Paediatrics: Parenteral nutrition

Parenteral nutrition

IV parenteral nutrition may be supplemental or provide TPN. Parents can be trained to give prolonged PN at home to children.

Indications

•   Post-operative, e.g. abdominal or cardiothoracic.

•   Treatment of IBD.

•   After severe trauma or burns.

•   Acute pancreatitis.

•   Oral feeds are contraindicated, e.g. NEC.

•   Intestinal failure, e.g. short bowel syndrome, congential enteropathy.

•   Protracted vomiting or diarrhoea.

•   GI obstruction, e.g. chronic intestinal pseudo-obstruction.

•   Very preterm infants.

•   Oncology patients, e.g. severe mucositis, graft versus host disease.

Administration

•   A multidisciplinary team of clinician, pharmacist, and paediatric dietitian should be involved in supervising PN.

•   Follow unit/hospital dietetic/pharmacy guidelines for individual needs.

•   Allowance should be made of body weight (you may need to estimate a working weight, e.g. if oedematous or gross ascites), recent weight trends, clinical condition, fluid and nutritional requirements, additional infused fluids.

Method

Once requirements are calculated, sterile pharmacy-prepared solutions are given via central (preferable) or peripheral venous lines. Rapid com-mencement of PN may risk ‘refeeding syndrome’ in chronically under-nourished patients. When significant malnutrition exists, measure and correct electrolyte abnormalities before commencing PN and introduce slowly.

PN is usually supplied and administered as two components.

•   Lipid component: contains fat (triglyceride emulsion, e.g. Intralipid 20%) and fat soluble vitamins. Usually infused over 20hr.

•   Aqueous component: contains carbohydrate (glucose solution), protein (crystalline L-amino acid solution), electrolytes, water soluble vitamins, minerals, trace elements (zinc, copper, manganese, selenium, +/– iron). Usually infused over 24hr.

Monitoring

Serious, unexpected biochemical disturbances occur rarely as a result of PN. An appropriate monitoring regimen is suggested in Table 10.2.

Weaning

PN should be weaned slowly so that hypoglycaemia is avoided. This also allows GI mucosal recovery as enteral feeding is increased. When wean-ing is protracted parenteral nutrition can be administered over shortened periods. A paediatric dietitian should assess the contribution of both enteral and parenteral feeds to ensure nutritional adequacy.

Complications/problems

• Sepsis: usually S. epidermidis, S. aureus, Candida, Pseudomonas, E. coli.

• Demanding: in expertise, cost, etc.

• Central-line: occlusion, breakage, displacement.

• Electrolyte/metabolic disturbances: e.g. glucose ‘rise’or d.

• Vascular: thrombophlebitis, thromboembolism, extravasation injuries.

• Cardiac tamponade: avoid by placing IV line tip proximal to right atrium.

• From amino acids: PN-associated liver disease, including, steatosis, cholestasis, or, rarely cirrhosis or portal hypertension.

• From lipids: platelet dysfunction, hyperlipidaemia, fatty liver, pulmonary hypertension.

• Metabolic bone disease: due to insufficient Ca²⁺ and PO₄^{3 –}.