BACKGROUND:Pulmonary alveolar proteinosis (PAP) is a rare disease. Only a small number of case reports describing lung transplantation (LTx) as a treatment option for PAP have been published. Due to this limited evidence, current guidelines on LTx for PAP remain vague. To address this gap, we collected cases of LTx for PAP worldwide. METHODS:214 centres were approached to contribute any cases of LTx performed for PAP. Re-transplantations and multi-organ transplantations were excluded. Patients were divided into two groups based on the presence of PAP recurrence after LTx. Time-to-event analyses were performed using Kaplan-Meier curves and Cox proportional-hazards modelling was performed with PAP recurrence as a time-dependent covariate. RESULTS:At a response rate of 64%, 31 centres contributed 63 patients. Most had primary PAP (n=20; 39.2%). Six patients with secondary PAP were identified (11.8%), while seven (13.7%) had congenital and 18 (35.3%) unclassified PAP. Aetiology was not specified in 12. Patients underwent transplantation at a median (interquartile range) 11 (3-17) years after initial diagnosis. Nine (15%) patients developed PAP recurrence after LTx. No significant difference was found regarding patient characteristics between the patients with versus without recurrence. Freedom from recurrence was 96.2% (1 year), 83.5% (5 years) and 70.1% (10 years) post-LTx. PAP recurrence as time-dependent covariate was not significantly associated with graft loss (hazard ratio 1.88, 95% CI 0.51-6.91; p=0.342) in a Cox proportional-hazards model. CONCLUSION:LTx provides excellent peri-operative and long-term outcomes for patients with end-stage PAP and should be recommended in treatment guidelines. Although recurrence of PAP occurs in ∼15% of cases, overall survival appeared unaffected in our limited dataset.

BACKGROUND:Operating room noise can result in provider- and patient-related adverse outcomes. The recommended sound pressure threshold in medical settings is 35-45 dB(A). This study aimed to quantify sound pressure across different types of bronchoscopy procedures. METHODS:Sound meters were placed in the bronchoscopy suite. Ambient sound pressure levels were measured continuously during flexible, rigid, and robotic bronchoscopy procedures. Procedures were classified as "quiet" or "loud" using the median equivalent continuous sound pressure level (Leq). A logistic regression model was used to identify associations between the type of bronchoscopy and "loud" or "quiet" procedures. RESULTS:A total of 186 procedures were analyzed, of which 64% were flexible, 11% were rigid, and 25% were robotic. Across all procedures, the median Leq was 56.8 (55.1 to 58.1) dB(A). Leq was 58.2 (57.5 to 58.9), 59.4 (58.6 to 60.5), and 57.9 (57.5 to 58.4) dB(A) for flexible, rigid, and robotic bronchoscopy, respectively (P<0.0001). In comparison to flexible bronchoscopy, rigid bronchoscopy was more likely to be loud, while robotic bronchoscopy was less likely to be loud. CONCLUSION:This is the first study to quantify sound pressure levels during bronchoscopy procedures. Across all types of bronchoscopy procedures, sound pressure levels exceeded those recommended by guidelines for the medical setting and were considered a moderate degree of noise. Rigid bronchoscopy was associated with higher sound pressure levels, whereas robotic-assisted bronchoscopy was associated with lower sound pressure levels when compared with flexible bronchoscopy. Future studies are needed to explore the potential deleterious effects of bronchoscopy noise on operators and patients to inform preventive measures.

RATIONALE:Excess weight contributes to impaired physical function among individuals with chronic obstructive pulmonary disease (COPD) and sleep apnea. Self-directed lifestyle-based weight management programs are an accessible option to promote weight loss and improve physical function, but their effectiveness has not been clearly demonstrated. OBJECTIVE:To test whether a self-directed lifestyle program improves 6-minute walk test (6MWT) distance among individuals with COPD and comorbid sleep apnea. STUDY DESIGN AND METHODS:We performed a subset analysis of participants previously enrolled in the INSIGHT-COPD randomized clinical trial (low-intensity lifestyle intervention vs usual care) who self-reported a diagnosis of sleep apnea. Our primary outcome was between-group differences for change in 6MWT distance (minimally important difference [MID] 30 m). Secondary outcomes included between-group differences in weight (a loss of 3% defines meaningful reduction) and quality of life (SF-12 Physical Component Score [PCS], MID 3-3.5 points). We also tested whether sleep apnea modified the effect of the intervention across the entire INSIGHT-COPD population. MEASUREMENTS AND MAIN RESULTS:Among 285 participants with sleep apnea (141 randomly allocated to intervention, 144 to usual care), those randomized to intervention could walk further (difference in 6MWT distance of 25.5 m, 95% CI 8.2 m to 42.9 m; 23.4% vs 20.1% had a MID increase in 6MWT distance) and had a greater reduction in weight (difference in weight of -2.4 kg, 95% CI -3.9 to -0.9 kg; 36.2% vs 23.6% had a 3% reduction in weight) at 12 months. The intervention group also reported a greater physical-function-related quality of life (difference in SF-12 PCS of 1.78 pts, 95% CI 0.10 to 3.49) in comparison to usual care at 12 months. CONCLUSIONS:Among patients with COPD and sleep apnea, a self-directed video-based weight management program led to favorable changes in 6MWT distance compared to usual care, though this did not meet the threshold of a clinically important improvement. However, fewer participants in the intervention group saw a decline in 6MWT distance, and more achieved meaningful weight loss. To effectively improve function in this population, additional interventions beyond self-directed weight management will be necessary.Clinical trial registered with www.clinicaltrials.gov (NCT02634268).

Background: Operating room noise can result in provider- and patient-related adverse outcomes. The recommended sound pressure threshold in medical settings is 35-45 dB(A). This study aimed to quantify sound pressure across different types of bronchoscopy procedures. Methods: Sound meters were placed in the bronchoscopy suite. Ambient sound pressure levels were measured continuously during flexible, rigid, and robotic bronchoscopy procedures. Procedures were classified as “quiet” or “loud” using the median equivalent continuous sound pressure level (Leq). A logistic regression model was used to identify associations between the type of bronchoscopy and “loud” or “quiet” procedures. Results: A total of 186 procedures were analyzed, of which 64% were flexible, 11% were rigid, and 25% were robotic. Across all procedures, the median Leq was 56.8 (55.1 to 58.1) dB(A). Leq was 58.2 (57.5 to 58.9), 59.4 (58.6 to 60.5), and 57.9 (57.5 to 58.4) dB(A) for flexible, rigid, and robotic bronchoscopy, respectively ( P <0.0001). In comparison to flexible bronchoscopy, rigid bronchoscopy was more likely to be loud, while robotic bronchoscopy was less likely to be loud. Conclusion: This is the first study to quantify sound pressure levels during bronchoscopy procedures. Across all types of bronchoscopy procedures, sound pressure levels exceeded those recommended by guidelines for the medical setting and were considered a moderate degree of noise. Rigid bronchoscopy was associated with higher sound pressure levels, whereas robotic-assisted bronchoscopy was associated with lower sound pressure levels when compared with flexible bronchoscopy. Future studies are needed to explore the potential deleterious effects of bronchoscopy noise on operators and patients to inform preventive measures.

Rationale: Excess weight contributes to impaired physical function among individuals with chronic obstructive pulmonary disease (COPD) and comorbid sleep apnea. Self-directed lifestyle-based weight management programs are an accessible option to promote weight loss and improve physical function, but their effectiveness in this population is unclear. We sought to test whether a self-directed lifestyle program improves 6-minute walk test (6MWT) distance among individuals with COPD and comorbid sleep apnea. Methods: INSIGHT-COPD was a randomized trial to test whether a self-directed video-based lifestyle intervention would lead to better physical function in participants with excess weight and COPD. We performed a retrospective subset analysis restricted to participants with a self-reported clinician-diagnosis of sleep apnea. Our primary outcome was between-group differences for change in 6MWT distance, which we measured using a linear mixed effects model. We also assessed secondary outcomes including weight and SF-12 physical function related quality of life. Finally, we assessed whether participants met meaningful thresholds for improvement and decline in 6MWT distance (30m) and weight loss (5% total body weight) using generalized linear regression models for binary outcomes. Results: Among the 684 participants randomized in INSIGHT-COPD, 285 had self-reported sleep apnea (141 randomized to intervention, 144 to control). At 12 months, those randomized to intervention could walk further relative to those randomized to control (adjusted between group difference for 6MWT distance +25.5 m [95% CI 8.2-42.9 m] for individuals with OSA in the intervention group compared to the control group). We did not observe a between-group difference in the likelihood of achieving meaningful improvement in 6MWT distance, though fewer intervention participants experienced a meaningful decline in 6MWT (Figure). Intervention participants also experienced a greater reduction in weight, (adjusted between-group difference of -2.4 kg, 95% CI -3.9 to -0.9 kg) and were more likely to experience meaningful weight loss (Figure). Participants in the intervention arm also experienced greater improvements in physical-function related quality-of-life (adjusted between-group difference: SF-12 PCS 1.78 pts, 95% CI 0.10 to 3.49. Conclusions: Among individuals with COPD and self-reported sleep apnea, a self-directed video-based weight management intervention did not lead to clinically meaningful improvements in 6MWT distance relative to usual care. However, fewer participants experienced a meaningful reduction in 6MWT distance, and a greater proportion of participants in the intervention group experienced clinically meaningful weight loss. Additional interventions beyond self-directed weight management will be needed to meaningfully improve function among patients with COPD and comorbid sleep apnea.

Introduction: Lung transplant recipients are at high risk for infections unusual in their presentation as well as causative organisms. While achromobacter species infections are recognized in patients who received a lung transplant for cystic fibrosis, it is rare for this infection to occur in patients with lung disease from other causes. Here, we present an unusual case of Achromobacter xylosoxidans infection in a bilateral lung transplant recipient with pulmonary fibrosis. Description of Case: A 67-year-old woman awaiting lung transplant for hypersensitivity pneumonitis induced pulmonary fibrosis was admitted to the intensive care unit for acute on chronic hypoxic respiratory failure requiring high flow nasal cannula oxygen at 80% FiO2. She had been treated for her lung condition with mycophenolate mofetil and prednisone. One week after admission, she underwent bilateral lung transplant receiving induction with basiliximab and methylprednisone per institutional protocol. She had no evidence of primary graft dysfunction; however, bronchoscopy completed at post-transplant days 7 and 10 showed mild ischemic injury at the medial right anastomosis. She was discharged home without oxygen. At her bronchoscopy one month post-transplant, black discoloration was identified throughout the tracheobronchial tree. Broncheoalveolar lavage (BAL) resulted positive for aspergillus galactomannan, and her voriconazole dose was increased to therapeutic range. Bronchoscopy two months post-transplant showed thick grey secretions adherent to the right anastomosis partially obstructing the right mainstem. BAL was again positive for aspergillus galactomannan, and newly positive for achromobacter species. She underwent endobronchial biopsy of the lesion, which also demonstrated achromobacter xylosoxidans with areas of necrosis and abscess formation. A computed tomography (CT) scan demonstrated scattered ground glass opacities. Given radiographic changes, multiple positive histopathologic specimens, and visual evidence of infection, the patient received six weeks of treatment with ceftazidime and inhaled polymyxin E. Subsequent bronchoscopy at six months post-transplant demonstrated complete resolution of right anastomotic lesion and negative BAL cultures. Discussion:Achromobacter xylosoxidans is a non-fermenting gram negative bacterium that produces colorless bacterial colonies; it is capable of causing colonization, as was initially suspected in our patient, but can also result in infections characterized by dark discoloration in immunocompromised individuals. In a retrospective study of a 288 person lung transplant cohort, only 2 non-cystic fibrosis patients had achromobacter xylosoxidans infections; similar to this patient, both had a history of pulmonary fibrosis. This case highlights the spectrum of achromobacter infections and the role of repeat post-transplant bronchoscopies in managing opportunistic infections.

Lung transplantation (LTx) is an important treatment option for many end-stage lung diseases. The goal of LTx is to restore pulmonary physiology (gas exchange and respiratory system mechanics) towards normal, so that LTx recipients can experience an improved quality of life and live significantly longer. An optimized approach to donor-to-recipient size matching is a strategy to increase opportunities for successful transplants and optimize outcomes. In this review we discuss relevant pulmonary gas exchange and respiratory systems mechanics principles as a framework to optimize donor-to-recipient size matching and LTX-recipient management. The predicted total lung capacity (pTLC) is a refined estimate of organ size utilizing regression equations to calculate lung size based on height, sex and age. In general, irrespective of the underlying lung disease the chest cavity is "reverse remolding" back towards normal size in most recipients. The parameter that can reflect the sizing goal to restore physiology towards normal is the recipient pTLC. A pragmatic size matching metric is the donor-to-recipient pTLC-ratio. Significant undersizing based on the pTLC-ratio is a risk factor for complications and lower LTx survival. If significant changes to the LTx candidate's chest cavity size occur (as can occur in severe restrictive lung disease or severe emphysema), or if the chest cavity cannot "reverse remodel" towards normal, it is important to consider additional donor-to-recipient sizing metrics. In addition to the recipient's measured actual total lung capacity imaging-based metrics can be considered. Chest X-ray and computer tomography based volumetric analyses can provide information facilitating a successful LTx.

Background:Hyperammonemia syndrome (HS) is a life-threatening complication primarily affecting lung transplant recipients (LTR). HS is strongly associated with mollicute infection. We implemented an active surveillance and prophylaxis protocol for HS in LTR. Herein, we evaluate the impact of our protocol on rates and outcomes of HS. Methods:This was a single-center retrospective cohort study of adult LTR performed from 1/1/2019 to 6/6/2024. Our surveillance and prophylaxis protocol was implemented on 8/1/2022 and included PCR testing for mollicutes on post-operative bronchoalveolar lavage samples, measurement of serum ammonia levels, and azithromycin prophylaxis. Comparisons between pre- and post-protocol implementation groups were performed. Results:151 patients received a lung transplant during the study period, 54 (35.8%) following protocol implementation. Mollicute testing was performed in 57 LTR with most tests sent after protocol implementation (87.0% vs 10.3%, p<0.0001). Ammonia levels were checked in 53.7%; however, only 24.1% had levels checked by post-operative day 3. Ten LTR (6.6%) were diagnosed with mollicute infection, six in the pre-protocol and four in the post-protocol arm, with 70% of infections due to Mycoplasma spp. All LTR received antimicrobial prophylaxis following protocol implementation. Pre-protocol, 3.1% of LTR were diagnosed with definite HS compared to 0% in the post-protocol arm, despite 4 patients being diagnosed with mollicute infection. Conclusions:Implementing a mollicute screening and prophylaxis protocol reduced cases of HS in LTR despite some LTR developing mollicute infection. Antimicrobial prophylaxis with azithromycin and doxycycline may further optimize LTR prophylaxis. Larger studies are needed to determine optimal screening and prophylaxis strategies for HS in LTR.

In this review, we discuss physiological principles that guided the management of a lung transplant for emphysema related to alpha-1-antitrypsin deficiency, where a lung allograft to thoracic cavity size mismatch occurred (donor-to-recipient predicted total lung capacity [pTLC] ratio was 0.89, donor pTLC-to-recipient actual-TLC ratio 0.62). In emphysema, the loss of lung elastic recoil and airway obstruction leads to air trapping and lung hyperinflation. Remodeling of the thoracic cavity (“barrel chest”) develops, which has implications for donor-to-recipient sizing and postoperative management of lung transplantation. We discuss the physiology of a relatively undersized allograft and the impact on chest tube, mechanical ventilation, and respiratory system mechanics management. This case also illustrates how chronic adaptations of the ventilatory pattern to advanced lung diseases are reversible and the chest cavity size can remodel back to normal after lung transplantation.

Lung transplantation is an established management strategy for advanced end-stage lung disease with the goal of restoring normal pulmonary physiology. This principle guided our management approach to the clinical challenge of a lung transplant recipient with a small chest cavity from fibrotic lung disease. Size matching should occur based on the recipient’s predicted total lung capacity, which best reflects the recipient’s normal chest cavity size. We present an instructive case that suggests that the small chest cavity size adjusts relatively quickly toward normal once the fibrotic lungs are removed, and normal allograft is implanted.

Lung transplantation is an elective treatment option for end-stage respiratory diseases in which all medical therapy options have been exhausted. The current study aimed to identify updated information on the postoperative conditions that may impair rehabilitation after lung transplantation and to provide specific considerations of their clinical relevance during the recovery process. The present study is a systematic review conducted by searching three primary databases: the United States National Library of Medicine PubMed system, Scopus, and the Cochrane Library. The databases were searched for articles published from database inception until May 2024; at the end of the selection process, 27 documents were included in the final analysis. The retrieved material identified 19 conditions of rehabilitative interest that potentially affect the postoperative course: graft dysfunction, dysphagia, postsurgical pain, cognitive impairment, chronic lung allograft dysfunction-bronchiolitis obliterans syndrome, phrenic nerve injury, delayed extracorporeal membrane oxygenation weaning, airway clearance, refractory hypoxemia, mediastinitis, reduced oxidative capacity, sternal dehiscence, coronavirus disease 2019 (COVID-19), gastroparesis, ossification of the elbow, Takotsubo cardiomyopathy, airway dehiscence, recurrent pleural effusion, and scapular prolapse. Although some patients are not amenable to rehabilitation techniques, others can significantly improve with rehabilitation.

Importance While beta-blockers are associated with decreased mortality in cardiovascular disease (CVD), exacerbation-prone patients with chronic obstructive pulmonary disease (COPD) who received metoprolol in the Beta-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease (BLOCK-COPD) trial experienced increased risk of exacerbations requiring hospitalization. However, the study excluded individuals with established indications for the drug, raising questions about the overall risk and benefit in patients with COPD following acute myocardial infarction (AMI). Objective To investigate whether beta-blocker prescription at hospital discharge is associated with increased risk of mortality or adverse cardiopulmonary outcomes in patients with COPD and AMI. Design, Setting, and Participants This prospective, longitudinal cohort study with 6 months of follow-up enrolled patients aged 35 years or older with COPD who underwent cardiac catheterization for AMI at 18 BLOCK-COPD network hospitals in the US from June 2020 through May 2022. Exposure Prescription for any beta-blocker at hospital discharge. Main Outcomes and Measures The primary outcome was time to the composite outcome of death or all-cause hospitalization or revascularization. Secondary outcomes included death, hospitalization, or revascularization for CVD events, death or hospitalization for COPD or respiratory events, and treatment for COPD exacerbations. Results Among 3531 patients who underwent cardiac catheterization for AMI, prevalence of COPD was 17.1% (95% CI, 15.8%-18.4%). Of 579 total patients with COPD and AMI, 502 (86.7%) were prescribed a beta-blocker at discharge. Among the 562 patients with COPD included in the final analysis, median age was 70.0 years (range, 38.0-94.0 years) and 329 (58.5%) were male; 553 of the 579 patients (95.5%) had follow-up information. Among those discharged with beta-blockers, there was no increased risk of the primary end point of all-cause mortality, revascularization, or hospitalization (hazard ratio [HR], 1.01; 95% CI, 0.66-1.54; P = .96) or of cardiovascular events (HR, 1.11; 95% CI, 0.65-1.92; P = .69), COPD-related or respiratory events (HR, 0.75; 95% CI, 0.34-1.66; P = .48), or treatment for COPD exacerbations (rate ratio, 1.01; 95% CI, 0.53-1.91; P = .98). Conclusions and Relevance In this cohort study, beta-blocker prescription at hospital discharge was not associated with increased risk of adverse outcomes in patients with COPD and AMI. These findings support use of beta-blockers in patients with COPD and recent AMI.

OBJECTIVES:Inspiratory muscle training is used in rehabilitation to exercise respiratory muscles in various conditions associated with limited ventilatory reserve. In this review, we investigated inspiratory muscle training in lung transplant candidates and recipients. MATERIALS AND METHODS:We searched 5 primary databases from inception through April 2024. Two key word entries, "lung transplantation" and "inspiratory muscle training," were matched using the Boolean operator AND. No filters were applied for document type, age, sex, publication date, language, and subject. RESULTS AND CONCLUSIONS:The searched databases returned 119 citations. Seven articles that considered 64 patients (47% female) were included in the final analysis, with 1 study involving a pediatric patient. Lung transplant recipients used a threshold trainer at 15% to 60% of maximal inspiratory pressure and mostly exercised twice daily for 10 to 15 minutes per session. Lung transplant candidates exercised at 30% to >50% of maximal inspiratory pressure twice daily, performing 30 to 60 inspirations or for 15 minutes. The highest inspiratory muscle strength was observed in a series of adult lung transplant recipients whose mean value improved by 31.8 ± 14.6 cmH2O versus baseline after treatment. To the same extent, the highest value of maximal inspiratory pressure was detected in a pediatric patient who scored 180 cmH2O after training. Overall, participants obtained improvements in lung function (forced expiratory volume in 1 second, forced vital capacity), functional performance, dyspnea intensity, and exercise tolerance. Inspiratory muscle training is easy to perform and can be done at home without specific supervision (in adults) before or after a lung transplant. Nevertheless, additional rigorous investigations should aim to replicate the positive effects reported in the present review.

BackgroundTwo long-acting muscarinic antagonist inhaler fixed dose combinations (olodaterol/tiotropium (OLO/TIO) and vilanterol/umeclidinium (VI/UMEC)) have once-a-day dosing for managing chronic obstructive pulmonary disease (COPD). This study aimed to compare clinical effectiveness of these inhalers in terms of ability to prevent severe COPD exacerbations in a United States Medicare population.Research Design and MethodsUsing nationally representative Medicare data (2013-2019), we employed a new user, active comparator design among beneficiaries aged 65 years and older with COPD. The outcome of interest was time to first occurrence of a severe COPD exacerbation. To ensure comparability between the groups, we performed 1:3 (OLO/TIO:VI/UMEC) nearest neighbor matching based on their high-dimensional propensity scores.ResultsThe study included 2,263 OLO/TIO new initiators matched to 6,789 VI/UMEC new initiators. The incidence rate of the first severe COPD exacerbation was 40.8 per 100 person-years among new initiators (39.9 per 100 person-years for OLO/TIO, 41.1 per 100 person-years for VI/UMEC). The adjusted hazard ratio of the time to first COPD exacerbation was 0.948 (95% Confidence interval: 0.813-1.105) for individuals initiating OLO/TIO versus VI/UMEC.ConclusionWe did not find a statistically significant difference between the OLO/TIO and VI/UMEC new users in terms of time to first severe exacerbation among Medicare COPD patients aged 65 or older.

