What is the procedure for placing a feeding tube in the post-pyloric position?

Techniques for Post-Pyloric Feeding Tube Placement

Endoscopic guidance is the most effective method for placing feeding tubes in the post-pyloric position, with success rates of 90-94% compared to bedside techniques. 1

Bedside Placement Techniques

• Blind bedside placement can be performed using a stiffened tube with a corkscrew motion, achieving an 83% success rate when patients are placed in the right lateral decubitus position 1
• Unweighted feeding tubes have higher success rates for spontaneous small bowel passage compared to weighted tubes 1
• Several assistive devices can improve bedside placement success:
  • Bedside magnet technique - 95% success rate with average placement time of 9.6 minutes 1
  • Electromagnetic transmitter tube with bedside monitor tracking - similar success rates to magnetic technique 1
  • Continuous gastric electromyography - uses ECG leads to confirm pylorus crossing when QRS complex in lead V5 changes polarity 1

Pharmacologic Assistance

• Metoclopramide may be used to facilitate small bowel intubation when the tube does not pass the pylorus with conventional maneuvers 2
• However, evidence for pharmacologic agents to promote tube passage through the pylorus has not reached statistical significance compared to placebo 1

Endoscopic Placement Techniques

• Endoscopy-guided placement can be performed at bedside with or without moderate sedation 1
• Five main endoscopic techniques with high success rates:
  1. Drag-and-pull method: Suture attached to tube end is dragged into position using grasping forceps (oldest technique) 1
  2. Over-the-wire technique: Guide wire placed through endoscope into small intestine, endoscope removed, feeding tube passed over wire (94% success rate) 1
  3. Small-caliber endoscope technique: Small endoscope passed nasally without sedation, guide wire advanced into jejunum, tube passed over wire (>90% success rate) 1
  4. Instrument channel technique: 8-10F feeding tube advanced through 3.7mm instrument channel of therapeutic gastroscope into small bowel 1
  5. Stiffened tube technique: 12F feeding tube stiffened with guide wires is passed blindly while endoscopist watches and assists passage through pylorus if needed 1

Fluoroscopic Placement

• Fluoroscopic guidance shows high success rates (90-93%) with average procedure times of 8.6 minutes for successful placements 3
• Endoscopic placement can be successful after fluoroscopic failure 3
• Electromagnetic-guided placement has comparable success rates to fluoroscopic placement (85% vs 93%) with shorter procedure times (13.4 vs 16.2 minutes) 4

Post-Placement Confirmation and Care

• Radiographic confirmation is essential before initiating feeding, as bedside auscultation can be misleading 1
• pH testing of tube aspirate can help confirm small bowel placement (alkaline pH) 1
• Secure tube properly to prevent dislodgement, which occurs in 40-80% of cases 5
• Consider nasal bridles for high-risk patients, which can reduce accidental removal from 36% to 10% 5

Important Considerations and Pitfalls

• Never apply suction to jejunal tubes as this can damage jejunal mucosa, cause fluid/electrolyte imbalances, and damage the tube 5, 6
• For patients requiring both jejunal feeding and gastric decompression, use a dual-lumen tube or separate tubes for each function 5, 6
• Jejunal feeding requires continuous infusion rather than bolus feeding due to limited jejunal capacity 5
• Monitor and replace electrolytes when any form of gastrointestinal suction is used 5, 6
• Complications of tube placement include tube dislodgement, occlusion (3.5-35% of cases), and mucosal damage 5, 7