This replication study examined the extent to which feeding-tube aspirates (pH and enzyme content) are effective predictors of feeding tube location in acutely ill children.
A convenience sample of 56 children was obtained at a metropolitan children’s hospital. Approximately 2.5 ml of fluid were withdrawn from children’s nasogastric, orogastric, or nasointestinal tubes within 30 minutes of radiographic examination. Fluid was tested for pH and enzymes, and results were compared with radiographic results of tube location.
Mean gastric pH was significantly lower than mean intestinal pH. Mean fasting gastric pepsin level was significantly higher than mean fasting intestinal pepsin level. Usual intestinal constituent, trypsin, was significantly higher in the small bowel than in the stomach. Mean fasting trypsin level was 70 μg/ml in the intestine, and only 10 μg/ml in the gastric site. Predictive positive value was >90% for all tests; predictive negative value was < 65%. Colors of the gastric aspirates were distinctly different from those observed in intestinal aspirates.
Methods of aspirating fluid from feeding tubes and testing visually or assaying for aspirate characteristics were found to be adaptable from adults to children. The clinical implications of being able to use a test as simple as pH of feeding aspirates means that nurses can easily test these aspirates in any clinical setting using reliable pH test strips, similar to what was done in this study. These data add evidence that suggests indicators of tube location effective in adults are also effective in children.
What is the best way to determine correct placement of a feeding tube in an infant or a child? This nurse can tell you the answer.
Nina Westhus is an Assistant Professor, Saint Louis University School of Nursing, Saint Louis, MO. She can be reached via e-mail at email@example.com.