Severely injured abdominal / thoracic trauma patients when given in
conjunction with early feeding and adequate protein / calorie support
•Malnourished elective GI surgical patients (albumin < 3.5 g/dL for upper GI
tract and < 2.8 g/dL for lower GI tract)

3. The enteral route should always be preferred except for the following
contraindications:
• Intestinal obstructions or ileus,
• Severe shock
• Intestinal ischaemia
• High output fistula
• Severe intestinal haemorrhage

6. Parenteral Nutrition
• The risks of parenteral nutrition therapy exceeded the benefits when total parenteral
nutrition (TPN) was administered to borderline or mildly malnourished patients
undergoing elective general surgery procedures.
• Perioperative TPN was shown to increase the risk of major infectious complications
without a benefit of improved patient outcome in such patients.
• Those patients at high-risk for malnutrition-related complications, however,
experienced a significant reduction in major non-infectious complications.
• The risk/benefit ratio of parenteral nutrition thus appears to be high in the less
severely ill and lower (and possibly more acceptable) in the critically ill patient who is
at risk for malnutrition-related complications.
• In general, use of parenteral nutrition should be limited to those patients in whom the
GI tract is not functional or cannot be accessed and in patients who cannot be
adequately nourished by either oral diets or enteral nutrition.

7. Enteral vs. Parenteral Nutrition
• Improved wound healing, fewer infectious complications, decreased intestinal
mucosal permeability, and decreased patient care costs with the use of enteral
feeding .
• Enteral nutrition is the preferred method of nutritional support as gut-associated
lymphoid tissue (GALT) contributes up to 60% of total body immunity and enteral
nutrition promotes mucosal viability and immunologic function.
• Patients with a nonfunctioning gastrointestinal tract, beyond the ligament of Treitz
experience fewer total complications, fewer septic complications and decreased
total hospital cost.

8. • Patients with a nonfunctioning gastrointestinal tract, as evidenced by severe peritonitis,
intestinal obstruction, short bowel syndrome, or intractable diarrhea, may benefit from
parenteral nutrition as opposed to intravenous fluids alone.
• Low rate, trophic enteral nutrition should always be considered in patients receiving
parenteral nutrition in order to preserve gut mucosal integrity.
• Enteral nutrition is safe, feasible and superior to TPN.
• Patients who receive such enteral feeding sbeyond the ligament of Treitz experience
fewer total complications, fewer septic complications and a decreased total hospital
cost.

9. Early" vs. “Delayed” Enteral Nutrition
• Several prospective, randomized trials, however, have demonstrated a high rate of
gastroparesis and enteral nutrition intolerance in patients where initiation of enteral
feedings are delayed by more than 12-24 hours post-injury.
• These findings were particularly pronounced in the severely head injured or burned
patient population where decreased gastric emptying appears particularly prevalent.
Early enteral nutrition within the first 12 hours post-injury has been demonstrated to
be safe and highly successful.
• Evidence suggests that early enteral nutrition, initiated at a low rate within 24 hours of
injury and gradually increased to goal rate over a several day period, may reduce the
incidence of gastroparesis and ileus that is seen when the start of enteral nutrition is
delayed for several days post-injury .
• Early "trophic" feedings, begun as resuscitation is being completed, may also serve to
maintain GI tract mucosal integrity and reduce the incidence of bacterial
translocation, SIRS, and MOSF.

10. Delivery of Enteral Nutrition
• In general, patients who are anticipated to require enteral feeding access for less than 1
month are best fed through nasoenteric feeding tubes while those who are anticipated to
require longer periods of enteral access should have a more definitive access placed
such as a percutaneous gastrostomy or jejunostomy tube.
• It has been theorized that post-pyloric small bowel feedings should reduce the risk for
aspiration, but this has not been borne out in the literature. Given its ease, relative
safety, and general overall tolerance across patient populations, intragastric feeding
should be considered the site of first choice.
• Medications that slow gastric emptying should be avoided wherever possible and
prokinetic motility agents (such as metoclopramide - 10 mg IV q 6 hrs and intravenous
erythromycin - 200 mg IV q 12 hrs) should be instituted where necessary to improve
intestinal motility and enteral nutrition tolerance

11. • Feedings should be started at full-strength with the patient's head of bed
elevated at 30-45 degrees at all times.
• Feedings should be slowed or held if gastric residuals are greater than 200 mL .
• Patients at risk for pulmonary aspiration due to gastroparesis (i.e., diabetics,
closed head injury), gastroesophageal reflux, or those who fail to tolerate
intragastric feedings within 24 hours of initiation should have a transpyloric
small bowel feeding access placed as soon as possible in order to continue
nutritional support.
• Enteral nutrition should be initiated cautiously in patients with evidence of
marginal systemic perfusion (oliguria or vasoconstriction) due to concern for
causing intestinal ischemia. In such patients, small bowel feedings should be
initiated and maintained at low rate (10-15 mL/hr) until the patient has been
adequately resuscitated.

