Lung isolation techniques

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.

Lung ultrasound is non-inferior to bronchoscopy for confirmation of double-lumen endotracheal tube positioning: a randomized controlled noninferiority study

BACKGROUND

Appropriate placement of left-sided double-lumen endotracheal tubes (LDLTs) is paramount for optimal visualization of the operative field during thoracic surgeries that require single lung ventilation. Appropriate placement of LDLTs is therefore confirmed with fiberoptic bronchoscopy (FOB) rather than clinical assessment alone. Recent studies have demonstrated lung ultrasound (US) is superior to clinical assessment alone for confirming placement of LDLT, but no large trials have compared US to the gold standard of FOB. This noninferiority trial was devised to compare lung US with FOB for LDLT positioning and achievement of lung collapse for operative exposure.

METHODS

This randomized, controlled, double-blind, noninferiority trial was conducted at the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from October 2017 to July 2019. The study enrolled 200 ASA classification 1-3 patients that were scheduled for elective thoracic surgery requiring placement of LDLT. Study patients were randomized into either the FOB group or the lung US group after initial blind placement of LDLT. Five patients were excluded due to protocol deviation. In the FOB group (n = 98), fiberoptic bronchoscopy was used to confirm lung collapse due to proper positioning of the LDLT, and to adjust the tube if necessary. In the US group (n = 97), lung ultrasonography of four pre-specified zones (upper and lower posterior and mid-axillary) was used to assess lung collapse and guide adjustment of the tube if necessary. The primary outcome was presence of adequate lung collapse as determined by visual grading by the attending surgeon on scale from 1 to 4. Secondary outcomes included the time needed to adjust and confirm lung collapse, the time from finishing LDLT positioning to the grading of lung collapse, and intraoperative parameters such has hypotension or hypertension, hypoxia, and hypercarbia. The patient, attending anesthesiologist, and attending thoracic surgeon were all blinded to the intervention arm.

RESULTS

The primary outcome of lung collapse by visual grading was similar between the intervention and the control groups, with 89 patients (91.8%) in the US group compared to 83 patients (84.1%) in the FOB group (p = 0.18) experiencing adequate collapse. This met criteria for noninferiority per protocol analysis. The median time needed to confirm and adjust LDLT position in the US group was 3 min (IQR 2-5), which was significantly shorter than the median time needed to perform the task in the FOB group (6 min, IQR 4-10) (p = 0.002).

CONCLUSIONS

In selected patients undergoing thoracic surgery requiring LDLT, lung ultrasonography was noninferior to fiberoptic bronchoscopy in achieving adequate lung collapse and reaches the desired outcome in less time.

TRIAL REGISTRATION

This study was registered at clinicaltrials.gov, NCT03314519 , Principal investigator: Kasana Raksamani, Date of registration: 19/10/2017.

COVID-19 safety: aerosol-generating procedures and cardiothoracic surgery and anaesthesia - Australian and New Zealand consensus statement

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is a contagious disease that is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Health care workers are at risk of infection from aerosolisation of respiratory secretions, droplet and contact spread. There are a number of procedures that represent a high risk of aerosol generation during cardiothoracic surgery. It is important that adequate training, equipment and procedures are in place to reduce that risk.

RECOMMENDATIONS

We provide a number of key recommendations, which reduce the risk of aerosol generation during cardiothoracic surgery and help protect patients and staff. These include general measures such as patient risk stratification, appropriate use of personal protective equipment, consideration to delay surgery in positive patients, and careful attention to theatre planning and preparation. There are also recommended procedural interventions during airway management, transoesophageal echocardiography, cardiopulmonary bypass, chest drain management and specific cardiothoracic surgical procedures. Controversies exist regarding the management of low risk patients undergoing procedures at high risk of aerosol generation, and recommendations for these patients will change depending on the regional prevalence, risk of community transmission and the potential for asymptomatic patients attending for these procedures.

CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT

This statement reflects changes in management based on expert opinion, national guidelines and available evidence. Our knowledge with regard to COVID-19 continues to evolve and with this, guidance may change and develop. Our colleagues are urged to follow national guidelines and institutional recommendations regarding best practices to protect their patients and themselves.

ENDORSED BY

Australian and New Zealand Society of Cardiac and Thoracic Surgeons and the Anaesthetic Continuing Education Cardiac Thoracic Vascular and Perfusion Special Interest Group.

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.

Severe postintubation tracheobronchial rupture

Tracheal injury is a rare complication after pediatric intubation. The choice of treatment depends on the size of the lesion and on the underlying disease. We present a complex case of severe tracheal injury treated with success with tracheal stent positioning.

