Background:Indwelling pleural catheters (IPCs) are increasingly used for recurrent pleural effusions, but carries a monthly 3% risk for developing pleural infection (PI) with a mean time from insertion to infection of 2 months, and with Staphylococci as the main pathogen. Little is known of IPC related PI in Danish patients. We aimed at filling the gap by determining monthly infection rate and to compare causative pathogens and clinical outcomes between IPC-related and non-IPC-related PI in our clinic. Methods:We conducted a single-centre retrospective review of electronic medical files to identify patients with IPC and/or PI treated in our department between 2018 and 2022. Data on basic demography, infection rate, time to IPC-related infection, RAPID score, pathogens, days of antibiotics (oral, intravenous), days in hospital, and mortality were recorded. Results:In total, the 54 patients had a median exposure to IPC of 290.9 months, and 13 (24%) developed PI with a median time to PI of 5.1 months with a monthly PI risk of 1.045 (95% CI 1.020-1.069). A comparator group of 28 patients were treated for non-IPC related PI. The causative pathogen was identified for 85% in the IPC group (Staphylococci 91%) compared to 50% in non-IPC group (Staphylococci 0%). Duration of intravenous drug therapy (10 vs 15 days) and hospital admission (13 vs 17 days) were significantly shorter (p-value 0.047). A high RAPID score (renal, age, purulence, infection source, and dietary factors) (62% vs 25%) and 30-days mortality (23% vs 4%) were significantly more common in the IPC group. However, PI-related death did not differ (8% vs 7%). Conclusion:We found that longer IPC exposure was related to increased pleural infection rate, but with the same pattern as earlier reports on shorter IPC exposure, thus a monthly infection rate below 5%, pathogens dominated by Staphylococci, and a low pleural infection-related mortality.

Background Eosinophilic pleural effusion (EPE) is a relatively uncommon condition. The objective of this study was to evaluate the clinical, laboratory and radiological features of EPE in a multicentre cohort of patients. Methods This retrospective study included patients with EPE, defined as pleural fluid in which eosinophils constitute ≥10% of the total nucleated cell count, treated between 2009 and 2021 at eight respiratory centres. Predefined data were collected in the International Multicentre Pleural Research Collaborative (IMPACT) registry. Results The study included 210 patients (144 (68.6%) males), with a median age of 67 years (interquartile range (IQR) 55–78 years). Radiological evaluation showed unilateral effusion in 194 (94.2%) patients. Most EPEs (199; 95.7%) were exudates. The median pleural fluid eosinophil percentage was 23% (IQR 14.8–43.3%). The most common aetiologies were malignancy (n=61, 29%), infection (n=43, 20.5%), heart diseases/cardiac intervention (n=17, 8.1%) or trauma (n=16, 7.6%). In 42 (20%) patients, the cause of EPE remained undetermined. In univariate and multivariable analyses incorporating available clinical and laboratory data, EPE was not a significant predictor of either malignancy or benign disease. Conclusion EPE is a nonspecific diagnostic entity and should not, by itself, be regarded as a relevant factor in clinical decision-making.

Introduction There is a wide global variation in research priorities and current clinical practise among pleural medicine practitioners. Research performed today will inform future clinical practice, but the patient’s voices are often not heard in setting the research agenda. The International Multicentre Pleural Research Collaborative (IMPACT) European Respiratory Society (ERS) Clinical Research Collaboration (CRC) aims to present a consensus document from both pleural disease experts and patients, which will guide pleural disease research in the immediate future. The objective is to ensure a focus on scientifically valid, clinically meaningful and patient-centred pleural disease research with global relevance.Methods and analysis The core working group will collate a list of previously identified research questions in the key topics in pleural disease: pleural infection, pleural malignancy, pneumothorax, pleural mesothelioma and non-malignant pleural effusions. These questions will be ranked in importance (based on a judgement of scientific merit, significance, innovation, relevance and feasibility) using a Delphi method, by a panel of pleural disease experts. The questions which reach consensus will be subject to a Delphi method survey of patients. The patient-modified list will be discussed in a consensus group meeting involving both experts and patients, who will produce the final prioritised list of research questions.Ethics and dissemination Ethical approval will be waived for the active involvement of patients as either advisors or participants in questionnaires. The results will be reported in the form of a peer-reviewed publication with an open access license, according to the ACCORD (ACcurate COnsensus Reporting Document) guidelines for consensus-based research.

