Insertion Depth of Left-sided Double-lumen Tube: a New Predictive Formula

Efficacy of Height-Based Formula to Predict Insertion Depth of Left-Sided Double Lumen Tube. A Prospective Observational Study

The authors developed a formula for predicting the accurate depth of DLT insertion into the appropriate bronchus based on height as follows [The predicted insertion depth of left DLT (cm) equals 0.249 × (BH)0.916] [R]. That pilot study showed comparable correlations between five formulae [Brodsky et al, Bahk and Oh R, Takita et al, Chow et al, Lin]. However, that formula developed has not been validated yet.

We hypothesized that previously published formula would predict the accurate depth of left-sided DLT insertion. We aimed to investigate the efficacy of this formula to estimate the optimum insertion depth of the DLT using a flexible bronchoscope and decrease the incidence of DLT displacement into the appropriate bronchus, the need for bronchoscopic adjustment, and complications including soreness of throat and mucosal injury.

Study Overview

• Status: Completed
• Conditions: Thoracic Surgery; One Lung Ventilation; Left-sided Double Lumen Tube
• Intervention / Treatment: Other: Predicted depth of insertion; Other: Optimized depth of insertion; Other: Adjustment of depth of insertion

Detailed Description

Accurate placement of the double-lumen tube [DLT], the commonly used tool to provide one-lung ventilation during thoracic surgery, is a real challenge for the thoracic anesthesiologists. Optimal DLT depth, defined as the blue endobronchial cuff below the carina, would decrease the incidence of obstructing the trachea and the contralateral bronchus (Brodsky). Additionally, deep insertion of the bronchial cuff of the DLT would obstruct the upper lobe bronchus (Brodsky). The careful adjustment of the depth and optimal positioning of the DLT using a flexible fiberoptic bronchoscope need a skilled anesthesiologist to reduce the time to DLT intubation. (Charles D. Boucek et al)

There are several methods have been described to predict the proper depth of DLT insertion. Chow et al. documented the validity of the developed formula based on the clavicular-to-carinal distance of trachea and height in 78% of patients studied. Brodsky et al. demonstrated that a height-and-gender-based formula could predict the depth of DLT insertion. Liu et al. reported an accurate depth of DLT insertion in 90% of patients studied measuring the distance between the vocal cord and carina according to the chest CT.

• Study Type: Interventional
• Enrollment (Actual): 65
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Saudi Arabia
  • Riyadh, Saudi Arabia, 11472
    • King Saud University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Underwent thoracic surgery
• Using a left-sided double-lumen tube for one-lung ventilation

Exclusion Criteria:

• Anticipated or known difficult airway
• Refuse to sign the consent
• Withdraw the consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• 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: Predicted depth of insertion; The predicted insertion depth of the DLT was calculated using the formula [0.249 x (BH) 0.916] before induction of anesthesia using an application on the smartphone

Other: Predicted depth of insertion; A left-sided double-lumen tube was introduced beyond the vocal cords when the train-of-four stimulation of the ulnar nerve revealed 1 or 2 twitches, the stylet was removed, the double-lumen tube was rotated 90° counterclockwise and then advanced blindly to the predicted depth of insertion.; Other: Optimized depth of insertion; The optimal position of the double-lumen tube, defined as the inflated endobronchial cuff is placed in the left main bronchus just below the carina without herniation, which was confirmed using a flexible bronchoscope in both supine and lateral decubitus positions.; Other: Adjustment of depth of insertion; If the endobronchial cuff was placed too deeply or too proximal, subsequently, the double-lumen tube was withdrawn or advanced, respectively, using the flexible bronchoscope until the optimum position of the double-lumen tube was achieved.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The rate of optimum position of the double-lumen tube	The rate of optimum position of a left-sided DLT without further adjustments, defined as the inflated endobronchial cuff is placed in the left main bronchus just below the carina without herniation	for 15 minutes after double-lumen tube insertion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The calculated predicted depth of insertion	The predicted insertion depth of the DLT was calculated using the formula [0.249 x (BH) 0.916] using an application an application on the smart phone	immediately before induction of general anesthesia
The initial depth of insertion	The "initial depth of insertion," was measured using the external centimeter markings on the DLT's lumen at the level of incisors	for 15 minutes after double-lumen tube insertion
Position of the double-lumen tube with the flexible bronchoscope	The position of the DLT with the flexible bronchoscope would be rated either (1) optimally placed, (2) too far out, or (3) too far in	for 15 minutes after double-lumen tube insertion
The need for bronchoscopic adjustments	If the endobronchial cuff was placed too deeply or too proximal, subsequently, the DLT was withdrawn or advanced, respectively, using the flexible bronchoscope until the optimum position of the DLT was achieved. The optimizing maneuvers were recorded	for 15 minutes after double-lumen tube insertion
The final correct depth of insertion	the "final correct depth of insertion", defined as the distance from the distal opening of the bronchial lumen to the corner of the mouth, was measured with a flexible bronchoscope passing through the bronchial lume	for 15 minutes after double-lumen tube insertion
Time to final correct double-lumen tube positioning	Time to final correct DLT positioning from time of laryngoscopy was recorded	for 25 minutes after double-lumen tube insertion
Changes in heart rate	Postintubation changes in heart rate was recorded	for 25 minutes after double-lumen tube insertion
Changes in mean arterial blood pressure	Postintubation changes in mean arterial blood pressure was recorded	for 25 minutes after double-lumen tube insertion
Changes in peripheral oxygen saturation	Postintubation changes in peripheral oxygen saturation was recorded	for 25 minutes after double-lumen tube insertion
Degree of lung collapse	degree of lung collapse was rated as excellent, good, poor, or very poor	for 30 minutes after start of surgery
The incidence of soreness of throat	Patients were asked about the occurrence and severity of postoperative sore throat	for 24 hours after start of surgery
The incidence of mucosal injury	The incidence of mucosal injury using the flexible bronchoscope was reported after intubation using the double-lumen tube	for 40 minutes after double-lumen tube insertion

Collaborators and Investigators

• Sponsor: Imam Abdulrahman Bin Faisal University
• Collaborators: King Saud University
• Investigators: Study Chair: Abdelazeem A Eldawlatly, MD, Professor of Anesthesia, College of Medicine, King Saud University; Study Director: Mohamed R El Tahan, MD, Associate Professor of Cardiothoracic Anaesthesia & Surgical Intensive Care, Imam Abdulrahman Bin Faisal University (formerly, University of Dammam), Dammam, Saudi Arabia,

Study record dates

Study Major Dates

• Study Start (Actual): May 7, 2019
• Primary Completion (Actual): March 1, 2020
• Study Completion (Actual): March 15, 2020

Study Registration Dates

• First Submitted: March 29, 2020
• First Submitted That Met QC Criteria: March 29, 2020
• First Posted (Actual): April 1, 2020

Study Record Updates

• Last Update Posted (Actual): April 1, 2020
• Last Update Submitted That Met QC Criteria: March 29, 2020
• Last Verified: March 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: E-18-3064

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The study protocol, statistical analysis plan, the anonymized database would be shared after publishing the paper
• IPD Sharing Time Frame: Unlimited time starting after publishing the paper
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No