Prediction of Double-Lumen Tube Size By Ultrasonography for Asian Women: A Prospective Observational Study

Effect of a 3D-printed reconstruction automated matching system for selecting the size of a left double-lumen tube: a study protocol for a prospective randomised controlled trial

INTRODUCTION

Lung isolation is primarily accomplished using a double-lumen tube (DLT) or bronchial blocker. A precise and accurate size of the DLT is a prerequisite for ensuring its accurate placement. Three-dimensional (3D) reconstruction technology can be used to accurately reproduce tracheobronchial structures to improve the accuracy of DLT size selection. Therefore, we have developed automatic comparison software for 3D reconstruction based on CT data (3DRACS). In this study, we aimed to evaluate the efficiency of using 3DRACS to select the DLT size for endobronchial intubation in comparison with using the 'blind' DLT intubation method to determine the DLT size, which is based on height and sex.

METHODS AND ANALYSIS

This is a prospective, single-centre, double-blind randomised controlled trial. In total, 200 patients scheduled for lung resection using a left DLT will be randomly allocated to the 3D group or the control group at a 1:1 ratio. A 3DRACS will be used for the 3D group to determine the size of the DLT, while in the case of the control group, the size of the DLT will be determined according to patient height and sex. The primary outcome is the success rate of placement of the left DLT without fibreoptic bronchoscopy (FOB). The secondary outcomes include the following: successful intubation time, degree of pulmonary atrophy, grade of airway injury, oxygenation during one-lung ventilation, postoperative sore throat and hoarseness, and number of times FOB is used.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from our local ethics committee (approval number: SCCHEC-02-2022-155). Written informed consent will be obtained from all participants before randomisation, providing them with clear instructions about the purpose of the study. The results will be disseminated through peer-reviewed publications and conferences.

TRIAL REGISTRATION NUMBER

NCT06258954.

Role of ultrasonography in upper airway assessment: A comparison with computerized tomography measurements

INTRODUCTION

This study aimed to compare ultrasonography (US) measurements of the upper airway to computerized tomography (CT) measurements. Our study's primary outcome is to research the accuracy of US measurements in the evaluation of upper airway diameters when CT is taken as the gold standard; the secondary outcome is to determine the time required to obtain US measurements.

METHODS

This prospective study included patients ≥18 years old that had undergone thoracic or neck CT due to current clinical necessity. The US measurement for each patient was performed by two researchers with different levels of experience, both of whom were blinded to each other and the CT measurements. Measurements were obtained from the vocal cords and subglottic region. The duration of the US performance was also recorded.

RESULTS

The US and CT measurements were obtained from 94 patients. Concordance between US and CT measurements was found in the Bland-Altman analysis, with a mean -0.05 mm difference for vocal cord diameter and -1.2 mm for subglottic diameter. The intra-class correlation coefficients (ICC) between the CT and US measurements were 0.993, and 0.609 for vocal cord and subglottic diameter measurements, respectively. The ICC between US performers was 0.992 for vocal cord diameter and 0.959 for subglottic diameter. The US's mean time for vocal cord diameter measurement was 38 ± 23 s, and the mean time for subglottic diameter measurement was 49 ± 30 s.

CONCLUSION

The concordance between US and CT measurements is high and the measurements of different practitioners with different experience levels are compatible with each other.

Choosing the correct-sized adult double-lumen tube: Quest for the holy grail

Appropriate size selection of double-lumen tubes (DLTs) for one-lung ventilation (OLV) in adults is still a humongous task. Several important factors are to be considered like patient height, gender, tracheal diameter, left main bronchial diameter, and cricoid cartilage transverse diameter. In addition to radiological assessment of the airway diameters, the manufacturing details of the particular DLT being used also play a significant role in size selection. Optimal positioning of the appropriately sized DLT is indispensable to avoid complications like airway trauma, cuff rupture, hypoxemia, and tube displacement. It is imperative to know whether the one-size-fits-all dictum holds for DLT size selection as claimed by certain studies. Further randomized studies are required for crystallizing standard protocols ascertaining the correct DLT size. This systematic review article highlights the various parameters employed for DLT size selection and explores the newer DLTs used for adult OLV.

Current Practice Issues in Thoracic Anesthesia

This review discusses the present strategies in lung separation, the various types of double-lumen tubes (DLTs), and the use of bronchial blockers (BBs). Methods of selecting the correct DLT size and the role of videolaryngoscopy in placing a DLT are reviewed. Mechanisms whereby inhaled anesthetics may be protective during one-lung ventilation (OLV) are highlighted. The risk and prevention of fire during thoracic procedures are discussed.

Double lumen tube: Size and insertion depth

Double lumen tubes (DLTs) are most commonly used to achieve one lung ventilation (OLV) in most thoracic surgical procedures unless contraindicated. Left-sided DLT (LDLT) is most commonly used nowadays for most thoracic surgical procedures. Though, the use of LDLT dates long back in history, two clinical and technical issues are yet to be resolved. The first issue is the ideal size of DLT which is defined as that which provides near-complete seal of the bronchial lumen without cuff inflation. There are no guidelines in literature which help in selecting the size of DLT. However, general consensus among thoracic anesthesiologists recommends the use of smaller sizes to avoid airway trauma. In our practice and for the last few years, we are using smaller size LDLT 35 F for females and 37 F for males with minimal airway trauma and had encouraging results. The second issue is the insertion depth of the LDLT. We have introduced a height-based formula to predict the insertion depth of LDLT with encouraging results. However, even with the use of the formula, we still recommend the use of fiberoptic bronchoscopic confirmation method for final positioning of the LDLT.

The Year in Thoracic Anesthesia: Selected Highlights From 2020

Selected highlights in thoracic anesthesia in 2020 include updates in the preoperative assessment and prehabilitation of patients undergoing thoracic surgery; updates in one-lung ventilation (OLV) pertaining to the devices used for OLV; the use of dexmedetomidine for lung protection during OLV and protective ventilation, recommendations for the care of thoracic surgical patients with coronavirus disease 2019; a review of recent meta-analyses comparing truncal blocks with paravertebral and thoracic epidural blocks; and a review of outcomes after initiating the enhanced recovery after surgery guidelines for lung and esophageal surgery.