What are the potential complications of nasogastric (NG) tube placement, particularly in patients with a history of nasal or esophageal conditions?

Complications of Nasogastric Tube Placement

Nasogastric tube placement carries significant risks including life-threatening pulmonary misplacement, intracranial insertion, and aspiration pneumonia, with approximately 25% of tubes becoming dislodged and requiring reinsertion. 1

Insertion-Related Complications

Life-Threatening Misplacements

• Accidental bronchial insertion is relatively common in patients with reduced consciousness or impaired gag/swallowing reflexes, and feeding into the lungs or pleural space can be fatal. 1
• Endotracheal tubes in ventilated patients do NOT prevent bronchial insertion, contrary to common assumptions. 1
• Tension pneumothorax and massive subcutaneous emphysema can occur from inadvertent pulmonary placement. 2
• Intracranial insertion of feeding tubes has been reported, particularly in patients with skull base fractures or facial trauma. 1

Gastrointestinal Perforations

• Perforation of pharyngeal or esophageal pouches can occur during insertion. 1
• Perforation risk increases when guidewires are reinserted and accidentally exit via side ports. 1
• Polyvinyl or polypropylene tubes without guidewires carry higher perforation risk. 1
• Oesophagogastric submucosal tunneling can occur, leading to gastrointestinal bleeding. 3

Hemorrhagic Complications

• NG tube insertion should be avoided for three days after acute variceal bleeding. 1
• Epistaxis can occur during insertion, though less common with fine bore tubes. 4

Post-Insertion Mechanical Complications

Tube Displacement

• Approximately 25% of nasogastric tubes fall out or are pulled out by patients soon after insertion. 1, 5
• Fine bore tubes are especially prone to displacement by coughing or vomiting. 1, 5
• Tube obstruction is more frequent in nasal tubes than PEG tubes, particularly in patients taking multiple medications. 5

Local Nasopharyngeal Complications

Acute Discomfort

• Nasopharyngeal discomfort occurs frequently in patients with nasoenteral tubes. 1
• Many patients suffer sore mouths, thirst, swallowing difficulties, and hoarseness. 1

Chronic Local Damage

• Local pressure effects cause nasal erosions, abscess formation, sinusitis, and otitis media, particularly with prolonged use beyond 3-4 weeks. 1, 5
• Swapping the tube to the other nostril when fine bore tubes need replacement (every 4-6 weeks) helps prevent these problems. 1, 5

Esophageal Complications

Short-Term Damage

• Short-term esophageal damage includes esophagitis and ulceration from local abrasion and gastro-esophageal reflux, though rare with fine bore tubes. 1, 5

Long-Term Damage

• Longer-term damage includes significant esophageal stricturing after months of continuous use. 1, 5
• Large stiff tubes can cause tracheoesophageal fistulation, especially when an endotracheal tube is present. 1

Respiratory Complications

Aspiration Risk

• The incidence of aspiration reaches 20% in patients unable to protect their airways. 5
• Patients with nasogastric tubes have approximately 9 times higher risk of aspiration than those without tubes. 6
• Ventilator-associated pneumonia occurs more frequently with nasogastric tubes compared to PEG tubes in mechanically ventilated patients. 1

Gastrointestinal Complications

• Constipation, diarrhea, vomiting, and abdominal pain may be caused by the underlying disease, drug treatment, enteral formula, or administration method. 5

Metabolic Complications

• Hyperglycemia, electrolyte disturbances, micronutrient deficiency, and refeeding syndrome can occur. 5

Critical Risk Factors for Complications

Patient-Specific Factors

• Reduced level of consciousness increases risk of bronchial insertion. 1
• Impaired gag or swallowing reflexes increase misplacement risk. 1
• History of esophageal varices increases bleeding and aspiration risk. 1
• Pre-existing gastrointestinal disease increases risk of perforation and bleeding. 3

Tube-Specific Factors

• Larger diameter tubes (>8 French) cause more local pressure damage and increase stricture risk. 1
• Use of tubes beyond 3-4 weeks dramatically increases sinusitis and stricture risk. 5

Prevention Strategies

Placement Verification

• Radiography remains the gold standard for confirming correct tube position before feeding. 1, 5
• Between 2005 and 2010,45% of all cases of harm from misplaced nasogastric tubes were due to misinterpreted radiographs. 1
• pH testing of gastric aspirate (should be <5.5) provides additional verification. 1, 5
• Auscultation for "whooshing sound" is unreliable and no longer recommended. 3

Tube Selection and Management

• Use small diameter nasogastric feeding tubes (8 French) to minimize pressure-related complications. 1
• Tubes with greater diameter should only be placed if gastric decompression is necessary. 1
• Replace nasogastric tubes with PEG tubes after 2 months or when feeding needs exceed 4-6 weeks to prevent serious long-term complications. 5, 6

Procedural Safeguards

• Placement should be performed by trained and technically experienced medical staff. 1
• Note any resistance during blind insertion, as this may indicate submucosal tunneling or other complications. 3
• Never reinsert guidewires after initial placement to avoid perforation through side ports. 1