The Role of Existing Formulas in the Double-lumen Tube in Thoracic Surgery Anesthesia

NCT07191002 | Recruiting

• 1 other identifier: 2024-BÇEK/344
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

In most clinical scenarios, left DLT is preferred for one-lung ventilation because of its anatomical ease of placement; these tubes allow separate ventilation of both lungs. If the DLT is not placed in the proper size and depth, it may result in repeated intubation attempts, airway and dental trauma, failed lung isolation, tube dislodgement, and various unwanted events such as hypoxemia. The first and most common method for correct placement of a DLT is the conventional technique, blindly advanced into the left main bronchus, and then confirmed with fiberoptic bronchoscopy (FOB). In this method, the depth at which the tube should be left before performing FOB is left to the clinician's experience. Generally, the DLT is advanced in the trachea until a slight resistance is felt. This may lead to excessive advancement of the DLT into the left main bronchus or premature resistance due to the tube tip touching the carina, causing the clinician to stop before entering the left main bronchus. Therefore, just as selecting the correct size of the DLT is crucial, correctly estimating the appropriate depth is also of great importance. For this reason, different formulas have been proposed in the literature, and new formulas are still being investigated. The patient's gender and height are determinant in selecting the appropriate size of the DLT. However, studies in the literature indicate that the accuracy of these formulas may be limited in Asian populations. Therefore, it is important to evaluate the applicability of these formulas in different populations and, if necessary, develop new formulas. In the Turkish population as well, verifying the accuracy of these formulas for determining the proper size and depth of DLT-and if needed, developing new recommendations and formulas-holds clinical importance. In this study, conducted at Ankara Atatürk Sanatorium Training and Research Hospital, the aim is to evaluate the accuracy of six different formulas available in the literature for predicting DLT depth in patients undergoing thoracic surgery. Additionally, the correlations between DLT depth and demographic parameters as well as external airway measurements (mouth opening, sternomental distance, thyromental distance, distance between the mentum and manubrio-sternal angle, distance between tragus and manubrio-sternal angle, distance between sternal angle and xiphoid process) will be analyzed. Furthermore, challenges during DLT application, malposition rates and types, and complications will be assessed. The primary objective of this study is to evaluate, in patients undergoing thoracic surgery at Ankara Atatürk Sanatorium Training and Research Hospital, how accurate and applicable six different formulas defined in the literature are for predicting the placement depth of the DLT. If the existing formulas are insufficient, the aim is to develop a new formula.

Conditions

Double-lumen Tube; One-lung Ventilation (OLV); Thoracic Anesthesia

Keywords

Double-Lumen Tube; Fiberoptic Bronchoscopy; Airway Measurements; One-Lung Ventilation; Tube Placement Depth; Thoracic Anesthesia

Outcome Measures

Primary Outcomes (1)

• consistency between the DLT depths calculated using six different formulas

  The primary outcome of the study is the consistency between the DLT depths calculated using six different formulas defined in the literature and the actual placement depth confirmed by fiberoptic bronchoscopy (FOB).

  during perioperative

Study Arms (1)

intubated with a left DLT

Patients who will undergo surgery under general anesthesia and be intubated with a left DLT

Other: placement depth of the double lumen tube

Interventions

placement depth of the double lumen tube OTHER

the anesthesiologist will select the appropriate DLT size and placement depth entirely at their discretion, as per routine practice, and confirm both using fiberoptic bronchoscopy (FOB). If malposition occurs, it will be corrected under FOB guidance, and the tube will be secured in the correct position

intubated with a left DLT

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study will begin prospectively after obtaining approval from the ethics committee and will be completed once the target number of patients has been reached. The study population will consist of patients aged 18-80 years who will undergo thoracic surgery at the operating rooms of the Department of Anesthesiology and Reanimation, Ankara Atatürk Sanatorium Training and Research Hospital.

You may qualify if:

• Patients older than 18 and younger than 80 years
• Patients who will undergo surgery under general anesthesia and be intubated with a left DLT
• Patients with an American Society of Anesthesiologists (ASA) score of I-II-III
• Patients with a body mass index (BMI) between 18-40 kg/m²
• Patients who provide informed consent

You may not qualify if:

• Patients requiring right DLT placement
• Patients with ASA score IV and above
• Patients intubated with a single-lumen tube
• Patients in whom lung isolation will be achieved with a method other than DLT
• Emergency cases
• Patients younger than 18 or older than 80 years

Sponsors & Collaborators

• Ankara Ataturk Sanatorium Training and Research Hospital: lead

Study Sites (1)

Ankara Ataturk Sanatorium Training and Research Hospital, Ankara, 06280

Ankara, Turkey (Türkiye)

RECRUITING

Study Officials

• ELİF DURMUŞ

  ANKARA ATATURK SANATORİUM TRAİNİNG AND RESEARCH HOSPITAL

  PRINCIPAL INVESTIGATOR

Central Study Contacts

ELİF DURMUŞ

CONTACT

+905423838232; elif.durmuss@hotmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinic Associate Professor

Study Record Dates

• First Submitted: September 17, 2025
• First Posted: September 24, 2025
• Study Start: September 29, 2025
• Primary Completion: February 15, 2026
• Study Completion: March 30, 2026
• Last Updated: October 2, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)