Enteral Nutrition Nursing Guide

Enteral vs Parenteral Nutrition

"If the gut works, use it." Enteral nutrition (EN) is always preferred over parenteral (PN) when the GI tract is functional. EN preserves gut mucosal integrity, reduces infection risk, is cheaper, and maintains the microbiome.

Route	Indication	Advantages
Oral supplements (sip feeds)	Inadequate oral intake, malnutrition	Simple, physiological, low cost
Nasogastric (NG)	Short-term feeding <4 weeks, impaired swallowing	Simple to insert, reversible
Nasojejunal (NJ)	Gastroparesis, recurrent aspiration, pancreatitis	Post-pyloric feeding reduces aspiration risk
PEG (percutaneous endoscopic gastrostomy)	Long-term feeding >4 weeks, stroke, motor neuron disease	More comfortable, no nasal tube; patient can go home
RIG (radiologically inserted gastrostomy)	Same as PEG but patient unable to undergo endoscopy	Doesn't require sedation/endoscopy

Indications for Enteral Nutrition

Dysphagia (stroke, MND, head/neck cancer, dementia)
Unconscious patient
Critical illness (ICU) — start EN within 24–48 hours of admission
Severe facial/oral trauma
Anorexia with malnutrition (cancer, inflammatory disease)

Contraindications to Enteral Nutrition

Bowel obstruction
High-output intestinal fistula
Paralytic ileus (severe)
Haemodynamically unstable requiring vasopressors (relative — may start low rate once stable)

NG Tube Management

Confirming NG Tube Position — CRITICAL

NEVER start feed without confirming correct NG tube placement. Feeding into the lungs = aspiration pneumonia, pneumothorax, and death. This is a NEVER EVENT.

Position Confirmation Methods

pH testing (first line): Aspirate gastric contents; test with CE-marked pH paper. pH ≤ 5.5 = stomach (safe to feed). If pH >5.5 — do NOT feed; confirm with CXR.
CXR (gold standard): Tube should be visible below left hemidiaphragm in stomach. Also used if pH uninterpretable (on PPI, post-gastrectomy, H₂ blockers).
Auscultation alone (air bubble test) is NOT acceptable — has caused deaths; not used as confirmation.

PPIs and H₂ blockers increase gastric pH — may give false reading >5.5. In these patients, check pH during first aspiration (may still be acidic) but have a low threshold for CXR confirmation.

NG Feed Protocol

Position patient at 30–45° head of bed elevation (reduces aspiration risk)
Check pH before each feed or at least every 4 hours
Flush tube with 30–50 mL sterile water 4-hourly and before/after each drug administration
Gastric residual volume (GRV): check 4-hourly; if GRV >500 mL, withhold feed and review (prokinetic agent — metoclopramide or erythromycin)
Start at low rate (20–30 mL/hr) and titrate up over 24–48 hours to target rate
Change giving set every 24 hours; change bag every 4–8 hours (standard formula) to prevent bacterial growth

PEG Tube Care

Clean PEG site daily with soap and water; dry thoroughly
Rotate external disc/bumper daily (prevents buried bumper syndrome)
Check for granulation tissue, infection, leakage at site
Flush with 30–50 mL water before and after feeds/medications
Never use a syringe <50 mL (pressure can crack the tube)

Refeeding Syndrome

A potentially life-threatening metabolic complication occurring when nutrition is reintroduced to a severely malnourished or starved patient. Caused by a sudden shift of electrolytes intracellularly when carbohydrate-driven insulin release begins.

Hallmark: Severe hypophosphataemia (phosphate <0.5 mmol/L) — can cause cardiac failure, respiratory failure, haemolytic anaemia, rhabdomyolysis, and death.

Risk Factors for Refeeding Syndrome

High risk if any 1 of:

BMI <16 kg/m²
Unintentional weight loss >15% in 3–6 months
Little/no nutritional intake for >10 days
Low pre-feeding electrolytes (K⁺, Mg²⁺, phosphate)
History of alcohol misuse, chemotherapy, antacids, diuretics

Or any 2 of:

BMI <18.5
Weight loss >10% in 3–6 months
Little/no intake >5 days

Prevention Protocol (NICE Guidelines)

Check baseline electrolytes before starting nutrition
Correct electrolyte deficiencies BEFORE starting feed
Start feed at 10 kcal/kg/day maximum (half or less of target calories initially)
Titrate up over 4–7 days
Give thiamine (vitamin B1) 200–300mg daily IV or oral for 10 days before and during refeeding — prevents Wernicke's encephalopathy
Monitor phosphate, K⁺, Mg²⁺ daily for first week
Replace deficits promptly