AIMS:To investigate the association of beta-blocker use after first-time myocardial infarction (MI) with all-cause mortality and cardiovascular mortality in patients with and without chronic obstructive pulmonary disease (COPD), and whether it varies by type of MI, and COPD severity, and mMRC dyspnoea burden. METHODS:Danish nationwide cohort study of patients discharged after hospitalisation for MI from 2003 to 2015 using the National Prescription Registry and other individual level registers. Multivariable Cox regression models with time-dependent variables using continuously updated data on claimed prescriptions on beta-blockers to account for varying use during follow-up. RESULT:Of 96,567 patients surviving MI, 10,884 (11.3%) had COPD. COPD patients had more often non-ST-elevation MI (NSTEMI) compared to non-COPD patients (88.5% vs. 79.5%), and were older (median age 75 vs. 68 years). Presence of COPD was associated with higher all-cause mortality both in STEMI (HR 1.60 [95% CI 1.46-1.77]) and NSTEMI (HR 1.47 [1.43-1.52]). For COPD patients, beta-blocker users had lower mortality independently of type of MI (HR 0.73 [0.61-0.88] in STEMI and HR 0.68 [0.65-0.72] in NSTEMI). Overall, estimates were similar in patients without COPD. Among high-risk COPD patients with severe COPD and frequent exacerbations (5-year mortality 63.5% and 62.6%, respectively) beta-blockers were also associated with lower mortality. Analyses of cardiovascular mortality showed similar results. CONCLUSION:Beta-blocker use was associated with lower risk of mortality following MI independently of type of MI, presence or abscense of COPD, and COPD severity. This supports that beta-blocker treatment carries no increased mortality risk in COPD, regardless of COPD severity and dyspnoea score.

Introduction:Lung abscess (LA) is a rare but severe necrotizing pulmonary infection associated with substantial morbidity and mortality. Current management relies on prolonged systemic antibiotic therapy without systematic use of abscess drainage. However, small case series and retrospective studies suggest that transthoracic drainage may be a safe and effective adjunctive intervention improving treatment response. Historically, drainage has been avoided for fear of fistulation, but evidence supporting this is weak. High-quality evidence from randomized trials regarding interventional treatment of LA is lacking. This trial aims to determine whether transthoracic drainage combined with standard antibiotic therapy reduces hospital stay, compared with standard antibiotics alone in patients with LA. Methods:This is a national, multicentre, randomized open-label trial. Adults diagnosed with an LA ≥ 4 cm in diameter, containing fluid, and in contact with the outer third of the lung, will be eligible for the study. A total of 84 patients will be randomized 1:1 to either (1) transthoracic drainage combined with standard antibiotic treatment or (2) standard antibiotic treatment alone. Patients will undergo clinical assessments, laboratory testing, microbiological analyses, CT imaging, and standardized patient-reported outcome measures. Follow-up is scheduled at 1, 4, and 12 weeks post‑discharge. The primary outcome is length of hospital stay. Recruitment started February 2026 with an anticipated inclusion period of 4 years. Perspective:This study will provide the first randomized evidence on the role of transthoracic drainage in LA management. The results may inform national and international clinical guidelines and improve outcomes in patients with this severe condition. Trial registration:ClinicalTrial.gov (NCT07247461).

The diagnostic accuracy of [18F] FDG PET/CT versus CT for NSCLC surveillance was compared using data from 692 patients from a randomized clinical trial. Compared to CT, PET/CT demonstrated higher sensitivity (88% vs. 62%, P < .001) but lower specificity (89% vs. 96%, P < .001) and overall accuracy (89% vs. 93%, P = .003) for detecting recurrence. Background: Following curative treatment for non-small cell lung cancer (NSCLC), surveillance to detect recurrence is recommended. While computed tomography (CT) is the current standard for follow-up imaging, the optimal surveillance strategy remains debated. This study compares the diagnostic accuracy of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT; hereafter referred to as PET/CT) and CT for NSCLC surveillance. Materials and Methods: This study represents a secondary analysis of data from a randomized controlled trial (SUPE_R, ClinicalTrials.gov NCT03740126) of patients with stage IA-IIIC NSCLC who completed curative-intent treatment between February 2019 and February 2022. CT and PET/CT scans were compared for recurrence detection using biopsy, multidisciplinary team assessment, or follow-up imaging as reference standards. Results: The analysis included 899 PET/CT scans and 852 CT scans from 692 patients (mean age 69 years +/- 8 [SD]; 412 female). For detecting recurrence, PET/CT demonstrated a higher sensitivity (88% [95% CI, 80%-93%] vs. 62% [95% CI, 50%- 73%]; P < .001) but lower specificity (89% [95% CI, 86%-91%] vs. 96% [95% CI, 94%-97%]; P < .001) compared to CT. PET/CT demonstrated a higher sensitivity compared to CT after treatment with chemoradiotherapy (100% [95% CI, 72%-100%] vs. 46% [95% CI, 19%-75%]; P = .006) and at 0 to 6 month after treatment (83% [95% CI, 63%-94%] vs. 41% [95% CI, 21%-65%]; P = .008). Conclusion: The higher sensitivity of PET/CT, particularly after chemoradiotherapy and early post-treatment, suggests it may be particularly valuable in these high-risk scenarios. However, CT remains preferred for routine surveillance of low-risk patients given its superior specificity.

