Research trends and hotspots in the field of electrical impedance tomography for mechanical ventilation: a bibliometric analysis.

Background: Electrical impedance tomography (EIT) is a relatively recent functional imaging technique that is both noninvasive and radiation free. EIT measures the associated voltage when a weak current is applied to the surface of the human body to determine the distribution of electrical resistance within tissues. We performed a bibliometrics-based review to explore the geographic hotspots of current research and future trends developing in the field of EIT for mechanical ventilation. Methods: The Web of Science database was searched from its inception to June 25, 2023. CiteSpace software was used to visualize and analyze the relevant literature and identify the most impactful literature, trends, and hotspots. Results: 363 articles describing EIT use in mechanical ventilation were identified. A fluctuating growth in the number of publications was observed from 1998 to 2023. Germany had the highest number of articles (n=154), followed by Italy (n=53) and China (n=52). A cluster analysis of keyword co-occurrence revealed that "titration", "ventilator-related lung injury", and "oxygenation" were the most actively researched terms associated with the use of EIT in mechanically ventilated patients. Conclusions: Significant progress has been made in EIT research for mechanical ventilation. EIT research is limited to a small number of countries with a present research focus on the prevention and treatment of ventilator-related lung injury, oxygenation status, and prone ventilation. These topics are expected to remain research hotspots in the future.

Spray Cryotherapy for Benign Large Airway Stenosis: A Multicenter Retrospective Cohort Study of Safety and Practice Patterns.

BACKGROUND: Benign airway stenosis (BAS) represents a significant burden on patients, providers, and healthcare systems. Spray cryotherapy (SCT) has been proposed as an adjunctive treatment to reduce BAS recurrence. We sought to examine safety and practice variations of the latest SCT system when used for BAS. METHODS: We conducted a retrospective multicenter cohort study in seven academic institutions within the Interventional Pulmonary Outcomes Group. All patients who underwent at least one SCT session with a diagnosis of BAS at the time of procedure at these institutions were included. Demographics, procedure characteristics, and adverse events were captured through each center's procedural database and electronic health record. RESULTS: A total of 102 patients underwent 165 procedures involving SCT from 2013 to 2022. The most frequent etiology of BAS was iatrogenic (n = 36, 35%). In most cases, SCT was used prior to other standard BAS interventions (n = 125; 75%). The most frequent SCT actuation time per cycle was five seconds. Pneumothorax complicated four procedures, requiring tube thoracostomy in two. Significant post-SCT hypoxemia was noted in one case, with recovery by case conclusion and no long-term effects. There were no instances of air embolism, hemodynamic compromise, or procedural or in-hospital mortality. CONCLUSION: SCT as an adjunctive treatment for BAS was associated with a low rate of complications in this retrospective multicenter cohort study. SCT-related procedural aspects varied widely in examined cases, including actuation duration, number of actuations, and timing of actuations relative to other interventions.

Transbronchial Lung Cryobiopsy Performed with Cone Beam Computed Tomography Guidance Versus Fluoroscopy: A Retrospective Cohort Review.

PURPOSE: Determining the cause of interstitial lung disease (ILD) remains challenging. While surgical lung biopsy remains the gold standard approach, risks associated with it may be prohibitive. Transbronchial lung cryobiopsy (TBLC) is a minimally invasive alternative with an improved safety profile and acceptable diagnostic accuracy. We retrospectively assessed whether the use of Cone Beam computed tomography guidance for TBLC (TBLC-CBCT) improves safety and diagnostic yield compared to performing TBLC with fluoroscopic guidance (TBLC-F). METHODS: A retrospective cohort review of 120 patients presenting for evaluation of newly diagnosed ILD was performed. Demographic data, pulmonary function test values, chest imaging pattern, procedural information, and final multidisciplinary discussion (MDD) diagnosis were recorded. RESULTS: 62 patients underwent TBLC-F and 58 underwent TBLC-CBCT. Patients undergoing TBLC-CBCT were older (67.86 ± 10.97 vs 61.45 ± 12.77 years, p = 0.004) and had a higher forced vital capacity percent predicted (73.80 ± 17.32% vs 66.00 ± 17.45%, p = 0.03) compared to the TBLC-F group. The average probe-to-pleura distance was 5.1 ± 2.3 mm in the TBLC-CBCT group with 4.0 ± 0.3 CBCT spins performed. Pneumothorax occurred more often in the TBLC-F group (n = 6, 9.7%) compared to the TBLC-CBCT group (n = 1, 1.7%, p = 0.06). Grade 2 bleeding only occurred in the TBLC-F group (n = 4, 6.5%). A final MDD diagnosis was obtained in 89% (n = 57) of TBLC-F patients and 95% (n = 57) of TBLC-CBCT patients. CONCLUSIONS: TBLC-CBCT appears to be safer compared to TBLC-F with both approaches facilitating an MDD diagnosis. Further studies from multiple institutions randomizing patients to each modality are needed to confirm these findings.

