Lung Isolation for Thoracic Surgery: From Inception to Evidence-Based

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.

Effect of intubation in lateral position on placement of a double-lumen tube in patients undergoing unilateral video-assisted thoracic surgery: a randomied clinical trial

Background

Approximately one-third of patients who undergo double-lumen tube (DLT) intubation in the conventional supine position experience DLT malposition. No randomized study investigates the effect of DLT intubation in the lateral position. We therefore aimed to evaluate the effect of intubation in lateral position on placement of a DLT compared to supine intubation, and to test primary hypothesis that lateral DLT intubation could reduce the incidence of DLT malposition.

Methods

We randomly allocated 108 patients undergoing video-assisted thoracic surgery to receive DLT intubation in the comfortable and surgically required lateral position (lateral group) or in the supine position (supine group) from October to December 2022. The primary outcome was the incidence of DLT malposition defined as movement >1.0 cm to correct the DLT position. The secondary outcomes included intubation time, the frequency and duration of fibreoptic bronchoscopy, the need for re-intubation, intra-operative vital signs, and post-operative recovery. This trial is registered with the Chinese Clinical Trial Registry (ChiCTR2200060794).

Findings

The incidence of DLT malposition was significantly lower in the lateral group (1/53 [2%]) than that in the supine group (16/53 [30%]; RR [95% confidence interval] of 0.06 [0.01-0.46]; P < 0.001). Lateral DLT intubation decreased the intubation time, the frequency and duration of fibreoptic bronchoscopy. The incidence of hypotension, post-operative sore throat, and upper-arm discomfort was lower in the lateral group. Other secondary outcomes were similar between groups.

Interpretation

Lateral DLT intubation reduced the incidence of DLT malposition for patients undergoing video-assisted thoracic surgery. These results support that lateral DLT intubation offers more benefits and may be a superior option compared to conventional supine intubation.

Funding

National Natural Science Foundation of China and of Zhejiang Province.

One-lung ventilation with a bronchial blocker in thoracic patients

BACKGROUND

Lung isolation is a technique used in a multitude of surgeries to ensure single-lung ventilation with collapse of the contralateral lung, as to achieve improved access and visualization of relevant anatomical structures. Despite being accepted and having favorable outcomes, bronchial blockers (BBs) are not to this day the main device of choice among anaesthesiologists.

METHODS

In this retrospective and descriptive study, we analyzed the safety and efficacy of a BB in all types of thoracic surgeries in our centre between 2015 and 2022, excluding patients with massive hemoptysis or empyema, or who had undergone a prior pneumonectomy.

RESULTS

One hundred and thirty-four patients were intervened due to lung cancer (67.9%), respiratory disease (23.9%), and non-respiratory disease (8.2%) undergoing lung surgeries (65.7%), pleural and mediastinal surgeries (29.9%), chest wall surgeries (3.0%) and other surgeries (1.5%). In most cases, lung collapse was considered excellent (63.9%) or good (33.1%) with only 4 cases (3.0%) of poor lung collapse. More than 90% of patients did not present intraoperative or immediate postoperative complications. No statistically significant differences were found between lung collapse and the demographic, clinical or BB-related variables (p > 0.05). However, we found a significatively higher proportion of excellent lung collapses in VATS surgeries and lateral decubitus positioning, as well as a significatively less proportion of poor lung collapses (p < 0.05). Moreover, there was a significantly higher proportion of excellent lung collapses when the BB was placed in the left bronchus (p < 0.05).

CONCLUSIONS

With these results, in our experience BBs constitute an effective alternative, capable of achieving pulmonary collapse in all kinds of thoracic procedures with satisfactory safety rates due to their minimal complications.

