The acute effect of inhaled nitric oxide on the exercise capacity of patients with advanced interstitial lung disease: a randomized controlled trial.

BACKGROUND: Inhaled nitric oxide (iNO) selectively acts on the pulmonary vasculature of ventilated lung tissue by reducing pulmonary vascular resistance and intrapulmonary shunt. This effect may reduce ventilation/perfusion mismatch and decrease pulmonary hypertension in patients with interstitial lung disease. METHODS: In a prospective, single-blinded, randomized, placebo-controlled trial, participants with advanced interstitial lung disease, underwent two separate six-minute walk tests (6MWT): one with iNO and the other with a placebo. The primary outcome measured the difference in meters between the distances covered in the two tests. Secondary outcomes included oxygen saturation levels, distance-saturation product, and Borg dyspnea score. A predefined subgroup analysis was conducted for patients with pulmonary hypertension. RESULTS: Overall, 44 patients were included in the final analysis. The 6MWT distance was similar for iNO treatment and placebo, median 362 m (IQR 265-409) vs 371 m (IQR 250-407), respectively (p = 0.29). Subgroup analysis for patients with pulmonary hypertension showed no difference in 6MWT distance with iNO and placebo, median 339 (256-402) vs 332 (238-403) for the iNO and placebo tests respectively (P=0.50). No correlation was observed between mean pulmonary artery pressure values and the change in 6MWT distance with iNO versus placebo (spearman correlation Coefficient 0.24, P=0.33). CONCLUSION: In patients with advanced interstitial lung disease, both with and without concurrent pulmonary hypertension, the administration of inhaled nitric oxide failed to elicit beneficial effects on the six-minute walk distance and oxygen saturation. The use of inhaled NO was found to be safe and did not lead to any serious side effects. TRIAL REGISTRATION: (NCT03873298, MOH_2018-04-24_002331).

Endobronchial closure of broncho-biliary fistula using Amplatzer device: Case report.

Broncho-biliary fistula (BBF) is an extremely rare but serious medical condition resulting from pathological communication between the biliary system and the bronchial tree. Treatment options include both surgical and non-surgical approaches. Several endobronchial techniques, such as the spigot and glue, can be used for this purpose. This report discusses a patient who developed a broncho-biliary fistula following a liver biopsy. The BBF was diagnosed during bronchoscopy and successfully treated with an endobronchial Amplatzer device. To the best of our knowledge, this is the first report of the use of the Amplatzer device to manage BBF.

A single center Israeli experience in pregnancy post lung transplantation: Feasibility of successful two or more full-term pregnancies in individual lung transplant recipients.

INTRODUCTION: Female lung transplant recipients (LTRs) of reproductive age are increasingly considering pregnancy due to advances in post-transplant management and improved survival. We report our experience with pregnancy in LTRs, with an emphasis on two or more successful full-term pregnancies in individual transplant recipients. METHODS: We conducted a retrospective analysis of pregnancies in LTRs at our transplant center and collected maternal and fetal outcomes. RESULTS: In our patient cohort, eight female LTRs conceived a total of 17 pregnancies, resulting in 13 newborns, 12 at full term, and 11 with a birth weight > 2.5 kg. Three of the LTRs had two or more successful full-term pregnancies. LTRs required a significant tacrolimus dose increase to maintain target trough levels during pregnancy. Six recipients are currently clinically stable and active, three with lung function comparable to pre-pregnancy values, and three with evidence of chronic lung allograft dysfunction (CLAD), but stable lung function. Two of the eight LTRs died subsequent to childbirth secondary to chronic respiratory failure due to CLAD, at a mean of 11 years post-transplantation and a mean of 4.5 years after childbirth. CONCLUSION: Pregnancy following lung transplantation is feasible and can be achieved with acceptable maternal and newborn outcomes. Importantly, LTRs can successfully have two or more full-term pregnancies.