Social vulnerability and lung malignancy mortality.

INTRODUCTION: Lung cancer is a major cause of death in the United States. Social determinants of health (SDOH) are important factors that impact the treatment and prognosis of lung cancer. The social vulnerability index (SVI) is a validated measure of SDOH. This cross-sectional study aimed to investigate the impact of the SVI on lung cancer mortality using descriptive epidemiology. METHODS: Mortality data for lung malignancies from 2014 to 2018 was obtained from the CDC database and was age-adjusted and standardized to the population in the year 2000. The SVI for the same years was obtained from the CDC Agency for Toxic Substances and Disease Registry database. Age-adjusted mortality rates (AAMR) were estimated for each SVI quartile (SVI-Q) and demographic subgroup. RESULTS: We found that counties in SVI-Q4 (most vulnerable) had a higher cumulative AAMR compared to counties in SVI-Q1 (least vulnerable), accounting for a 4.48 excess death rate per 100,000 person-years. AAMR among males in SVI-Q4 was higher compared to SVI-Q1, accounting for a 9.96 excess death rate per 100,000 person-years, whereas no mortality differences were observed for female populations between SVI-Q4 and SVI-Q1. AAMR in SVI-Q4 was higher for both Hispanic and non-Hispanic populations, except for American Indian/Alaska Native populations. Similar trends were observed in both metropolitan and non-metropolitan counties. CONCLUSION: Our study suggests that the SVI may play a significant role in lung cancer mortality and highlights the need for interventions targeting vulnerable populations to improve outcomes.

Prognostic value of initial routine laboratory blood tests in patients with aneurysmal subarachnoid hemorrhage requiring mechanical ventilation: a retrospective cohort study.

Background: Aneurysmal subarachnoid hemorrhage (aSAH) necessitating mechanical ventilation (MV) presents a serious challenge for intensivists. Laboratory blood tests reflect individual physiological and biochemical states, and provide a useful tool for identifying patients with critical condition and stratifying risk levels of death. This study aimed to determine the prognostic role of initial routine laboratory blood tests in these patients. Methods: This retrospective cohort study included 190 aSAH patients requiring MV in the neurosurgical intensive care unit from December 2019 to March 2022. Follow-up evaluation was performed in May 2022 via routine outpatient appointment or telephone interview. The primary outcomes were death occurring within 7 days after discharge (short-term mortality) or reported at time of follow-up (long-term mortality). Clinico-demographic and radiological characteristics, initial routine laboratory blood tests (e.g., metabolic panels and arterial blood gas analysis), and treatment were analyzed and compared in relation to mortality. Multivariable logistic and Cox regression analyses, with adjustment of other clinical predictors, were performed to determine independent laboratory test predictors for short- and long-term mortality, respectively. Results: The patients had a median age of 62 years, with a median World Federation of Neurosurgical Societies grade (WFNS) score of 5 and a median modified Fisher grade (mFisher) score of 4. The short- and long-term mortality of this cohort were 60.5% and 65.3%, respectively. Compared with survivors, non-survivors had more severe disease upon admission based on neurological status and imaging features and a shorter disease course, and were more likely to receive conservative treatment. Initial ionized calcium was found to be independently associate with both short-term [adjusted odds ratio (OR): 0.92; 95% confidence interval (CI): 0.86 to 0.99; P=0.020] and long-term mortality [adjusted hazard ratio (HR): 0.95; 95% CI: 0.92 to 0.99; P=0.010], after adjusting for potential confounders. Moreover, the admission glucose level was found to be associated only with short-term mortality (adjusted OR: 1.19; 95% CI: 1.06 to 1.34; P=0.004). Conclusions: Laboratory screening may provide a useful tool for the management of aSAH patients requiring MV in stratifying risk levels for mortality and for better clinical decision-making. Further study is needed to validate the effects of calcium supplementation and glucose-lowering therapy on the outcomes in this disease.

