Is nasogastric (NG) tube placement recommended for patients with anorexia nervosa?

NG Tube Placement in Anorexia Nervosa

NG tube feeding should be placed in patients with anorexia nervosa when severe malnutrition threatens life or when oral refeeding alone is insufficient, as it can be a lifesaving intervention that produces superior weight gain compared to oral nutrition alone. 1, 2

Legal and Ethical Framework

Under specified circumstances, it is legal to enforce nutritional treatment for an unwilling patient with anorexia nervosa, as severe malnourishment can render a patient incompetent to make rational decisions regarding their care. 1 The doctor undertaking care is responsible for decisions about tube feeding in incompetent adults, with a duty to act in the patient's best interest. 1

Clinical Indications for NG Tube Placement

Place an NG tube when:

• Severe malnutrition threatens life and oral intake is inadequate 1, 2
• The patient cannot achieve sufficient caloric intake orally despite intensive intervention 2, 3
• Medical stabilization requires more rapid nutritional rehabilitation than oral feeding can provide 2, 4

Expected Outcomes and Efficacy

Weight gain benefits are substantial:

• Patients receiving NG tube feeding gain 1 kg/week compared to 0.77 kg/week with oral refeeding alone when tube feeding is used for at least half the length of stay 2
• When controlling for severity of illness and caloric intake differences, tube-fed patients gain significantly more weight per treatment week 2
• Recent systematic review confirms NG tube feeding results in similar or higher weight gain than oral nutrition 3

Psychological outcomes:

• Global eating disorder parameters improve with nutritional rehabilitation via NG tube 3
• However, weight and shape concerns may not improve during the tube feeding period 3
• Recovery from psychological aspects of anorexia shows no difference between tube-fed and orally-fed patients 2
• Patient satisfaction with treatment is comparable between groups 2

Technical Specifications

Use fine bore 5-8 French gauge NG tubes for feeding, as large bore PVC tubes irritate the nose and esophagus and increase risks of gastric reflux and aspiration. 1, 5

Duration considerations:

• NG tubes are appropriate for feeding periods up to 4-6 weeks 1, 6
• For anticipated feeding beyond 4-6 weeks, consider percutaneous gastrostomy placement 1, 6
• However, in well-tolerated cases, NG tubes can be maintained longer than 4-6 weeks in selected patients 6

Implementation Under Restraint

Specialized dietetic guidelines exist for NG tube feeding under restraint in anorexia nervosa, developed through modified Delphi consensus process by specialist mental health dietitians. 7 These guidelines detail the lawful process, rate, and volume of feed administration. 7

Key considerations for feeding under restraint:

• This intervention can be lifesaving in severe cases 7, 4
• All three cases in a recent case series tolerated feeds well and were discharged eating solid food 4
• Approximately 30% of patients may be nonadherent as evidenced by tube manipulation 8
• Additional psychological support may be needed to mitigate potential trauma related to feeding under restraint 3

Medical Safety

Medical complications are comparable between NG tube feeding and oral refeeding when appropriate monitoring is in place. 2 Refeeding syndrome parameters are similar between NG tube and oral nutrition, with some indication that prophylactic phosphate supports mitigation of hypophosphataemia. 3

Critical Pitfalls to Avoid

• Do not delay nutritional intervention in severely malnourished patients awaiting specialist treatment—recent high-profile deaths have occurred when patients received no or minimal nutrition while awaiting care 4
• Do not underestimate patient capacity to make decisions simply to achieve what the clinician believes is in the patient's best interest 1
• Do not use large bore tubes for feeding—they increase complications 1, 5
• Monitor for tube manipulation—nearly 30% of patients may attempt to interfere with the tube 8

Transition Planning

Evidence gaps exist regarding transition from NG tube to oral intake, indicating need for additional support strategies during this phase. 3 Patients may attach specific meanings to the tube that require psychological intervention during transition. 3