Amplatzer Occluders for Effective Nonsurgical Management of Bronchopleural Fistulae.

BACKGROUND: To assess the safety and efficacy of bronchopleural fistulae closure with Amplatzer occluder devices (AGA Medical, Golden Valley, MN) through our experience of over 14 years. METHODS: Retrospective data review of patients from Rabin Medical Center who underwent Amplatzer occluder device placement between March 2007 and September 2021 for bronchopleural fistulae closure. RESULTS: In total, 72 patients had 83 Amplatzer occluder devices implanted for bronchopleural fistulae closure. The median age was 65.5 (interquartile range 56.0-72.3) years. The primary diseases were lung malignancy (48 [66.7%]) and thoracic infection (9 [12.5%]). Bronchopleural fistulae developed mainly following pneumonectomy (40.3%) and lobectomy (33.3%), with a median time from surgery to Amplatzer placement of 3.9 (interquartile range 1.4-16.4) months. We encountered no procedural or immediate postprocedural complications or deaths. Six months after Amplatzer insertion, there were 7 (8.4%) Amplatzer removals and 11 (15.3%) fistula-related deaths. CONCLUSIONS: Amplatzer occluders are a safe modality for nonsurgical bronchopleural fistulae management with ease of placement under moderate sedation and flexible bronchoscopy with good short- and long-term effectivity.

Bronchoscopy for management and identification of etiology of right middle lobe syndrome: Analysis of 66 cases.

BACKGROUND: Right middle lobe (RML) syndrome is a recurrent or chronic obstruction of the RML causing atelectasis of the right middle lobe due to mechanical and nonmechanical etiologies. The consequences of untreated RML syndrome range from chronic cough to post-obstructive pneumonia and bronchiectasis. We report here our bronchoscopy experience in patients with RML syndrome. METHODS: We conducted a retrospective study of adult patients who underwent bronchoscopy for RML syndrome at Rabin Medical Center from 2008 through 2022. Demographic data and medical history, bronchoscopy findings and procedures, and follow-up results were collected. RESULTS: A total of 66 patients (57.6% male, mean age 63 ± 13 years) underwent bronchoscopy for RML syndrome during the study period. Bronchoscopy revealed a mechanical etiology in 49 (74.2%) cases, including endobronchial mass (21, 31.8%) and external compression (7, 10.6%). Malignancy was identified in 20 (30.3%) cases. In 62 patients (93.9%), the bronchoscopy resulted in partial or complete reopening of the RML bronchus. The therapeutic bronchoscopic procedures were balloon dilatation (19), laser ablation (17), mechanical debridement (12), endobronchial stent insertion (11), and cryoablation (6). CONCLUSIONS: Malignancy was identified as the etiology of RML syndrome in approximately 25% of cases, suggesting bronchoscopy should be performed in every case of RML atelectasis. To our knowledge, this is the first reported series of endobronchial stenting of the RML bronchus in the context of RML syndrome.

Immunogenicity of a Third Dose of BNT162b2 Vaccine among Lung Transplant Recipients-A Prospective Cohort Study.

Two doses of mRNA SARS-CoV-2 vaccines elicit an attenuated humoral immune response among immunocompromised patients. Our study aimed to assess the immunogenicity of a third dose of the BNT162b2 vaccine among lung transplant recipients (LTRs). We prospectively evaluated the humoral response by measuring anti-spike SARS-CoV-2 and neutralizing antibodies in 139 vaccinated LTRs ~4-6 weeks following the third vaccine dose. The t-cell response was evaluated by IFNγ assay. The primary outcome was the seropositivity rate following the third vaccine dose. Secondary outcomes included: positive neutralizing antibody and cellular immune response rate, adverse events, and COVID-19 infections. Results were compared to a control group of 41 healthcare workers. Among LTRs, 42.4% had a seropositive antibody titer, and 17.2% had a positive t-cell response. Seropositivity was associated with younger age (t = 3.736, p < 0.001), higher GFR (t = 2.355, p = 0.011), and longer duration from transplantation (t = -1.992, p = 0.024). Antibody titer positively correlated with neutralizing antibodies (r = 0.955, p < 0.001). The current study may suggest the enhancement of immunogenicity by using booster doses. Since monoclonal antibodies have limited effectiveness against prevalent sub-variants and LTRs are prone to severe COVID-19 morbidity, vaccination remains crucial for this vulnerable population.

