Application of Manometry to Verify Nasogastric Tube Placement in Intubated, Mechanically Ventilated Patients: A Prospective Descriptive Study

Abstract

Objective: Confirmation of nasogastric tube (NGT) placement is sometimes difficult in clinical practice. Hence, the purpose of this study is to validate the accuracy of manometry for intragastric NGT placement confirmation in intubated, mechanically ventilated patients. Methods: A total of 100 adult patients who underwent elective open abdominal surgery and required gastric decompression were enrolled in this prospective descriptive study at a university-affiliated teaching hospital. The position of NGTs was verified by two blinded investigators, of whom the first investigator used the manometric technique and the second investigator used a fiberscope for verification. The manometric technique involved using a cuff pressure manometer to verify NGT placement. The primary measurements, sensitivity and specificity of the manometric technique in verifying NGT placement were calculated according to the standard findings of fiberoptic inspection. Results: In 81 of 100 NGT placements, intragastric placement was interpreted by the manometric technique. All of these 81 placements were confirmed by fiberoptic inspection. The manometric technique was therefore 100% sensitive. The 19 placements interpreted as extragastric placement by the manometric technique were confirmed by fiberscopy as being in the oral cavity, trachea, or esophagus, indicating 100% specificity. These results revealed 100% accuracy of the manometric technique in verifying intragastric placement of NGTs in intubated, mechanically ventilated patients. Conclusions: The manometric technique is a convenient, inexpensive, and highly accurate method for verifying NGT placement. This technique may be used to verify correct NGT placement for the purpose of gastric decompression and in those environments where a roentgenogram is not available.