Verifying placement of small-bore feeding tubes: electromagnetic device images versus abdominal radiographs.

BACKGROUND: Clinicians are unsure if radiography is needed to confirm correct positioning of feeding tubes inserted with assistance from an electromagnetic system. OBJECTIVES: To compare radiographic reports of feeding tube placement with images generated by an electromagnetic feeding tube placement device. METHODS: The medical records of 200 consecutive patients who had feeding tubes inserted with assistance from an electromagnetic feeding tube placement device were reviewed retrospectively. Radiographic reports of tube site were compared with images generated by the device. RESULTS: Radiographic evidence of tube sites was available in 188 cases: 184 tubes were located in portions of the gastrointestinal tract. Ninety of the 188 tubes were situated in the optimal site (distal duodenum or jejunum) radiographically. Images generated by the electromagnetic device were available in 176 cases; of these, 52 tubes appeared to end in the expected left lower quadrant. Tubes shown on radiographs to be in other sites also occasionally appeared to end in the left lower quadrant. Nurses using the device did not recognize 4 of the 188 tubes (2.1%) that were inadvertently placed in the lung. No consistent pattern of quadrant distribution was found for tubes positioned in the stomach or proximal duodenum. CONCLUSIONS: Images generated by the electromagnetic tube placement device provided inconsistent results regarding tube location. A small percentage of seriously malpositioned tubes were not detected by using the electromagnetic device. These findings do not support eliminating radiographs to confirm correct tube placement following use of an electromagnetic tube placement device.

Determining feeding tube location by gastric and intestinal pH values.

BACKGROUND: The purpose of this study was to evaluate a series of pH values of aspirates from feeding tubes to differentiate between gastric and intestinal tube placement. METHODS: One hundred ventilator-supported subjects, with an order for nasoduodenal feeding tube placement were randomly selected. The feeding tube was placed into the stomach, verified by auscultation, and 2 pH measurements were obtained. After the pH measurements were taken, tube location was then verified by fluoroscopy. When the tube was advanced into the small intestine, location was verified by fluoroscopy, and 2 additional pH measurements were obtained. RESULTS: From the selected subjects, both a gastric and intestinal aspirate were obtained from 82 subjects. For the 82 subjects, the mean gastric and intestinal pH values were 4.8 +/- 2.3 and 7.1 +/- 1.0, respectively. For patients receiving acid-suppressing agents, these values were 5.0 +/- 2.3 and 7.2 +/- 1.0, respectively. For subjects not receiving acid-suppressing agents, these pH values were 4.0 +/- 2.5 and 6.7 +/- 1.1, respectively. For all patients, using a pH value of 6.5 as a predictor of feeding tube location, the sensitivity and specificity were 0.66 and 0.90. In addition, when an increase in pH > or = 1.0 was used as a predictor of location change for all patients, the sensitivity was 0.58. CONCLUSIONS: The pH value was a reliable predictor of nasoduodenal tube placement. However, radiographic confirmation of location could not be excluded because of the low sensitivity using pH measurements alone. An increase of > or = 1.0 in gastric vs intestinal pH specimens could be useful to determine use of radiography confirmation of tube placement.