Lung Transplantation for Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation: A Single-center Experience.

BACKGROUND: Late-onset pulmonary complications can occur following hematological stem cell transplantation (HSCT). In allogeneic HSCT these complications are often associated with chronic graft-versus-host disease (GVHD). Lung transplantation (LTx) often remains the only viable therapeutic option in these patients. OBJECTIVES: To describe our experience with LTx due to GVHD after HSCT and to compare the long-term survival of this group of patients to the overall survival of our cohort of LTx recipients for other indications. METHODS: We retrospectively retrieved all data on patients who had undergone LTx for end-stage lung disease as a sequela of allogeneic HSCT, between 1997 and 2021, at Rabin Medical Center in Israel. RESULTS: A total of 15 of 850 patients (1.7%) from our cohort of LTx recipients fulfilled the criteria of LTx as a sequela of late pulmonary complication after allogeneic HSCT. The median age at the time of HSCT was 33 years (median 15-53, range 3-60). The median time between HSCT and first signs of chronic pulmonary GVHD was 24 months (interquartile range [IQR] 12-80). The median time from HSCT to LTx was 96 months (IQR 63-120). Multivariate analysis showed that patients transplanted due to GVHD had similar survival compared to patients who were transplanted for other indications. CONCLUSIONS: LTx for GVHD after allogeneic HSCT constitutes an important treatment strategy. The overall survival appears to be comparable to patients after LTx for other indications.

Prognostic Significance of the N-Terminal Pro-B-Type Natriuretic Peptide in Lung Transplant Candidates on the Waiting List.

We investigated the prognostic significance of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in lung transplant candidates, in a retrospective single-center study. Data regarding various baseline characteristics and all-cause mortality were collected for 205 lung transplant candidates placed on waitlist for transplantation from November 2017 to December 2019. Associations of NT-proBNP levels with baseline characteristics and mortality were analyzed. Results showed NT-proBNP values correlated positively with age, forced vital capacity, mean pulmonary artery pressure (MPAP), and pulmonary capillary wedge pressure; and negatively with diffusing lung capacity for carbon monoxide and cardiac index. The optimal cut-off of NT-proBNP for predicting MPAP levels > 35 mmHg was 251 pg/mL; with 58.1% sensitivity, 85.7% specificity, 45.0% positive predictive value, and 91.0% negative predictive value. During a median follow-up period of 2.2 years, 97 patients underwent lung transplantation, 42 died waiting for donation, and 66 were alive and still waiting for transplantations. On multivariate analysis, higher NT-proBNP levels were strongly associated with increased mortality among waitlisted lung transplant candidates (HR 1.49, 95% CI 1.10−2.03, p = 0.01). In conclusion NT-proBNP can predict mortality among waitlisted lung transplant candidates. Lower levels of NT-proBNP can preclude severe pulmonary artery hypertension. Assessment of NT-proBNP may improve risk stratification among lung transplant candidates.

Successful treatment of acute relapse of chronic eosinophilic pneumonia with benralizumab and without corticosteroids: A case report.

