Routes of administration

After a burn injury, the route of nutrition may be either enteral or parenteral. Enteral is preferred as it protects the small bowel mucosa, limits the translocation of bacteria, limits stress ulceration and minimizes the risk of acalculous cholecystitis. Ideally, it should be commenced within 6-18 hours of the burn. This may be impossible in the presence of an intestinal ileus, in which case a nasogastric tube should be passed to reduce the risk of vomiting and aspiration.

Oral feeding may be impossible if the patient is sedated, intubated or non-compliant. Also, patients with large burns often are too weak to feed. In these cases, feeding may be commenced early by passing a small-bore (8 or 10 gauge), soft nasogastric tube. There are special feeds for this route of administration. They should be given by continuous infusion rather than bolus feeding as the latter is associated with incomplete gastric transit. Before administration the stomach should be aspirated to ensure that there is no gastric residual. The bed should be elevated to 30 degrees while the feeds are given to limit the tendency to aspiration. Introducing enteral feeds slowly reduces the likelihood of diarrhoea. A nasogastric tube can be tolerated for up to a month, but if enteral feeding is established but needed for longer, a PEG tube should be considered. If there is prolonged gastric ileus, a nasoduodenal tube is an alternative conduit.

Parenteral nutrition may be peripheral or central. They are a less favoured option as they do not support integrity of the small bowel mucosa. Total peripheral nutrition is preferred but there are high rates of complications such as sepsis and they should be changed regularly. Peripheral parenteral nutrition is unlikely to deliver an adequate protein or energy load and there may be no suitable venous access. It should be reserved for use only as an adjunct to oral feeding.