First real-time imaging of bronchoscopic lung volume reduction by electrical impedance tomography.

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) with one-way endobronchial valves (EBV) has better outcomes when the target lobe has poor collateral ventilation, resulting in complete lobe atelectasis. High-inspired oxygen fraction (FIO2) promotes atelectasis through faster gas absorption after airway occlusion, but its application during BLVR with EBV has been poorly understood. We aimed to investigate the real-time effects of FIO2 on regional lung volumes and regional ventilation/perfusion by electrical impedance tomography (EIT) during BLVR with EBV. METHODS: Six piglets were submitted to left lower lobe occlusion by a balloon-catheter and EBV valves with FIO2 0.5 and 1.0. Regional end-expiratory lung impedances (EELI) and regional ventilation/perfusion were monitored. Local pocket pressure measurements were obtained (balloon occlusion method). One animal underwent simultaneous acquisitions of computed tomography (CT) and EIT. Regions-of-interest (ROIs) were right and left hemithoraces. RESULTS: Following balloon occlusion, a steep decrease in left ROI-EELI with FIO2 1.0 occurred, 3-fold greater than with 0.5 (p < 0.001). Higher FIO2 also enhanced the final volume reduction (ROI-EELI) achieved by each valve (p < 0.01). CT analysis confirmed the denser atelectasis and greater volume reduction achieved by higher FIO2 (1.0) during balloon occlusion or during valve placement. CT and pocket pressure data agreed well with EIT findings, indicating greater strain redistribution with higher FIO2. CONCLUSIONS: EIT demonstrated in real-time a faster and more complete volume reduction in the occluded lung regions under high FIO2 (1.0), as compared to 0.5. Immediate changes in the ventilation and perfusion of ipsilateral non-target lung regions were also detected, providing better estimates of the full impact of each valve in place. TRIAL REGISTRATION: Not applicable.

How Bacteria Cope with Oxidative Stress Induced by Cadmium: Volatile Communication Is Differentially Perceived among Strains.

Soil is an environment with numerous niches, where bacteria are exposed to diverse conditions. Some bacteria are exposed earlier than others to pressure, and the emission of signals that other bacteria can receive and perceive may allow a better response to an eminent stimulus. To shed light on how bacteria trigger their response and adapt to changes in the environment, the intra- and interspecific influences of volatiles on bacterial strains growing under non-stressed and cadmium-stressed conditions were assessed. Each strain was exposed to its volatiles emitted by cells growing under different conditions to test whether the environment in which a cell grows influences neighboring cells. The five genera tested showed different responses, with Rhizobium displaying the greatest influence. In a second experiment, 13 strains from different genera were grown under control conditions but exposed to volatiles released by Cd-stressed Rhizobium cells to ascertain whether Rhizobium's observed influence was strain-specific or broader. Our results showed that the volatiles emitted by some bacteria under stress are differentially perceived and translated into biochemical changes (growth, alteration of the antioxidant response, and oxidative damage) by other bacteria, which may increase the adaptability and resilience of bacterial communities to environmental changes, especially those with a prooxidant nature. Cadmium (Cd) contamination of soils constitutes a risk to the environment and human health. Here, we showed the effects of Cd exposure on bacteria and how volatile communication influences the biochemistry related to coping with oxidative stress. This knowledge can be important for remediation and risk assessment and highlights that new biological features, such as volatile communication, should be considered when studying and assessing the impact of contaminants on soil ecosystems.

Comparison between contact diode laser with 980 nm and 1470 nm wavelengths for posterior laryngofissure in pigs.

