An orogastric (OG) tube is a medical device inserted through the mouth, guided past the pharynx and esophagus, and positioned with its tip resting inside the stomach. This placement allows healthcare providers to bypass the normal swallowing process. The tube is primarily used to deliver liquid nutrition and necessary medications directly into the stomach, or for gastric decompression, which involves removing excess air or fluid. Accurately determining the necessary length of the tube before insertion is a safety measure that prevents misplaced delivery of substances or injury to the patient.
Preparing for Measurement
Before measuring the tube, the proper equipment must be collected. This includes the correct size OG tube, a non-allergenic securing device such as medical tape, a clean pair of non-sterile gloves, and an indelible marker or pen to mark the tube’s length.
The patient needs to be positioned correctly to ensure the measurement reflects the true anatomical distance from the mouth to the stomach. The person should typically be lying flat on their back (supine), with their head resting in the midline. In some cases, the head may be slightly elevated, but maintaining a neutral neck alignment prevents distortion of the internal pathway.
Executing the Standard Measurement Technique
The anatomical landmark technique is used to estimate the depth of insertion for an orogastric tube. This technique aims to approximate the length of the pathway from the oral cavity, through the esophagus, and into the gastric body. The measurement begins at the corner of the patient’s mouth.
The tube is unrolled and held taut but not stretched. The distal tip is placed at the corner of the mouth and extended backward along the side of the face to the tip of the earlobe. This initial segment estimates the distance through the pharynx and upper esophagus.
The measurement continues from the earlobe, extending down the chest to the xiphoid process. The xiphoid process is the small, cartilaginous tip at the lower end of the sternum, or breastbone. This second segment approximates the length of the mid-to-lower esophagus.
Once this final anatomical point is reached, the tube must be marked clearly and permanently at the point corresponding to the xiphoid process. A small piece of non-allergenic tape or a line from an indelible marker is placed on the tube at this location. This mark serves as a reference point during and after insertion to confirm that the correct, pre-measured length has been successfully advanced into the patient.
Confirming Measurement Accuracy
A small error in length can lead to significant complications. If the measured length is too short, the tube’s tip will stop in the esophagus, potentially above the lower esophageal sphincter. This misplacement creates a risk that any fluid delivered through the tube could be regurgitated and then aspirated into the patient’s trachea and lungs.
Conversely, if the determined length is too long, the tube may advance too far into the gastrointestinal tract. An excessively long tube can coil up inside the stomach, causing discomfort and potentially leading to a blockage. It can also migrate past the stomach and into the duodenum, which is the first part of the small intestine. Placement in the duodenum is particularly problematic when delivering bolus feedings, as it can cause a rapid shift of fluid into the intestine.
After the orogastric tube has been inserted, the final, immediate confirmation of accurate length placement involves checking the mark made during the measurement process. The indelible mark on the tube must be visible at the point where the tube exits the patient’s mouth. If the mark is visible, it confirms that the intended length has entered the body, indicating the tube’s tip is likely positioned within the stomach as planned.