BACKGROUND: Currently, the mainstay of chronic eosinophilic pneumonia (CEP) treatment is corticosteroids, usually with a favorable response and good prognosis. However, relapse is common, requiring long-term use of corticosteroids, with risk of significant treatment-related complications. The dire need to develop new treatments for patients with CEP, who are dependent on, or resistant to corticosteroids has led to exploring novel therapies. We herein describe a patient with acute relapse of CEP, who was successfully treated with benralizumab, an IL-5Rα antagonist that has demonstrated rapid anti-eosinophil action in patients with asthma. Currently, only three recent patient reports on CEP relapse, also demonstrated successful treatment with benralizumab alone, without corticosteroids. CASE SUMMARY: A 31-year-old non-smoking woman presented in our hospital with a 3 wk history of shortness of breath, dry cough and fever up to 38.3 °C. Laboratory examination revealed leukocytosis 10240 K/µL, eosinophilia 900 K/µL and normal values of hemoglobin, platelets, creatinine and liver enzymes. Computed tomography of the chest showed a mediastinal lymphadenopathy and consolidations in the right upper and left lower lobes. CEP was diagnosed, and the patient was treated with hydrocortisone intravenously, followed by oral prednisone, with prompt improvement. Three months later, she presented with relapse of CEP: aggravation of dyspnea, rising of eosinophilia and extension of pulmonary infiltrates on chest X-ray. She was treated with benralizumab only, with clinical improvement within 2 wk, and complete resolution of lung infiltrates following 5 wk. CONCLUSION: Due to Benralizumab's dual mechanism of action, it both neutralizes IL-5Rα pro-eosinophil functions and triggers apoptosis of eosinophils. We therefore maintain benralizumab can serve as a reasonable therapy choice for every patient with chronic eosinophilic pneumonia and a good alternative for corticosteroids.

Mediastinal "deep freeze"-transcarinal lymph node cryobiopsy.

BACKGROUND: The diagnostic yield of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) from mediastinal lymph nodes ranges from 66%-89%. However, in many cases cytologic material is not sufficient for full molecular evaluation. A novel method of transcarinal cryobiopsy aims to provide bronchoscopically obtained, larger specimen samples from mediastinal lymph nodes. We aimed to assess the efficacy and safety of transcarinal EBUS-guided lymph node cryobiopsy. METHODS: Patients referred for EBUS-TBNA, based on abnormal mediastinal clinical and radiographic findings, were enrolled into this prospective interventional study between July 2020 and August 2021. All EBUS-TBNA procedures were performed using ProCore 22G needle (Cook Medical) to create, both a transcarinal tract for the cryoprobe and to obtain TBNA samples. For EBUS guided transcarinal cryobiopsy, we used flexible 1.1 mm or 1.7 mm cryoprobe inserted into the working channel of the EBUS scope and into the target subcarinal lymph node. RESULTS: Twenty-four patients with male predominance 2:1 and mean age of 60.12 ± 10.16 years were enrolled. All target lymph nodes had hypoechoic, homogenic consistency with demarcated borders, without central structures. Cryobiopsy provided pathological diagnosis in 20 cases (83.33%), with 1.1 mm cryoprobe in 14 and with 1.7 mm cryoprobe in 6 cases. In one case each, pathology was provided by TBNA or by cryoprobe alone. No immediate or late complications were encountered during the procedures. CONCLUSION: Transcarinal EBUS guided lymph node cryobiopsy following EBUS-TBNA proved to be efficient with a high diagnostic yield and can be considered safe, because no immediate or late complications occurred.

Marked safety and high diagnostic yield of freehand ultrasound-guided core-needle biopsies performed by pulmonologists.

