• BMI <18.5 kg/m²
• Unintentional weight loss >10% within the past 3-6 months
• BMI <20.0 kg/m² + unintentional weight loss >5% within the past 3-6 months

• Eaten little or nothing for >5 days and/or likely to eat little or nothing for the next 5 days or longer
• Poor absorptive capacity and/or high nutrient losses and/or increased nutritional needs from causes (e.g. catabolism)

• There is inadequate / unsafe oral intake (e.g. dysphagia, reduced GCS), AND
• Functional and accessible GI tract
  • i.e. the gut works and can be reached with a feeding tube, allowing nutrition to be delivered and absorbed effectively

Stop enteral feeding when the patient is established on adequate oral intake.

• 1st line: nasogastric (NG) tube (alternative: orogastric tube)
• 2nd line: post-pyloric feeding (via nasoduodenal or nasojejunal feeding tube)
  • Indicated if there is upper GI dysfunction (e.g. severe gastroparesis, high aspiration risk) / inaccessible upper GI (e.g. tumour obstruction)
• Consider a motility agent (e.g. metoclopramide) in those with delayed gastric emptying who are not tolerating enteral feeding

If a patient is expected to require enteral feeding for ≥4 weeks, long-term or permanent access should be considered.

The mainstay is gastrostomy feeding (the delivery of nutrition directly into the stomach via a stoma), which can be established by:

• Percutaneous endoscopic gastrostomy (PEG) – gastrostomy tube is inserted percutaneously under endoscopic guidance (direct endoscopic vision)
• Radiologically inserted gastrostomy (RIG) – gastrostomy tube is placed under radiological (ultrasound / fluoroscopic) guidance
• If gastric enteral feeding is not appropriate, jejunostomy tube and gastrojejunostomy tube are alternative options

• Most patients → bolus or continuous (based on patient preference, convenience, and drug administration)
• Patients in intensive care → continuous delivery (over 16-24 hours, or over 24 hours if the patient needs insulin)

• Osmotic diarrhoea (most common)
• GORD
• Nausea, vomiting, bloating

• Aspiration pneumonia
• Aspiration pneumonitis

Note that the aspiration risk is higher in nasogastric feeding (than post-pyloric feeding), as the feed can reflux into the oesophagus easily (as the feed is delivered into the stomach), and the tube reduces LOS tone

• Tube blockage
• Tube dislodgement
• Tube misplacement (see section below on how to confirm correct placement)

• pH of 1.0-5.5 (‘safe range’) can exclude placement in the respiratory tract (as the pH in healthy lungs is 7.38-7.42)
• Action based on pH of gastric aspirate:
  • If pH is 1.0-5.5 → the nasogastric tube can be safely used for feeding
  • If the pH is >5.5 → perform X-ray

Confirmatory test: X-ray

• X-ray should NOT be routinely performed in all patients
• X-ray will be required if the gastric aspirate is NOT within the 1.0-5.5 ‘safe range’

ALL of the following 4 must be seen and met on X-ray, before the nasogastric tube can be safely used for feeding:

• The tube follows the oesophagus path and avoids the contours of the bronchi
• The tube clearly bisects the carina of the bronchi
• The tube crosses the diaphragm in the midline
• The tip is clearly visible (7cm) below the left hemidiaphragm

• Confirmation should be done with an abdominal X-ray (unless placed radiologically)

• There is inadequate / unsafe oral intake (e.g. dysphagia, reduced GCS), AND
• The GI tract is non-functional / inaccessible / perforated
  • i.e. the gut doesn’t work or cannot be reached with a feeding tube

Short-term access (<30 days):

• PICC line – suitable for patients who do not otherwise require central access and need parenteral nutrition for <14 days, or
• Central venous catheter (e.g. internal jugular and subclavian vein lines), or
• A dedicated lumen of an existing multi-lumen central venous catheter

Long-term access (>30 days): tunnelled subclavian central venous catheter (e.g. Hickman line)

• Critically ill patients: continuous administration
• Patients with PICC line: cyclic delivery
• Patients requiring parenteral nutrition for >2 weeks: consider cyclic delivery

• Catheter-associated infection and sepsis (esp. in short-term lines) (tunnelled long-term lines reduce the risk)
• Cholestatic LFTs and hepatic steatosis
• Hypertriglyceridaemia