Impedance study

A small tube with a thin wire inside and a probe at the end is passed down your child's nose, down the back of the throat and left at the top of the stomach. An X Ray is taken to confirm the tube is in the correct place, and that it has not gone down the trachea instead of the oesophagus. It is uncomfortable having the tube passed and it is often done under anaesthetic in conjunction with an endoscopic scope to check the state of the oesophagus and to take biopsies to ascertain whether there is any cell level change due to reflux. Once correctly placed the tube is taped to the child's cheek, the other end is attached to a small black box and you are free to go and return in 24 hours - although some hospitals keep you inpatient overnight. There are several buttons on the box and you have to press the correct ones to "tell" the box and record when you are lying/standing or sitting, eating or drinking and then finished eating and drinking. Sometimes you are asked to make notes about behaviours (coughing, choking etc) and sometimes there is a button to press for these. On one occasion my daughter's hands were gently bound for the first two hours because she ripped the probe tube out first time. It is not pleasant but is immediately forgotten about once the tube is removed the next day. An impedance test measures alkaline as well as acidic reflux and also pressure changes in the oesophagus. It is now the gold standard for reflux testing. You can have a normal ph result, often with a high baseline ph reading and an abnormal pressure change result. This is common in allergic reflux, especially EGID.