What monitoring is required for a patient receiving TPN?

Monitoring	Suggested Initial Frequency2
Clinical Monitoring
	Patient examination temp,pulse,RR	daily
	Bloop Pressure	4 hourly
	Ward urine analysis	daily
	Fluid balance	daily
	Nutrient intake	daily
	Body weight	weekly
Laboratory monitoring
	Full Blood Count	daily
	Prothrombin time	2 x weekly
	Folate and B	as clinically indicated
	Iron, transferrin, ferritin	as clinically indicated
	Blood urea and electrolytes, creatinine	daily
	Glucose	daily or as indicated
	Calcium, phosphate	3 x weekly
	Liver function tests	2 x weekly
	Magnesium, zinc, copper	weekly
	Acid Base measurement	as clinically indicated
	Urine-urea & electrolytes, creatinine (24 hour collection)	as indicated
	Other fluids-electrolytes (timed collection)	as indicated
	Bacteriology-parenteral catheter, skin puncture site	as indicated
	Blood Culture	as indicated
	Catheter tip culture	on removal

Nutritional requirements for average 70 kg adult

• Protein/Albumin - 4kcal/g/day
• Fat - 9kcal/g/day

Note- TPN bags supplied in this hospital does not contain vitamins. Vitamin preparations e.g. Cernevit must be prescribed separately and administered daily through a central or peripheral line. The recommended method of infusion is in 100mls of normal saline over one hour.

The specific type of nutrition (TPN or jejunal feed etc) is not often available in short notice. Doctor in charge must be responsible for nutrition of their patient with the help of the dietician, they must ensure that nutrition is commenced at weekends when dietician is not available.

Monitoring patients on parenteral nutrition (PN) requires a multidisciplinary approach with effective communication throughout the team. This will help to minimise potential complications, and will aid safe, effective and appropriate use of PN. The team should include, at minimum, input from a Doctor, Nurse, Dietitian and Pharmacist, all experienced in PN.

When establishing a new patient on PN, daily review is recommended until the patient is stable in terms of electrolytes, nutrient provision and fluid balance. Achieving stability requires detailed, timely review, with appropriate alterations made to the PN.

Adapted from NICE (2006) ESPEN (2009)

Goals

The rationale for PN, together with clear goals, should be established at the initial assessment. Goals should then be reviewed at each contact to facilitate effective monitoring and appropriate use of PN (NCEPOD, 2010).

Nutritional status

Nutritional status is most effectively assessed and monitored through a combination of anthropometric data, biochemical and clinical measures. A stand-alone measure e.g. weight, can rarely provide adequate information.

Clinical parameters

Adapted from NICE (2006) Nutrition support in adults.

Biochemistry

Careful interpretation of biochemistry can provide important information relating to a number of factors including hydration status, renal function, risk of re-feeding syndrome, sepsis, and both electrolyte deficiencies and excesses. Responding appropriately to this, in turn, will help to minimise the risk of complications.

Electrolytes (Sodium, Potassium & Magnesium), bone profile (Calcium & Phosphate), infection markers (such as C Reactive Protein and white blood cells) and liver function tests should be taken at baseline, reviewed daily until stable and then at each planned follow up.

Cholesterol and triglycerides should be reviewed weekly initially, reducing to 3 monthly once stable to monitor the risk of potential hyperlipidaemia.

Trace elements (zinc, copper, selenium and manganese) and vitamins (A, D, E, B12, Folate) should be checked at baseline if there is previous evidence of malnutrition. This should then be repeated 3 monthly in long term patients (NICE, 2006) to detect deficiencies or raised concentrations. It is important to interpret these results with caution and monitor clinical symptoms, as serum concentrations can be reduced or raised when inflammatory markers are raised during the acute phase response, and may not reflect total body stores.

Electrolyte disturbances

Electrolyte disturbances are a common complication of PN. Before altering the PN prescription, the following points should be considered:

• Trends – is the disturbance an acute or chronic issue?
• Clinical symptoms - some patients may become symptomatic at even mild disturbances and may need to be treated more aggressively.
• Establish the possible cause for disturbances e.g. re-feeding syndrome, GI losses, fluid overload, dehydration, medications, excessive replacement, IV therapy and clinical condition. Consider the composition of fluids lost by clinical condition to calculate PN electrolyte additions (NICE, 2013).
• What are the patients estimated requirements?
• What is the patient already receiving? e.g. through PN, enteral, IV therapy and other medications.
• Consider natural daily variation in electrolytes. These will require monitoring but do not always need to be acted upon.

Adapted from Austin and Stroud (2007)

Liver function tests (LFTs)

PN can contribute to abnormal LFTs; however, it is rarely the main cause. Factors such as sepsis, medications and underlying liver problems also lead to raised LFTs and must be taken into account.

Minimising risk of complications:

• Fat/lipid <1.5g/kg/day and change to an anti-inflammatory source. Long term PN may require lipid at 0.5-1.0g/kg/d.
• Do not exceed glucose oxidation rate.
• Do not over-feed energy or nitrogen. Gauge requirement on metabolic stress.
• Introduce even a small amount, ‘trophic’ / enteral feed if possible.
• Reduce PN to cyclical feeding e.g. 12-18hrs after 2 weeks of PN feeding.
• Liaise with the medical team regarding treatment of sepsis and review of medications.

References

ESPEN (2009) Guidelines on Parenteral Nutrition: Home Parenteral Nutrition (HPN) in adults patients.

NCEPOD (2010) PN: A mixed bag report. National confidential enquiry into patient outcome and death.

NICE (2006) Nutrition support in adults: Oral nutrition support, enteral tube feeding and parenteral nutrition.

NICE (2013) Intravenous fluid therapy in adults in hospital.

Austin, P and Stroud, M (2007) Prescribing Adult Intravenous Nutrition. RPS publishing. London.

Rhys White in Todorovic V and Micklewright A (2011). The Parenteral and Enteral nutrition Group (2011) Pocket guide to clinical nutrition 4th Edition. British Dietetic Association