University Hospital of Wales Paediatric Intensive Care Unit Guideline Printed on Wed 23-jul-08
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Last updated December 9, 2016 11:17 AM

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02920 744622

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Noah's Ark Childrens Hospital for Wales
Heath Park
Cardiff
CF14 4XW
02920 747747


TPN

Useful telephone numbers

 

 

Bleep

Ext

Nutrition Pharmacist

Anthony Lewis

6630

3710

PICU Pharmacist

Zoe Taylor

4586

8026

Paediatric Speech Therapist

Bev Curtis/ Karen Sealey

 

20 536807

General principles

Ordering TPN:

Order TPN before 11am, using yellow paediatric PN prescription sheet if > 1 month old or white neonatal prescription sheet if < 1month old.
Order TPN for the weekend before Friday 11 am, prescribe 3 bags (Friday, Saturday, Sunday) and remember to prescribe in advance to cover bankholidays.
TPN is made in a 24hrs-bag, if the patient is very stable consider a 48hrs-bag in view of less infection risks (braking of lines etc)

You will need to know the following to accurately prescribe TPN:

TPN must be written up on the daily PICU fluid chart. Lipid and aqueous-TPN bags should be written up separately.

TPN Lines

TPN may be given peripherally only if glucose concentration <12.5%.
TPN needs a dedicated line.
The lumen that is used for TPN should not be used for blood sampling or giving of other iv drugs or fluids

TPN is built up over several days, during which time the protein, fat and carbohydrate contents are gradually increased.
Complete exclusion of nutrients via the oral route is associated with marked atrophic changes in gut and pancreatic function. It's therefore important to use the gut when ever possible, even when it's just minimal enteral feeds.
When TPN is required during infancy, it's essential that patient maintains an oral experience (e.g. dummies). Queries: ask speech therapist (number above)

Indications for TPN

Nutritional support is aimed at adequately supplying the body's nutritional requirements for growth and development. Infants and children are particularly at risk from effects of under nutrition due to their limited energy reserves e.g. a pre-term infant of 1 kg will survive 4 days if starved compared to 3 months in adults. Survival times are decreased in times of catabolic stress and therefore nutrition must be considered early in all infants and children!

When prolonged GI malfunction can be predicted TPN may be commenced in order to prevent later malnutrition.

Indications may be:
Prematurity
Necrotising enterocolitis
Intestinal failure (e.g. short gut, protracted diarrhoea, chronic intestinal pseudo-obstruction, acute obstruction)
Poor bowel perfusion (e.g. severe sepsis, certain cardiac conditions)
Organ failure (e.g. acute renal or liver failure)
Hypercatabolism (e.g. extensive burns, severe trauma)

  • Fluid Requirement
  • Electrolyte requirement
  • Calorie requirement
  • Worked examples

The body mainly consists of fluid, the percentage of which will decrease in the first few years of life (i.e. 80% in a newborn which decreases to 60% after 1 year). Hence why the fluid requirement is depending on a patient age and weight.

The basic fluid requirement consists of insensible loss (evaporation via skin (2/3) & breathing (1/3)) + water losses (mainly urine).

There are different ways of calculating the daily fluid requirement. Rule 1 is the most used way of doing so (approved by the APLS guidelines). The second way is calculating the insensible and ongoing losses (rule 2), which may be helpful in patients with SIADH etc.

In both cases one has to adjust fluid intake for ongoing losses (i.e. diarrhoea, gastric aspirates, etc)

Rule 1

First 10 kg

100 ml/kg

Second 10 kg

50 ml/kg

Subsequent kg

20ml/kg

Rule 2

Insensible loss

300 ml/m2/day

Faeces

100 ml/m2/day

Urine (2ml/kg/h)

1440 ml/m2/day

 

 

Body Surface Area = sq. root of (body weight (kg) x length (cm))/ 3600 or use the UKSCG chart (on hydrocortisone monograph in the bedside folder)

There are different factors that have their influence on the insensible loss as shown in the next table.

Adjustment of insensible losses

Increased insensible loss

Decreased insensible loss

Hyperventilation

Humidified air (ie ventilation)

Hypertermia (100ml/m2/1°C temp increase /24hours)

Hypothermia

Activity reduced

Sedation

Burns (>10% of BSA: (%burn x weight(kg) x 4ml)/24hr)

Paralysis

Phototherapy

Activity reduced

These increased insensible losses are electrolyte free.

In consideration of TPN prescribing

Consider whether total fluid requirement is to include drugs or whether volume from drugs/infusions is to be allowed in addition
If total fluid includes drugs you will need to calculate the volume left over once daily drugs/infusions have been given and prescribe the TPN to this volume. In this way the patient will get all of their nutrients
Consider the effect any potential increases in drugs/infusions throughout the day may have on the volume available for TPN. Consider prescribing a lesser amount of TPN in view of the possibility of the necessity of increasing drugs throughout the day.
NB Stability of the TPN may affect the minimum volume that can be made. The pharmacist will advise you if this is a problem.