TABLE 1.
Advantages and disadvantages of nasogastric tube placement verification.
| Tip position verification | Specific method | Advantages | Disadvantages |
|---|---|---|---|
| The ‘whooshing test’ or air insufflation method | Rapidly injected air down the NGT while auscultating ‘whooshing sound’ over the epigastrium | Simple, convenient and widely used 10 , 11 |
This method remains controversial and is no longer recommended. Gas injected into the lungs or trachea may produce a similar sound. The lack of specificity can lead to confusion. 12 |
| pH testing | To confirm the location of the NGT, pH testing of its aspirate was performed as a first‐line method. A pH of ≤5.5 indicates that the NGT is correctly placed in the stomach, while a pH of ≥6 may indicate placement in the gut or respiratory tract. 13 | Fast and convenient |
The pH of the gastric fluid aspirate can increase to 6 or higher by antacids and acid inhibitors. Colorimetric test strips require subjective interpretation, posing challenges for accurate readings. No aspirate can be obtained. 14 |
| X‐ray | X‐ray examination 15 | X‐ray is the gold standard for distinguishing between gastric and pulmonary placement of an NGT. 15 | Misreading the X‐ray. Excessive radiation. X‐rays are not readily available in nursing homes, rehabilitation centres and home care settings 16 as well as in the ICU. 17 |
| End‐tidal carbon dioxide monitoring | Connect the instrument directly to the end of the NGT tube. If the pressure reading is ≥15 mmHg, the NGT may have entered the airway. Conversely, a pressure reading of ≥10 mmHg indicates that the NGT may not be in the airway. 18 | The presence of NGT in the stomach or airway was confirmed using quantifiable indicators. | Detecting instruments in ordinary wards can be challenging. Only NGT placed in the airway can be detected. 19 , 20 |
| Bedside abdominal ultrasound | NGT was detected in the upper abdominal gastric region using an ultrasound probe. 16 | Ultrasound can directly and clearly visualize the presence or absence of an NGT in the stomach. This technique is straightforward for ICU medical staff to understand. 21 , 22 | Identifying the entire tube from the nose to the gastrointestinal tract is challenging. Two operators are needed. Technical difficulties arise in obese patients, patients who undergo laparotomy and patients with an open abdomen, abdominal wall defect or drainage. 23 , 24 |
| A single‐use, small‐bore nasogastric feeding tube with a miniature camera embedded in the distal end | An indwelling NGT directly placed using camera navigation 16 | Clear images of the stomach were obtained, which allowed for direct observation and prevented malposition. 25 , 26 | Trained clinicians are required to accurately identify the anatomical landmarks of the oesophagus, trachea or stomach. Additionally, they must consider the potential discomfort from passing the camera tip through the patient's nose and the high cost of the device. 24 , 27 |
| Electromagnetic‐guided postpyloric feeding tube placement | The feeding tube's electromagnetic emitter at the tip was used to monitor the tube's trajectory during placement through the receiver device and display placed outside the body. The position of the tip of the feeding tube was determined in real time. 28 | Lung misplacement or gastric twisting can be easily detected by the system, allowing the operator to make timely adjustments and reduce the risk of X‐ray radiation. 28 | Proficient clinicians are required. 29 |
Abbreviations: ICU, intensive care unit; NGT, nasogastric tube.