Real-world utility of a genomic classifier in establishing a diagnosis of newly identified interstitial lung disease.

BACKGROUND: Diagnosing interstitial lung disease (ILD) remains challenging. Guidelines recommend utilizing a multidisciplinary discussion (MDD) to review clinical and radiographic data and if diagnostic uncertainty persists, then to obtain histopathology. Surgical lung biopsy and transbronchial lung cryobiopsy (TBLC) are acceptable methods, but risks of complications may be prohibitive. The Envisia genomic classifier (EGC) represents another option to determine a molecular usual interstitial pneumonia (UIP) signature to facilitate an ILD diagnosis at MDD with high sensitivity and specificity. We evaluated the concordance between TBLC and EGC at MDD and the safety of this procedure. METHODS: Demographic data, pulmonary function values, chest imaging pattern, procedural information, and MDD diagnosis were recorded. Concordance was defined as agreement between the molecular EGC results and histopathology from TBLC in the context of the patient's High Resolution CT pattern. RESULTS: 49 patients were enrolled. Imaging demonstrated a probable (n = 14) or indeterminate (n = 7) UIP pattern in 43% and an alternative pattern in 57% (n = 28). EGC results were positive for UIP in 37% (n = 18) and negative in 63% (n = 31). MDD diagnosis was obtained in 94% (n = 46) with fibrotic hypersensitivity pneumonitis (n = 17, 35%) and IPF (n = 13, 27%) most common. The concordance between EGC and TBLC at MDD was 76% (37/49) with discordant results seen in 24% (12/49) of patients. CONCLUSIONS: There appears to be reasonable concordance between EGC and TBLC results at MDD. Efforts clarifying the contributions of these tools to an ILD diagnosis may help identify specific patient populations that may benefit from a tailored diagnostic approach.

Interstitial lung disease progression after genomic usual interstitial pneumonia testing.

BACKGROUND: A genomic classifier for usual interstitial pneumonia (gUIP) has been shown to predict histological UIP with high specificity, increasing diagnostic confidence for idiopathic pulmonary fibrosis (IPF). Whether those with positive gUIP classification exhibit a progressive, IPF-like phenotype remains unknown. METHODS: A pooled, retrospective analysis of patients who underwent clinically indicated diagnostic bronchoscopy with gUIP testing at seven academic medical centres across the USA was performed. We assessed the association between gUIP classification and 18-month progression-free survival (PFS) using Cox proportional hazards regression. PFS was defined as the time from gUIP testing to death from any cause, lung transplant, ≥10% relative decline in forced vital capacity (FVC) or censoring at the time of last available FVC measure. Longitudinal change in FVC was then compared between gUIP classification groups using a joint regression model. RESULTS: Of 238 consecutive patients who underwent gUIP testing, 192 had available follow-up data and were included in the analysis, including 104 with positive gUIP classification and 88 with negative classification. In multivariable analysis, positive gUIP classification was associated with reduced PFS (hazard ratio 1.58, 95% CI 0.86-2.92; p=0.14), but this did not reach statistical significance. Mean annual change in FVC was -101.8 mL (95% CI -142.7- -60.9 mL; p<0.001) for those with positive gUIP classification and -73.2 mL (95% CI -115.2- -31.1 mL; p<0.001) for those with negative classification (difference 28.7 mL, 95% CI -83.2-25.9 mL; p=0.30). CONCLUSIONS: gUIP classification was not associated with differential rates of PFS or longitudinal FVC decline in a multicentre interstitial lung disease cohort undergoing bronchoscopy as part of the diagnostic evaluation.

Reclassification of risk of malignancy with Percepta Genomic Sequencing Classifier following nondiagnostic bronchoscopy.

