An orogastric (OG) tube is a flexible tube inserted through the mouth and guided down the esophagus into the stomach. It provides access to the stomach for administering medication and nutrition (enteral feeding). It is also used for gastric decompression, which involves draining the stomach of air, fluid, or blood to prevent vomiting or aspiration. The oral route is chosen over the nasal route when nasal passages are compromised, such as in cases of severe facial trauma, a suspected basal skull fracture, or bleeding disorders.
Pre-Procedure Planning and Equipment Preparation
Preparation for placing an orogastric tube begins with assessing the patient’s medical history and reviewing the provider’s orders. Obtaining informed consent and checking for contraindications, such as esophageal varices or recent gastric surgery, must be done before gathering equipment. Supplies needed include:
- The appropriate size of the radio-opaque OG tube
- Water-soluble lubricating jelly
- A 60-milliliter syringe
- pH indicator strips
- A securement device or tape
The patient must be positioned correctly to facilitate the tube’s passage into the esophagus. For conscious adult patients, a semi-Fowler’s position, with the head of the bed elevated 30 to 45 degrees, is recommended. Neonates are placed in a supine position with the head kept in the midline.
Accurate measurement of the required insertion length ensures the tube tip rests securely in the stomach. To estimate this length, measure the distance from the corner of the patient’s mouth to the earlobe, and then continue the measurement down to the tip of the xiphoid process. This length is then marked on the tube with tape or a marker.
Step-by-Step Insertion Technique
The insertion process begins with lubricating the distal tip of the tube, using only water-soluble jelly. The lubricated tube is gently introduced into the patient’s mouth, guiding it over the tongue and toward the back of the throat. If the patient is awake, they should be instructed to flex their neck, bringing their chin toward their chest, which helps close the opening to the trachea.
The patient should be encouraged to swallow, often by giving small sips of water, as this action helps propel the tube past the pharynx and into the esophagus. The tube is then advanced to the pre-measured mark. The clinician must continuously monitor the patient for signs of respiratory distress, which suggests the tube has entered the airway.
Warning signs of tracheal misplacement include:
- Sudden coughing
- Choking
- A change in the patient’s voice
- A drop in the oxygen saturation level
If any of these signs appear, the tube must be immediately withdrawn until the distress resolves, and the insertion attempt should be paused or the tube removed entirely. Placing the tube in sedated or unconscious patients is challenging, as they lack protective reflexes that signal misplacement.
Confirming Correct Tube Placement
Verifying that the tube tip is securely positioned in the stomach is essential for patient safety, as administering substances into a misplaced tube can have severe consequences. The definitive method for confirming initial placement is a chest and abdominal radiograph (X-ray). A radiologist or trained medical officer must review the image to confirm the tube tip is below the diaphragm and coiled within the stomach cavity.
For routine checks or as a primary bedside method, testing the acidity of the aspirated fluid is considered the most reliable technique. A small amount of stomach fluid is drawn back into a syringe, and a drop is placed onto pH indicator paper. Gastric fluid is highly acidic, and a pH reading of 5.5 or lower reliably indicates that the tube is in the stomach.
Certain medications, such as proton pump inhibitors, can elevate the stomach’s pH, which may yield misleading results. Auscultation involves injecting 10 to 30 milliliters of air through the tube while listening over the upper abdomen for a gurgling sound. This method is discouraged by national safety organizations, as air sounds can be transmitted to the stomach even if the tube is mistakenly in the lungs, making it an unreliable indicator of correct placement.
Ongoing Tube Management and Removal
Once correct placement has been confirmed, the orogastric tube must be secured to the patient’s cheek or face using a securement device or tape. It is necessary to mark the tube’s exit site to provide a visual reference point for monitoring tube migration. Tubes can shift due to coughing or patient movement, so the external position must be checked frequently, especially before each use.
Routine flushing is performed to maintain the tube’s patency and prevent blockages, which typically involves instilling a small volume of sterile water. This should be done before and after administering feeds or medications to ensure the lumen remains clear. Care of the skin around the insertion site is important, as the tube can cause pressure injuries or irritation.
When the orogastric tube is no longer needed, it must be removed to prevent aspiration of residual stomach contents. The securement devices are removed. The patient is then instructed to take a deep breath and hold it or exhale forcefully, and the tube is withdrawn smoothly and quickly in one continuous motion.