What are the guidelines for nasogastric tube feeding in patients with various ages, weights, and medical conditions?

Nasogastric Tube Feeding Guidelines

Indications and Patient Selection

Nasogastric tube feeding should be initiated in patients who cannot meet nutritional requirements orally and are expected to require enteral support for less than 4-6 weeks. 1, 2

Primary Indications:

• Dysphagia with aspiration risk (most common indication in elderly patients) 1, 3
• Inadequate oral intake with malnutrition when oral intake is below 50% of estimated requirements for more than 3 days 1
• Neurologic disorders including stroke patients with swallowing difficulties 1
• Comatose states or impaired consciousness 3
• Oropharyngeal or upper GI malignancies preventing adequate oral intake 3

Route Selection Algorithm:

• Use nasogastric route as first-line for short-term feeding (<4-6 weeks) 1, 2
• Switch to orogastric route if patient has maxillofacial trauma, nasal obstruction, coagulopathy, or recent nasal surgery 4
• Consider early PEG placement (within 1-2 weeks) if prolonged feeding >4-6 weeks is anticipated 1, 2

Tube Selection and Placement

Fine bore tubes (5-8 French gauge) must be used for feeding to minimize nasal trauma and pressure injuries. 1, 2

Placement Technique:

• Placement should be performed by trained, technically experienced staff to minimize misplacement risk 1
• Small diameter tubes (8 French) are specifically recommended for stroke patients to reduce internal pressure sores 1
• Larger diameter tubes should only be used when gastric decompression is necessary 1

Position Verification (Critical Safety Step):

• pH testing must be performed before every use with pH ≤5.0 indicating gastric position 1, 2, 5
• Radiographic confirmation is required before initiating feeding in all cases 4, 5
• Auscultation alone is unreliable and should not be used as the sole verification method 4, 5
• Alternative verification: aspiration of gastric content or pH measurement 1, 2

Feed Administration Protocol

Initial Feed Regimen:

• Starter regimens with reduced volumes are unnecessary in patients with reasonable recent nutritional intake 1
• Do not dilute feeds as this risks infection and osmolality problems 1
• Standard dosing: 30 ml/kg/day of 1 kcal/ml feed is appropriate for most patients, but may be excessive in undernourished or metabolically unstable patients 1

Feeding Position and Timing:

• Patients must be positioned at 30° or greater during feeding and maintained upright for 30 minutes post-feeding to minimize aspiration risk 1
• Gastric route permits hypertonic feeds, higher feeding rates, and bolus feeding compared to jejunal route 1
• Monitor gastric residuals: if 4-hour aspirate exceeds 200 ml, review the feeding regimen 1

Medication Administration:

• Flush tubes with water before and after every feed or medication to prevent blockage 1, 2
• Use elixirs or suspensions rather than syrups after establishing compatibility 1, 2
• Avoid hyperosmolar drugs, crushed tablets, potassium, iron supplements, and sucralfate as these cause tube blockage 1, 2

Duration and Tube Replacement

Long-term NG tubes should be changed every 4-6 weeks, alternating nostrils. 1, 2

Transition to Long-Term Access:

• Consider gastrostomy or jejunostomy at 4-6 weeks if continued feeding is needed 1, 2
• Some evidence supports considering PEG at 14 days in appropriate candidates 1
• The 4-week timeframe is somewhat arbitrary and mainly aims to prevent premature gastrostomy 1, 2
• Well-tolerated NG tubes may be used beyond 4-6 weeks in selected cases 1, 2

Special Consideration for Stroke Patients:

• In mechanically ventilated stroke patients requiring >14 days of feeding, early PEG (within 1 week) is preferred due to lower ventilation-related pneumonia rates 1
• NG tubes do not impair swallowing therapy and dysphagia rehabilitation should start immediately regardless of tube presence 1
• If worsening dysphagia occurs with NG tube, check for pharyngeal coiling and consider reinsertion or endoscopic evaluation 1

Monitoring and Complication Prevention

Critical Metabolic Monitoring:

Close monitoring of fluid, glucose, sodium, potassium, magnesium, calcium, and phosphate is essential in the first few days to prevent refeeding syndrome 1

Common Complications and Management:

• Tube dislodgement (occurs in 48.5% of cases): ensure adequate skin fixation; consider nasal loop if frequent dislodgement occurs despite proper fixation 1, 2, 6
• Tube blockage (12.5% incidence): flush with warm water first, then alkaline pancreatic enzyme solution if needed 1, 2, 6
• Aspiration risk: use acid suppression for oesophagitis symptoms, though this does not prevent aspiration pneumonia 1
• GI intolerance (diarrhea in 30-60% of patients): review feed osmolality and administration rate 1, 6

Special Precautions:

• Avoid NG tube insertion for 3 days after acute variceal bleeding, and only use fine bore tubes thereafter 1
• In patients with coagulopathy, prefer orogastric route to avoid epistaxis 4
• Daily reassessment of tube necessity with removal as early as possible 2, 7

Oral Intake During Tube Feeding

Tube-fed patients should be encouraged to maintain oral intake as far as safely possible. 1

Rationale and Implementation:

• Oral intake provides sensory input, swallowing training, improved quality of life, and enhanced oropharyngeal cleaning 1
• Texture-modified diets should be prescribed only after clinical swallow exam or instrumental assessment (VFSS or FEES) 1
• Thickened liquids reduce aspiration risk but may increase post-swallow residues and risk insufficient fluid intake 1
• Monitor liquid intake closely when using thickened liquids due to high risk of inadequate oral intake 1

Discharge Planning

Before discharge, ensure comprehensive coordination with community carers and confirm feed/equipment availability. 1

Required Discharge Elements:

• Full training provided on pump use, infection control, feeding stoma care 1
• Written protocols followed to ensure smooth discharge 1
• All community carers informed: district nurses, community dietitians, GPs 1
• Patient/carer receives list of expert contacts and instructions on feed type, volume, duration, and tube fixation 2

Ethical Considerations

ETF must never be started without considering all ethical issues and must be in the patient's best interests. 1

• In stroke patients with unfavorable prognosis, semi-invasive NG feeding may be more appropriate initially than PEG 1
• Daily reconsideration of artificial nutrition indication is required, with thorough reassessment before transfer to nursing home or palliative care 1
• Tube feeding may be discontinued when medical indication no longer exists, particularly in palliative situations 1
• PEG insertion should not be a criterion for rehabilitation ward or nursing home admission if NG tube is well tolerated 1