RESUMO
BACKGROUND: Multichannel intraluminal impedance combined with pH (MII-pH) is the gold standard test for diagnosing gastro-esophageal reflux disease (GERD). It provides an opportunity to study acid and non-acid GOR and temporal association between symptoms and reflux. Accurate catheter placement is essential to prevent erroneous recording of reflux events. The aims of our study were to assess the accuracy of our devised method in predicting the catheter length for MII-pH in children (Great Ormond Street Hospital (GOSH) Table) and to compare the results with Strobel and Monreau methods. METHODS: Retrospective review of all records of infants and children who underwent MII-pH studies between January to October 2014. Desired catheter position was calculated using Strobel, Monreau and GOSH formulas and compared to X ray position. KEY RESULTS: One hundred and forty-four children were included; mean age was 5.1 (±4.5) years, 73 males and 71 females. In the whole group, the correlation between desired catheter position and GOSH Table was 0.95, for Strobel was 0.84, and Monreau was 0.85. In the first group (age <3 years), the correlation was: GOSH Table 0.91, Strobel 0.56, and Monreau 0.6; in the second group (3-10 years): GOSH Table 0.78, Strobel 0.82, and Monreau 0.82; the third group (>10 years): GOSH 0.81, Strobel 0.43, and Monreau 0.43. CONCLUSIONS & INFERENCES: GOSH Table is an accurate method to estimate the insertion length of MII-pH catheters from nares to a point of approximately two vertebral bodies above the diaphragm in children. Although radiography is required to confirm final catheter position, using GOSH Table will reduce the need for repeated catheter manipulation after initial insertion and will reduce the use of a mathematically complicated formulae.