Summary
Simpler alternatives to the use of an intravenous reference electrode for potential
difference measurement in the gastrointestinal tract were considered. Lancet puncture
of the forearm skin, and intradermal injection of 0.1 ml 154 mmol/l NaCl into the
forearm were shown to effectively abolish the skin-blood potential difference, thereby
rendering such sites suitable for reference electrode placement. Another acceptable
method was to use an intravenous “butterfly” cannula filled with heparinized saline.
The tip of the electrolyte bridge was inserted into the distal end of the cannula,
there-by making indirect contact with the bloodstream.
It is suggested that the use of any one of these three methods of reference electrode
placement would facilitate the measurement of esophageal or gastrointestinal potential
difference during a routine endoscopy without significantly altering the accuracy
of the measurements.
Key words:
Gastric mucosa - Esophageal mucosa - Potential difference
