Standardizing and optimizing sensor position for double-probe pH-metry in children with reflux-associated pulmonary disorders

Pathological gastroesophageal reflux activity causes numerous chronic lung diseases. However, proving this correlation poses a diagnostic challenge. Initially, classic pH-metry was employed as the standard diagnostic tool, but in the past few years the 24-h double-probe method for monitoring pH to clarify the relationship between reflux and lung disease has proved to be superior and has become an established procedure. Some working groups have developed standard values for the proximal measuring point. As yet no binding agreement exists on standards for measurement such as the precise topographical position of the sensor so that data are only conditionally comparable since the position of the electrodes significantly influences the resultant measurements. Our newly calculated positioning formulae SL(d) for the distal and SL(p) for the proximal measuring point serve to optimize positioning the sensor and enable working groups to establish comprehensive standardized methods so that the results are comparable and can be interpreted based on universally valid reference values.