Peri-operative nutrition

Various factors can reduce the magnitude of the stress response, which has a strong theoretical basis for reducing complications. This is essentially talking about the concept of ERAS.

Components

• Excessive fluid administration has been shown to cause ileus and delayed gastric emptying, and various other complications. Fluid should be titrated to maintain intravascular volume and modest urine production in the early post-operative period.
• Minimise bowel handling
• Consider whether to use the operation to create enteral access for feeding (e.g. jejunostomy)
• Minimise the development of insulin resistance in the post-operative period
  • Good pain relief, with local/regional techniques preferred to systemic opioids wherever possible
  • Pre-operative carbohydrates - 'CHO-loading' - with a carbohydrate drink - 800mL the night before and 400mL 3-4 hours before surgery.
  • Immediate post-operative feeding

Pre-operative nutrition

• Refer dieticians for patients with malnutrition having major surgery, especially those with cancer
• Pre-operative enteral nutrition does have some evidence support in these patients
• Pre-operative TPN should only be given in patients with severe malnutrition (weight loss >15kg)  where energy requirement cannot be adequately met by enteral nutrition. A period of 7-14 days is recommended.

Post-operative nutrition

• Tube feeding within 24 hours in patients in whom early oral nutrition can't be started, and oral intake will be <50% for more than 7 days
  • Especially:
    • Head and neck or GIT surgery for cancer
    • Severe trauma including brain injury
    • Obvious malnutrition at time of surgery
  • Start at 20mL/hour and increase carefully due to limited intestinal tolerance. Can take up to 7 days to reach goal rate.
  • If persistently high aspirates are found (>250mL every four hours), can either reduce feed rate or trial prokinetics (metoclopramide/erythromycin/domperidone)
  • If still getting high aspirates after a good trial (1-2 days), may need to consider post-pyloric or parenteral feeding
• Refer to dieticians for potential ongoing enteral support on discharge for most patients who received nutritional support peri-operatively