Esophageal Manometry During Recovery From Anesthesia: Pilot Study (EMAP)

1. An intact pharyngoesophageal reflex is essential to protect the upper airway from aspiration of either mouth contents or regurgitated gastric refluxate. This reflex is essential at protecting the airway in all patients.
2. In patients, while under general anesthesia, it is postulated that an identifiable upper esophageal sphincter and esophageal peristalsis are not present.
3. With the cessation of general anesthetics, accompanied by the reversal of nerve block, normal pharyngoesophageal peristaltic activity correlates with awakening the patient from anesthesia. This would be identified by the performance of esophageal manometry.
4. A return of normal verbally stimulated pharyngoesophageal swallowing sequence accurately identifies a safe time to remove endotracheal tubes and/or reverse anesthesia. This verbally stimulated swallowing sequence correlated precisely with the return of objective pharyngoesophageal function.

Study Overview

• Status: Completed
• Conditions: Motility Function
• Intervention / Treatment: Device: Motility Procedure

Detailed Description

This pilot study will examine esophageal manometry in patients emerging from routine general anesthesia. Manometry of the esophagus is not a standard part of surgery or general anesthesia. The investigators will be using standard solid state high resolution manometry. One of the authors (JPC) evaluates all routine manometry for patients undergoing such procedures at both UCSF and SFGH. The use of manometry in patients recovering from anesthesia will permit the investigators to assess the recovery of a normal swallowing mechanism. An adequate determination of return of normal swallowing sequence is likely to determine the safe time for extubation. The investigators propose to, as a research study, investigate esophageal motor function using standard high resolution esophageal manometry in 10 patients recovering from general anesthesia. These studies are likely to document that the return of normal pharyngoesophageal function will coordinate with verbal commands to initiate swallowing. This pilot study will help clarify the precise timing of the return of normal function in the oropharynx and the proximal esophagus and thus determine the safe time for removal of the endotracheal or nasotracheal intubation.

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94110
      • Zuckerberg San Francisco General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients between 18 and 70 years of age (ASA I or II).
• Already scheduled for routine general anesthetic procedure requiring an endotracheal tube for anesthesia administration.
• Scheduled abdominal surgical procedure including endoscopy, colonoscopy, ERCP, cholecystectomy, appendectomy, colectomy or small bowel resection.
• Willing and able to give informed consent in either English or Spanish.

Exclusion Criteria:

• Pregnant, breastfeeding, or unwilling to practice birth control during participation in the study.
• Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data.
• Patients not meeting entry criteria above.
• Refusal to give informed consent.
• Coagulopathy (INR > 2 and/or platelet count < 100,000.
• White Blood Cell count < 5,000/mm3
• Arrhythmia
• Serum creatinine > 2 mg/dl
• Prior known or suspected nasal obstruction.
• Known or suspected Zenker's diverticulum of esophagus, esophageal stricture, head/neck radiation therapy, hereditary telangiectasis, esophageal varices, cirrhosis.
• Anticoagulant usage such as heparin or Plavix

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Manometry Device; During the last 10 minutes of subjects "waking up" from anesthesia, the motility procedure will be performed.	Device: Motility Procedure; The use of esophageal manometry device during general anesthesia

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Time of the Return of Normal Pharyngoesophageal Function	Our primary objective is to determine the timing of the return of normal pharyngoesophageal function upon withdrawal of general anesthesia.	From withdrawal of general anesthesia until the return of normal pharyngoesophageal function, assessed up to 40 minutes.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Normal Pharyngoesophageal Function.	Correlation of the return of normal pharyngoesophageal function with other markers generally used by Anesthesia staff to indicate a safe time for removal of endotracheal tubes.	From withdrawal of general anesthesia until the return of normal pharyngoesophageal function, assessed up to 40 minutes.

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Investigators: Principal Investigator: Stanley Rogers, MD, University of California, San Francisco

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2016
• Primary Completion (Actual): March 5, 2019
• Study Completion (Actual): March 5, 2019

Study Registration Dates

• First Submitted: January 19, 2016
• First Submitted That Met QC Criteria: January 20, 2016
• First Posted (Estimated): January 22, 2016

Study Record Updates

• Last Update Posted (Actual): August 20, 2026
• Last Update Submitted That Met QC Criteria: July 30, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 14-15466

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO