Early Spirometry Following Bronchoscopic Lung Volume Reduction with Endobronchial Valves

Bronchoscopic lung volume reduction (BLVR) by endobronchial valve (EBV) implantation has been shown to improve dyspnea, pulmonary function, exercise capacity, and quality of life in highly selected patients with severe emphysema and hyperinflation. The most frequent adverse event is a pneumothorax (PTX), occurring in approximately one-fifth of the cases due to intrathoracic volume shifts. The majority of these incidents are observed within 48 h post-procedure. However, the delayed occurrence of PTX after hospital discharge is a matter of concern. There is currently no approved concept for its prevention. Particularly, it is unknown whether and when respiratory manoeuvers such as spirometry post EBV treatment are feasible and safe. As per standard operating procedure at the University Hospital Zurich, early spirometry is scheduled after BLVR and prior to the discharge of the patient in order to monitor treatment success. The aim of our retrospective study was to investigate the feasibility and safety of early spirometry. In addition, we hypothesized that early spirometry could be useful to identify patients at risk for late PTX, which may occur after hospital discharge. All patients who underwent BLVR using EBVs between January 2018 and January 2020 at our hospital were enrolled in this study. After excluding 16 patients diagnosed post-procedure with PTX and four patients for other reasons, early spirometry was performed in 61 cases. There was neither a clinically relevant PTX during or after early spirometry nor a late PTX following hospital discharge. In conclusion, we found early spirometry, conducted not sooner than three days following EBV treatment, to be feasible and safe. Furthermore, early spirometry seems to be a useful predictor for successful BLVR, and it may help to decide whether a patient can be discharged. Given the small sample size and the retrospective design of our study, a prospective study that includes routine chest imaging after early spirometry to definitively exclude PTX is needed to recommend early spirometry as part of the standard protocol following EBV treatment.

Airway to Lung Volume Ratio on CT is Associated with Pulmonary Function Transition from Obstructive to Restrictive Pattern in Obesity

Background: Obesity is associated with excessive airway collapse and reduced lung volume; it is unknown whether it affects airway-lung interactions. We sought to compare the airway tree to lung volume ratio, assessed by CT, in obese individuals with and without ventilation disorders.Methods: Participants underwent inspiratory chest CT and pulmonary function. The percentage ratio of the whole airway tree to lung volume, automatically segmented via deep learning, was defined as CT airway volume percent (AWV%). Total airway count (TAC), airway wall area percent (WA%), and other CT indexes were also measured. Results: We evaluated 88 participants including adolescents(age: 14-18, n= 12) and adults (age: 19-25, n= 17; age: 26-35, n= 39; age> 35, n= 20). Obese adolescents had higher forced vital capacity (FVC) (P = 0.001) and lower AWV% (P = 0.008) than obese adults (age >35). Among obese adults, participants with restrictive disorders had larger AWV% (P < 0.001) and those with obstructive disorders showed smaller AWV% (P < 0.001) compared to participants with normal ventilation. AWV% was positively correlated with age and forced expiratory volume in 1 second (FEV1)/FVC and adversely related to FVC (P< 0.05 for all), and in multivariate models, AWV% independently predicted FEV1/FVC (R2 = 0.49, P < 0.001) and FVC (R2 = 0.60, P < 0.001).Conclusion: Transitions in lung function patterns between obese adolescents and adults are associated with airway to lung ratios. The obesity-induced disproportion between the airway tree and lung volume may adversely affect and complicate lung ventilation.

Risk factors for radiation pneumonitis after rotating gantry intensity-modulated radiation therapy for lung cancer

The risk factors for severe radiation pneumonitis (RP) in patients with lung cancer who undergo rotating gantry intensity-modulated radiation therapy (IMRT) using volumetric modulated arc therapy (VMAT) or helical tomotherapy (HT) are poorly understood. Fifty-two patients who received rotating gantry IMRT for locally advanced lung cancer were included in this retrospective study. In total, 31 and 21 patients received VMAT and HT, respectively. The median follow-up duration was 14 months (range, 5.2–33.6). Twenty (38%) and eight (15%) patients developed grade ≥ 2 and ≥ 3 RP, respectively. In multivariate analysis, lung V5 ≥ 40% was associated with grade ≥ 2 RP (P = 0.02), and past medical history of pneumonectomy and total lung volume ≤ 3260 cc were independently associated with grade ≥ 3 RP (P = 0.02 and P = 0.03, respectively). Rotating gantry IMRT was feasible and safe in patients with lung cancer undergoing definitive radiotherapy. Reducing lung V5 may decrease the risk of symptomatic RP, and care should be taken to avoid severe RP after radiotherapy in patients with a past medical history of pneumonectomy and small total lung volume.