To compare two different wavelengths of the surgical contact diode laser (CDL) for producing a posterior laryngofissure in in-vivo pigs. Anesthetized pigs underwent a tracheostomy and an anterior laryngofissure through a cervicotomy. They were randomly selected for the CDL wavelength and Power, according to the peak of Power set at device (980nm wavelength: Ppeak power of 10 W, 15 W, and 20 W, or 1470 nm wavelength: Ppeak 3 W, 5 W, 7 W, 10 W). At the end of the experiment, the laryngotracheal specimen was extracted and sent for histology and morphometry measurements (incision size, depth, area, and lateral thermal damage). Hemodynamic data and arterial blood gases were recorded during the incisions. Statistical analysis of the comparisons between the parameters and groups had a level of significance of p < 0.05. Twenty-six pigs were divided into CDL 980 nm (n = 11) and 1470 nm (n = 15). There was a greater incision area at the thyroid level in the 980 nm CDL and a wider incision at the trachea level, with a larger distance between mucosa borders. There were no significant differences in the area of lateral thermal damage between the two groups and neither difference among the power levels tested. Both wavelengths tested showed similar results in the various combinations of power levels without significant differences in the lateral thermal damage. The posterior laryngofissure incision can be performed by either of the wavelengths at low and medium power levels without great difference on lateral thermal damage.

The ESTS-AIR database-initial results of a multi-institutional database on airway surgery.

OBJECTIVES: Compared to lung resections, airway procedures are relatively rare in thoracic surgery. Despite this, a growing number of dedicated airway centres have formed throughout Europe. These centres are characterized by a close interdisciplinary collaboration and they often act as supra-regional referring centres. To date, most evidence of airway surgery comes from retrospective, single-centre analysis as there is a lack of large-scale, multi-institutional databases. METHODS: In 2018, an initiative was formed, which aimed to create an airway database within the framework of the ESTS database (ESTS-AIR). Five dedicated airway centres were asked to test the database in a pilot phase. A 1st descriptive analysis of ESTS-AIR was performed. RESULTS: A total of 415 cases were included in the analysis. For adults, the most common indication for airway surgery was post-tracheostomy stenosis and idiopathic subglottic stenosis; in children, most resections/reconstructions had to be performed for post-intubation stenosis. Malignant indications required significantly longer resections [36.0 (21.4-50.6) mm] when compared to benign indications [26.6 (9.4-43.8) mm]. Length of hospital stay was 11.0 (4.1-17.3) days (adults) and 13.4 (7.6-19.6) days (children). Overall, the rates of complications were low with wound infections being reported as the most common morbidity. CONCLUSIONS: This evaluation of the 1st cases in the ESTS-AIR database allowed a large-scale analysis of the practice of airway surgery in dedicated European airway centres. It provides proof for the functionality of ESTS-AIR and sets the basis for rolling out the AIR subsection to all centres participating in the ESTS database.

Brazilian airway surgery survey indicates low overall numbers and need for improved teaching skills.

OBJECTIVES: The Brazilian Society of Thoracic Surgeons conducted an online survey to determine the number of surgeons that perform adult and paediatric airway surgery and to understand the practice patterns along the country. METHODS: Active members were electronically invited to complete the questionnaire through the REDCapR platform. Invitations were sent from January to April 2020. The survey encompassed 40 questions that explored 4 different topics in the assessment of tracheal diseases: (i) surgeon's demography; (ii) institutional profile, (iii) education and training in laryngo-tracheal surgery and (iv) preoperative and postoperative evaluation. RESULTS: Eighty-nine percentage of the responders declared to perform tracheal surgery with a median of 5 tracheal resection procedures per year [interquartile range (IQR) 3-12]. Interaction with other specialties occurs in 37.3% of cases. Access to technology and devices is highly variable across the country. Resident training in airway surgery consists in traditional lectures in 97% of the cases. Training in animals (15.2%), cadavers (12.1%) and simulators (6.1%) are rare. Preoperatory evaluation encompasses flexible bronchoscopy (97.8%) and/or computed tomography (CT) scan of the airways (90.6%). Swallowing (20.1%) and voice (14.4%) disorders are rarely evaluated. Eighty-nine percentage of the surgeons consider bronchoscopy to be the preoperatory gold-standard exam, followed by CT scan (38.8%) and CT-3D reconstruction (37.4%). CONCLUSIONS: Brazilian surgeons refer that airway resection and reconstruction are part of their current practice, but the total number of procedures per surgeon per year is low. Access to high-end technology and equipment is heterogenous. Training offered to residents in most academic institutions relies on traditional lectures.

Robotic Lung Volume Reduction Surgery With Extracorporeal Membrane Oxygenation.

