Our protocol facilitates a comprehensive evaluation of acid exposure in a very challenging patient cohort with atypical GERD symptoms. In addition, it provides guidance on complementary laryngopharyngeal and esophageal pH monitoring. Different thresholds and probe locations make comparing both methods challenging.
Our protocol facilitates simultaneous performance of esophageal and laryngopharyngeal pH monitoring and provides guidance on results analysis. Before beginning the analysis, calibrate the esophageal catheter in a solution with pH of 4 and a solution with pH of 7, rinsing the probe in water between solutions. To calibrate the laryngopharyngeal probe, select study and Hydrate in the laryngopharyngeal pH monitoring software and briefly agitate the laryngopharyngeal probe tip in clear water, then press any round key to start the laryngopharyngeal probe hydration process.
When the probes have been calibrated, with the patient in the upright position, and looking forward, provide the patient with a small glass of water with a straw to assist swallowing and insert the esophageal probe straight into the patient's nose. Use the measuring scale on the probe shaft to position the probe 5 centimeters above the lower esophageal sphincter as previously determined by high resolution manometry. When the probe is in place, loop over the ear and use surgical tape to secure the probe to the cheek as close to the nares as possible, using tape to affix the probe behind and below the ear lobe.
To place the laryngopharyngeal catheter, insert the probe straight into the other nostril posteriorly. When the probe is in place, the red light will be clearly visible, lateral to, or slightly below the uvula. Use surgical tape to secure the probe as close as possible to the nare and use a clip to secure the transmitter to the patient's clothing.
When both probes are in place, simultaneously start the esophageal and laryngopharyngeal pH studies, selecting a 24-hour study for the laryngopharyngeal pH measuring device, then give the patient a diary and ask them to detail their meal times, exact times of supine periods, and any symptoms that they experienced during the study. At the end of the analysis, simultaneously press the two buttons located in the middle of the esophageal device until upload later appears on the display. To end the laryngopharyngeal pH study, simultaneously press the cough, escape, and heartburn buttons until complete appears on the display, then remove the tape and gently remove both catheters.
To analyze the esophageal pH study data, connect the esophageal catheter device to a computer and upload the data into the appropriate analysis software program. Manually enter the patient data and information from the patient diary and delete any button presses that might have accidentally been performed by the patient during the study period, then use important parameters and thresholds from the report such as the composite score the total upright and supine percent pHs below baseline and the number of events to determine an abnormal esophageal acid exposure. To analyze the laryngopharyngeal pH study data, insert the SD card from the laryngopharyngeal catheter device into the computer and open analysis software.
Click Retrieve to upload the study. Left-click and drag on the graph to highlight the area of interest to select the respective event. Delete any button presses that might have accidentally been performed by the patient during the study period, then use important parameters and thresholds to determine an abnormal oropharyngeal acid exposure.
In this representative analysis, a total of 181 patients were evaluated as demonstrated. All of the patients presented with atypical symptoms, including chronic cough, hoarseness, sore throat, or pharyngeal burning. In addition, most patients suffered from typical GERD symptoms, such as regurgitation, heartburn and dysphagia.
A normal oropharyngeal acid exposure obtained by laryngopharyngeal pH testing was defined as a RYAN score of less than 9.4 upright and/or less than 6.8 supine. A normal esophageal pH test result was defined as a DeMeester score of less than 14.72. Abnormal oropharyngeal acid exposure was observed in 76 patients more frequently in the upright position, with 72 patients demonstrating an abnormal RYAN score upright compared to nine patients in supine position.
A normal oropharyngeal test result was reported for 105 patients. Most important for this protocol is the correct probe placement, with the esophageal probe being placed 5 centimeters above the LES and the oropharyngeal probe being placed lateral to the uvula.
