The feasibility and accuracy of the method for selecting the optimal size of double-lumen tube in thoracic surgery: a prospective, randomized controlled trial.

Double-lumen tubes (DLTs) are commonly used for one-lung ventilation (OLV) in thoracic surgery and the selection of an optimal size of DLTs is still a humongous task. The purpose of this study was to assess the feasibility and accuracy of the method for selecting an optimal size of DLTs in thoracic surgery. Sixty adult patients requiring a left side double-lumen tube (LDLT) for elective thoracoscopic surgery were included in this study. All patients were randomly allocated to the following two groups: Cuffs Collapsed group (CC group, n = 30) and Cuffs Inflated group (CI group, n = 30). In the Cuffs Collapsed group, the outer diameter of LDLT (the outer diameter of the tracheal and bronchial cuffs when they were collapsed as the outer diameter of the LDLT) matched with the inner diameter of the trachea and bronchus measured by the anesthesiologist on the chest CT slice; In the Cuffs Inflated group, the outer diameter of LDLT (the outer diameter of the tracheal and bronchial cuffs when they were inflated as the outer diameter of the LDLT) matched with the inner diameter of the trachea and bronchus measured by the anesthesiologist on the chest CT slice. The primary outcomes were the incidences of airway complications postoperative such as hoarseness and sore throat. The time of intubation and alignment, the incidences of LDLT displacement and adjustment, the peak airway pressure, the plateau airway pressure and the end-tidal carbon dioxide were also recorded. The incidences of airway complications postoperative such as sore throat and hoarseness were lower in the CI group than the CC group (P < 0.05), the intubation times was shorter in the CI group than the CC group (P < 0.05), while the peak airway pressure, the plateau airway pressure and the end-tidal carbon dioxide during two-lung ventilation and one-lung ventilation were no significant difference between two groups (P > 0.05). The method which matched the inner diameter of the trachea and bronchus measured on chest CT slice with the outer diameter of the tracheal and bronchial cuffs when they were inflated to select an appropriate size of LDLT can reduce the incidence of airway complications.Trials registration: Clinical Trials: gov. no. NCT05739318. Registered at https://classic.clinicaltrials.gov 22/02/2023.

Common double-lumen tube selection methods overestimate adequate tube sizes in individual patients - a 3D reconstruction study.

BACKGROUND: Appropriate selection of double-lumen tube sizes for one-lung ventilation is crucial to prevent airway damage. Current selection methods rely on demographic factors or 2D radiography. Prediction of left bronchial diameter is indispensable for choosing the adequate tube size. This prospective observational study investigates if current selection methods sufficiently predict individuals' left bronchial diameters for DLT selection compared to the 3D reconstruction. METHODS: 100 patients necessitating thoracic surgery with one-lung ventilation and left-sided double-lumen tubes, ≥ 18 years of age, and a set of chest X-rays and 2D thorax CT scans for 3D reconstruction of the left main bronchus were included between 07/2021 and 06/2023. The cross-validated prediction error and the width of the 95%-prediction intervals of the 3D left main bronchial diameter utilizing linear prediction models were based on current selection methods. RESULTS: The mean bronchial diameter in 3D reconstruction was 13.6 ± 2.1 mm. The ranges of the 95%-prediction intervals for the bronchial diameter were 6.4 mm for demographic variables, 8.3 mm for the tracheal diameter from the X-ray, and 5.9 mm for bronchial diameter from the 2D-CT scans. Current methods violated the suggested '≥1 mm' safety criterion in up to 7% (men) and 42% (women). Particularly, 2D radiography overestimated women's left bronchial diameter. Current methods even allowed the selection of double-lumen tubes with bronchial tube sections greater than the bronchial diameter in women. CONCLUSIONS: Neither demographic nor 2D-radiographic methods sufficiently account for the variability of the bronchial diameter. Wide 95%-prediction intervals for the bronchial diameter hamper accurate individual double-lumen tube selection. This increases women's risk of bronchial damage, particularly if they have other predisposing factors. These patients may benefit from 3D reconstruction of the left main bronchus. TRIAL REGISTRATION: Not applicable.

Curious Case of Pediatric One-Lung Ventilation with Two Endotracheal Tubes: A Case Report.