INTRODUCTION: Bronchoscopic sampling of pulmonary lesions suspicious for lung cancer is frequently nondiagnostic. A genomic sequencing classifier utilizing bronchial brushings obtained at the time of the bronchoscopy has been shown to provide an accurate reclassification of the risk of malignancy (ROM) based on pre-procedure risk. Our objectives for this study were to determine the frequency with which the classifier up- or down-classifies risk in regular clinical practice and to model the potential clinical utility of that reclassification. METHODS: This observational study retrospectively assessed data from four clinical sites that regularly use the genomic classifier in the bronchoscopic evaluation of indeterminate lesions. Demographics and pre-bronchoscopy ROM were recorded. The frequency of up- and down-classification was calculated. Modeling based on reclassification rates and the performance characteristics of the classifier was performed to demonstrate the potential clinical utility of the result. RESULTS: 86 patients who underwent classifier testing following a nondiagnostic bronchoscopy were included. 45% of patients with high ROM prior to bronchoscopy were reclassified very high-risk. 38% of patients with intermediate ROM were up-or down-classified. 56% of patients with low ROM were reclassified to very low-risk. Overall, 42% of patients had a change in classification. 35% of the study cohort could potentially have avoided additional unnecessary procedures with subsequent guideline-adherent management. CONCLUSIONS: The classifier can guide decision-making following a nondiagnostic bronchoscopy, reclassifying risk in a significant percentage of cases. Use of the classifier should allow more patients with early-stage cancer to proceed directly to curative therapy while helping more patients with benign disease avoid further unnecessary procedures.

Does transbronchial lung cryobiopsy improve diagnostic yield of digital tomosynthesis-assisted electromagnetic navigation guided bronchoscopic biopsy of pulmonary nodules? A pilot study.

INTRODUCTION: Bronchoscopic biopsies have limited sensitivity for small, peripheral lung nodules. Electromagnetic navigation guided bronchoscopy (ENB) with fluoroscopic digital tomosynthesis and a 1.1 mm cryoprobe for transbronchial lung cryobiopsy (TBLC) may improve diagnostic yield. We evaluated the diagnostic yield and safety of this approach. METHODS: 42 patients (45 nodules) underwent sequential biopsies by transbronchial needle aspiration (TBNA), then forceps biopsy (FB), and finally TBLC. Demographic data, nodule characteristics, biopsy results, and procedural complications were recorded. RESULTS: Nodules were predominantly solid (n = 35, 78%), without a bronchus sign (n = 30, 67%), and 33% (n = 15) were <2 cm in all dimensions (mean axial: 25.7 ± 15.3 mm, coronal: 21.0 ± 10.1 mm, sagittal 25.5 ± 16.5 mm). TBNA was the most informative biopsy modality (31/45 diagnoses total, five unique, 69% modality diagnostic yield (MDY)) compared to FB (27/45, one unique, 60% MDY) or TBLC (27/45, six unique, 60% MDY). FB contributed four additional diagnoses, improving diagnostic yield to 80% (36/45). TBLC contributed six additional diagnoses for a final diagnostic yield of 93% (42/45). No bleeding that required intervention or pneumothoraxes occurred. In unadjusted logistic regression models, solid nodules had increased odds of obtaining a diagnosis with TBNA (OR: 5.06; 95% CI: 1.14-22.49) and increased axial dimension nodule size had increased odds of obtaining a diagnosis with TBLC (OR: 1.10; 95% CI: 1.02-1.19). CONCLUSION: ENB guided TBLC of lung nodules appears safe and may increase the final diagnostic yield when combined with other modalities. Future studies identifying nodule characteristics and comparing biopsy tools may clarify the most efficacious approach to maximize yield and minimize risk.

Size and vision: Impact of fluoroscopic navigation, digital tomosynthesis, and continuous catheter tip tracking on diagnostic yield of small, bronchus sign negative lung nodules.

