Practical interpretation of pH impedance in infants and young children

Multichannel intraluminal impedance with pH (MII pH) is increasingly used in children and adults for investigating gastro-oesophageal reflux disease and associated symptoms, but the indications in paediatrics are expanding. Adults’ normal values are obtained from healthy volunteers; however, paediatric values are mostly extrapolated and supported by expert consensus. Some aspects of performing and interpreting MII pH are peculiar to paediatric practice, such as the reliance on liquid and purée feed in infants and children with neurodisability, proxy symptom reporting from guardians and the increasing use of MII pH in children with enteral feeding tubes. In these settings, manual analysis with careful inspection of meal time is encouraged. General anaesthesia may impact the validity and quality of the study and clinicians should weigh this risk against the benefit of inserting the catheter under anaesthesia. A preprocedure preparatory discussion to identify any potential child and/or procedure-specific challenges is considered a good practice to improve the technical success.