INTRODUCTION:Patients who have undergone curative surgery for non-small cell lung cancer (NSCLC) often experience long-term reduced quality of life (QoL), high symptom burden, risk of physical deconditioning and comorbidity. Current Danish rehabilitation offers are heterogeneous and not specifically tailored to the disease-specific needs and no long-term targeted support is currently available. Previously, singing-delivered as a structured training modality-has conferred both physiological and psychological improvements in chronic obstructive pulmonary disease, which may likely be transferable to NSCLC, as the two conditions share overlapping symptoms and characteristics. We aim to explore whether a singing-based intervention improves physical function, QoL and symptom burden 6-18 months postsurgery in NSCLC. Moreover, we aim to explore the underpinning physiological mechanisms of singing. METHODS AND ANALYSIS:We will conduct a multicentre randomised controlled trial, comparing 10 weeks' online-delivered structured singing training to usual care. Trial outcomes include primary outcome, physical capacity (measure: Six-Minute Walking Test), and secondary outcomes, QoL and symptoms (measures: St. George's Respiratory Questionnaire (SGRQ); the European Organisation for Research and Treatment of Cancer Questionnaire (QLQ-C30; QLQ-LC13); Hospital Anxiety and Depression Scale (HADS) and airway physiology (measure: forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC)). Explorative outcomes include aerobic fitness/maximal oxygen uptake (VO2-max); exercise-induced adaptations; respiratory muscle strength and control; inflammatory biomarkers. ANALYSIS:Descriptive statistics, stratified analyses, regression models and association and independence between objective and subjective outcomes. ETHICS AND DISSEMINATION:The trial was approved by the Committee on Health Research Ethics (SJ-1027) and the Danish Act on Processing of Personal Data (p-2024-19634). Results will be reported in peer-reviewed scientific journals. TRIAL REGISTRATION NUMBER:NCT07460999.

Background The urgent-referral Cancer Patient Pathway for Non-Specific Symptoms and Signs of Cancer (NSSC-CPP) was introduced in Denmark in 2012 to reduce delays in cancer diagnoses. In Region Zealand, it includes direct referral from GPs to contrast-enhanced computed tomography of thorax, abdomen, and pelvis (ceCT-TAP). In 2013, the NSSC-CPP cancer prevalence was 20%, but easy access to computed tomography (CT) may change referral patterns. Aim To examine cancer prevalence, diagnostic accuracy of ceCT-TAP, and changes in NSSC-CPP referral patterns. Design and setting Retrospective cohort study conducted in Region Zealand, Denmark. Method We included patients with non-specific symptoms or signs of cancer who were referred by GPs between 1 July and 31 December 2019. Primary endpoints were cancer prevalence and diagnostic accuracy of ceCT-TAP. Secondary endpoints were cancer types, referral trends between 2012 and 2019, and prevalence of GP-reported symptoms and clinical findings. Patients were followed up until cancer diagnosis or up to 12 months after ceCT-TAP, whichever came first. Results In total, 729 referrals were recorded, a five-fold increase compared with 140 referrals in the same period of 2013. Malignancy was diagnosed in 95 (13%) patients. Twelve patients had a false-negative ceCT-TAP result, yielding a negative likelihood ratio (LR) for malignancy of 0.15. Conclusion Despite a five-fold increase in GP referrals for ceCT-TAP since 2012, it remains an important diagnostic tool, identifying malignancy in one in seven patients. However, as the LR- was >0.10, a normal ceCT-TAP does not convincingly rule out cancer and should not stand alone as the only decision-support tool.

INTRODUCTION:Sex disparities in lung cancer risk assessment may lead to inequities in screening eligibility. Criteria based on smoking history and age can underrepresent women. Systemic inflammatory indexes derived from routine blood tests are potential biomarkers in cancer risk assessment. We investigated the association between systemic inflammatory indexes and lung cancer risk, stratified by sex, in a Danish cohort. METHODS:We conducted a population-based cohort study using data from the Lolland-Falster Health Study (LOFUS) linked to the Danish Pathology Data Bank (Patobank). Participants aged 40-74 years without a history of lung cancer were included. We calculated four systemic inflammatory indexes and assessed their association with lung cancer using logistic regression models adjusted for age, sex, and smoking status. Optimal cut-off points were determined using the Youden index. Bootstrapping was applied for internal validation. RESULTS:Among 10,887 participants with complete data, 58 (0.53%) were diagnosed with lung cancer during a maximum follow-up period of 6.6 years. High levels of all four inflammatory indexes were associated with increased lung cancer risk. Sex-stratified analyses revealed stronger associations between Neutrophil-to-Lymphocyte Ratio (NLR) and Systemic Immune Inflammatory Index (SII) and lung cancer in men, and between C-reactive protein to albumin ratio (CAR) and lung cancer in women. Model discrimination improved after adding inflammatory indexes. CONCLUSION:Our findings support sex-specific lung cancer risk assessment and personalised screening strategies. Pre-diagnostic inflammatory indexes may serve as biomarkers to complement existing screening criteria. Further research is needed to validate their potential in improving lung cancer prediction models.

BACKGROUND:Surgical resection is essential in the treatment of early-stage non-small cell lung cancer (NSCLC), followed by rehabilitation with physical exercise training to improve physical capacity, quality of life (QoL) and symptom burden. In Denmark, rehabilitation is municipality-based and not disease-specific and without a maintenance model. We aimed to investigate QoL and symptoms 6-12 months after NSCLC surgery, hypothesising impaired QoL and symptom levels. Moreover, we explored rehabilitation attendance. METHODS:An observational, cross-sectional, survey-based study was conducted from March to June 2025 across two Danish regions in patients after surgery for stage I or II NSCLC and without adjuvant oncological treatment (preregistration: osf.io/vmpft). Each site contacted their own eligible patients via digital mail. Registry data from the Danish Lung Cancer Registry and electronic patient registries: socio-demographics, disease-specific characteristics and surgical procedure. Survey data: QoL and symptoms burden (measure: The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30; Reporting: Raw and transformed scores and dichotomised according to defined thresholds and cut-offs for clinical importance) and self-reported information about rehabilitation attendance. DATA ANALYSES:descriptive and stratified analyses. RESULTS:We identified 168 patients, 94 (56% of 168) were eligible and 67 (71% of 94) responded to the survey. No differences were found in baseline characteristics and overall mean time since surgery was 8.9±1.8 months. Current QoL and symptoms were clinically impaired (eg, physical functioning: 51%; dyspnoea: 70%). Around half (54%) reported having attended a rehabilitation programme and those having attended were more likely to have clinically impaired physical functioning and dyspnoea at present. CONCLUSIONS:QoL and symptoms were impaired 6-12 months after NSCLC surgery, and the current level did not seem to be related to having attended a postsurgical rehabilitation programme. Disease-specific challenges should be addressed in future rehabilitation and maintenance models.

Background Influenza and SARS-CoV-2 can cause severe respiratory failure, but the metabolic pathways that lead to clinical deterioration are not fully uncovered. Tryptophan catabolism has been linked to disease progression and adverse outcomes. We aimed to find out whether the link between tryptophan catabolism and disease progression is shared by the 2 viral infections and, in an exploratory manner, to assess other metabolic pathways.Methods Adults hospitalized due to influenza or SARS-CoV-2 from 3 prospective studies were pooled in a nested case-control study design. Cases were defined by disease progression: an increase in oxygen supplementation, intensive care unit admission, or death within 28 days. Cases were matched 1:2 to nonprogressors by pathogen and initial disease severity. We tested associations of plasma kynurenine, tryptophan, and the kynurenine/tryptophan ratio with disease progression. Metabolic profiles were investigated by unsupervised clustering-based, pathway-resolved methods.Results We included 303 patients hospitalized with influenza or SARS-CoV-2. Higher levels of kynurenine and higher kynurenine/tryptophan ratios were associated with disease progression (odds ratio per log2 increase [95% CI], 1.81 [1.21-2.70] and 1.89 [1.26-2.84], respectively) independent of pathogen. Two metabolite modules were associated with disease progression. One module contained multiple amino acids, including kynurenine and 10 other tryptophan catabolism metabolites. The other module contained mainly lipids and xenobiotics.Conclusions Several groups of metabolites were associated with disease progression independent of the pathogen. This indicates that biological mechanisms related to disease severity are shared in influenza and COVID-19. These mechanisms could be used for risk stratification of patients for potential disease-modifying treatments.