BACKGROUND: Adequate tissue sampling is fundamental for establishing a definitive diagnosis, assessing prognosis and tailoring therapy. Each of the methods for obtaining tissue (e.g., endoscopic, image guidance and surgical biopsies) results in a different diagnostic yield and complication rate profile. OBJECTIVES: Present feasibility, and assess safety and efficacy of freehand transthoracic ultrasound-guided core-needle biopsies (USGNB) of thoracic lesions performed by pulmonologist. METHODS: A retrospective analysis study of ultrasound-guided core-needle biopsies of thoracic lesions performed at the Pulmonary Institute of Rabin Medical Center was conducted from September 2020 to October 2021. All core-needle biopsies were performed under local anesthesia with guidance of Mindray TE7 2019 US system. Procedural variables including complications and pathological diagnostic yield were the primary end point. IRB 0671-21-RMC. RESULTS: In total 91 biopsy procedures were analyzed in38 females and 53 males, average age 71.1 years. Twenty-three (25.3%) cases were lung lesions, 7 (7.7%) - mediastinal, 13 (14.3%) - chest wall, 27 (29.7%) - pleural, and 21 (23.1%) supraclavicular lesions. Average lesion size was 51.6 mm, the largest in the mediastinum and the smallest in supraclavicular locations (97.7mm and 28.0 mm, respectively). Overall pathological diagnostic yield was 90%, highest success in chest wall (100%) and lowest in mediastinal biopsies (71.4%). We had only one complication -hemothorax resolved by chest tube drainage- accounting for only 1.1% complication rate. CONCLUSION: Safety and efficacy were demonstrated in freehand US-guided core-needle biopsy of thoracic lesions performed by pulmonologists. We suggest thoracic ultrasound and USG-CNB be part of training and clinical practice in interventional pulmonology.

Dexmedetomidine versus propofol sedation in flexible bronchoscopy: a randomized controlled trial.

BACKGROUND: Dexmedetomidine (DEX), is a highly selective alpha2 adrenoceptor (α2-AR) agonist, successfully used in various procedures including flexible bronchoscopy. Randomized controlled trials (RCTs) evaluating DEX sedation during bronchoscopy report equivocal results regarding respiratory and hemodynamic outcomes. METHODS: We conducted an RCT to evaluate the efficacy and safety of dexmedetomidine compared to propofol for sedation during bronchoscopy. The primary outcome was the number of desaturation events, secondary outcomes were transcutaneous Pco2 level, hemodynamic adverse events and physician and patient satisfaction. RESULTS: Overall, 63 patients were included, 30 and 33 in the DEX and propofol groups, respectively. The number of desaturation events was similar between groups, median (IQR) 1 (0-1) and 1 (0-2) in the DEX and control groups, respectively (P = 0.29). Median desaturation time was 1 (0-2) and 1 (0-3) minutes in the DEX and control groups, respectively (P = 0.48). Adverse events included hypotension, 33% vs 21.1% in intervention and control groups, respectively (P = 0.04), bradycardia, cough, and delayed recovery from sedation. Total adverse events were 22 and 7 in DEX and propofol groups, respectively (P = 0.009). CONCLUSION: Dexmedetomidine sedation during bronchoscopy did not show differences in oxygen saturation and transcutaneous CO2 level in comparison to propofol. Moreover, DEX sedation required a significantly higher number of rescue boluses, due to inadequate sedation and was associated with a higher rate of adverse events. Trial registration NCT04211298, registration date: 26.12.2019.

Preoperative evaluation of pulmonary hypertension in lung transplant candidates: echocardiography versus right heart catheterization.

BACKGROUND: Right heart catheterization (RHC) and echocardiography are both routinely used for pulmonary artery systolic pressure (PASP) assessment in lung transplantation (LT) candidates, although this is not mandated by current guidelines. We aimed to explore the performance of echocardiographic PASP as an indicator of pulmonary hypertension in LT candidates, in order to assess the necessity of RHC. METHODS: From a retrospective registry of 393 LT candidates undergoing RHC and echocardiography during 2015-2019, patients were assessed for the presence of pulmonary hypertension (PH), defined as mean pulmonary artery pressure (mPAP) above 20 mmHg, according to two methods-echocardiography and RHC. The primary outcome was the correlation between the PASP estimated by echocardiography to that measured by RHC. Secondary outcomes were the prediction value of the echocardiographic evaluation and its accuracy. RESULTS: The mean value of PASP estimated by echocardiography was 49.5 ± 20.0 mmHg, compared to 42.5 ± 18.0 mmHg measured by RHC. The correlation between the two measurements was moderate (Pearson's correlation: r = 0.609, p < 0.01). Echocardiography PASP measurements were moderately discriminative to diagnose PH, with an area under the curve (AUC) of 0.72 (95% CI 0.66-0.77). Echocardiographic overestimation of PASP of more than 10 mmHg was found in 35.0% of the patients, and underestimation was found in 11.6% of the patients. CONCLUSION: In the pre-surgical evaluation of LT candidates, echocardiographic estimation of PASP had moderate correlation and limited accuracy compared to the PASP measured by RHC. We thus recommend performing routine RHC to all LT candidates, regardless of the echocardiographic estimation of PASP.

