NUTRITION IN CRITICALLY SICK CHILD

Critically sick children are in hyper-catabolic state and need additional nutrition to maintain their nitrogen balance. Conventional fluid and electrolyte supplementation with simple dextrose-solutions is grossly inadequate to meet nutritional requirements of these children except for brief periods.

Nutritional requirements of a critically sick child are actually higher than those of a normal child but complete supplementation is often difficult. However, these children should at least receive ~25-30 cal/kg/day (~40-45 cal/kg/day in burns or trauma) and 1.5-2.5 gm/ day of proteins (2.5-3.0 gm/day in burns), via enteral or parenteral route, which should be increased gradually.

Enteral feeding is the preferred route of nutrition in sick children, which prevents intestinal mucosal damage and overgrowth of gut pathogens in critically sick children. However, it is contraindicated in many situations, e.g. paralytic ileus, gut perforation or gut hemorrhage.

Enteral feeding may be given via nasogastric tube intermittently or as continuous intragastric/small bowel drip. Milk or milk-based feeds are preferred enteral feeds in sick children, while commercially available oligomeric diets, e.g. glucose polymers, free aminoacid preparations, medium chain triglycerides, etc. may be necessary in selected cases. Bolus feeds are preferred than continuous feeding, unless transpyloric feeding is required.

Enteral feeding is contraindicated in intestinal obs­truction, severe GIT bleeding and recent GIT surgery. Common complications of prolonged enteral feeding include: (a) aspiration due to displaced nasogastric tube, (b) diarrhea due to hyperosmolar feeds, and (c) local nasopharyngeal trauma.

Total parenteral nutrition (TPN) aims to provide all essential nutrients, e.g. proteins, fats, carbohydrates, vitamins and trace elements via parenteral route, when enteral nutrition is not possible for longer periods (gt;7 days).

Indications: Common indications for TPN are given in Table 27.16.

Preparations: Various IV commercial preparations are available for TPN, which include:

• Lipids preparations, containing 10-20% of emulsified Soyaben or Safflower oil, should be started with 0.5 gm/kg/day and increased gradually to reach 2 gm/kg/day within a week.

TABLE 27.16: Indications for TPN

Newborns:

• Very low birth weight newborns

• Prolonged resp. distress or mechanical ventilation

• Gut malformations or necrotizing enterocolitis

• Post-operative GIT surgery

Older children

• Gut malformations, e.g. short gut syndrome

• Persistent diarrhea or paralytic ileus

• Chronic liver/renal failure

• Severe trauma or burns

• Amino acids mixtures, containing at least 40% as essential amino acids, should be started with 1.0 gm/ kg/day and increased gradually to 1.5-2.0 gm/kg/ day.

• Carbohydrates as 10% dextrose infusion provide remaining caloric requirements, which should begin with 5-6 mg/kg/minutes before increasing gradually.

• Microelements, e.g. vitamins, mineral and electrolytes, must be added in IV fluids as per daily requirements.

Mode: Peripheral venous lines are preferred for TPN due to higher risk of complications with central catheters, which should be used only when high dextrose concentration (gt;10%) is necessary to meet caloric demands. TPN should be introduced gradually over a period of 2-4 days. Amino acids, dextrose and electrolytes can be mixed in the same bottle under asepsis, while lipids have to be administered by separate IV lines. Enteral feeding should be started as soon as possible and TPN can be stopped when gt;3/4^th requirement may be given enterally/orally.

Monitoring: All patients on TPN should be monitored for blood glucose thrice a day, apart from daily weight record and periodic serum electrolytes, BUN, triglycerides and complete blood counts for infection.

Complications of TPN are directly related to duration of therapy as well as quality of care, and include:

• Local thrombophlebitis, extravasation gangrene.

• Infections: Local abscess, septicemia

• Metabolic: Dyselectrolytemia, acidosis, hyperglycemia, hypertriglyceridemia.

• Thromboembolic: Pulmonary, air or lipid embolism

• Systemic bleeding diathesis

• Mechanical vascular/thoracic duct injury

• Late complications: Cholestatic liver dysfunction and essential fatty acid deficiency.

27.4.6