Bulb Syringe or Colorimetric Capnography to Confirm Naso-Orogastric Tube Placement

Options for confirming naso-orogastric (NG) tube placement include chest radiography (the traditional standard), litmus or pH paper, ultrasound imaging, bulb syringe aspiration, and capnography. Investigators evaluated a self-inflating bulb syringe and a colorimetric CO₂ indicator in 202 critically ill patients, 60% of whom were mechanically ventilated.

The NG tube was inserted to a depth of 30 cm, then an attempt was made to aspirate air with a self-inflating bulb syringe; if the syringe did not inflate within 5 seconds, the tube was deemed to be in the esophagus. A colorimetric CO₂ indicator was then attached to the NG tube and the result was recorded (presumably external ventilation was provided); absence of color change indicated esophag…