A Practical Guide for Using the EZ-Blocker Endobronchial Blocker: Tips and Tricks After 10 Years of Experience

The EZ-Blocker (EZB) is a "Y-shaped," semirigid endobronchial blocker used for lung isolation and one-lung ventilation during thoracic surgery. Like many medical tools, initial efforts to use this endobronchial blocker may prove challenging for the uninitiated. However, some tips and tricks can be applied fairly rapidly to aid the clinician in properly placing the device, and, furthermore, may help the clinician get the most out of this innovative device. This article focuses on some of the technical aspects of its placement that the authors have developed over time. Additionally, other facets and potential pitfalls are discussed that relate to intraprocedural issues that may sometimes arise when using this device. The following aspects of the EZB as a lung-isolation device are discussed: standard positioning techniques, alternative positioning techniques, use in pediatric patients, approaches to achieving exceptional lung isolation, advanced uses, and limitations and potential issues. Although some information was taken from the authors' rather extensive experience with using this endobronchial blocker, some of the relevant literature are also reviewed, with the goal of being to improve the reader's knowledge of the device and improve the likelihood of its successful placement. The underlying design of the EZB remains unique among commercially available bronchial blockers in improving positional stability. The Y-shaped conformation, however, can lead to challenges when positioning the device in some patients. Therefore, some very practical tips and tricks are provided to assist the clinician in correctly positioning the device and other hints to improve the quality of lung isolation and surgical conditions.

Effect of intubation in the lateral position under general anesthesia induction on the position of double-lumen tube placement in patients undergoing unilateral video-assisted thoracic surgery: study protocol for a prospective, single-center, parallel group, randomized, controlled trial

BACKGROUND

The double-lumen tube (DLT) is an essential equipment for thoracic anesthesia and the precise position of DLT placement is particularly important for anesthesia and surgery. However, the incidence of DLT malposition remains high and it leads to lung isolation failure and hypoxemia during one-lung ventilation. This trial aims to explore the clinical application and efficacy of intubation in the lateral position under general anesthesia induction to reduce the incidence of DLT malposition in patients undergoing unilateral video-assisted thoracic surgery (VATS).

METHODS

In this prospective, single-center, parallel group, randomized, controlled trial, we will recruit 108 patients, aged 18-80 years, scheduled for elective unilateral VATS with DLT intubation under general anesthesia, and they will be randomly assigned to two groups: a lateral DLT intubation group (group L) and a conventional supine DLT intubation group (group C). The left-sided DLT will be used to intubate in patients of both groups. The position of DLT will be confirmed and adjusted by using the fiberoptic bronchoscopy (FOB). The primary outcome is the incidence of DLT malposition observed via the FOB, and the secondary outcomes include the time of intubation, the frequency and duration of re-adjustments of DLT placement under FOB, whether to re-intubate, intraoperative vital signs, and postoperative recovery.

DISCUSSION

Accurate DLT positioning is crucially important for thoracic surgery, but the incidence of DLT malposition is still high in the present clinical practice of thoracic anesthesia. This trial aims to investigate whether lateral DLT intubation can reduce the incidence of DLT malposition, with more stable intraoperative vital signs and less postoperative complications.

TRIAL REGISTRATION

The study protocol was registered at Chinese Clinical Trial Registry ( http://www.chictr.org.cn ) with registration number: ChiCTR2200060794 on June 11, 2022.

Recent advances in double-lumen tube malposition in thoracic surgery: A bibliometric analysis and narrative literature review

Thoracic surgery has increased drastically in recent years, especially in light of the severe outbreak of the 2019 novel coronavirus disease (COVID-19). Routine "passive" chest computed tomography (CT) screening of inpatients detects some pulmonary diseases requiring thoracic surgeries timely. As an essential device for thoracic anesthesia, the double-lumen tube (DLT) is particularly important for anesthesia and surgery. With the continuous upgrading of the DLTs and the widespread use of fiberoptic bronchoscopy (FOB), the position of DLT in thoracic surgery is gradually becoming more stable and easier to observe or adjust. However, DLT malposition still occurs during transferring patients from a supine to the lateral position in thoracic surgery, which leads to lung isolation failure and hypoxemia during one-lung ventilation (OLV). Recently, some innovative DLTs or improved intervention methods have shown good results in reducing the incidence of DLT malposition. This review aims to summarize the recent studies of the incidence of left-sided DLT malposition, the reasons and effects of malposition, and summarize current methods for reducing DLT malposition and prospects for possible approaches. Meanwhile, we use bibliometric analysis to summarize the research trends and hot spots of the DLT research.