Lobectomy for consolidation of failed endoscopic lung volume reduction for emphysema has been reported in selected patients with favorable results but with considerable morbidity. The challenging issues in such patients are frailty caused by severe emphysema itself, poor tolerance to single-lung ventilation, target lobe hyperinflation, and inability to use gas inflation for the minimally invasive resection. Careful planning, including use of a robotic platform and extracorporeal membrane oxygenation support, can circumvent such difficulties and ensure a safe, minimally invasive resection in the high-risk emphysematous patient.

Decannulation: a retrospective cohort study of clinical and swallowing indicators of success

Abstract Objective: To investigate the clinical and swallowing indicators related to a successful decannulation process during the hospital stay. Methods: A retrospective cohort clinical study. The study sample comprised a heterogeneous patient population who had submitted to a tracheostomy procedure in a tertiary hospital. Patients were divided into two groups (dec-annulated vs. non-decannulated) and compared not only in terms of demographic and clinical data but also the results of a swallowing assessment and intervention outcome. Results: Sixty-four patients were included in the present study: 25 (39%) who had been successfully decannulated, and 39 (61%) who could not be decannulated. Between-group comparisons indicated that both groups presented similar clinical and demographic characteristics. The groups also presented similar swallowing assessment results prior to intervention. However, significant differences were observed regarding the time to begin swallowing rehabilitation. The decannulated group was assessed nine days earlier than the non-decannulated group. Other significant differences included the removal of the alternate feeding method (72.0% of decannulated patients vs. 5.1% of non-decannulated patients) and the reintroduction of oral feeding (96.0% of decannulated patients vs. 41.0% of non-decannulated patients) and functional swallowing level at patient disclosure. The non-decannulated patient group presented higher death rates at disclosure. Conclusion: The results of the present study indicated that the following parameters were associated with a successful decannulation process: early swallowing assessment, swallowing rehabilitation, and improvement in the swallowing functional level during the hospital stay. The maintenance of low swallowing functional levels was found to be negatively associated with successful decannulation. HIGHLIGHTS Deccanulation indicators were investigated in patients who were submitted to a tracheostomy procedure. Early swallowing evaluation and rehabilitation were associated with a successful decannulation process. Low swallowing functional levels were negatively associated with the success of decannulation.

O Teste de Caminhada de 6 Minutos prevê a melhora física em longo prazo de sobreviventes à unidade de terapia intensiva: um estudo de coorte prospectiva / The 6-Minute Walk Test predicts long-term physical improvement among intensive care unit survivors: a prospective cohort study

RESUMO Objetivo: Avaliar a capacidade do Teste de Caminhada de 6 Minutos para predizer a melhora do estado funcional físico em longo prazo de pacientes sobreviventes à unidade de terapia intensiva. Métodos: Foram avaliados, de forma prospectiva, entre fevereiro de 2017 e agosto de 2018, em um ambulatório pós-unidade de terapia intensiva, 32 sobreviventes à unidade de terapia intensiva. Foram inscritos consecutivamente os pacientes com permanência na unidade de terapia intensiva acima de 72 horas (para admissões emergenciais) ou acima de 120 horas (para admissões eletivas) que compareceram ao ambulatório pós-unidade de terapia intensiva 4 meses após receberem alta da unidade de terapia intensiva. A associação entre a distância percorrida no Teste de Caminhada de 6 Minutos realizado na avaliação inicial e a evolução do estado funcional físico foi avaliada durante 8 meses, com utilização do Índice de Barthel. Resultados: A distância média percorrida no Teste de Caminhada de 6 Minutos foi significantemente mais baixa nos sobreviventes à unidade de terapia intensiva do que na população geral (405m versus 557m; p < 0,001). A idade (β = -4,0; p < 0,001) e a fraqueza muscular (β = -99,7; p = 0,02) se associaram com a distância percorrida no Teste de Caminhada de 6 Minutos. A distância percorrida no Teste de Caminhada de 6 Minutos se associou com melhora do estado funcional físico no período de 8 meses de acompanhamento desses pacientes (razão de chance para cada 10m: 1,07; IC95% 1,01 - 1,16; p = 0,03). A área sob a curva Característica de Operação do Receptor para predição da melhora funcional física pelo Teste de Caminhada de 6 Minutos foi de 0,72 (IC95% 0,53 - 0,88). Conclusão: O Teste de Caminhada de 6 Minutos, realizado 4 meses após a alta da unidade de terapia intensiva, predisse com precisão moderada a melhora do estado funcional físico de sobreviventes à unidade de terapia intensiva.