ABSTRACT: One-lung ventilation is indicated during thoracic surgery for visualization and exposure of surgical site. It is achieved with bronchial blockers, double-lumen endobronchial tube, single-lumen endotracheal tubes and Univent tube for infants and children. Fibreoptic bronchoscope is required for placing and confirming the correct position of these tubes. We report a perioperative management of safe conduct of one lung ventilation for a 6-year child undergoing left lower lobe lobectomy through C-MAC video laryngoscope guided two single lumen tubes in limited resource settings where paediatric-sized fibreoptic bronchoscope is unavailable.

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.

Manejo de la hipoxia durante ventilación unipulmonar en un paciente con absceso mediastinal y mediastinitis para toracotomía abierta. Reporte de caso / Hypoxia Management during One-Lung Ventilation in a Patient with Mediastinal Abscess and Mediastinitis for Open Thoracotomy. Case Report

Introducción: la mayoría de los pacientes que se someten a cirugía torácica pueden ser clasificados en el grupo de alto riesgo para hipoxia, especialmente cuando se decide por una ventilación unipulmonar, debido al desequilibrio V/Q; por lo tanto, se han desa-rrollado nuevas estrategias ventilatorias y maniobras de rescate para hipoxia. Curso clínico: presentamos una paciente de 85 años de edad sin comorbilidades programada para toracotomía abierta y manejada con ventilación unipulmonar. Durante el mane-jo anestésico, se presenta hipoxia secundaria a desequilibrio V/Q y choque hipovolémi-co hemorrágico, con respuesta positiva a las maniobras de rescate para hipoxia. Con-clusión: es importante prevenir en la medida de lo posible la hipoxia en la ventilación unipulmonar, siguiendo las nuevas estrategias ventilatorias. Sin embargo, cuando se presenta una crisis, no debemos retrasar las maniobras de rescate de forma moderna. (AU)

Introduction: most of the patients undergoing thoracic surgery fit in the high risk group for hypoxia, especially when deciding to use one-lung ventilation due to the V/Q mis-match; therefore, new ventilation strategies and hypoxia rescue manoeuvres have been developed. Clinical course: we present an 85-year old female with no major co-morbidities scheduled for open thoracotomy and managed with one-lung ventilation. During the course of the anaesthetic management, hypoxia presents secondary to V/Q mismatch and haemorrhagic hypovolemic shock, with a positive response to hypoxia rescue manoeuvres. Conclusion: it is important to prevent as much as we can the hy-poxia in a one-lung ventilation following the new ventilation strategies. Although when facing a crisis, proper hypoxia management with a modern approach should not be de-layed. (AU)

Bronchial rupture following endobronchial blocker placement: a case report of a rare, unfortunate complication.

BACKGROUND: Lung separation may be achieved through the use of double lumen tubes or endobronchial blockers. The use of lung separation techniques carries the risk of airway injuries which range from minor complications like postoperative hoarseness and sore throat to rare and potentially devastating tracheobronchial mucosal injuries like bronchus perforation or rupture. With few case reports to date, bronchial rupture with the use of endobronchial blockers is indeed an overlooked complication. CASE PRESENTATION: A 78-year-old male patient with a left upper lobe lung adenocarcinoma underwent a left upper lobectomy with a Fuji Uniblocker® as the lung separation device. Despite an atraumatic insertion and endobronchial blocker balloon volume within manufacturer specifications, an intraoperative air leak developed, and the patient was found to have sustained a left mainstem bronchus rupture which was successfully repaired and the patient extubated uneventfully. Unfortunately, the patient passed on in-hospital from sepsis and other complications. CONCLUSION: Bronchial rupture is a serious complication of endobronchial blocker use that can carry significant morbidity, and due care should be exercised in its use and placement. Bronchoscopy should be used during insertion, and the volume and pressure of the balloon kept to the minimum required to prevent air leak. Bronchial injury should be considered as a differential in the presence of an unexplained air leak.

Anaesthetic management in a patient requiring one lung ventilation during COVID-19 pandemic.

Placement of a double-lumen tube to achieve one lung ventilation is an aerosol-generating procedure. Performing it on a patient with COVID-19 will put healthcare workers at high risk of contracting the disease. We herein report a case of its use in a patient with traumatic diaphragmatic rupture, who was also suspected to have COVID-19. This article aims to highlight the issues, it presented and ways to address them as well as the perioperative impact of personal protective equipment.