Double-Lumen Endotracheal Tube-Predicting Insertion Depth and Tube Size Based on Patient's Chest X-ray Image Data and 4 Other Body Parameters

In thoracic surgery, the double lumen endotracheal tube (DLT) is used for differential ventilation of the lung. DLT allows lung collapse on the surgical side that requires access to the thoracic and mediastinal areas. DLT placement for a given patient depends on two settings: a tube of the correct size (or ‘size’) and to the correct insertion depth (or ‘depth’). Incorrect DLT placements cause oxygen desaturation or carbon dioxide retention in the patient, with possible surgical failure. No guideline on these settings is currently available for anesthesiologists, except for the aid by bronchoscopy. In this study, we aimed to predict DLT ‘depths’ and ‘sizes’ applied earlier on a group of patients (n = 231) using a computer modeling approach. First, for these patients we retrospectively determined the correlation coefficient (r) of each of the 17 body parameters against ‘depth’ and ‘size’. Those parameters having r > 0.5 and that could be easily obtained or measured were selected. They were, for both DLT settings: (a) sex, (b) height, (c) tracheal diameter (measured from X-ray), and (d) weight. For ‘size’, a fifth parameter, (e) chest circumference was added. Based on these four or five parameters, we modeled the clinical DLT settings using a Support Vector Machine (SVM). After excluding statistical outliers (±2 SD), 83.5% of the subjects were left for ‘depth’ in the modeling, and similarly 85.3% for ‘size’. SVM predicted ‘depths’ matched with their clinical values at a r of 0.91, and for ‘sizes’, at an r of 0.82. The less satisfactory result on ‘size’ prediction was likely due to the small target choices (n = 4) and the uneven data distribution. Furthermore, SVM outperformed other common models, such as linear regression. In conclusion, this first model for predicting the two DLT key settings gave satisfactory results. Findings would help anesthesiologists in applying DLT procedures more confidently in an evidence-based way.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

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.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

Laryngeal mask combined with bronchial tube achieves one-lung ventilation for transthoracic oesophagectomy

Laryngeal mask combined with bronchial blocker provides an alternative for lung isolation but lacks adequate access to the non-dependent lung. Substituting the blocker with a bronchial tube may overcome this limitation. In this report, a #4.5 cuffed bronchial tube was introduced into the non-dependent lung through a second-generation laryngeal mask for transthoracic oesophagectomy. During the 2.5-hour thoracotomy, one-lung ventilation was achieved by isolating the left lung with the bronchial tube and ventilating the right lung via the laryngeal mask, using volume-control mode (7 mL/kg × 12/min) with P_IP21-23 cm H₂O, pH 7.36 and PaCO₂ 38.3. Prior to thoracotomy closure, suction and reinflation of the left lung were performed through the bronchial tube. Bronchoscopy via the laryngeal mask revealed no injury to the airway after removal of the bronchial tube. The case shows that laryngeal mask combined with bronchial intubation provides one-lung ventilation with access to the isolated lung.

Cardiothoracic Anesthesia and Critical Care in the United Kingdom (UK) Part 1: Some Insights Into the History and Development

This review is intended to highlight some of the historic events that contributed to the development of thoracic and cardiac anesthesia and surgery in Great Britain and Northern Ireland (UK). The aim of this first of two parts is to concentrate on the development of techniques, facilities, and pharmacology that allowed progress and advancement in patient management that were developed primarily in the UK. However, progress usually requires input from a wide variety of sources of knowledge, and cardiothoracic practice is no exception. Reference is, thus, made to sources outside of the UK that guided, influenced, or inspired changes in practice, such as the techniques of operating on the heart and great vessels in war casualties, developed by Dr. Dwight Harken, or the demonstration of the Blalock-Thomas-Taussig shunt by Alfred Blalock. In addition to advances in medical equipment, such as computed tomography, the UK contributed greatly to pharmacologic interventions that were unique at the time in such varied areas as nonflammable volatile anesthetic agents, heart failure treatments, and neuromuscular blocking agents for both cardiac and thoracic surgical practice.

