Total parenteral nutrition can provide an individual with the necessary nutritional support and provision of therapeutic nutrients to maintain or restore optimal nutrition status and health. Total Parenteral Nutrition bypasses the digestive system by dripping a nutritionally adequate hypertonic solution containing glucose, protein, hydrolysates, minerals and vitramins directly into the venous system through an indwelling catheter into the superior vena cava or another main vein.
Total Parenteral Nutrition Contents
MACRO-NUTRIENTS:
- Carbohydrates (glucose)
- Proteins (amino acids)
- Lipids (fatty acids)
OTHERS:
- Electrolytes
MICRO-NUTRIENTS:
- Multi-Vitamins (eg. Vitamin B)
- Trace Elements/Minerals (eg. Selenium & Manganese)
A bag of TPN provides the patient with about 2270kcal nutritional intake. This high calorie intake is not considered to be too much since patients on TPN are usually fighting inflammation, requiring wound healing etc.
Indications for Total Parenteral Nutrition
Total Parenteral Nutrition is indicated for patients who:
- are lacking nutritional requirements (commonly related to health-related conditions)
- have documented inadequate oral intake (common indication in the elderly)
- experience an unpredictable return of their GI function (eg. malabsorption leading to lack of good nutritional outcome)
- are on a prolonged nil-by-mouth period (eg. patients undergoing GI surgery)
DIGESTIVE DISORDERS:
- GI fistulae
- major GI surgery
- uncontrolled malabsorption (eg. in Chron’s Disease)
- short bowel syndrome (gastroschisis, volvulus & necrotising enterocolitis)
- severe enteropathy (genetic-related issues such as microvillus atrophy, tufting enteropathy, congenital, auto-immune)
- dysmotility or pseudo-obstruction
- severe acute pancreatitis
NON-DIGESTIVE DISORDERS:
- post-chemotherapy
- radiotherapy
- severe mucositis
- bone marrow transplant
- multi-organ failure in extensive trauma and burns
- immature gut
Contraindications for Total Parenteral Nutrition
- functioning GI tract (if the problem is with the upper GI tract and the lower GI tract is fully functioning, enteral feeding directly into the jenunum would be recommended)
- need for <5 days of TPN with no severe malnutrition
- difficulty in obtaining venous access
- poor prognosis that doesn’t warrant aggressive nutritional support
- if risks outweigh the benefits
TPN and CVCs Complications
- catheter and systemic infections
- catheter obstruction eg. blocked lumens
- pneumothorax (may happen during catheter insertion)
- thrombosis (may happen during catheter insertion)
- bone disease
- hepatobiliary disease (eg. TPN-induced liver failure due to the nutritional infusion being administered directly into the venous system)
- renal disease
Patient Monitoring
- vital signs (temperature to monitor for sepsis; blood glucose monitoring due to TPN containing 40% glucose)
- intake & output
- weight (especially malnourished patients)
- fluid requirements
- patient complaints
- CVC exit site (monitor for signs of inflammation)
- overall clinical status
- blood (renal: U&E, Mg, Ca, Phos, Cr; heamat: CBC, INR; liver function: Alk Phos, Bil.; Glucose and Lipid, Iron and Ferritin; Albumin)
- MRSA nasal swabbing (if patient is colonised with MRSA, treatment is required prior to developing into an infection)
TPN Bag Changing Technique
- use an aseptic non-touch technique
- hand hygiene
- don apron
- clean work surface with 70% alcohol and let dry
- cover with sterile drape
- place all sterile items on it: sterile IVI tubing, syringe and needle
- other needed items should be placed in a cleaned tray
- apply alcohol handrub
- don gloves
- switch off volumetric pump
- disconnect previous TPN line from the needleless valve attached to the central venous catheter
- mix the 3 compartments of the new TPN bag and hang on drip stand – DO NOT TOUCH CONNECTION PARTS
- disinfect the needleless valve with 2% chlorhexidine in 70% alcohol and leave to dry
- spike TPN bag with infusion line and prime whilst still capped
- remove cap and connect to patient through the needleless valve
- add additives Additrace and Cernevit to the TPN bag from the injectable port using an aseptic non-touch technique
- dispose of materials appropriately
Below you can find a video that can help provide a more visual approach to total parenteral nutrition.
Total Parenteral Nutrition OSCE
Special thanks to the creators of the featured video on this post, specifically Youtube Channel University of Manitoba Nursing Skills. Featured image credit: https://badgut.org/information-centre/a-z-digestive-topics/parenteral-nutrition/
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