Standard protocol devised by the Japanese Pediatric Impedance Working Group for combined multichannel intraluminal impedance-pH measurements in children

Abstract

Multichannel intraluminal impedance-pH measurements (MII-pH) are useful for evaluating acid and non-acid gastroesophageal reflux (GER). However, the use of MIH-pH is not yet established in Japan. The Japanese Pediatric Impedance Working Group (Japanese-PIG) convened to devise a standard protocol for MII-pH in Japanese children. The expert members of the Japanese-PIG collected data on pediatric MII-pH from the relevant literature in English, including the standard protocol of MII-pH presented by the European PIG, and the insights of international experts. The resultant consensus was included in the contents of the standard protocol of MII-pH. The standard protocol included standardization of the indication, methodology, and interpretation of MII-pH in Japanese children. The criteria for abnormal GER by MII-pH were defined using the Reflux Index and number of total reflux episodes independently in children aged < 1 year and those aged ≥ 1 year. Moreover, a significant relationship between GER and symptoms was identified using the symptom index and symptom association probability approach. We conclude that the current version of the protocol for MII-pH is tentative because it is not based on data from Japanese children. Further studies are needed to render this protocol clinically beneficial and expand its use in Japan.

Keywords: Children; Gastroesophageal reflux; Multichannel intraluminal impedance-pH measurements; Standard protocol.

Fig. 1

Types of catheters used for MII-pH measurements in pediatric and adult patients. a Infant catheter (ZIN-BS-51): the impedance channels are distributed at 1.5-cm intervals and the pH sensor is positioned at the center of the most distal interval of the impedance channels. b, c Pediatric and adult catheters: the impedance channels are distributed at 2-cm intervals, and the pH sensor is positioned at the center of the most distal (CZPN-BG-57, ZPN-BG-07) or the second most distal interval of the impedance channels (ZAN-BG-44). The layouts of the sensors on CZPN-BG-57 and ZPN-BG-07 are identical, except for the position of the pH sensor. The distance between the 2 pH sensors in CZPN-BG-57 and ZPN-BG-07 is 7 cm and 12 cm, respectively