Computer-Generated Three-Dimensional Airway Models as a Decision-Support Tool for Preoperative Evaluation and Procedure-Planning in Pediatric Anesthesiology

Technology improvements have rapidly advanced medicine over the last few decades. New approaches are constantly being developed and utilized. Anesthesiology strongly relies on technology for resuscitation, life-support, monitoring, safety, clinical care, and education. This manuscript describes a reverse engineering process to confirm the fit of a medical device in a pediatric patient. The method uses virtual reality and three-dimensional printing technologies to evaluate the feasibility of a complex procedure requiring one-lung isolation and one-lung ventilation. Based on the results of the device fit analysis, the anesthesiology team confidently proceeded with the operation. The approach used and described serves as an example of the advantages available when coupling new technologies to visualize patient anatomy during the procedural planning process.

Efficacy of Automatic Retention Pressure of a Double-Lumen Tube Cuff: An Artificial Intubation Model

BACKGROUND

The movement of a double-lumen endotracheal tube (DLT) out of its appropriate position during thoracic surgery can result in the loss of one-lung ventilation (OLV), especially during pulmonary resection and node dissection. Our study aimed to validate the efficacy of automatic retention pressure control of the DLT bronchial cuff in maintaining OLV in an artificial intubation model.

MATERIALS AND METHODS

A 35-Fr left-sided DLT was intubated to the left main bronchus in an intubation simulator and connected to an anesthesia machine. The inspiratory volume, respiratory rate, and inspiratory-expiratory ratio were set at 500 mL, 12 times/min, and 1:2, respectively. A 1-kg right main bronchial traction in the lateral right was provided after OLV was established. SmartCuff (Smiths Medical, Minneapolis, Minnesota, USA) was used to maintain cuff pressure. The efficacy of retention pressure with SmartCuff (Group S) and without SmartCuff (Group WS) was compared. The primary outcome was the rate of tidal volume (TV) reduction following bronchial traction in the two groups.

RESULTS

The TVs were 289.8 ± 28.9 mL and 242.8 ± 31.9 mL in Group S and Group WS, respectively (P = 0.003). The rate of TV reduction after bronchial traction was significantly lower in Group S (29 ± 5%) than in Group WS (43 ± 6%) (P < 0.001).

CONCLUSIONS

Automatic retention pressure control of the DLT bronchial cuff improves the rate of TV reduction during right main bronchial traction in an artificial intubation model. Continuous retention cuff pressure may be useful in maintaining OLV during thoracic surgery.

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.

The disconnection technique with the use of a bronchial blocker for improving nonventilated lung collapse in video-assisted thoracoscopic surgery

Background

Methods

Results

Conclusions

A Prospective, Ex Vivo Trial of Endobronchial Blockade Management Utilizing 3 Commonly Available Bronchial Blockers

BACKGROUND

Lung isolation with bronchial blockers is a well-described and accepted procedure, often described for use during the management of massive hemoptysis. Recommendations for balloon inflation are sparse, with some advocating for saline whereas other suggest air, including the manufacturers. We sought to evaluate the optimal method for balloon inflation in an ex vivo trial.

METHODS

We performed a prospective trial utilizing 3 commercially available bronchial blockers commonly described for use in lung isolation and massive hemoptysis management. We utilized the Arndt Endobronchial Blocker (Cook Medical), the Cohen Tip Deflecting Endobronchial Blocker (Cook Medical), and the Fogarty Venous Thrombectomy Catheter (Edwards LifeSciences). Balloon size and deflation assessment were tested within 3 different scenarios comparing air versus saline.Welch t test was performed to compare means between groups, and a generalized estimating equation model was utilized to compare balloon diameter over time to account for correlation among repeated measures from the same balloon.

RESULTS

All 3 endobronchial blocker systems were observed in triplicate. During free-standing balloon inflation, all 3 endobronchial systems displayed a greater degree of balloon deflation over time with air as opposed to saline (P < .001). Within a stent-based model, inflation with air of all 3 endobronchial systems, according to manufacturer recommendations, demonstrated significantly decreased time until fluid transgression occurred when compared to a saline model (P < .001). Within a stent-based model, inflation with air, according to clinical judgment, demonstrated significantly decreased time until fluid transgression in the Arndt (P = .016) and the Fogarty (P < .001) system, but not the Cohen (P = .173) system, when compared with saline.