ABSTRACT Objective: To evaluate the ability of the 6-Minute Walk Test to predict long-term physical functional status improvement among intensive care unit survivors. Methods: Thirty-two intensive care unit survivors were prospectively evaluated from February 2017 to August 2018 in a post-intensive care unit outpatient clinic in Brazil. Individuals with intensive care unit stays > 72 hours (emergency admissions) or > 120 hours (elective admissions) attending the post-intensive care unit clinic four months after intensive care unit discharge were consecutively enrolled. The association between the 6-Minute Walk Test distance at baseline and physical functional status was assessed over 8 months using the Barthel Index. Results: The mean 6-Minute Walk Test distance was significantly lower in intensive care unit survivors than in the general population (405m versus 557m; p < 0.001). Age (β = -4.0; p < 0.001) and muscle weakness (β = -99.7; p = 0.02) were associated with the 6-Minute Walk Test distance. A 6-Minute Walk Test distance was associated with improvement in physical functional status over the 8-month follow-up (odds ratio for each 10m of 1.07; 95%CI 1.01 - 1.16; p = 0.03). The area under the Receiver Operating Characteristic curve for the 6-Minute Walk Test prediction of physical functional status improvement was 0.72 (95%CI 0.53 - 0.88). Conclusion: The 6-Minute Walk Test performed 4 months after intensive care unit discharge predicted long-term physical functional status among intensive care unit survivors with moderate accuracy.

Effects of volatile sulfur compounds on growth and oxidative stress of Rhizobium leguminosarum E20-8 exposed to cadmium.

Volatile sulfur compounds (VSCs) have been reported to be produced by many bacterial species. Depending on the compound, they can negatively influence some organisms (fungi, nematodes and insects) or promote plant growth. Some of these compounds have also been hypothesized to play a role in bacterial response to cadmium (Cd) induced stress. This study aimed to assess the potential effects of four VSCs (dimethyl sulfide - DMS, dimethyl disulfide - DMDS, dimethyl trisulfide - DMTS and methyl thioacetate - MTA) on the growth and oxidative status of Rhizobium sp. strain E20-8 via airborne exposure, in order to test the hypothesis that these volatile compounds can influence growth and tolerance to cadmium. Our results show that, overall, the tested compounds triggered similar antioxidant mechanisms in Rhizobium in the presence of Cd. The protective effect at the membrane level by DMDS and DMTS particularly demonstrates the antioxidant effect of these volatiles, with reductions of up to 50% (DMS) and 80% (DMTS) in lipid peroxidation levels. Due to the volatile nature of these compounds, the low concentrations tested (1 nM to 100 mM), and considering that they are released by bacteria and other organisms such as plants, it is possible that these effects also occur in the soil ecosystem.

Hybrid Desobstruction of Blind-end Subglottic Stenosis With Long-term Stenting.

Blind-end stenosis (Myer-Cotton IV) is an extreme response to airway injury, resulting in phonatory ablation and dependence on a tracheostomy. A minimally invasive airway desobstruction and stenting can be beneficial in such cases. We present 2 cases of Myer-Cotton IV stenosis that were treated with a minimally invasive desobstruction using a hybrid (endoscopic-surgical) approach followed by the placement of a silicone T-tube.

Treatment of tracheal stenosis with extracorporeal membrane oxygenation support in infants and newborns.