Sertraline-Associated Interstitial Lung Disease: A case series and Literature Review.

Sertraline-associated interstitial lung disease (ILD) is a rare entity. A search of the English medical literature retrieved only 9 such cases. We report herein on an additional 12 patients who developed ILD during treatment with sertraline. The patients met the criteria for drug-induced pulmonary toxicity such as exposure to drug, correlation of the drug with clinical symptoms, lung imaging, lung biopsy findings, exclusion of other potential causes and improvement after drug removal. We review the available data and discuss various aspects of this entity. The possibility of drug-induced ILD should be considered in an individual who during treatment with sertraline develops dyspnea, cough, and radiographic findings compatible with ILD. Further epidemiological studies should be conducted to explore the association of sertraline treatment with ILD, and to delineate, substantiate, and broaden our knowledge of this rare entity.

Effect of Endobronchial Coils on Exercise Tolerance and Lung Functions in Patients with Severe Emphysema - A Retrospective Cohort Study of 48 Patients.

BACKGROUND: Lung volume reduction with endobronchial coils treatment (ECT), for patients with severe emphysema, has shown modest improvement in exercise capacity and lung functions in clinical trials, yet the benefit of this procedure is still unclear. METHODS: We conducted a multicenter retrospective cohort study including all patients who underwent ECT in Israel and a propensity score matched control group of patients with chronic obstructive pulmonary disease (COPD) that were treated with usual care. The primary outcome was six-minute walk test distance (6MWTD), secondary outcomes were lung function tests and patient survival. RESULTS: Overall, 46 patients were included in the ECT group. Their mean 6MWTD at baseline and at 6 and at 24 months post procedure was 331.0±101.4, 372.9±76.8 and 338.8±104.8, respectively (overall P=0.04, pairwise comparison: baseline to 6 months (P=0.1), baseline to 24 months (P=1.0)). Mean FEV1 values at baseline and at 6 and at 24 months post procedure were 0.86±0.38, 0.92±0.37 and 0.82±0.36 liters, respectively (overall P=0.003, pairwise comparison: baseline to 6 months (P=0.04), baseline to 24 months (P=0.75)). The median 6MWTD for the ECT and control groups at 24 months were 333.0 (262.5-390) and 280 (210-405), respectively (P=0.16). There was no difference in overall survival (P=0.84). Heterogenous emphysema was a significant predictor of treatment success in univariate analysis (p=0.004). CONCLUSION: Lung volume reduction with endobronchial coils may improve the exercise capacity and FEV1 of COPD patients. However, the majority of the effect was diminished after 24 months. The current state of evidence does not support regulatory approval of ECT and warrant its use only after consideration of the benefit-harm ratio in a highly selected patient population.

Quantitation of Silica Contents in Lung Explants of Transplanted Patients: Artificial Stone-Induced Silicosis vs. Idiopathic Pulmonary Fibrosis.