CONCLUSIONS

The utilization of saline for balloon inflation during bronchial blockade allows for more consistent balloon inflation. The use of saline during balloon inflation appears to delay passive, spontaneous balloon deflation time when compared to air during a model of endobronchial blockade. The approach of saline inflation should be tested in humans to demonstrate the overall applicability and validity of the current findings.

Airway management in anesthesia for thoracic surgery: a "real life" observational study

Background

One-lung ventilation (OLV) in thoracic anesthesia is required to provide good surgical exposure. OLV is commonly achieved through a double lumen tube (DLT) or a bronchial blocker (BB). Malposition is a relevant issue related to these devices use. No prospective studies with adequately large sample size have been performed to evaluate the malposition rate of DLTs and BBs.

Methods

A total of 2,127 patients requiring OLV during thoracic surgery were enrolled. The aim of this multicenter prospective observational study performed across 26 academic and community hospitals is to evaluate intraoperative malposition rate of DLTs and BBs. We also aim to assess: which device is the most used to achieve OLV, the frequency of bronchoscope (BRO) use, the incidence rate of desaturation during OLV and the role of other factors that can correlate to this event, and incidence of difficult airway.

Results

Malposition rate for DLTs was 14%, for BBs 33%. DLTs were used in 95% of patients and BBs in 5%. Mean positioning time was shorter for DLT than BB (156±230 vs. 321±290 s). BRO was used in 54% of patients to check the correct positioning of the DLT. Desaturation occurred in 20% of all cases during OLV achieved through a DLT. Predicting factors of desaturation were dislocation (OR 2.03) and big size of DLT (OR 1.15). BRO use (OR 0.69) and left surgical side (OR 0.41) proved to be protective factors. Difficult airway prevalence was 16%; 10.8% predicted and 5.2% unpredicted.

Conclusions

DLT has a low malpositioning rate and is the preferred device to achieve OLV. BRO use recorded was unexpectedly low. The possibility of encountering a difficult airway is frequent, with an overall prevalence of 16%. Risk factors of desaturation are malposition and increased size of DLT. Left procedures and BRO use could lead to fewer episodes of desaturation.

Posttreatment With the Fatty Acid Amide Hydrolase Inhibitor URB937 Ameliorates One-Lung Ventilation-Induced Lung Injury in a Rabbit Model

BACKGROUND

One-lung ventilation (OLV)-induced inflammation is a risk factor for acute lung injury that is responsible for 20% of postoperative pulmonary complications after lung resection. Inflammation is an important trigger for acute lung injury. Fatty acid amide hydrolase (FAAH) is the major enzyme that degrades the endocannabinoid arachidonoylethanolamine (AEA), an important regulator of inflammation, and its downstream metabolites such as arachidonic acid (AA) are also involved in inflammation. Importantly, AEA is also found in lung parenchyma. However, it remains unclear whether pharmacological inhibition of FAAH inhibitor using compounds such as URB937 can attenuate OLV-induced lung injury.

MATERIALS AND METHODS

New Zealand white rabbits were anesthetized to establish a modified OLV-induced lung injury model. Twenty-four male rabbits were randomly divided into four groups (n = 6): TLV-S (2.5-h two-lung ventilation [TLV] + 1.5 mL/kg saline + 1-h TLV), OLV-S (2.5-h OLV + 1.5 mL/kg saline + 0.5-h OLV + 0.5-h TLV), U-OLV (1.5 mL/kg URB937 + 3.0-h OLV + 0.5-h TLV), and OLV-U (2.5-h OLV + 1.5 mL/kg URB937 + 0.5-h OLV + 0.5-h TLV). Arterial blood gases, lung wet/dry ratio, and lung injury score of the nonventilated lungs were measured. The levels of AEA, AA, prostaglandin I2 (PGI2), thromboxane A2 (TXA2), and leukotriene B4 (LTB4) in the nonventilated lung were also quantified.