Tracheal stenosis in children is a challenge for the healthcare team, since it is a rare disease. Patients usually have other clinical comorbidities, mainly previous cardiac surgical interventions. This retrospective single-center study included infants with tracheal stenosis (congenital or acquired) operated between 2016 and 2020 on venoarterial extracorporeal membrane oxygenation (VA ECMO). Five patients were operated and the median age of detection of the tracheal disease was 3.7 months, and the median age at the operation was 5 months. All patients had associated cardiac anomalies. Four patients had congenital tracheal stenosis; two with associated pig bronchus. One patient had acquired subglottic stenosis with concomitant stenosis at the carina. After the operation, the patients were referred to ICU on ECMO with an open chest. Minor ECMO-related complications occurred in two patients (hemothorax and wound infection). All patients required endoscopic evaluation during the postoperative care; median of 3.2 procedures. Two patients are currently in follow-up and three have died. Slide tracheoplasty with VA-ECMO can be successfully performed in infants with prior cardiac surgery. Nevertheless, a difficult postoperative course should be anticipated, with possible prolonged ECMO use, readmissions, and higher morbidity and mortality than in children with tracheal stenosis alone.

EBUS-TBNA versus surgical mediastinoscopy for mediastinal lymph node staging in potentially operable non-small cell lung cancer: a systematic review and meta-analysis.

OBJECTIVE: Lung cancer (LC) is one of the leading causes of death worldwide. Accurate mediastinal staging is mandatory in order to assess prognosis and to select patients for surgical treatment. EBUS-TBNA is a minimally invasive procedure that allows sampling of mediastinal lymph nodes (LNs). Some studies have suggested that EBUS-TBNA is preferable to surgical mediastinoscopy for mediastinal staging of LC. The objective of this systematic review and meta-analysis was to compare EBUS-TBNA and mediastinoscopy in terms of their effectiveness for mediastinal LN staging in potentially operable non-small cell lung cancer (NSCLC). METHODS: This was a systematic review and meta-analysis, in which we searched various databases. We included studies comparing the accuracy of EBUS-TBNA with that of mediastinoscopy for mediastinal LN staging in patients with NSCLC. In the meta-analysis, we calculated sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios. We also analyzed the risk difference for the reported complications associated with each procedure. RESULTS: The search identified 4,201 articles, 5 of which (with a combined total of 532 patients) were selected for inclusion in the meta-analysis. There were no statistically significant differences between EBUS-TBNA and mediastinoscopy in terms of the sensitivity (81% vs. 75%), specificity (100% for both), positive likelihood ratio (101.03 vs. 95.70), or negative likelihood ratio (0.21 vs. 0.23). The area under the summary ROC curve was 0.9881 and 0.9895 for EBUS-TBNA and mediastinoscopy, respectively. Although the number of complications was higher for mediastinoscopy, the difference was not significant (risk difference: -0.03; 95% CI: -0.07 to 0.01; I2 = 76%). CONCLUSIONS: EBUS-TBNA and mediastinoscopy produced similar results for mediastinal staging of NSCLC. EBUS-TBNA can be the procedure of first choice for LN staging in patients with NSCLC.

Early complications in flexible bronchoscopy at a university hospital.

OBJECTIVE: To analyze the complications related to flexible bronchoscopy (FB) and its collection procedures in outpatients and inpatients with various lung and airway diseases treated at a university hospital. METHODS: This was a retrospective analysis of complications occurring during or within 2 h after FB performed between January of 2012 and December of 2013, as recorded in the database of the respiratory endoscopy department of a hospital complex in the city of São Paulo, Brazil. RESULTS: We analyzed 3,473 FBs. Complications occurred in 185 procedures (5.3%): moderate to severe bleeding, in 2.2%; pneumothorax, in 0.7%; severe bronchospasm, in 0.8%; general complications (hypoxemia, psychomotor agitation, arrhythmias, vomiting, or hypotension), in 1.6%; and cardiopulmonary arrest, in 0.03%. There were no deaths related to the procedures. Specifically, among the 1,728 patients undergoing biopsy, bronchial brushing, or fine-needle aspiration biopsy, bleeding occurred in 75 (4.3%). Among the 1,191 patients undergoing transbronchial biopsy, severe pneumothorax (requiring chest tube drainage) occurred in 24 (2.0%). CONCLUSIONS: In our patient sample, FB proved to be a safe method with a low rate of complications. Appropriate continuing training of specialist doctors and nursing staff, as well as the development of standardized care protocols, are important for maintaining those standards.

Rhizobium response to sole and combined exposure to cadmium and the phytocompounds alpha-pinene and quercetin.