Percutaneous radiofrequency ablation of lung metastases from colorectal carcinoma under C-arm cone beam CT guidance

PURPOSE

The aim of this study was to assess the feasibility, safety and efficacy of percutaneous radiofrequency ablation of lung metastases from colorectal carcinoma using C-arm cone beam computed tomography (CBCT) guidance.

MATERIAL AND METHODS

This single-center prospective observational study was performed from August 2013 to August 2016, and included consecutive patients referred for radiofrequency ablation of lung metastases from colorectal cancer. Radiofrequency ablation procedures were performed under C-arm CBCT guidance. Feasibility was assessed by probe accuracy placement, time to accurate placement and number of C-arm CBCT acquisitions to reach the target lesion. Safety was assessed by the report of adverse event graded using the common terminology criteria for adverse events (CTCAE-V4.0). Efficacy was assessed by metastases response rate using RECIST 1.1 and ¹⁸FDG-PET-CT tumor uptake at 6months.

RESULTS

Fifty-four consecutive patients (32 men, 22 women) with a mean age of 63±8 (SD) years (range: 51-81years) with a total of 56 lung metastasis from colorectal metastases were treated in a single session. The mean tumor diameter was 25.6±4.5 (SD)mm (range: 17-31mm). Median time to insert the needle into the target lesion was 10min (range: 5-25min). Median number of needles repositioning and C-arm CBCT acquisition per patient was 1 (range: 0-3) and 4 (range: 3-6) respectively. The accuracy for radiofrequency ablation probe placement was 2±0.2 (SD)mm (range: 0-9mm). Pneumothorax requiring chest tube placement occurred in one patient (CTCAE-V4.0 grade 3). At 6months, all patients were alive with tumor response rate of -27% and had no significant activity on the ¹⁸FDG-PET CT follow-up.

CONCLUSION

Percutaneous radiofrequency ablation of lung metastases from colorectal cancer under C-arm CBCT guidance is feasible and safe, with immediate and short-term results similar to those obtained using conventional CT guidance.

One-Lung Anesthesia Update

One-lung ventilation is used during a variety of cardiac, thoracic, and major vascular procedures. Endobronchial tubes, bronchial blockers, and occasionally, single-lumen tubes are used to isolate the lungs. Patients with difficult airways and pediatric patients provide special challenges for lung isolation. Finally, intraoperative hypoxia and hypercarbia in patients with intrinsic lung disease frequently complicate one-lung anesthesia. The concepts and controversies in lung isolation techniques are discussed.

Teaching basic lung isolation skills on human anatomy simulator: attainment and retention of lung isolation skills

Background

Lung isolation skills, such as correct insertion of double lumen endobronchial tube and bronchial blocker, are essential in anesthesia training; however, how to teach novices these skills is underexplored. Our aims were to determine (1) if novices can be trained to a basic proficiency level of lung isolation skills, (2) whether video-didactic and simulation-based trainings are comparable in teaching lung isolation basic skills, and (3) whether novice learners’ lung isolation skills decay over time without practice.

Methods

First, five board certified anesthesiologist with experience of more than 100 successful lung isolations were tested on Human Airway Anatomy Simulator (HAAS) to establish Expert proficiency skill level. Thirty senior medical students, who were naive to bronchoscopy and lung isolation techniques (Novice) were randomized to video-didactic and simulation-based trainings to learn lung isolation skills. Before and after training, Novices’ performances were scored for correct placement using pass/fail scoring and a 5-point Global Rating Scale (GRS); and time of insertion was recorded. Fourteen novices were retested 2 months later to assess skill decay.

Results

Experts’ and novices’ double lumen endobronchial tube and bronchial blocker passing rates showed similar success rates after training (P >0.99). There were no differences between the video-didactic and simulation-based methods. Novices’ time of insertion decayed within 2 months without practice.

Conclusion

Novices could be trained to basic skill proficiency level of lung isolation. Video-didactic and simulation-based methods we utilized were found equally successful in training novices for lung isolation skills. Acquired skills partially decayed without practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-015-0169-7) contains supplementary material, which is available to authorized users.

Endobronchial intubation in thoracic surgery: Which side should be preferred?

AIM

This study was undertaken to compare the clinical performance of right versus left double-lumen endotracheal tubes placed without using fiberoptic bronchoscopy in thoracic surgery operations.