Background Inhaled corticosteroid (ICS) is frequently used for COPD. Based on the considerable adverse effects and the knowledge that many such patients do not gain benefit from this treatment, it remains unresolved whether ICS treatment can be managed with lower doses, or via an ICS-sparing strategy with periods with and without this medicine. The blood eosinophil count is a useful biomarker for steroid-responsive airway inflammation, and we want to investigate whether an individualized and eosinophil-guided approach on ICS treatment reduces ICS over-treatment and side effects. High dose (500 mg thrice weekly or 250 mg daily) long-term azithromycin has been shown to reduce acute exacerbations of COPD in selected patients. Frequent gastro-intestinal adverse effects remain a challenge, but many patients tolerate lower doses, however, the effect of the treatment at lower doses is unknown, although many physicians prefer such doses. We want to investigate whether oral low-dose prophylactic azithromycin 250 mg three times weekly reduces acute exacerbations of COPD and improves time alive and out of hospital. Methods This is an ongoing, actively recruiting randomized, double-blinded, multicenter, four-arm factorial intervention clinical trial aiming to recruit 444 patients with specialist verified COPD GOLD risk class E and/or FEV1 < 30% who are currently on ICS. The patients are followed for one year and are randomized 1:1:1:1 to one of the four treatment arms: (1) eosinophil-guided ICS sparing treatment and low dose azithromycin, (2) eosinophil-guided ICS treatment and placebo, (3) continued ICS treatment and low dose azithromycin, or (4) continued ICS treatment and placebo. If blood-eosinophils (measured every 3 months) are < 0.3 x 109 cells/L, ICS treatment will be paused in the arms with eosinophil-guided ICS sparing treatment. Azithromycin/placebo is double-blinded and administered three times weekly. The primary endpoints are (1) “days alive and out of hospital within 365 days after recruitment” and (2) number of hospitalization-requiring exacerbations and/or death within 365 days. Discussion Severe ICS-adverse effects like bacterial infections should be reduced. The ICS-sparing intervention, we test, may provide a useful tool to do this safely. Azithromycin low dose prophylaxis is practiced by many physicians. This trial will provide evidence of whether this is effective. Trial registration ClinTrials.gov. NCT04481555. Registered 14AUG2020, https://clinicaltrials.gov/study/NCT04481555.

BACKGROUND:Long-term consequences after a pulmonary embolism include lung function deficits, dyspnea, and chronic thromboembolic pulmonary hypertension. Recent studies suggest patients who experience pulmonary embolism may also be at increased risk of asthma. METHODS:We tested the hypothesis that individuals with pulmonary embolism or deep vein thrombosis (venous thromboembolism) have lower lung function, or higher risks of dyspnea and asthma using data from 21,205 random adults from the Danish General Suburban Population Study. RESULTS:Prevalences of pulmonary embolism, deep vein thrombosis, and venous thromboembolism were 0.60%, 1.7%, and 1.9%, respectively. Individuals with pulmonary embolism or deep vein thrombosis had FEV1% predicted of 86% and 89% compared with 95% in individuals without venous thromboembolism (t-test: p < .001). Corresponding values for FVC% predicted were 92% and 94% versus 99% (p < .001). Individuals with versus without venous thromboembolism had adjusted odds ratios for light, moderate, and severe dyspnea of 1.6 (95% CI: 1.1-2.2), 1.8 (1.2-2.6), and 2.6 (1.8-3.8), respectively. Individuals with versus without venous thromboembolism had adjusted odds ratios for asthma and use of asthma medication of 1.6 (1.2-2.2) and 1.9 (1.4-2.6), respectively. The adjusted odds ratio for asthma in individuals with versus without venous thromboembolism was increased among individuals who received no treatment with anticoagulants (2.0, 1.4-3.0) compared to those who received treatment (1.0, 0.6-1.6) (p for interaction = .02). CONCLUSIONS:Individuals with venous thromboembolism have lower lung function, 2.6-fold higher risk of severe dyspnea, and 1.6-fold higher risk of asthma in the Danish population.