Soils can be contaminated with substances arising from anthropogenic sources, but also with natural bioactive compounds produced by plants, such as terpenes and flavonoids. While terpenes and flavonoids have received much less attention from research studies than metals, the effects that phytocompounds can have on soil organisms such as beneficial microorganisms should not be neglected. Herein we report the sole and combined exposure of Rhizobium to cadmium, to the monoterpene alpha-pinene and to the flavanol quercetin. A range of environmentally relevant concentrations of the phytocompounds was tested. Physiological (growth, protein content and intracellular Cd concentration), oxidative damage (lipid peroxidation, protein carbonylation) and antioxidant mechanisms (superoxide dismutase, catalase, glutathione, glutathione-S-transferases, protein electrophoretic profiles) were assessed. Results suggest that exposure to both phytocompounds do not influence Rhizobium growth, but for combined exposure to phytocompounds and Cd, different responses are observed. At low concentrations, phytocompounds seem to relieve the stress imposed by Cd by increasing antioxidant responses, but at high concentrations this advantage is lost and membrane damage may even be exacerbated. Thus, the presence of bioactive phytocompounds in soil may influence the tolerance of microorganisms to persistent toxicants, and may change their impact on the environment.

Airborne exposure of Rhizobium leguminosarum strain E20-8 to volatile monoterpenes: Effects on cells challenged by cadmium.

Volatile organic compounds (VOCs) are produced by plants, fungi, bacteria and animals. These compounds are metabolites originated mainly in catabolic reactions and can be involved in biological processes. In this study, the airborne effects of five monoterpenes (α-pinene, limonene, eucalyptol, linalool, and menthol) on the growth and oxidative status of the rhizobial strain Rhizobium leguminosarum E20-8 were studied, testing the hypothesis that these VOCs could influence Rhizobium growth and tolerance to cadmium. The tested monoterpenes were reported to have diverse effects, such as antibacterial activity (linalool, limonene, α-pinene, eucalyptol), modulation of antioxidant response or antioxidant properties (α-pinene and menthol). Our results showed that non-stressed cells of Rhizobium E20-8 have different responses (growth, cell damage and biochemistry) to monoterpenes, with α-pinene and eucalyptol increasing colonies growth. In stressed cells the majority of monoterpenes failed to minimize the detrimental effects of Cd and increased damage, decreased growth and altered cell biochemistry were observed. However, limonene (1 and 100 mM) and eucalyptol (100 nM) were able to increase the growth of Cd-stressed cells. Our study evidences the influence at-a-distance that organisms able to produce monoterpenes may have on the growth and tolerance of bacterial cells challenged by different environmental conditions.

Impact of gastroesophageal reflux in the pathogenesis of tracheal stenosis.

Benign airway stenosis is a multifactorial and heterogeneous disease often occurring after tracheal intubation. Despite the frequent finding of pathological gastroesophageal reflux (GER) in benign tracheal stenosis, the cause-and-effect relationship between these two entities and its impact on the outcome of the stenosis itself have not been established. The altered ventilatory dynamics caused by an increased thoracoabdominal pressure gradient in such patients has been proposed as a central cause. The presence of GER in a setting of microaspiration can also induce changes in the local collagen proliferation response, as well as in the local microbiome of the tracheal stenosis site, which may potentially cause and enhance the harm imposed to the already diseased tracheal wall. Diagnosis of GER remains underestimated in the general population, thus making its accurate detection and treatment in central airway stenosis a matter of investigation. The high prevalence of GER in tracheal stenosis patients often occurs in the absence of typical upper digestive signs and symptoms, therefore requiring an objective assessment using a 24-hour ambulatory esophageal pH/impedance study that has shown abnormal results in more than half the patients. The impact of the treatment of GER in patients with benign tracheal has been scarcely reported. Our group showed recently that the surgical control of GER through laparoscopic fundoplication in selected patients with tracheal stenosis can improve substantially the chance of resolution of the tracheal stenosis as opposed to the medical management with high dose proton pump inhibitors. This chapter describes the impact of GER in the pathogenesis of tracheal stenosis with a focus on its mechanisms, diagnosis and treatment strategy.