METHODS

This was a retrospective review of patients who were operated on in our institution between January 2013 and February 2014. We analyzed clinical performance in terms of hypoxia, hypercapnia, and adequate deflation of the lungs with both left- and right-sided double-lumen endotracheal tubes.

RESULTS

There were 80 patients with a mean age of 53.74 ± 15.59 years. Right-sided double-lumen tubes were used in 33 patients, and left-sided double-lumen tubes were used in 47. Perioperative hypoxi (p < 0.05), hypercapnia (p < 0.01), and inadequate deflation of the lung (p < 0.001) were found more frequently with the use of right-sided double-lumen endotracheal tubes. Arterial blood gas analyses in the post-anesthesia care unit showed that high pCO2 (>45 mm Hg), low pH (<7.36), and high lactate levels (>4 mmol L(-1)) were more frequent with right-sided double-lumen endotracheal tubes (p < 0.001). The incidence of atelectasis was greater (p < 0.001) and the duration of hospital stay was longer (p = 0.02) with the use of right-sided double-lumen endotracheal tubes.

CONCLUSION

Right-sided double-lumen endotracheal tubes resulted in poorer clinical performance. Therefore, a left-sided double-lumen endotracheal tube should be preferred in thoracic surgery operations when an appropriate size of fiberoptic bronchoscope is not available.

Cardiovascular collapse and hypoxemia in a man with a right-sided mediastinal mass, undiagnosed atrial septal defect, and right-to-left shunt

A 65 year old man presented with fever, pancytopenia, hypoxemia, and cardiovascular collapse requiring intensive care unit admission. Computed tomographic pulmonary angiogram showed a right-sided mediastinal mass adjacent to the right atrium. The patient had a video-assisted thoracoscopic surgical biopsy of the mass, with selective bronchial blockade to maximize oxygenation during lung isolation. Intraoperative transesophageal echocardiography showed an unexpected large atrial secundum defect with a right-to-left shunt and intracardiac mass. This shunt could be reversed with a norepinephrine infusion, resulting in improved oxygenation. Histopathology showed potentially curative diffuse large B cell lymphoma (DLBCL).

A new method of securing the airway for differential lung ventilation in intensive care

Differential lung ventilation to achieve optimised ventilation for each lung is a procedure rarely used in the intensive care unit, to treat select cases of severe unilateral lung disease in intensive care. However, existing techniques both for securing the airway and ventilating the lungs are challenging and have complications. We present the use of differential lung ventilation in the intensive care setting, securing the airway with a technique not previously described, using endotracheal tubes inserted through a tracheotomy and orally. In the course of 1 month, we treated three patients with unilateral atelectatic and consolidated lungs by differential lung ventilation. The left lung was ventilated through an endotracheal tube inserted into the left main stem bronchus through a tracheotomy. The right lung was ventilated through an endotracheal tube with the cuff positioned immediately under the vocal cord. In patient 1, the diseased lung remained consolidated after 24 h of differential lung ventilation. In the two other patients, the diseased lungs responded to differential lung ventilation by increased compliance and radiographic increased aeration. Differential ventilation of the lungs with this novel technique is feasible and may increase the likelihood of successful treatment of atelectatic lungs refractory to conventional ventilator strategies.

Modified right-sided Broncho-Cath™ double lumen tube improves endobronchial positioning: a randomized study

OBJECTIVE

A left-sided double lumen tube is recommended for one-lung ventilation for most thoracic surgeries, but for certain indications, a right-sided double lumen tube (R-DLT) may be mandatory. Frequent malposition of R-DLTs has been reported. We propose an innovative modification of Mallinckrodt's Broncho-Cath R-DLT consisting of an enlarged area of the lateral orifice, and studied the impact of this modification on the adequacy of R-DLT positioning.

METHODS

Eighty adult patients scheduled for elective thoracic surgery were randomized into two groups: standard Broncho-Cath R-DLT, or modified Broncho-Cath R-DLT. After induction of anesthesia, the R-DLT was positioned using a fibreoptic bronchoscope. The position of the R-DLT was assessed on three occasions: with the patient supine (T1), then immediately following the patient's transfer to the lateral position (T2), and after repositioning of the tube, when needed, with the patient in lateral position (T3). A score ranging from 1 to 4 was accorded to the relative position of the right upper lobe (RUL) orifice in relation to the origin of the RUL bronchus.

RESULTS

The modified Broncho-Cath R-DLT was more frequently in an adequate position at T2: 77% vs 37% of patients (P = 0.0121), and easier to reposition at T3: 97% vs 74% of patients (P = 0.0109) in comparison to the standard Broncho-Cath R-DLT group.