BACKGROUND:Circulating tumor DNA (ctDNA) has the potential to become a reliable biomarker for identifying minimal residual disease (MRD) and predicting recurrence in patients with non-small cell lung cancer (NSCLC) following curative treatment. However, there is a lack of studies that investigate the clinical validity of ctDNA using a tumor-agnostic approach, which can provide significant clinical benefits. METHODS:We analyzed samples from 45 NSCLC patients recruited in a prospective national multicenter study, all of whom had undergone curative treatment. A total of 38 pre-treatment plasma samples and 76 post-treatment plasma samples were examined using a commercially available cancer personalized profiling by deep sequencing (CAPP-seq) strategy, and a tumor-agnostic approach. Post-treatment samples were collected at two distinct landmark time points: Follow-up 1 (0.5-4.5 months post-treatment) and Follow-up 2 (4.5-7.5 months post-treatment). RESULTS:Detectable ctDNA post-treatment was significantly associated with increased risk of tumor recurrence and shorter recurrence-free survival (RFS). Using only a single blood sample taken from Follow-up 2, we correctly identified MRD in 50% of the patients who later experienced recurrence. However, subgroup analysis further revealed that in patients treated with radiotherapy or chemoradiotherapy (CRT), ctDNA detection was significantly linked to shorter RFS in the MRD analysis from Follow-up 2, but not in the MRD analysis from Follow-up 1. CONCLUSION:These findings suggest that post-treatment ctDNA, detected using a tumor-agnostic approach, is a reliable biomarker for predicting recurrence in NSCLC patients following curative treatment. However, the optimal timing for blood sampling to detect MRD appears to depend on the type of curative treatment received.

BACKGROUND:Telecommunication (telephone, video) is increasingly being used in healthcare, including in the cancer area. Still, patients' lived experiences of receiving bad news over the telephone of first a suspected and later a confirmed cancer diagnosis remain sparsely researched. OBJECTIVE:This study aimed to explore the lived experience of receiving results and plans by telephone in patients during an invasive workup for suspected lung cancer. METHODS:Individual interviews were conducted with 11 patients 2 to 3 months after the final disclosure of cancer. Data were analyzed and interpreted within a phenomenological-hermeneutic framework. RESULTS:When "being on a journey from anticipation to the fact of the cancer diagnosis," patients appreciated being gently guided via ongoing information by telephone. However, some calls were confusing or inconvenient or did not involve desired relatives. When "transferring toward the next step of treatment and care," patients felt warned and prepared for the planned disclosure of a cancer diagnosis by telephone. CONCLUSIONS:Using telephone communication during the diagnostic workup is well-suited to support patients during the vulnerable time of receiving a cancer diagnosis. To be effective, informing patients by telephone must involve a relational structure of anticipation, including a warning and personalized approach to help them and their relatives gradually realize the bad news. IMPLICATION FOR PRACTICE:This study contributes to the evidence base for breaking bad news via telecommunication. When connecting with patients remotely, an optimal procedure must be arranged so that matters of confidentiality, emotional concerns, and needs for involvement of relatives are explicitly ensured.

Background Iatrogenic pneumothorax is a common complication of diagnostic and therapeutic pulmonary procedures. New guidelines on primary spontaneous pneumothorax suggest ambulatory approaches may be suitable. However, guidance on iatrogenic pneumothorax occurring in patients with impaired lung function, increased age, comorbidity and frailty is lacking, and the safety profile of ambulatory management is not known. The objective was to study the safety of iatrogenic pneumothorax treated with chest tubes and to identify the risks of life-threatening events.Methods In a retrospective cohort of patients admitted and treated with an adhesive valve-integrated chest tube system, we recorded the incidence of complications. The primary outcome was the incidence of life-threatening events that required urgent medical action. Incidences of serious adverse events, adverse events, serious device-related events and whether outpatient ambulatory treatment would be safe were recorded based on the review of the medical charts.Results In 97 patients, 6 (6%) life-threatening events occurred, including episodes of respiratory failure and an urgent need for new chest tube insertion. The event incidence was 21% in patients with pre-biopsy saturation below 95% and 1% in patients with saturation above 95%, p = 0.003, and greater if the lung had not expanded on the first radiograph, 25%, after insertion of the chest tube, than if the lung had fully expanded, 4%, or partially expanded, 2%, p = 0.009.Conclusions The incidence of life-threatening events during chest tube-treated iatrogenic pneumothorax is significant, but acceptable in patients without impaired lung function prior to the procedure and early response to treatment.