Parenteral & Enteral Nutrition Support Flashcards
When should nutriotnal support be considered?
- Cannot tolerate oral feeding
-
Malnourished
- BMI < 18.5 kg/m2
- Unintentional weight loss > 10% in last 3-6 months
- BMI < 20.0 kg/m2 and unintentional weight loss > 5% in last 3-6 months
-
At risk of malnutrition
- Little or no oral intake > 5 days and/or anticipated poor intake for at least another 5 days.
- Poor absorptive capacity, high nutrient losses, increased nutritional requirements
Why is the GI tract preferred to eneteral support?
- Maintain GI endocrine/exocrine secretions
- Maintenance of GI integrity – tight junctions between intestinal epithelial cells require energy obtained directly from local absorption
- Maintain GI microflora
- Cheaper
- Fewer complications
- Safer
What are indications for Enteral Nutrition?
- Dysphagia: Stroke, Neurological disease
- Upper GI Obstruction: Stricture, Malignancy
- Inability To Eat: Coma, ICU, Head & neck surgery
- High Nutritional Requirements: Burns, Sepsis, Malignancy
- Loss Of Appetite: Anorexia, Cancer
What are route for enteral feeding?
- Naso-Gastric (NG) / Naso-Jejunal (NJ)
- Percutaneous Endoscopic Gastrostomy (PEG)
What is the composition of enteral Feeds?
Commercially prepared feeds usually used, ‘standard’ feed has following characteristics:
- Approx 1 kcal/mL
- Isotonic
- Contains fibre
- Lactose free
- Non hydrolysed protein content approx 40 g/L
- Mixture of simple and complex CHOs
- Long chain FAs (some medium chain and omega-3)
- Essential vitamins and trace elements
Approx 50% calories supplied by CHO, 30% as fat. Additional fluids are also required and will vary according to patient requirements
What are Type of Enteral Feeds?
Concentrated
- Critically ill patients requiring volume restriction
- Hyperosmolar, up to 2 kcal/mL
Polymeric
- Non hydrolysed intact protein as nitrogen source
Elemental/Pre-digested
- Short oligopeptides provide nitrogen source
- Less complex CHOs
- Used for e.g malabsorption, short bowel
Disease specific
- Paediatric in-born errors of metabolism – PKU feeds, renal failure feeds
- Renal e.g low phosphate
What are some complicatons of Enteral Feeding?
- Mechanical: Tube blockage, Tube misplacement (Aspiration), Physical damage
- Gastrointestinal: Nausea, Constipation, Diarrhoea, Abdominal distension
- Biochemical: Re-feeding, Electrolyte disturbances, Micronutrient deficiencies, Hyperglycaemia
- Other: Infection
What is Parenteral Nutrition?
- Parenteral is Intravenous
- Reserved for patients in whom enteral intake is inadequate or unsafe, or where GI tract is non-functional or inaccessible
- Although evidence suggests improved outcomes for malnourished patients on short term feeding, due to potential complications PN is rarely indicated for use for just a few days
What are indication for Paraenteral Nutrition?
- Intestinal Failure / Short bowel
- Inflammatory Bowel Disease – Chron’s, Ulcerative cholitis
- GI obstruction – Malignancy, Stricture, Ileus
- Gut ‘rest’ – Pancreatitis, Post-op bowel resection
- Radiation enteritis
- Congenital bowel defects in paediatrics
What are features of Short Term PN feeds?
- PN feed osmolality approx 900-1500 mosmol/Kg
- Plasma osmolality approx 290 mosmol/Kg
- PN ideally infused into large central vein where rapid blood flow quickly dilutes the high osmolality feed
- Infusion into peripheral veins can result in thrombophlebitis
- Reduce glucose content of feed to reduce osmolality
How is PN administered in the long term?
- Peripherally Inserted Central Catheter (PICC)
- Tunelled central line eg Hickman line
What are the types of Infusion schedules for PN feeds?
- Continuous
- Cyclical
What are features of Continuous Infusion feeds?