CONCLUSION

These data suggest the superiority of the modified Broncho-Cath R-DLT compared to a standard Broncho-Cath R-DLT for optimal R-DLT positioning to facilitate one-lung ventilation during thoracic surgery.

Clinical review: Independent lung ventilation in critical care

Independent lung ventilation (ILV) can be classified into anatomical and physiological lung separation. It requires either endobronchial blockade or double-lumen endotracheal tube intubation. Endobronchial blockade or selective double-lumen tube ventilation may necessitate temporary one lung ventilation. Anatomical lung separation isolates a diseased lung from contaminating the non-diseased lung. Physiological lung separation ventilates each lung as an independent unit. There are some clear indications for ILV as a primary intervention and as a rescue ventilator strategy in both anatomical and physiological lung separation. Potential pitfalls are related to establishing and maintaining lung isolation. Nevertheless, ILV can be used in the intensive care setting safely with a good understanding of its limitations and potential complications.

An update on bronchial blockers during lung separation techniques in adults

Techniques for one-lung ventilation (OLV) can be accomplished in two ways: The first involves the use of a double-lumen endotracheal tube (DLT). The second involves blockade of a mainstem bronchus (bronchial blockers). Bronchial blockade technology is on the rise, and in some specific clinical situations (e.g., management of the difficult airway during OLV or selective lobar blockade) it can offer more as an alternative to achieve OLV in adults. Special emphasis on newer information for the use of Fogarty embolectomy catheter as a bronchial blocker, the torque control blocker Univent, and the wire-guided endobronchial blocker (Arndt blocker) is included. Also this review describes placement, positioning, complications, ventilation modalities, and airflow resistances of all three bronchial blockers. Finally, the bronchial blockers can be used in many cases that require OLV, taking into consideration that bronchial blockers require longer time for placement, assisted suction to expedite lung collapse, and the use of fiberoptic bronchoscopy. The current use of bronchial blockers, supported by scientific evidence, dictates that bronchial blockers should be available in any service that performs lung separation techniques.

A comparison of a left-sided Broncho-Cath with the torque control blocker univent and the wire-guided blocker

Lung isolation can be accomplished in two ways: the first, a double-lumen endotracheal tube (DLT) and the second, a bronchial blocker (Univent or Arndt blocker). Previous studies have found that the DLT and the Univent are comparable when providing lung isolation. A new bronchial blocker, the wire-guided endobronchial blocker (Arndt blocker), has been introduced. However, there is no study to report its effectiveness with lung isolation during elective thoracic surgical cases. Therefore, we designed a prospective, randomized trial to compare the effectiveness of lung isolation among the 3 endotracheal tubes: the left-sided DLT Broncho-Cath Group A (n = 16 patients), the torque control blocker Univent Group B (n = 16 patients), and the wire-guided Arndt blocker Group C (n = 32 patients). The following variables were recorded: 1) time to initially position the assigned tube, 2) frequency of malpositions, 3) frequency of use of fiberoptic bronchoscope, 4) overall surgical exposure, and 5) tube acquisition cost. The Arndt blocker took longer to place (3:34 min/s) compared with the other 2 groups: the DLT group (2:08 min/s) or the Univent group (2:38 min/s) (P < 0.0004). There was no statistical difference in tube malpositions among the three groups: two for the DLT group, four for the Univent group, and nine in the Arndt group. Excluding the time for tube placement, the Arndt group also took longer for the lung to collapse (26:02 min/s), compared with the DLT group (17:54 min/s) or Univent group (19:28 min/s) (P < 0.0060). Furthermore, unlike the other two groups, the majority of the Arndt patients required suction to achieve lung collapse. Once lung isolation was achieved, overall surgical exposure was rated excellent for the three groups. Acquisition cost for the DLT group was $1663.20 (21 tubes opened), $2329.00 for the Univent group (17 tubes opened), and $3567.00 for the Arndt group (33 wire-guided blockers opened). This study demonstrates that the Arndt blocker takes longer to position and longer to deflate the isolated lung. For elective thoracic surgical cases, once the lung was isolated, the management seemed to be similar for all three tube groups.

IMPLICATIONS

We compared the latest design of double-lumen tubes Broncho-Cath, Univent, and Arndt blockers during lung isolation. Our results show that the Arndt blocker takes longer to position and longer to deflate the isolated lung. Once the lung was isolated, the management seemed to be similar for all three devices.