A Comparison of the Required Bronchial Cuff Volume Obtained by 2 Cuff Inflation Methods, Capnogram Waveform-Guided Versus Pressure-Guided: A Prospective Randomized Controlled Study.

BACKGROUND: Double-lumen endobronchial tubes (DLTs) are used for one-lung ventilation (OLV) during thoracic surgery. Overinflation into the bronchial cuff causes damage to the tracheobronchial mucosa, whereas underinflation leads to an incomplete collapse of the nonventilated lung or incomplete ventilation of the ventilated lung. However, how to determine the appropriate bronchial cuff volume and pressure during OLV is unclear. The objective of this study is to compare the required bronchial cuff volume for lung separation obtained by 2 different cuff inflation methods under closed- and open-chest conditions. METHODS: A total of 64 patients scheduled to undergo elective thoracic surgery requiring OLV were recruited. Left DLTs were used for both right- and left-sided surgery. The patients were randomly assigned to 1 of 2 inflation-type groups to estimate the bronchial cuff volume. In the capnogram waveform-guided bronchial cuff inflation group (capno group, n = 27), the bronchial cuff was inflated until a capnometer sampling gas containing CO2 from the nonventilated lung displayed a flat line. The corresponding bronchial cuff volume and pressure were then recorded. In the pressure-guided bronchial cuff inflation group (pressure group, n = 29), the bronchial cuff was inflated by a cuff inflator to a pressure of 20 cm H2O. Lung separation was confirmed when a flat line of a capnometer was observed after gas sampling from the nonventilated lung. RESULTS: Under closed-chest conditions, the bronchial cuff sealing volume for the capno group was significantly lower than that for the pressure group (mean [standard deviation {SD}], 1.00 [0.65] mL vs 1.44 [0.59] mL, mean difference, -0.44; 97.5% confidence interval [CI], -0.78 to -0.11; P = .010). Under open-chest conditions, the bronchial cuff sealing volume for the capno group was also significantly lower than that for the pressure group (mean [SD], 0.65 [0.66] mL vs 1.22 [0.45] mL, mean difference, -0.58; 97.5% CI, -0.88 to -0.27; P < .001). CONCLUSIONS: The lowest cuff volume providing an air-tight bronchial seal was obtained by the capnogram waveform-guided bronchial cuff inflation method. Since the cuff volume required to achieve an air-tight seal decreases after opening the chest, readjustment of the bronchial cuff volume to prevent bronchial cuff damage to the tracheobronchial mucosa after opening the chest may be advisable.

A randomized, prospective, comparative trial of a variable-angle versus fixed-angle endoscope for exploratory thoracoscopy in canine cadavers.

OBJECTIVE: To compare the efficacy of a variable-angle endoscope (VAE) for canine thoracoscopic exploration to a traditional fixed-angle endoscope (FAE). STUDY DESIGN: Randomized, prospective, comparative study. SAMPLE POPULATION: Five fresh canine cadavers. METHODS: Twelve predetermined anatomical locations were labeled after median sternotomy in each cadaveric thorax. Two board-certified veterinary surgeons performed thoracoscopic evaluation of each thorax using a fixed-angle (30°) and a variable-angle (0°-120°) endoscope with and without lungs mechanically ventilated. The order of surgeon, lung ventilation, and endoscope were determined using a randomized block design. Time to visualize each anatomical location was compared for surgeon, endoscope, and lung ventilation status. Primary outcome measures were time to individual anatomical location, total simulated thoracoscopic exploration time, and ability to identify anatomical location within the designated time period. RESULTS: Lung ventilation (difference = 184 seconds, P = .015, 95% CI = 45-342 seconds) and endoscope type (difference = 112 seconds, P = .029; 95% CI = 10-213 seconds) had an effect on the cumulative time for complete thoracoscopic exploration. The VAE shortened the time to identify three of the 12 anatomical locations when controlling for the effects of lung ventilation. Use of the VAE did not improve time to identification for any locations compared to the FAE when lungs were not ventilated. The VAE facilitated significantly shorter cumulative thoracoscopic exploration time compared with the FAE. Failure to identify predetermined locations was more common with the FAE than with the VAE. CONCLUSION: Use of a rigid VAE decreased cumulative thoracoscopic exploration time and provided an alternative to one-lung ventilation for circumventing the visual impediments of lung ventilation. CLINICAL SIGNIFICANCE: This cadaveric study provides evidence that one-lung ventilation and use of a VAE may improve surgeon efficiency during exploratory thoracoscopy.

