A Randomized, Comparative, Controlled Study of Differences in the Incidence of Postoperative Sore Throat (POST) by Inner Diameter Size of the TaperGuardTM Endotracheal Tube (ETT)

March 30, 2026 updated by: Jinyoung Oh, Kyungpook National University Chilgok Hospital

Postoperative sore throat (POST) is a common complication following general anesthesia involving endotracheal intubation, often leading to decreased patient satisfaction. The TaperGuard™ endotracheal tube (ETT) features a tapered-shaped cuff designed to reduce micro-aspiration and has been shown to result in a lower incidence of POST compared to conventional cylindrical ETTs. While previous studies using standard cylindrical ETTs suggested that a smaller inner diameter (ID) reduces the risk of POST, this relationship has not been fully established specifically for the TaperGuard™ ETT.

This study aims to compare the incidence of POST between a standard-sized TaperGuard™ ETT (ID 7.0 mm) and a smaller-sized TaperGuard™ ETT (ID 6.0 mm) in female patients. The investigators hypothesize that using a smaller ID TaperGuard™ ETT will significantly reduce the occurrence of POST within 24 hours after surgery.

Patients will be randomly assigned to either the control group (ID 7.0 mm) or the small group (ID 6.0 mm). Throughout the procedure, cuff pressure will be strictly maintained at 22 cmH2O to minimize mucosal damage. The primary outcome is the presence of sore throat, and secondary outcomes include the severity of the pain and the incidence of hoarseness at several time points up to 24 hours postoperatively.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

  1. Background and Rationale Postoperative sore throat (POST) is a frequent complication following general anesthesia with endotracheal intubation, significantly impacting patient satisfaction. The mechanism of POST involves localized trauma and subsequent inflammatory responses or mucosal edema caused by the endotracheal tube (ETT) and its cuff. The TaperGuard™ ETT, designed with a tapered polyvinyl chloride cuff, aims to reduce micro-aspiration compared to conventional cylindrical ETTs. Previous studies have demonstrated that the TaperGuard™ ETT results in a lower incidence of POST than cylindrical ETTs. Additionally, while research on cylindrical ETTs has shown that a smaller inner diameter (ID) correlates with a lower incidence of POST, this effect has not been specifically validated for the TaperGuard™ ETT. This study aims to evaluate whether using a one-size smaller TaperGuard™ ETT (ID 6.0 mm) further reduces POST compared to a standard size (ID 7.0 mm) in female patients.
  2. Study Population and Randomization Female patients aged 19 to 70 with an ASA physical status of I-III scheduled for surgery under general anesthesia in the supine or lithotomy position will be enrolled. Participants will be randomly assigned to either the Control Group (Group C: ID 7.0 mm) or the Small Group (Group S: ID 6.0 mm) using a computer-generated random number sequence.

  3. Anesthesia Protocol Induction: After 5 minutes of preoxygenation, anesthesia will be induced using intravenous lidocaine (40 mg), propofol (2 mg/kg), and rocuronium (0.8 mg/kg).

    Intubation: Tracheal intubation will be performed using direct laryngoscopy. The ETT position will be confirmed via a fiberoptic bronchoscope to be 4 cm above the carina. The cuff will be inflated with air, and the pressure will be strictly adjusted to 22 cmH2O using a manometer.

    Maintenance: Anesthesia will be maintained with sevoflurane (1.5-3.0%) and remifentanil (Target-Controlled Infusion, 2-3 ng/mL). Mechanical ventilation will be set to a tidal volume of 8 ml/kg and a respiratory rate of 10-12 cycles/min to target an EtCO2 of 30-35 mmHg.

  4. Emergence and Recovery Five minutes before the end of surgery, fentanyl (50 mcg) will be administered intravenously. Upon completion of surgery, sevoflurane and remifentanil will be discontinued, and sugammadex (100 mg) will be administered for neuromuscular blockade reversal. Extubation will be performed when the patient's spontaneous tidal volume exceeds 200 ml and they follow verbal commands to open their eyes.
  5. Outcome Assessment A blinded co-investigator, who is not involved in the anesthesia administration, will assess the presence and severity of POST and hoarseness. Assessments will be conducted at four time points: immediately upon arrival at the Post-Anesthesia Care Unit (PACU), and at 1, 6, and 24 hours postoperatively. The severity of POST will be recorded using an 11-point Numerical Rating Scale (NRS).

