A nasogastric tube (NG tube) is a flexible, thin tube designed for temporary medical use, extending from the nose, down the throat and esophagus, and into the stomach. It provides nutrition and administers medication directly into the gastrointestinal tract when a person cannot safely eat or swallow. The tube is also used for gastric decompression, which involves removing air or stomach contents to relieve pressure or suction out poisons. Maintaining correct placement within the stomach is a priority, as movement can compromise its function or endanger the patient’s health.
Safety relies on the tube’s tip resting in the stomach. Misplacement can occur during insertion or if the tube shifts, making recognition of incorrect placement vital for preventing complications.
Urgent Signs of Lung Misplacement
The most serious risk is inadvertent placement into the respiratory tract (trachea or lungs). If the tube enters the respiratory tract, administering formula or medication can lead to aspiration, potentially causing severe pneumonia, lung abscess, or a collapsed lung (pneumothorax).
A sudden, persistent, and forceful coughing or gagging reflex upon insertion or during use warns that the tube may be irritating the airway. This acute reaction is often accompanied by signs of respiratory distress, such as shortness of breath (dyspnea) or a rapid breathing rate (tachypnea). The patient may exhibit noisy, gurgling breath sounds, indicating interference with normal airflow.
Changes in skin color indicate compromised oxygen exchange. A bluish tint to the skin, lips, or nail beds, known as cyanosis, signals low oxygen saturation in the blood. Conscious patients might exhibit hoarseness or an inability to vocalize normally because the tube is obstructing the vocal cords.
In a clinical setting, an immediate drop in oxygen saturation levels, measured by a pulse oximeter, confirms respiratory compromise. While listening for bubbling over the stomach is unreliable, bubbling or gurgling sounds heard over the lungs strongly suggest tracheal misplacement. Any acute respiratory symptom signals a medical emergency and requires immediate attention.
Indicators of Tube Migration
An NG tube can also migrate within the gastrointestinal system or move externally, compromising its function. A common sign of internal migration is a functional problem, such as experiencing resistance when attempting to push feed or medication through the tube.
Inability to aspirate stomach contents (gastric residual) indicates the tube tip has shifted out of the stomach. The tube may have coiled back up into the esophagus or moved too far forward past the stomach and into the small intestine. Conversely, a new onset of discomfort, including nausea, vomiting, or abdominal pain and distention, may suggest the tube has coiled within the stomach or is causing an obstruction.
Externally, the most straightforward sign of migration is a significant change in the tube’s length visible outside the nose. The insertion length is marked and recorded upon placement; if this external measurement changes (lengthening or shortening), the tube has moved internally and its position must be re-verified. Increased drooling or a patient complaining of tasting formula or stomach contents can indicate the tube has migrated proximally.
Immediate Steps to Take
If signs of misplacement or migration are observed, immediately stop all flow of formula, water, or medication through the tube, as administering anything into a misplaced tube can have severe consequences. The tube should be secured at the nose to prevent further movement, but do not attempt to push or pull the tube in or out.
Contact the healthcare provider, nurse, or emergency services without delay, depending on symptom severity. Respiratory distress, such as cyanosis or severe difficulty breathing, warrants an immediate emergency call. Signs of migration or functional issues require prompt communication with the medical team. While waiting for assistance, monitor and record specific symptoms, such as the patient’s breathing rate, any change in skin color, and the exact external length measurement of the tube.
A healthcare professional must confirm the tube’s location before it can be used again. Confirmation is typically achieved by testing the pH of the aspirated fluid; a pH of 5.5 or lower confirms the tube is in the acidic environment of the stomach. If the aspirate cannot be obtained or the pH is inconclusive, a chest X-ray will be ordered, as radiological imaging is the gold standard for visually verifying the tube’s tip is correctly positioned below the diaphragm.