An Update on One-Lung Ventilation in Children.

One-lung ventilation in children continues to present technical and sometimes physiologic challenges to the clinician. The rarity of these cases at any single institution, however, has led to very few prospective trials to guide best practices. As a result, most clinicians continue to be guided by local tradition and preference. That said, the development of new bronchial blockers such as the EZ-Blocker or blocking devices such as the Univent tube have continued to evolve the practice of lung isolation in children. Further, the development of a variety of extraluminal blocker techniques has led to innovations in practice through a relatively diverse landscape of published case series offering different approaches to one-lung ventilation during the past 15 years. The Arndt bronchial blocker continues to represent the most well documented of these devices. Additionally, recent advances have occurred in our understanding of the relevant anatomic constraints of the lower pediatric airway. This review is intended to provide a comprehensive and practical update to practicing pediatric anesthesiologists to further their understanding of the modern practice of one-lung ventilation for thoracic surgery in children.

Silicone Y-stent insertion under extracorporeal membrane oxygenation (ECMO) in a patient with tracheal tear.

Tracheal tear after endotracheal intubation is extremely rare. The role of silicone Y-stent in the management of tracheal injury has been documented in the previous studies. However, none of the studies have mentioned the deployment of silicone Y-stent via rigid bronchoscope with the patient solely supported by extracorporeal membrane oxygenation (ECMO) without general anaesthesia delivered via the side port of the rigid bronchoscope. We report a patient who had a tracheal tear due to endotracheal tube migration following a routine video-assisted thoracoscopic surgery sympathectomy, which was successfully managed with silicone Y-stent insertion. Procedure was done while she was undergoing ECMO; hence, no ventilator connection to the side port of the rigid scope was required. This was our first experience in performing Y-stent insertion fully under ECMO, and the patient had a successful recovery.

A special double lumen tube for use in pigs is suitable for different lung ventilation conditions.

Previous studies of haemodynamic and blood gas variables during one-lung ventilation in pigs have used a double lumen tube designed for use in humans. However, because of interspecies differences in bronchial anatomy, a special design for pigs is required. In this study, we evaluated a new left-sided double lumen endobronchial tube designed for use in pigs under different lung ventilation conditions. Ten female pigs (weighing 35-40 kg) were transorally intubated, first with a single lumen tube and then with the left-sided double lumen tube for pigs, and mechanically ventilated. Haemodynamic and blood gas variables were recorded before and after intubation with the double lumen tube and before and after one-lung flooding of the left lung with saline solution. Each pig was repositioned (left lateral, to dorsal, to right lateral) every 30 min during one-lung flooding. Bronchoscopy and thoracic radiography were performed at fixed intervals. Blood gas variables during two-lung ventilation were not impaired by intubation with the double lumen endobronchial tube for pigs, compared with intubation with the single lumen tube. Haemodynamic and blood gas variables were not impaired by one-lung flooding. Complete flooding of the left lung was achieved for all pigs. Two-lung ventilation to reventilate the previously flooded lung provided complete air filling for all pigs. Use of this tube resulted in lung separation without obstruction of bronchi or resultant atelectasis. In this study, the new double lumen tube for pigs was safe for one-lung flooding and prevented fluid entry into the non-flooded lung.

Intraoperative Anesthetic Management of the Thoracic Patient.

The intraoperative anesthetic management for thoracic surgery can impact a patient's postoperative course, especially in patients with significant lung disease. One-lung ventilation poses an inherent risk to patients, including hypoxemia, acute lung injury, and right ventricular dysfunction. Patient-specific ventilator management strategies during one-lung ventilation can reduce postoperative morbidity.

Awake intubation and extraluminal use of Uniblocker for one-lung ventilation in a patient with a large mediastinal mass a case report.