Spectrophotometric techniques provide qualitative but not quantitative data on lung particles. We aimed to quantitate silica content in biopsies of lung-transplanted silicosis patients by applying X-ray fluorescence (XRF) spectrometry. Lung biopsies of 17 lung-transplanted artificial patients were quantitated for silica and other minerals particles by Niton XL3 XRF spectrometry. Occupational and clinical history data were assessed. Lung biopsies of artificial stone-induced silicosis (ASIS) patients contained significantly higher levels of silica compared to those of idiopathic pulmonary fibrosis (IPF) patients (7284.29 ± 4693.75 ppm vs. 898.88 ± 365.66 ppm, p < 0.0001). Silica content correlated negatively with age, body mass index, and pulmonary function test results. A 1128 ppm silica cut-off value yielded 100% sensitivity and 94% specificity for predicting ASIS (AUC = 0.94, p < 0.0001). In conclusion, XRF measurements in lung biopsies can differentiate between silica and mineral particles in ASIS and IPF.

The LungVision navigational platform for peripheral lung nodule biopsy and the added value of cryobiopsy.

BACKGROUND: The LungVision system is a novel augmented-fluoroscopy-based real-time navigation and guidance technology for bronchoscopy that can be integrated with any standard biopsy tool, including the cryoprobe, to enable real-time visualization and localization of pulmonary nodules. OBJECTIVES: To evaluate the diagnostic yield and safety among patients undergoing peripheral pulmonary nodule biopsy with the LungVision system. METHODS: This prospective, single-center study was conducted at Rabin Medical Center in Israel. All patients that underwent peripheral pulmonary nodule biopsy with the LungVision system from January 2016 to August 2020 were included. All procedures were performed under moderate sedation. The primary outcome was tissue diagnosis by either identification of malignant cells or benign diagnosis. Secondary outcomes were safety and the added value of cryobiopsy. RESULTS: Sixty-three procedures were performed during the study period. Median lesion size (interquartile range) was 25.0 mm (18-28 mm). The diagnostic yield overall was 27/33 (81.8%) and for lesions smaller than 20 mm was 13/18 (72.2%). In nine cases the transbronchial cryobiopsy showed tissue with malignant cells that were not found in any other biopsy material taken with other sampling tools. One patient was treated with a chest tube for a pneumothorax. No other major complications were reported. CONCLUSIONS: The LungVision system showed good feasibility and safety for peripheral pulmonary nodule biopsy. The system is compatible with all biopsy tools, including the cryoprobe. Randomized controlled trials are needed to accurately ascertain its diagnostic yield.

Use of capnography for prediction of obstruction severity in non-intubated COPD and asthma patients.

BACKGROUND: Capnography waveform contains essential information regarding physiological characteristics of the airway and thus indicative of the level of airway obstruction. Our aim was to develop a capnography-based, point-of-care tool that can estimate the level of obstruction in patients with asthma and COPD. METHODS: Two prospective observational studies conducted between September 2016 and May 2018 at Rabin Medical Center, Israel, included healthy, asthma and COPD patient groups. Each patient underwent spirometry test and continuous capnography, as part of, either methacholine challenge test for asthma diagnosis or bronchodilator reversibility test for asthma and COPD routine evaluation. Continuous capnography signal, divided into single breaths waveforms, were analyzed to identify waveform features, to create a predictive model for FEV1 using an artificial neural network. The gold standard for comparison was FEV1 measured with spirometry. MEASUREMENTS AND MAIN RESULTS: Overall 160 patients analyzed. Model prediction included 32/88 waveform features and three demographic features (age, gender and height). The model showed excellent correlation with FEV1 (R = 0.84), R2 achieved was 0.7 with mean square error of 0.13. CONCLUSION: In this study we have developed a model to evaluate FEV1 in asthma and COPD patients. Using this model, as a point-of-care tool, we can evaluate the airway obstruction level without reliance on patient cooperation. Moreover, continuous FEV1 monitoring can identify disease fluctuations, response to treatment and guide therapy. TRIAL REGISTRATION: clinical trials.gov, NCT02805114. Registered 17 June 2016, https://clinicaltrials.gov/ct2/show/NCT02805114.