Introduction In 2019, BLOCK-COPD (Beta-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease) evaluated the effect of metoprolol on exacerbation risk and mortality in a COPD population without indications for beta-blocker use. We hypothesized that an imaging metric of coronary artery disease (CAD), the coronary artery calcium (CAC) score, would predict exacerbation risk and identify a differential response to metoprolol treatment. Methods The study population includes participants in BLOCK-COPD from multiple study sites. Participants underwent clinically indicated thoracic CT scan ± 12 months from enrollment. The Weston scoring system quantified CAC. Adjusted Cox proportional hazards models evaluated for associations between CAC and time to exacerbation. Results Data included 109 participants. The mean CAC score was 5.1±3.7, and 92 participants (84%) had CAC scores greater than 0. Over a median (IQR) follow-up time of 350 (280 to 352) days, there were 61 mild exacerbations and 19 severe/very severe exacerbations. No associations were found between exacerbations of any severity and CAC>0 or total CAC. Associations were observed between total CAC and CAC>0 in the LCx and time to exacerbation of any severity (aHR=1.39, CI: 1.08-1.79, p=0.01) and (aHR=1.96, 95% CI: 1.04-3.70, p= 0.04), respectively. Conclusions CAD is a prevalent comorbidity in COPD accounting for significant mortality. Our study confirms high prevalence of CAD using the CAC score; however, we did not discover an association between CAC and exacerbation risk. We did find novel associations between CAC in the LCX and exacerbation risk which warrant further investigation in larger cohorts.

Lung retransplantation (LRT) involves a second or subsequent lung transplant (LT) in a patient whose first transplanted graft has failed. LRT is the only treatment option for irreversible lung allograft failure caused by acute graft failure, chronic lung allograft dysfunction, or postoperative complications of bronchial anastomosis. Prehabilitation (rehabilitation before LT), while patients are on the waiting list, is recognized as an essential component of the therapeutic regimen and should be offered throughout the waiting period from the moment of listing until transplantation. LRT is particularly fraught with challenges, and prehabilitation to reduce frailty is one of the few opportunities to address modifiable risk factors (such as functional and motor impairments) in a patient population in which there is clearly room to improve outcomes. Although rehabilitative outcomes and quality of life in patients receiving or awaiting LT have gained increased interest, there is a paucity of data on rehabilitation in patients undergoing LRT. Frailty is one of the few modifiable risk factors of retransplantation that is potentially preventable. As such, it is imperative that professionals involved in the field of retransplantation conduct research specifically exploring rehabilitative techniques and outcomes of value for patients receiving LRT, because this area remains unexplored.