- Non-interrupted infusion over 24 hr
- Well tolerated
- Increased propensity for PN associated liver disease
- Reduced mobility
- Reduced quality of life
What are the features of Cyclical feeds?
- Intermittent administration usually over 12-18 hr
- Less well tolerated in critically ill patients
- Approx. normal physiology of intermittent feeding
- Improved mobility
- Improved quality of life
Wat factors should be monitored when giving infusions of PN feeds?
- Nutrient content of feed: Daily, reducing to twice weekly when stable
- Volume of feed: Daily, reducing to twice weekly when stable
- Weight: Daily if concerns regarding fluid balance, otherwise weekly reducing to monthly
- Fluid Balance: Daily, then twice weekly when stable
- Temperature/Blood pressure: Daily
- Anthropometric measurements: Monthly
- Evidence of GI dysfunction (vomiting, diarrhoea, constipation, abdominal distension): Daily, reducing to twice weekly
What are Paraenteral feed complications?
Lines
- Infection
- Air / Venous embolism
- Blockage
- Misplacement
Thrombophlebitis
- Peripheral line administration
Metabolic
- Re-feeding
- Electrolyte disturbances
- Micronutrient deficiencies
- Hyperglycaemia
- Bone disease
Liver disease
What are signs of PNALD?
- Common to find elevated bilirubin, ALP and ALT in patients on short term PN
- Usually mild, transient and resolve once PN discontinued
- PNALD – up to 60% children and 40% adults on long term PN
What is Prolonged PN associated with in the Liver?
- Hypertriglyceridaemia
- Steatohepatitis
- Cholestasis
- Fibrosis / Cirrhosis – more common in paediatrics
What is the Aetiology of PNALD?
- Underlying Disease: Pre-existing liver disease, Sepsis, IBD, Intestinal bacterial overgrowth, Short bowel (impaired bile acid circulation/metabolism)
- Lack of enteral nutrition
- Parenteral nutrient deficiency: Protein, Essential FAs, Choline, Taurine, Carnitine
- Parenteral nutrient toxicity: Glucose, Lipids, Mn, Al
What is the treatment for PNALD?
Manage underlying disease:
- Avoid and treat sepsis
- Treat bacterial overgrowth
- Avoid hepatotoxic medication
- Treat underling liver disease
Modify enteral and parenteral nutrition:
- Avoid overfeeding
- Optimise parenteral lipid
- Cyclical PN
- Maximise enteral nutrition where possible
Pharmacological treatment:
- Bile acid sequestrants – Ursodeoxycholic acid
- Parenteral choline / taurine
Small intestine and/or liver transplantation. It has a 1 yr survival of:
- Combined liver + SI = 60%
- SI alone = 77%
How can PN Fat Content after PNALD?
Composition of lipids in PN may have bearing on development of PNALD
- Very small amount lipid required to provide essential fatty acids, but recommended ~50% kcal requirements derived from lipids
- Lipid usually soyabean based long chain triglyceride (LCT) emulsified into chylomicrons with egg derived phospholipids
What are other formulations of Fat in PN feeds that may reduce the likelihood of PNALD?
- 50:50 LCT:MCT mixtures (MCTs possibly more easily absorbed and metabolised)
- Monounsaturated fatty acids (MUFA)
- Omega-3 fish oils / MCT (SMOF)
Cyclical lipid feeding also used to help avoid PNALD
What afeatures of Home Parenteral Nutrtion?
An option for patients with medium/long term or permanent loss of gut function.
- Quicker discharge from hospital
- Improved rehabilitation in the home
- Improved quality of life
Patients must be rigorously trained in sterile techniques for line care and line/feed handling
What is required for Home Parenteral Nutrition?
- Private home care nursing provider / GP funding
- Regular visits from PN nurses
- Facilities in the home for keeping PN bags at 4ºC plus lots of other kit (pump etc)
- Self-care/self-awareness of eg infection, temperature
- Regular clinic visits and bloods from overseeing hospital team