RESULTS

The arterial oxygenation index (PaO₂/FiO₂) decreased after 0.5-h OLV in the three OLV groups. The PaO₂/FiO₂ in the OLV-U group was better than that in the OLV-S and U-OLV groups and was accompanied with reductions in the wet/dry ratio and lung injury scores of the nonventilated lungs. The FAAH inhibitor URB937 administered not before but 2.5 h after OLV attenuated OLV-induced lung injury by increasing AEA levels and reducing the levels of downstream metabolites including AA, PGI2, TXA2, and LTB4.

CONCLUSIONS

Posttreatment with the FAAH inhibitor URB937 attenuated OLV-induced lung injury in rabbits and was associated with increased AEA levels and decreased levels of AA and its downstream metabolites.

VivaSight™ single-lumen tube guided bronchial blocker placement for one-lung ventilation in a patient with a tracheal tumor under video-assisted transthoracic surgery: a case report

BACKGROUND

Video-assisted transthoracic surgery (VATS) is a minimally invasive procedure that has been reported as a valid method for tracheal resection and reconstruction. However, for patients with tracheal tumors, one-lung ventilation during VATS is difficult to achieve, and utilizing a double-lumen tube is not applicable in these types of situations. When using a bronchial blocker, a fiberoptic bronchoscope is required to verify the position of bronchial blocker, though the repeated use of the fiberoptic bronchoscope increases the risk of tumor rupture and hemorrhage.

CASE PRESENTATION

We report a case with a middle tracheal tumor received tracheal resection and reconstruction under VATS, in which VivaSight™ single-lumen tube guided bronchial blocker placement was used for achieving one-lung ventilation. The VivaSight™ single-lumen tube can provide real-time and continuous monitoring of the position of bronchial blocker. Moreover, it does not require the aid of fiberoptic bronchoscopy.

CONCLUSIONS

VivaSight™ single-lumen tube combined with a bronchial blocker is a feasible choice for one-lung ventilation in this type of surgery.

Correlation between controlled lung collapse and early lung injury in dogs

A new type of pulmonary sequestration ventilator was used to compare the relationship between controlled lung collapse and early lung injury in thoracic surgery for dogs. Eighteen experimental dogs were randomly divided into three groups (G1-G3 groups). After general anesthesia, the shunt balance in lung was controlled and the pulmonary sequestration tube was placed in the femoral artery and vein, and the Swan-Ganz tube was placed into the right internal jugular vein as well. Two-lung ventilation (TLV) was first performed for 20 min, followed by one-lung ventilation (OLV). The degree of collapse was 100% (G1), 90% (G2), and 50% (G3). Blood samples were extracted from femoral artery and jugular vein prior to collapse (T0), and at 30 (T1), 60 (T2), and 120 (T3) min after collapse for blood gas analysis to determine the shunt ratio (Qs/Qt). Blood samples were also subjected to enzyme linked immunosorbent assay (ELISA) to determine serum tumor necrosis factor-α (TNF-α), intercellular immune adhesion molecule-1 (ICAM-1) and interleukin-6 (IL-6) levels. Arterial blood pressure, heart rate, pulmonary artery pressure and other physiological indicators were monitored during the experiment. Lung tissues were collected at T3 to calculate the wet/dry weight ratio (W/D). Histopathological changes were observed and compared by microscopic observation and blind scoring of pathological section after hematoxylin and eosin (H&E) staining. There were no significant differences in the physiological indexes between the two groups during TLV (P>0.05). Mean pulmonary arterial pressure (MPAP) in G2 and G3 groups was significantly more stable than that in G1 group after OLV (P<0.05); shunt ratio Qs/Qt, W/D, and serum TNF-α, ICAM-1 and IL-6 levels in the lung were decreased; and the degrees of pulmonary edema, hemorrhage, inflammatory cell infiltration and lung injury were also decreased. There was no statistically significant difference in each index at each time-point between G2 and G3 groups (P>0.05). Compared with complete lung collapse (collapse degree: 100%), controlled lung collapse (collapse degree: 90% and 50%) can better reduce the intraoperative lung injury, but there was no significant difference between the collapse degrees of 90 and 50%.