SESSION TITLE: Lung Pathology: Show and Tell SESSION TYPE: Case Reports PRESENTED ON: 10/08/2023 10:45 am - 11:45 am INTRODUCTION: Polyvinyl-pyrrolidone-(PVP)-based hair-grooming spray first came into widespread use in the 1950s. Bergmann et al. reported the first case of hairspray-induced lung injury in 1958, termed theusaurosis or storage disease. But by 1978, the controversy regarding the impact of chlorofluorocarbons on the Earth's ozone layer led to a ban on their use as propellants in the USA, and ever since, theusaurosis in the US is rarely reported. CASE PRESENTATION: A 60-year-old woman presented to our lung transplant clinic after experiencing four months of dyspnea on exertion with a rapidly worsening obstructive ventilatory defect. She has a past medical history of CD-30+ cutaneous non-Hodgkin's lymphoma, which was diagnosed in 1999, and remains in remission status post radiation to the left thigh and right hand. Her subacute dyspnea on exertion began 7-months prior following a viral prodrome, with rhinorrhea, nasal congestion, and cough with clear sputum. She was "out of breath" from ordinary activities with daily living (i.e., walking from the bedroom to the bathroom), a stark contrast to prior when she walked daily (>1 mile). She grew up locally in Maryland and retired from a position as the local municipal administrator. She and her husband resided in the same house for 35-years, and he reported no respiratory symptoms. Physical exam, laboratory tests, trans-thoracic echocardiography, and cancer screening showed no abnormalities. CT chest with expiratory phase demonstrated mosaicism and physiological collapse of the tracheobronchial tree with severe diffuse air trapping (Figure or video) . The most concerning was aspect of her presentation involved her rapidly declining FEV1 on her pulmonary function tests.Due to her rapidly declining lung function, our patient underwent bilateral lung transplantation. The histology of her lung explant demonstrated diffused obliterative (constrictive) bronchiolitis (figure 1), where under high power, her airways were severely stenotic or completely obliterated by subepithelial fibrosis. We observed foreign materials (linear fibers) in multiple airways with surrounding inflammation and epithelial scarring, and smooth muscle hypertrophy. The foreign materials were characteristic of polyvinyl-pyrrolidone. DISCUSSION: Today, PVP, a polymer that thickens or stiffens hairstyles, is a key ingredient in hair-grooming spray. Leftover monomers, 1-ethenyl-2-pyrrolidinone, can be found in consumer products from the polymerization process. PVP, or hairspray, exposure is determined by consumer use patterns. The average spray release time per application is 10 seconds, and approximately 10 g of spray is emitted during a spray period. The aerosol is highly respirable, with an estimated 0.03–0.4 mg of aerosol inhaled over a 5-min period following 10 sec of spraying.The majority of theusaurosis cases were characterised by histological findings of interstitial fibrosis with infiltration by mononuclear cells, diffuse uniform thickening of the alveolar septum accompanied by deposition of collagen and elastic fibres, and/or foreign body granulomas composed of cholesterin clefts surrounded by foreign-body giant cells. Radiographic findings include diffuse ground-glass opacities and/or nodular infiltrates. CONCLUSIONS: To our knowledge, we report the first case of severe and rapidly progressive hairspray-induced obliterative (constrictive) bronchiolitis, confirmed by lung explant histology of PVP within the airway lumens, associated with surrounding inflammation, collagen deposition, and fibrosis. REFERENCE #1: 1. Bergmann M, Flance IJ, Cruz PT, Klam N, Aronson PR, Joshi RA, et al. Thesaurosis due to inhalation of hair spray. New England Journal of Medicine. 1962;266(15):750–5. REFERENCE #2: 2. N-vinyl-2-pyrrolidone [Internet]. National Center for Biotechnology Information. PubChem Compound Database. U.S. National Library of Medicine; [cited 2022Aug27]. REFERENCE #3: 3. Polyquaternium-11 [Internet]. CPID. [cited 2022Aug27]. Available from: https://www.whatsinproducts.com/chemicals/view/1/882 DISCLOSURES: No disclosure on file for Michael Eberlein No relevant relationships by Kam Sing Ho No relevant relationships by Robert Reed No relevant relationships by Nevins Todd

BACKGROUND: Severe hemorrhage is an uncommon yet potentially life-threatening complication of transbronchial lung biopsy. Lung transplantation recipients undergo multiple bronchoscopies with biopsy and are considered to be at an increased risk for bleeding from transbronchial biopsy, independent of traditional risk factors. We aimed to evaluate the efficacy and safety of endobronchial administration of prophylactic topical epinephrine in attenuating transbronchial biopsy-related hemorrhage in lung transplant recipients.METHODS: The Prophylactic Epinephrine for the Prevention of Transbronchial Lung Biopsy-related Bleeding in Lung Transplant Recipients study was a 2-center, randomized, double blind, placebo-controlled clinical trial. Participants undergoing transbronchial lung biopsy were randomized to receive 1:10,000-diluted topical epinephrine vs saline placebo administered prophylactically into the target segmental airway. Bleeding was graded based on a clinical severity scale. The primary efficacy out -come was incidence of severe or very severe hemorrhage. The primary safety outcome was a composite of 3-hours all-cause mortality and an acute cardiovascular event.RESULTS: A total of 66 lung transplantation recipients underwent 100 bronchoscopies during the study period. The primary outcome of severe or very severe hemorrhage occurred in 4 cases (8%) in the pro-phylactic epinephrine group and in 13 cases (24%) in the control group (p = 0.04). The composite primary safety outcome did not occur in any of the study groups.CONCLUSIONS: In lung transplantation recipients undergoing transbronchial lung biopsy, prophylactic administration of 1:10,000-diluted topical epinephrine into the target segmental airway before biopsy attenuates the incidence of significant endobronchial hemorrhage without conveying a significant cardiovascular risk. (ClinicalTrials.gov identifier: NCT03126968). J Heart Lung Transplant 2023;42:1205-1213 & COPY; 2023 International Society for Heart and Lung Transplantation. All rights reserved.