Study Type

Interventional

Enrollment (Estimated)

246

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • South Korea
    • Daegu
      • Daegu, Daegu, South Korea, 41404
        • Kyungpook National University Chilgok Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Female patients.
  • Aged between 19 and 70 years.
  • American Society of Anesthesiologists (ASA) physical status I, II, or III.
  • Patients scheduled to undergo elective surgery under general anesthesia requiring endotracheal intubation.
  • Patients undergoing surgery in the supine or lithotomy position.
  • Patients who voluntarily provide written informed consent after receiving a full explanation of the study's purpose and procedures

Exclusion Criteria:

  • Predicted difficult intubation.
  • Confirmed diseases or anatomical abnormalities of the head and neck, including the pharynx and larynx.
  • Presence of preoperative sore throat.
  • Risk of pulmonary aspiration.
  • Requirement for the prone position or other surgical positions where airway management with a TaperGuard™ ETT is difficult.
  • Scheduled for head and neck surgery or other procedures where the use of a TaperGuard™ ETT is challenging.
  • Potential pregnancy.
  • Inability to provide informed consent or make a decision to participate after receiving the study explanation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Standard ID TaperGuard™ ETT (TaperGuard ETT ID 7.0mm)
atients in this group will be intubated using a TaperGuard™ endotracheal tube with a standard inner diameter of 7.0 mm.
Device: TaperGuard™ Endotracheal Tube
A tapered-cuff ETT. Cuff pressure is maintained at 22 cmH2O
Experimental: Small Group S (TaperGuard ETT ID 6.0mm)
Patients intubated with TaperGuard™ ETT ID 6.0mm
Device: TaperGuard™ Endotracheal Tube
A tapered-cuff ETT. Cuff pressure is maintained at 22 cmH2O

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Postoperative Sore Throat (POST)
Time Frame: Up to 24 hours after surgery (Assessment time points: immediately upon arrival at the Post-Anesthesia Care Unit [PACU], and at 1, 6, and 24 hours postoperatively)
The presence or absence of sore throat (Yes/No) will be assessed by a blinded co-investigator
Up to 24 hours after surgery (Assessment time points: immediately upon arrival at the Post-Anesthesia Care Unit [PACU], and at 1, 6, and 24 hours postoperatively)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Severity of Postoperative Sore Throat
Time Frame: Up to 24 hours postoperatively (at PACU arrival, 1h, 6h, and 24h).
The intensity of sore throat will be evaluated using an 11-point Numerical Rating Scale (NRS), where 0 represents no pain and 10 represents the worst imaginable pain.
Up to 24 hours postoperatively (at PACU arrival, 1h, 6h, and 24h).
Incidence of Hoarseness
Time Frame: Up to 24 hours postoperatively (at PACU arrival, 1h, 6h, and 24h).
The presence or absence of hoarseness (Yes/No) will be recorded by a blinded investigator.
Up to 24 hours postoperatively (at PACU arrival, 1h, 6h, and 24h).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Kyungpook National University Chilgok Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 26, 2025

Primary Completion (Actual)

February 27, 2025

Study Completion (Estimated)

May 12, 2026

Study Registration Dates

First Submitted

March 30, 2026

First Submitted That Met QC Criteria

March 30, 2026

First Posted (Actual)

April 6, 2026

Study Record Updates

Last Update Posted (Actual)

April 6, 2026

Last Update Submitted That Met QC Criteria

March 30, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2023-06-015

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data that underlie the results reported in this article (text, tables, figures, and appendices) will be made available.

IPD Sharing Time Frame

Beginning 6 months and ending 3 years following article publication.

IPD Sharing Access Criteria

Researchers whose proposed use of the data has been approved by an independent review committee identified for this purpose. Proposals should be directed to the corresponding author.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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