Implementation of Bronchoscopic Lung Volume Reduction Using One-Way Endobronchial Valves: A Retrospective Single-Centre Cohort Study

<b><i>Background:</i></b> Bronchoscopic lung volume reduction (BLVR) using 1-way endobronchial valves (EBV) has become a guideline treatment in patients with advanced emphysema. Evidence from this minimally invasive treatment derives mainly from well-designed controlled trials conducted in high-volume specialized intervention centres. Little is known about real-life outcome data in hospitals setting up this novel treatment and which favourable conditions are required for a continuous successful program. <b><i>Objectives:</i></b> In this study, we aim to evaluate the eligibility rate for BLVR and whether the implementation of BLVR in our academic hospital is feasible and yields clinically significant outcomes. <b><i>Method:</i></b> A retrospective evaluation of patients treated with EBV between January 2016 and August 2019 was conducted. COPD assessment test (CAT), forced expiratory volume in 1 s (FEV₁), residual volume (RV), and 6-min walking test (6MWT) were measured at baseline and 3 months after intervention. Paired sample <i>t</i> tests were performed to compare means before and after intervention. <b><i>Results:</i></b> Of 350 subjects screened, 283 (81%) were not suitable for intervention mostly due to lack of a target lobe. The remaining 67 subjects (19%) underwent bronchoscopic assessment, and if suitable, valves were placed in the same session. In total, 55 subjects (16%) were treated with EBV of which 10 did not have complete follow-up: 6 subjects had their valves removed because of severe pneumothorax (<i>n</i> = 2) or lack of benefit (<i>n</i> = 4) and the remaining 4 had missing follow-up data. Finally, 45 patients had complete follow-up at 3 months and showed an average change ± SD in CAT −4 ± 6 points, FEV₁ +190 ± 140 mL, RV −770 ± 790 mL, and +37 ± 65 m on the 6MWT (all <i>p</i> &#x3c; 0.001). After 1-year follow-up, 34 (76%) subjects had their EBV in situ. <b><i>Conclusion:</i></b> Implementing BLVR with EBV is feasible and effective. Only 16% of screened patients were eligible, indicating that this intervention is only applicable in a small subset of highly selected subjects with advanced emphysema, and therefore a high volume of COPD patients is essential for a sustainable BLVR program.

Effects of airway smooth muscle contraction and inflammation on lung tissue compliance

There are renewed interests in using the parameter K of Salazar-Knowles' equation to assess lung tissue compliance. K either decreases or increases when the lung's parenchyma stiffens or loosens, respectively. However, whether K is affected by other common features of respiratory diseases, such as inflammation and airway smooth muscle (ASM) contraction, is unknown. Herein, male C57BL/6 mice were treated intranasally with either saline or lipopolysaccharide (LPS) at 1 mg/Kg to induce pulmonary inflammation. They were then subjected to either a multiple or a single-dose challenge with methacholine to activate ASM to different degrees. A quasi-static pressure-driven partial pressure-volume maneuver was performed before and after methacholine. The Salazar-Knowles' equation was then fitted to the deflation limb of the P-V loop to obtain K, as well as the parameter A, an estimate of lung volume (inspiratory capacity). The fitted curve was also used to derive the quasi-static elastance (Est) at 5 cmH2O. The results demonstrate that LPS and both methacholine challenges increased Est. LPS also decreased A, but did not affect K. In contradistinction, methacholine decreased both A and K in the multiple-dose challenge, while it decreased K but not A in the single-dose challenge. These results suggest that LPS increases Est by reducing the open lung volume (A) and without affecting tissue compliance (K), while methacholine increases Est by decreasing tissue compliance with or without affecting lung volume. We conclude that lung tissue compliance, assessed using the parameter K of Salazar-Knowles' equation, is insensitive to inflammation but sensitive to ASM contraction.