Electrolyte Changes in Refeeding Syndrome

Electrolyte	Change	Consequence
Phosphate	↓ Critical fall (used for ATP synthesis)	Respiratory muscle failure, cardiac failure, haemolysis
Potassium	↓ Shift into cells	Arrhythmias
Magnesium	↓ Shift into cells	Arrhythmias, neuromuscular symptoms
Glucose	↑ Hyperglycaemia	Osmotic diuresis, fluid shifts
Sodium	↓ Dilutional hyponatraemia	Cerebral oedema if severe

Enteral Feed Monitoring

Parameter	Frequency	Target/Action
pH of aspirate	Before each feed; every 4 hours	≤ 5.5 = safe. >5.5 = do not feed, seek advice
Gastric residual volume (GRV)	Every 4–6 hours	>500 mL = withhold feed; prokinetic; review
Blood glucose	4-hourly during initiation; 6-hourly when stable	4–10 mmol/L (ICU: insulin infusion if consistently >10)
Electrolytes (U&E, Mg, Phos)	Daily initially; then 2–3× week when stable	Replace deficits proactively
Weight	Daily or 3× weekly	Fluid balance; nutritional progress
Bowel function	Daily	Diarrhoea (excess feed rate, osmolality, Clostridioides difficile); constipation (dehydration, opioids)
Nutritional adequacy	Weekly review by dietitian	Ensure energy/protein targets met; adjust formula

Common Problems in Enteral Feeding

Problem	Causes	Management
Diarrhoea	High osmolality, rapid rate, C. diff, antibiotics, sorbitol in liquid meds	Slow rate; check for C. diff; switch formula; review medications
Constipation	Dehydration, opioids, low fibre formula, immobility	Increase water flushes; laxatives; change to high-fibre formula
Tube blockage	Inadequate flushing; crushed tablets; formula precipitation	Warm water flush; enzyme solution (pancreatic enzymes); replace tube
Aspiration	Incorrect position; gastroparesis; flat positioning	HOB 30–45°; check pH position; consider NJ tube
Nausea/vomiting	Gastroparesis; high GRV; rapid increase	Slow rate; prokinetics (metoclopramide); check GRV

MCQ Practice — Enteral Nutrition

Q1. A nurse tests a newly inserted NG tube aspirate with pH indicator paper. The result shows pH 7.0. What should the nurse do?

A) Start the feed — pH 7 is normal for the stomach

B) Withdraw 5 cm and retest

C) Do NOT start feed — pH >5.5 requires CXR to confirm position before feeding

D) Auscultate with 50 mL air to confirm placement

✅ C — Safe feeding requires pH ≤5.5. pH 7.0 could indicate the tube is in the lungs (lung fluid pH ~6–7.4) or oesophagus. Do NOT feed. Request CXR for definitive confirmation. Auscultation (air bubble test) is NOT acceptable as confirmation.

Q2. A patient with no nutritional intake for 14 days and BMI 14 kg/m² is about to start NG feeding. What is the MOST important preventive measure for refeeding syndrome?

A) Start at full target calories immediately to catch up on lost nutrition

B) Give high-dose vitamin C before starting

C) Start feed at 10 kcal/kg/day maximum + thiamine supplementation + check/correct electrolytes first

D) Wait until electrolytes are completely normal before starting any nutrition

✅ C — High refeeding risk: start at ≤10 kcal/kg/day, give thiamine 200–300mg daily, check and replace electrolytes (especially phosphate) BEFORE starting. Titrate up slowly over 4–7 days. Never rush refeeding in malnourished patients.

Q3. What is the MOST important electrolyte to monitor and replace in refeeding syndrome?

A) Sodium

B) Calcium

C) Phosphate

D) Chloride

✅ C — Hypophosphataemia is the hallmark and most dangerous electrolyte derangement in refeeding syndrome. Phosphate is essential for ATP synthesis — severe deficiency causes respiratory failure, cardiac failure, haemolysis, and death. Replace IV phosphate urgently if <0.5 mmol/L.

Q4. A patient's gastric residual volume is 550 mL at a 4-hourly check. What is the appropriate nursing action?

A) Flush the tube and continue feed at the same rate

B) Discard the aspirate and restart the feed

C) Withhold the feed; return aspirate; notify medical team; consider prokinetic agent

D) Aspirate the stomach completely, then restart at double rate to catch up

✅ C — GRV >500 mL = withhold feed and notify medical team. Return the aspirate to avoid electrolyte/fluid losses. A prokinetic (metoclopramide 10mg IV/oral TDS, or erythromycin 250mg oral) may be prescribed. Consider post-pyloric (NJ) tube if gastroparesis persists.

Enteral Nutrition — Nursing Guide