nasogastric tube

An NG tube is passed through the nasal cavity, down the esophagus, into the stomach. Uses include: (1) Gastric decompression—removing air/fluid in bowel obstruction, postoperative ileus, or before certain surgeries; (2) Diagnostic/therapeutic lavage—assessing upper GI bleeding or removing toxins in overdose; (3) Enteral feeding/medication administration in patients unable to swallow safely (e.g., stroke, intubated patients) for short-term use (<4-6 weeks; longer-term requires PEG tube); (4) Administration of contrast or medications. Placement confirmation is critical—auscultation of insufflated air ('whoosh test') is unreliable; gold standard is chest X-ray showing the tube crossing the diaphragm and terminating in the stomach, or pH testing of aspirate (<5.5 suggests gastric placement). Malposition into the trachea/lungs is a serious complication, especially in patients with altered mental status or absent gag reflex, risking pneumothorax or aspiration pneumonia. Contraindications include severe facial trauma/basilar skull fracture (risk of intracranial placement—use orogastric tube instead), esophageal varices or strictures (relative), and recent nasal surgery. Complications include nasal/esophageal irritation or necrosis, sinusitis, epistaxis, aspiration, and electrolyte imbalances from prolonged suction (metabolic alkalosis due to loss of gastric HCl). NG tube output and character (e.g., bilious, bloody, feculent) can provide diagnostic clues in surgical patients (e.g., high-grade obstruction, upper GI bleed).