A Gastrostomy tube, commonly called a G-tube, is a flexible device surgically placed through the abdominal wall directly into the stomach. This access route delivers nutrition, fluids, and medication to patients who cannot safely ingest enough by mouth. Confirming the correct position of the tube tip within the stomach is important before any substance is administered. An improperly placed tube can lead to serious complications, such as aspiration of feeding formula into the lungs or injury to the peritoneal cavity. Therefore, a check is performed before each feeding or medication dose to ensure the tube has not moved.
Required Materials and Patient Positioning
Before attempting to check the tube’s position, the necessary supplies must be gathered and the patient prepared. You will need a stethoscope, a 30 to 60 milliliter (mL) syringe with a catheter tip, and non-sterile gloves. The patient should be positioned comfortably, ideally in a semi-Fowler’s position, which involves raising the head of the bed to a 30 to 45-degree angle. This elevated position helps pool gastric contents, making the subsequent steps more effective. If the G-tube is a low-profile device, an extension set will also be needed to connect the syringe for the procedure.
Performing the Air Auscultation Check
The air auscultation check is a tactile and auditory procedure used to predict if the tube is properly seated in the stomach. First, draw about 5 to 10 mL of air into the syringe; this volume is adequate to produce an audible sound within the stomach cavity. The syringe is then attached securely to the G-tube’s feeding port or extension set.
Next, place the diaphragm of the stethoscope directly onto the patient’s abdomen, specifically over the upper left quadrant, the anatomical location of the stomach. This placement is crucial because it allows the best chance of hearing the air enter the gastric space. While listening intently, rapidly inject the air from the syringe into the G-tube with a quick push of the plunger.
The speed of the injection is important because it creates a sudden rush of air required to generate a clear sound. This technique, known as insufflation, aims to create an acoustic signal differentiated from normal intestinal noises. If the procedure is performed too slowly, the air may dissipate without creating a reliable sound. After the air is injected, the syringe can be gently detached and the tube clamped or capped before administering any feed or medication.
Analyzing the Sounds
When the injected air reaches the stomach, the expected sound is a short, rushing, or gurgling noise, sometimes described as a “whoosh” or “growl,” heard clearly through the stethoscope. This sound confirms that the air has moved into the stomach cavity, suggesting the tube’s tip is correctly positioned. The quality and clarity of the sound should be strong and immediate, localizing directly beneath the stethoscope’s diaphragm.
Conversely, a muffled sound, a faint bubble, or no sound at all should immediately raise concerns about the tube’s placement. Sounds heard over the chest cavity or lungs suggest the tube may have accidentally migrated into the respiratory tract, a serious misplacement. If there is any doubt about the sound, or if no positive sound is detected, feeding or medication must be stopped immediately. In such cases, a healthcare professional must be contacted for further guidance and alternative confirmation methods before proceeding.
Critical Limitations of the Stethoscope Method
The air auscultation method, while common, is not considered a definitive confirmation of G-tube placement in a clinical setting. Research has shown that injecting air can produce a sound indistinguishable from the expected stomach gurgle even if the tube is misplaced in the esophagus, small intestine, or bronchial tree. This phenomenon is often referred to as pseudoconfirmatory gurgling, leading to a false sense of security regarding tube position.
Due to this unreliability, many healthcare institutions no longer rely solely on the stethoscope check, especially for initial placement or whenever misplacement is suspected. The primary methods for confirming G-tube position are X-ray imaging or testing the pH of fluid aspirated from the tube. Gastric aspirate typically registers a highly acidic pH of 5.5 or lower, which is a much more reliable indicator of stomach location.
The air auscultation check is used as a quick, supplementary method to monitor the tube’s position, particularly in home care settings where definitive methods are unavailable. Caregivers should always follow the institutional or physician guidelines provided for their patient. If a tube is newly placed, or if there is any sign of patient distress or tube migration, one should never rely on the sound check alone.