BACKGROUND: The anesthesia of patients with large mediastinal mass is at high-risk. Avoidance of general anesthesia in these patients is the safest option, if this is unavoidable, maintenance of spontaneous ventilation is the next safest technique. In these types of patients, it is not applicable to use double-lumen tube (DLT) to achieve one-lung ventilation (OLV) because the DLT has a larger diameter and is more rigid than single-lumen tube (SLT), so the mass may rupture and bleed during intubation. Even using a bronchial blocker, a small size of SLT is required for once the trachea collapses the SLT can pass through the narrowest part of trachea. However, it is difficult to control the fiberoptic bronchoscopy (FOB) and the bronchial blocker simultaneously within the lumen of a small size SLT with traditional intubation methods. CASE PRESENTATION: The current study presented a 66 years old female patient with a large mediastinal mass that presented with difficulty breathing when lying flat. In this case, we combined use of dexmedetomidine and remifentanil to preserve the patient's spontaneous ventilation during intubation and achieved one-lung ventilation with extraluminal use of Uniblocker. CONCLUSIONS: Extraluminal use of Uniblocker and maintenance of spontaneous ventilation during intubation may be an alternative to traditional methods of lung isolation in such patients with a large mediastinal mass.

Cadaveric evaluation of fluoroscopy-assisted placement of one-lung ventilation devices for video-assisted thoracoscopic surgery in dogs.

OBJECTIVE: To evaluate the feasibility of fluoroscopy-assisted placement of one-lung ventilation (OLV) devices in dogs. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Canine cadavers (n = 8) weighing between 20.2 and 37.4 kg. METHODS: Thoracoscopic access with a two-port approach was established to evaluate bilateral lung ventilation patterns. Advancement of a left-sided Robertshaw double-lumen endobronchial tube (DLT) and the EZ-blocker (EZ) were evaluated under direct fluoroscopic guidance. Each dog also underwent bronchoscopy-assisted placement of an Arndt endobronchial blocker (EBB). Time to initial placement, success of creating complete OLV (after initial placement attempt and after up to two repositionings), and ease of placement score were recorded. Device position was evaluated bronchoscopically after each fluoroscopy-assisted placement attempt. RESULTS: Time to initial placement was significantly shorter for EZ than for DLT and EBB. The rate of successful placement after up to two repositioning attempts was 87.5%, 87.5%, and 100.0% on the right and 87.5%, 100.0%, 100.0% on the left for DLT, EZ, and EBB, respectively, and was not different between devices. Ease of placement scores were significantly higher for DLT compared with EZ and EBB on both the left and the right sides. CONCLUSION: Fluoroscopy-assisted placement of DLT and EZ appears feasible in canine cadavers. EZ-blocker placement was efficient and technically easier than DLT, but positioning must be adapted for dogs. Bronchoscopy-assisted placement of EBB remains highly successful. CLINICAL SIGNIFICANCE: Fluoroscopy-assisted placement of EZ and DLT is a useful alternative to bronchoscopy-assisted placement of these OLV devices.

Bronchial blocker versus double-lumen endobronchial tube in minimally invasive cardiac surgery.

BACKGROUND: To compare the therapeutic value of a bronchial blocker (BB) with a double-lumen tube (DLT) in minimally invasive cardiac surgery (MICS). METHODS: Sixty patients who underwent MICS were randomized to use either a DLT (Group D, n = 30) or a BB (Group B, n = 29; one failed was omitted). The following data were collected: time of intubation and tube localization; incidence of tube displacement; postoperative sore throat and hoarseness; time of cardiopulmonary bypass; maintenance time for SpO2 < 90% (PaCO2 < 60 mmHg); mean arterial pressure and heart rate; SpO2, PaO2, PaCO2, EtCO2, mean airway pressure, and airway peak pressure; surgeons' satisfaction with anesthesia; and short-term complications. RESULTS: The times of intubation and tube localization were significantly longer in Group B than in Group D (P < 0.05). Patients in Group B exhibited significantly lower incidence of tube displacement, postoperative sore throat, and hoarseness when compared with patients in Group D (P < 0.05). Mean arterial pressure and heart rate were significantly lower in Group B than in Group D after tracheal intubation (P < 0.05). The mean airway pressure and airway peak pressure were significantly lower in Group B than in Group D after one-lung ventilation (P < 0.05). SpO2 and PaO2 in Group B were significantly higher than in group D after cardiopulmonary bypass (P < 0.05). No short-term postoperative complications were observed in patients of Groups B and D during 3 month follow-up. CONCLUSION: BB can be a potential alternative to the conventional DLT for lung isolation in MICS. TRIAL REGISTRATION: ChiCTR1900024250, July 2, 2019.