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Transnasal intubation of the manometry catheter is often the least pleasant component of the test for patients. Patients should be asked if they have a preference for which nostril to place the catheter, as anatomic conformation (e.g. deviated septum) or other factors such as piercings may make one side preferable to the other. A topical anesthetic (e.g. 2% lidocaine jelly) should be applied to the inside of the nostril, aided by a cotton‐tipped swab; instructing the patient to sniff deeply while the swab is in place can help further anesthetize the nasal passage.

The tip of the manometry catheter should then be lubricated and slowly passed through the nasal passage. As the catheter reaches the nasopharynx, we instruct the patient to start taking small sips of water while the catheter continues to be slowly advanced. Having the patient tuck their chin may aid passage as well. Some mild resistance may be encountered with passage through the pharynx, but if passage through one nare is difficult, the alternate nare can be anesthetized and placement reattempted. Once the upper esophageal sphincter (UES) is traversed, the catheter should be advanced until the HRM catheter traverses the EGJ by 3–5 cm, which can be visualized in real time on the EPT display. Correct catheter placement traversing the EGJ is paramount to accurately assess EGJ pressures. Positioning of the HRM catheter across the diaphragmatic hiatus can be confirmed by identifying the pressure inversion point: the point at which the negative intra‐thoracic pressures associated with inspiration inverts to the positive intra‐abdominal pressure. Instructing the patient to take several deep breaths or perform a straight leg raise can improve identification of the pressure inversion point by exaggerating intra‐thoracic and intra‐abdominal pressures as well as augmenting the EGJ pressure.

In certain scenarios, adequate placement of the manometry catheter may not be possible. This can occur with abnormal esophageal anatomy, e.g. achalasia with tortuous esophagus and non‐relaxing LES, or with some patients unable to tolerate awake transnasal intubation despite topical anesthetic. In these situations, placement of a precalibrated manometry catheter under sedation with endoscopic guidance may be necessary. However, performance of the manometry test requires an alert and awake patient, so it cannot be done until after the sedative effects have cleared. This practice may alter the results of the manometry, as both benzodiazepines and opioids used for conscious sedation can cause modest changes in esophageal motor findings, most notably causing increased LES relaxation pressures with opioids [16–19]. Additionally, the added time that the HRM catheter resides in the esophagus can exaggerate the thermal drift associated with solid‐state pressure sensors, potentially making the measurements less accurate [20].

In the setting of abnormal esophageal anatomy requiring an endoscopic assist in placing the manometry catheter, it is important to note that solid‐state HRM assemblies are very easily damaged and should not be grasped with any endoscopy accessories: foreign‐body retrieval devices, forceps, or snares. Instead, the tip of the endoscope should be maneuvered to nudge the tip of the HRM catheter as the catheter is advanced until appropriate positioning is obtained. This can be tedious, but the alternative of a damaged catheter is followed by an expensive repair or replacement.