Comparison of Ultrasound, CT, and Classical Methods for Selecting Sizes and Placement of Left-Sided Double-Lumen Tubes

Ankara City Hospital

Status: Completed

Conditions: Thoracic Neoplasms

Treatments: Procedure: intubation

Study type: Observational

Funder types: Other

Identifiers

NCT06731517

ANKCHBILKENT-ANES-SO-01

Details and patient eligibility

About

Investigators aimed to compare anatomical measurements obtained using ultrasound and computed tomography with classical methods to select the appropriate size of double-lumen tubes more quickly and easily and to determine the optimal depth of placement.

Full description

In modern thoracic anesthesia, one-lung ventilation (OLV) is essential for managing surgeries, and double-lumen tubes (DLTs) have been a key advancement. DLTs allow separate lung ventilation, facilitating lung deflation and preventing material transfer to the healthy lung. However, improper DLT placement can compromise these functions, emphasizing the importance of correct sizing and positioning.

Choosing the right DLT size depends heavily on patient-specific factors. Undersized DLTs can cause airway injuries, increased resistance, and displacement, while oversized DLTs are linked to postoperative issues like sore throat and difficult intubation. Despite this, no universal criterion exists for DLT size selection. Traditional methods rely on height and gender, but weak correlations with airway size often lead to improper choices, especially in shorter individuals.

Imaging techniques like chest X-rays, Computed Tomography (CT), and ultrasonography (USG) offer a more precise approach to airway measurements for DLT selection. USG is especially advantageous due to its accessibility, speed, and ease of use in operating rooms and emergencies. To improve the accuracy and ease of DLT size selection and placement, investigators aimed to compare anatomical measurements from USG and CT with traditional methods.

Enrollment: 150 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Requiring lung isolation in thoracic surgery,
• American Society of Anesthesiologists (ASA) risk score of 1-2-3,
• Patients who are literate and able to provide informed consent

Exclusion criteria

• Patients with an ASA score of 4 or higher,
• Criteria for difficult intubation,
• Difficulty in mouth opening, small jaw deformities,
• Abnormal cricoid cartilage appearance,
• A history of laryngeal or neck surgery,
• Preoperative throat pain and hoarseness,
• Tumors and deformities in the main airway

Trial design

150 participants in 3 patient groups

Classical group

Description:

In the classical group, Double Lumen Tube selection was based on gender and height. For males, a 41 F tube was chosen if height \>170 cm, and a 39 F tube if height ≤170 cm. For females, a 37 F tube was used if height \>160 cm, and a 35 F tube if height ≤160 cm. The depth was determined using the formula: 12 + (patient height/10). The calculated depth was marked on the DLT, and after intubation, the mark was positioned at the level of the upper teeth.

Treatment:

Procedure: intubation

Ultrasonography group

Description:

In the Ultrasonography (USG) group, Double Lumen Tube selection was based on the transverse cricoid cartilage diameter measured preoperatively using ultrasound. A 41 F tube was selected if the cricoid diameter was ≥18 mm, 39 F for 16-17.9 mm, 37 F for 15-15.9 mm, 35 F for 13-14.9 mm, and 32 F for \<13 mm (Table 5) (5). To determine placement depth, the distance between the vocal cords and the Louis angle was measured (the Louis angle was used as a guide as it anatomically aligns with the carina). The position of the vocal cords was identified using USG. The measured length was marked starting from the bronchial cuff line, and this mark was positioned at the level of the vocal cords during intubation.

Treatment:

Procedure: intubation

Computed Tomography

Description:

In the Computed Tomography (CT) group, Double Lumen Tube selection was based on CT measurements. Radiologists measured the cricoid diameter and the distance between the carina and the vocal cords. A 41 F tube was selected if the cricoid diameter was ≥18 mm, 39 F for 16-17.9 mm, 37 F for 15-15.9 mm, 35 F for 13-14.9 mm, and 32 F for \<13 mm (Table 5) (5). The calculated depth was marked starting from the bronchial cuff line, and this mark was positioned at the level of the vocal cords during intubation.

Treatment:

Procedure: intubation