12. Is preoperative fasting necessary?
• Preoperative fasting from midnight is unnecessary in most patients.
• Patients undergoing surgery, who are considered to have no specific risk of
aspiration, shall drink clear fluids until two hours before anaesthesia. Solids
shall be allowed until six hours before anaesthesia.
• Allowing intake of clear fluids including coffee and tea minimizes the
discomfort of thirst and headaches from withdrawal symptoms.

13. Is preoperative metabolic preparation of the elective patient using carbohydrate
treatment useful?
• In order to reduce perioperative discomfort including anxiety oral preoperative
carbohydrate treatment (instead of overnight fasting) the night before and two hours
before surgery should be administered.
• To impact postoperative insulin resistance and hospital length of stay, preoperative
carbohydrates can be considered in patients undergoing major surgery.
• Preoperative intake of a carbohydrate drink (so-called “CHO loading”) with 800 ml
the night before and 400 ml before surgery does not increase the risk of aspiration.
• Fruit-based lemonade may be considered a safe alternative with no difference in
gastric emptying time.

14. • Parenteral glutamine supplementation may be considered in patients who
cannot be fed adequately enterally and, therefore, require exclusive PN. (not
oral)
• Arginine alone- neither oral nor iv
• Postoperative parenteral nutrition including omega-3-fatty acids should be
considered only in patients who cannot be adequately fed enterally and,
therefore, require parenteral nutrition
• Peri or at least postoperative administration of specific formula enriched with
immunonutrients (arginine, omega-3-fatty acids, ribonucleotides) should be
given in malnourished patients undergoing major cancer surgery.

15. • Patients with severe nutritional risk shall receive nutritional therapy prior to
major surgery even if operations including those for cancer have to be
delayed. A period of 7 to 14 days may be appropriate.
• For surgical patients “severe” nutritional risk has been defined according to
the ESPEN working group (2006) as the presence of at least one of the
following criteria:
• Weight loss >10e15% within 6 months
• BMI <18.5 kg/m2
• Serum albumin <30 g/l (with no evidence of hepatic or renal dysfunction)

16. • In most patients, a standard whole protein formula is appropriate.
• For technical reasons with tube clogging and the risk of infection the use of
kitchen-made (blenderized) diets for tube feeding is not recommended in
general.
• Home-made diets for tube feeding may be considered in the home care setting
(preparation is solely for one patient, and risk for contamination is lower than in
an institution where several preparations are made at the same time).
• Tube blockage due to high viscosity may be reduced if the concentration is 1
cal/ml and if standard enteral formulae are added as milk base.
• If tube feeding is indicated, it shall be initiated within 24 h after surgery.
• It is recommended to start tube feeding with a low flow rate (e.g. 10 , max. 20
ml/h) and to increase the feeding rate carefully.

17. Fluid requierment:
• daily requirement + abnormal loss
• Daily requirement = 1500 ml (for first 20 kg) + 20 ml/kg for rest weight..

18. Energy requirement :
• Simple body weight calculation- REE kcal/day= 25* weight.
• Harris Benedict -
• Man = 66 + (13.7*W) + (5*H) -(6.7*A)
• Women= 65.5 + (9.6*W) + (1.8*H) -(4.7*A)
• Indirect calorimetery-
• (3.9*VO2) + (1.1* VCO2) -61

19. • Ideal body weight for obese person, corrected for undernourished.
• Total energy expendature= REE*AF*DF*TF
• AF= 1.2 at bed, 1.3 out of bed
• DF= 1.2 for Gen Sx, 1.3 for sepsis, 1.6 for Multiorgan failure.
• TF= 1.1, 1.2, 1.3, 1.4 (38,39,40,41 degree)
• Carb= 50-70%,
• Fat= 20-30%,
• Protein= 15-20%