INTRODUCTION: Accurate biopsies of lung nodules, including small (<2 cm), bronchus sign negative lesions, remain challenging. Technological advances, however, may improve outcomes. We describe our experience using a novel system combining fluoroscopic navigation with digital tomosynthesis and continuous catheter tip tracking to guide lung nodule biopsies. METHODS: Demographic data, procedural characteristics, and biopsy results from prospectively enrolled patients were collected. RESULTS: 159 nodules (144 patients) were biopsied. Average nodule size was 22.2 ± 15.2 mm (axial), 21.7 ± 13.9 mm (coronal), and 33.2 ± 20.5 mm (sagittal), with 45% (n = 72) <2 cm in all dimensions and 66% (n = 105) without a bronchus sign. Diagnostic yield was 84% (134/159), with malignancy (n = 75, 47%) most common. A diagnosis was obtained in 75% (n = 54/72) of lesions that were <2 cm in all dimensions and 79% (n = 83/105) of bronchus sign negative lesions. Unadjusted generalized mixed-effects logistic regression models showed that nodule size as a categorical variable (>2 cm in any dimension) and as a continuous variable in the coronal dimension, the presence of a bronchus sign, and a concentric radial EBUS view had an increased odds ratio for diagnosis. A concentric radial EBUS view also had an increased OR for diagnosis in a fully adjusted mixed-effects logistic regression model. CONCLUSION: Fluoroscopic navigation with digital tomosynthesis and continuous catheter tip tracking shows an overall improved diagnostic accuracy compared to historical controls, including for small, bronchus sign negative lesions. Future studies clarifying the optimal modality for patients with different nodules will be of importance to provide the most appropriate procedure tailored to each individual lesion's unique characteristics.

Efficacy and Safety of Cone-Beam CT Augmented Electromagnetic Navigation Guided Bronchoscopic Biopsies of Indeterminate Pulmonary Nodules.

Bronchoscopic biopsy results for indeterminate pulmonary nodules remain suboptimal. Electromagnetic navigation bronchoscopy (ENB) coupled with cone beam computed tomography (CBCT) for confirmation has the potential to improve diagnostic yield. We present our experience using this multimodal approach to biopsy 17 indeterminate nodules in 14 consecutive patients from April to August 2021. Demographic information, nodule characteristics, and biopsy results were recorded. Procedures were performed in a hybrid operating room equipped with a Siemens Artis Q bi-plane CBCT (Siemens, Munich, Germany). After ENB using the superDimension version 7.1 (Medtronic, Plymouth, MN, USA) to target the lesion, radial endobronchial ultrasound was used as secondary confirmation. Next, transbronchial needle aspiration was performed prior to CBCT to evaluate placement of the biopsy tool in the lesion. The average nodule size was 21.7+/−15 mm with 59% (10/17) < 2 cm in all dimensions and 35% (6/17) showing a radiographic bronchus sign. The diagnostic yield of CBCT-guided ENB was 76% (13/17). No immediate periprocedural or postprocedural complications were identified. Our experience with CBCT-guided ENB further supports the comparable efficacy and safety of this procedure compared to other mature biopsy modalities. Studies designed to optimize the lung nodule biopsy process and to determine the contributions from different procedural aspects are warranted.

Noninvasive Management of Fractured Indwelling Tunneled Pleural Catheter Valve.

Tunneled indwelling pleural catheters (IPCs) are frequently used to palliate symptomatic dyspnea due to recurrent pleural effusions. The drainage valve of IPCs is an important component of the catheter as fracture of the valve leads to malfunctioning of the IPCs. Replacement of the catheter includes risks such as pain, infection, pneumothorax, and procedure cost. We report two cases of malfunctioning tunneled IPC drainage valves repaired by our noninvasive method and discuss the need for a repair kit and a standardized approach to this repair in case of nonavailability of repair kits.

An 80-year-old woman with myelofibrosis and diffuse mosaic attenuation on chest computed tomography.

An 80-year-old woman with myelofibrosis sought evaluation for progressive dyspnea. Her past medical history included essential thrombocytosis, which transformed to myelofibrosis. Inspiratory computed tomography of chest showed diffuse mosaic attenuation with lymphadenopathy. Flexible bronchoscopy with lymph node and pulmonary parenchymal cryo biopsy revealed nodular deposits of extramedullary hematopoiesis in lung parenchyma and moderate to severe vascular medial and intimal thickening of pulmonary vasculature consistent with pulmonary parenchymal extramedullary hematopoiesis associated with pulmonary hypertension (a rare compensatory mechanism in myeloproliferative disorders). In this report, we explore the manifestations, pathogenesis, treatment, and prognosis of pulmonary extramedullary hematopoiesis reported in the literature.

A 31-Year-Old Man With Fever, Atypical Chest Pain, and Mediastinal Mass.