Monitoring Expired CO2 Kinetics to Individualize Lung-Protective Ventilation in Patients With the Acute Respiratory Distress Syndrome

Mechanical ventilation (MV) is a lifesaving supportive intervention in the management of acute respiratory distress syndrome (ARDS), buying time while the primary precipitating cause is being corrected. However, MV can contribute to a worsening of the primary lung injury, known as ventilation-induced lung injury (VILI), which could have an important impact on outcome. The ARDS lung is characterized by diffuse and heterogeneous lung damage and is particularly prone to suffer the consequences of an excessive mechanical stress imposed by higher airway pressures and volumes during MV. Of major concern is cyclic overdistension, affecting those lung segments receiving a proportionally higher tidal volume in an overall reduced lung volume. Theoretically, healthier lung regions are submitted to a larger stress and cyclic deformation and thus at high risk for developing VILI. Clinicians have difficulties in detecting VILI, particularly cyclic overdistension at the bedside, since routine monitoring of gas exchange and lung mechanics are relatively insensitive to this mechanism of VILI. Expired CO2 kinetics integrates relevant pathophysiological information of high interest for monitoring. CO2 is produced by cell metabolism in large daily quantities. After diffusing to tissue capillaries, CO2 is transported first by the venous and then by pulmonary circulation to the lung. Thereafter diffusing from capillaries to lung alveoli, it is finally convectively transported by lung ventilation for its elimination to the atmosphere. Modern readily clinically available sensor technology integrates information related to pulmonary ventilation, perfusion, and gas exchange from the single analysis of expired CO2 kinetics measured at the airway opening. Current volumetric capnography (VCap), the representation of the volume of expired CO2 in one single breath, informs about pulmonary perfusion, end-expiratory lung volume, dead space, and pulmonary ventilation inhomogeneities, all intimately related to cyclic overdistension during MV. Additionally, the recently described capnodynamic method provides the possibility to continuously measure the end-expiratory lung volume and effective pulmonary blood flow. All this information is accessed non-invasively and breath-by-breath helping clinicians to personalize ventilatory settings at the bedside and minimize overdistension and cyclic deformation of lung tissue.

Literature Review : Hubungan Obesitas dengan Kejadian Asma

Asthma can be worsened by obesity because obesity can cause a decrease in the pulmonary compliance system, lung volume, and airway diameter. Therefore, it is necessary to maintain an ideal body weight to prevent obesity and the incidence of asthma.The purpose of this literature review study was to describe the correlation between obesity and the incidence of asthma.This research used the Google Scholar database, Garuda Portal and PUBMED. The keywords used in searching for articles on the Google Scholar database and Garuda Portal were “obesity” and “asma”, while on PUBMED ere “obesity and asthma”.The results of a literature review of 5 article showed that there was a correlation between obesity and the incidence of asthma.The conclusion from this study showed that the result of obesity and asthma was 52% and the result from the “non-overweighted but have asthma” respondent was 48%. The p-value was less than 0,005. It means that the p-value is smaller. Therefore, it can be concluded that there is a correlation between obesity and the incidence of asthma. Keywords : Asthma, Obesity AbstrakAsma dapat diperburuk dengan adanya obesitas disamping itu obesitas dapat menyebabkan penurunan sistem komplians paru, volume paru dan diameter saluran napas. Oleh karena itu harus menjaga berat badan agar tetap ideal supaya tidak terjadi obesitas dan kejadian asma. Tujuan dari penelitian literature review ini adalah untuk mengetahui apakah ada hubungan obesitas dengan kejadian asma.Penelitian ini menggunakan database Google Schoolar, Portal Garuda dan PUBMED. Untuk database Google Schoolar dan Portal Garuda menggunakan kata kunci “obesitas dan asma” sedangkan pada PUBMED menggunakan kata kunci “obesity and asthma”.Hasil literature review dari 5 artikel didapatkan bahwa adanya hubungan antara obesitas dengan kejadian asma.Simpulan dari penelitian literature review ini menunjukan hasil obesitas dan asma sebanyak 52% serta hasil tidak obesitas tetapi mengalami asma sebanyak 48% dan nilai p value menghasilkan < 0,005 yang bearti nilai p value lebih kecil. Jadi dapat disimpulkan adanya hubungan antara obesitas dengan kejadian asma. Kata kunci : Asma, Obesitas