Surgical Nutrition Flashcards
What are the causes of malnutrition?
- starvation
- > social: poverty, neglected elderly
- > dysphagia: carcinoma of esophagus
- > loss of appetite: depression, malignancy, chronic toxemia
- > repeated vomiting: intestinal obstruction
- > malabsorption: short bowel syndrome (presence of ileocecal valve is v. imp)
- catabolism
- > major burn: >20%
- > major trauma
- > severe sepsis
- > major surgery
- > acute pancreatitis
How does malnutrition affect surgical patients?
- impaired wound healing -> burst abdomen
- depressed immunity
- reduced tolerance to chemotherapy & radiotherapy
How should a surgical patient’s nutritional status be assessed?
- body weight
- mid-arm circumference
- triceps skin fold thickness
- serum albumin
how is nutritional support given?
1- oral intake
2- enteral feeding
3- parenteral feeding
Which route of feeding is the easiest & safest, and least expensive route?
Oral intake -> natural route
when should enteral feeding be used?
- unconscious patients
- facial & oral trauma or burns
- dysphagia
- operations on esophagus
What are the types of tubes used in case of enteral feeding?
- Nasogastric tube
- Gastrostomy tube -> milk, juice, blenderized foods
- Jejunostomy tube -> 15cm away from the ligament of Treitz using special commercial enteral formula
What are the complications of enteral feeding?
- malposition & blockage of tube
- gastroesophageal reflux, nausea & vomiting
- feeding intolerance
- fistulae formation or leakage
- over or under nutrition
When is parenteral feeding indicated?
short term access in case of
- massive bowel resection (short bowel)
- radiation enteritis (functional short bowel)
- high output intestinal fistula (<500cc conserve)
- prolonged ileus
What are the routes of administration in parenteral feeding?
- central venous catheter -> for hyperosmolar solutions
- peripheral catheter -> isotonic lipid preparations
What are the complications of parenteral feeding?
NUTRITIONAL
- over or underfeeding
- electrolyte disturbances
- hypo or hyperglycemia
CVC
- misplacement
- hemothorax or pneumothorax
- injury to adjacent nerves of arteries
- venous thrombosis (due to catheter)
- sepsis (catheter related)
- air embolism
GUT MUCOSAL ATROPHY
DETERIORATION OF LIVER FUNCTION TESTS
What is the cause of refeeding syndrome?
severe electrolyte & fluid imbalance in severely malnourished patients while starting the proper feeding
- more common in TPN
- common in chronic starvation, severe anorexia, & alcoholic patients
What does refeeding syndrome lead to?
- causes hypomagnesaemia, hypocalcemia & hypophosphataemia
- myocardial dysfunction
- respiratory changes
- altered liver functions
- altered level of consciousness
- convulsions
- death
what causes disruption in nitrogen balance?
1g protein = 6.25g nitrogen
POSITIVE NITROGEN BALANCE (intake > urinary output) -> anabolic state
NEGATIVE NITROGEN BALANCE (urinary output > intake) -> catabolic state
imp physiological facts
- carbs & proteins = 4Kcal/g
- fats = 9Kcal/g
- glucose if the only source of energy for the brain, RBC & adrenal medulla
- excess calories are stored as fat
- proteins are used to build muscle & help in synthesis of enzymes & some hormones