CASE PRESENTATION: A 31-year-old Asian male never-smoker living in the upper Midwest with a past medical history of congenital bilateral hearing loss sought treatment with a 1-week history of fever, fatigue, right-sided pleuritic chest pain, shortness of breath, productive cough with mild intermittent hemoptysis, night sweats, and unintentional 10-lb weight loss over 4 weeks. He was adopted from South Korea as an infant, and thus the family history was unknown. He worked in the heating, ventilation, and air conditioning business, performing installations and repairs. There was no known exposure to animals, caves, rivers, lakes, or wooded areas. He travelled to South Korea and New Hampshire approximately 9 months previously. He did not take any medication.

Photodynamic therapy for treatment of recurrent adenocarcinoma of the lung with tracheal oligometastasis.

Introduction: Tracheal neoplasms account for less than 0.1% of all malignancies. The majority of tracheal malignancies are secondary neoplasms from direct tracheal invasion from adjacent structures and less commonly from hematogenous or lymphatic spread from distal malignancies. Evidence-based guidelines for management are lacking. Less invasive bronchoscopic ablation modalities are an option for non-operable patients. We report a case of endotracheal oligometastatic adenocarcinoma successfully treated with photodynamic therapy. Case: A 59-year-old man with past medical history of stage 1 right upper and left upper lobe neoplasm treated with right lobectomy 2 years ago and wedge resection of the lingula ten months ago presented with cough and hemoptysis. Flexible bronchoscopy revealed a 10 mm endoluminal exophytic lesion of the mid-trachea confirmed as lung adenocarcinoma on biopsy. Considering the lack of extra-cartilaginous spread and the small size, a multidisciplinary team recommended local treatment using photodynamic therapy. Surveillance biopsies out to 2 years confirmed lack of disease recurrence. The patient did not experience any adverse effects. Conclusion: PDT as first line therapy for a 10 mm oligometastatic endotracheal adenocarcinoma from recurrent pulmonary malignancy with no extra-cartilaginous spread is an effective modality that is well tolerated and produces a durable response, which in our patient led to complete response without recurrence at 24 months and with no adverse effects or complications. Determining depth of tumor penetration is paramount if the treatment is with curative intent. PDT should be considered as part of a multidisciplinary approach for endotracheal malignant disease.

Transbronchial Lung Cryobiopsy is Safe and Effective for Diagnosing Acutely Ill Hospitalized Patients with New Diffuse Parenchymal Lung Disease.

INTRODUCTION: Transbronchial lung cryobiopsy (TBLC) is an accepted alternative to surgical lung biopsy (SLB) for diagnosing diffuse parenchymal lung disease (DPLD) that is less invasive and results in comparable diagnostic yields. Performing lung biopsies on hospitalized patients, however, has increased risk due to the patient's underlying disease severity. Data evaluating the safety and efficacy of TBLC in hospitalized patients are limited. We present a comparison of TBLC for hospitalized and outpatients and provide the safety and diagnostic yields in these populations. METHODS: Demographic data, pulmonary function values, chest imaging pattern, procedural information, and diagnosis were recorded from enrolled patients. Complications from the procedure were the primary outcomes and diagnostic yield was the secondary outcome. RESULTS: 77 patients (n = 22 hospitalized vs n = 55 outpatient) underwent TBLC during the study period. Comparing adverse events between hospitalized and outpatients revealed no statistically significant differences in pneumothorax (9%, n = 2 vs 5%,n = 3), tube thoracostomy placement (5%, n = 1 vs 2%, n = 1), grade 2 bleeding (9%, n = 2 vs 0%, n = 0), escalation in level of care (5%, n = 1 vs 0%, n = 0), 30-day mortality (9%, n = 2 vs 2%, n = 1), and 60-day mortality (9%, n = 2 vs 4%, n = 2) (p > 0.05 for all). No deaths were attributed to the procedure. 95% of cases received a multidisciplinary conference diagnosis (hospitalized 100%, n = 22 vs outpatients 93%, n = 51, p = 0.32). CONCLUSION: Our experience supports that TBLC may be a safe and effective modality for acutely ill-hospitalized patients with DPLD. Further efforts to enhance procedural safety and to determine the impact of an expedited tissue diagnosis on patient outcomes are needed.