ABSTRACT
Pleural infection is usually treated with empirical broad-spectrum antibiotics, but limited data exist on their penetrance into the infected pleural space. We performed a pharmacokinetic study analysing the concentration of five intravenous antibiotics across 146 separate time points in 35 patients (amoxicillin, metronidazole, piperacillin-tazobactam, clindamycin and cotrimoxazole). All antibiotics tested, apart from co-trimoxazole, reach pleural fluid levels equivalent to levels within the blood and well above the relevant minimum inhibitory concentrations. The results demonstrate that concerns about the penetration of commonly used antibiotics, apart from co-trimoxazole, into the infected pleural space are unfounded.
Subject(s)
Anti-Bacterial Agents , Pleural Effusion , Humans , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/therapeutic use , Pleural Effusion/metabolism , Pleural Effusion/drug therapy , Male , Female , Middle Aged , Aged , Adult , Aged, 80 and overABSTRACT
Background: Malignant pleural effusion (MPE) is the build-up of pleural fluid in the space between the lung and chest wall due to advanced cancer. It is treated initially by large volume drainage (therapeutic aspiration). If the fluid reaccumulates, a definitive procedure is performed. There is wide variation in rate of reaccumulation. Patients with rapid reaccumulation often attend hospital as an emergency. Conversely, patients with slow reaccumulation do not need a definitive procedure and may experience cancelled or unnecessary procedures. This study aims to create and validate a multivariable prediction model to predict how quickly pleural fluid will reaccumulate in patients with MPE following therapeutic aspiration. Research question: Can we predict how quickly pleural fluid will reaccumulate in patients with MPEs? Methods: A total of 200 patients with known or suspected MPE attending for therapeutic aspiration will be recruited from 5-10 UK hospitals over 20 months. Patients will be enrolled prior to undergoing aspiration. Following this, they will undergo chest X-ray, which will be repeated one week later (treatment as usual). Rate of reaccumulation will be calculated based on change of size of the effusion seen on X-ray. Data will be collected on common clinical biomarkers e.g., size of effusion on pre-aspiration chest X-ray, volume of fluid drained. This data will be analysed to create a clinical score.A further validation cohort of 40 patients will be enrolled in parallel with creation of the score. Anticipated impact: The ability to predict rate of reaccumulation of MPE will enable patients and clinicians to make better informed treatment decisions. For patients with predicted rapid reaccumulation, a definitive procedure could be offered as first-line treatment, rather than a therapeutic aspiration. This will prevent emergency hospital admissions and decrease number of procedures. By contrast, patients whose effusions will recur slowly may avoid an unnecessary procedure.
People with incurable cancer commonly feel breathless due to buildup of fluid around the lung. We treat this by draining fluid off, but it often comes back. When this happens, we offer the patient a permanent implanted drain, so they can drain the fluid off at home. However, sometimes the fluid builds up very quickly. The patient becomes very breathless and needs an emergency hospital admission. In other people, the fluid builds up slowly and they may never need another drain. The aim of this study is to improve treatment by finding a way to predict how quickly fluid will come back. It will be run in five hospitals across England and involve 240 patients over three years. When patients first come to have fluid drained, we will record information about them and their disease. We will measure how quickly the fluid comes back and record hospital admissions and need for fluid drainage over the following three months. We will use this information to create a clinical score. We will then test this score in a second group of patients to make sure it works. The idea for this study came from one of our patients who had just had fluid drained and asked, 'when will it come back?' We couldn't answer his question and therefore developed this study. Our patients and the public have been involved in the design of this study and will continue to be involved. This score will be used to inform patients so they can choose the best treatment for them. If we know the fluid will build up quickly, we can offer patients a permanent drain straight away. If patients know their fluid will build up slowly, they may choose to have the fluid drained when needed without a permanent drain.
ABSTRACT
Coronavirus disease-19 (COVID-19) causes immune perturbations which may persist long term, and patients frequently report ongoing symptoms for months after recovery. We assessed immune activation at 3-12 months post hospital admission in 187 samples from 63 patients with mild, moderate, or severe disease and investigated whether it associates with long COVID. At 3 months, patients with severe disease displayed persistent activation of CD4+ and CD8+ T-cells, based on expression of HLA-DR, CD38, Ki67, and granzyme B, and elevated plasma levels of interleukin-4 (IL-4), IL-7, IL-17, and tumor necrosis factor-alpha (TNF-α) compared to mild and/or moderate patients. Plasma from severe patients at 3 months caused T-cells from healthy donors to upregulate IL-15Rα, suggesting that plasma factors in severe patients may increase T-cell responsiveness to IL-15-driven bystander activation. Patients with severe disease reported a higher number of long COVID symptoms which did not however correlate with cellular immune activation/pro-inflammatory cytokines after adjusting for age, sex, and disease severity. Our data suggests that long COVID and persistent immune activation may correlate independently with severe disease.
Subject(s)
COVID-19 , Humans , Post-Acute COVID-19 Syndrome , CD8-Positive T-Lymphocytes , SARS-CoV-2/metabolism , Cytokines/metabolismABSTRACT
Pulmonary function tests are fundamental to the diagnosis and monitoring of respiratory diseases. There is uncertainty around whether potentially infectious aerosols are produced during testing and there are limited data on mitigation strategies to reduce risk to staff. Healthy volunteers and patients with lung disease underwent standardised spirometry, peak flow and FENO assessments. Aerosol number concentration was sampled using an aerodynamic particle sizer and an optical particle sizer. Measured aerosol concentrations were compared with breathing, speaking and voluntary coughing. Mitigation strategies included a standard viral filter and a full-face mask normally used for exercise testing (to mitigate induced coughing). 147 measures were collected from 33 healthy volunteers and 10 patients with lung disease. The aerosol number concentration was highest in coughs (1.45-1.61 particles/cm3), followed by unfiltered peak flow (0.37-0.76 particles/cm3). Addition of a viral filter to peak flow reduced aerosol emission by a factor of 10 without affecting the results. On average, coughs produced 22 times more aerosols than standard spirometry (with filter) in patients and 56 times more aerosols in healthy volunteers. FENO measurement produced negligible aerosols. Cardiopulmonary exercise test (CPET) masks reduced aerosol emission when breathing, speaking and coughing significantly. Lung function testing produces less aerosols than voluntary coughing. CPET masks may be used to reduce aerosol emission from induced coughing. Standard viral filters are sufficiently effective to allow guidelines to remove lung function testing from the list of aerosol-generating procedures.
Subject(s)
Lung , Masks , Aerosols , Healthy Volunteers , Humans , Particle Size , Respiratory Function TestsABSTRACT
INTRODUCTION: continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) provide enhanced oxygen delivery and respiratory support for patients with severe COVID-19. CPAP and HFNO are currently designated as aerosol-generating procedures despite limited high-quality experimental data. We aimed to characterise aerosol emission from HFNO and CPAP and compare with breathing, speaking and coughing. MATERIALS AND METHODS: Healthy volunteers were recruited to breathe, speak and cough in ultra-clean, laminar flow theatres followed by using CPAP and HFNO. Aerosol emission was measured using two discrete methodologies, simultaneously. Hospitalised patients with COVID-19 had cough recorded using the same methodology on the infectious diseases ward. RESULTS: In healthy volunteers (n=25 subjects; 531 measures), CPAP (with exhalation port filter) produced less aerosol than breathing, speaking and coughing (even with large >50 L/min face mask leaks). Coughing was associated with the highest aerosol emissions of any recorded activity. HFNO was associated with aerosol emission, however, this was from the machine. Generated particles were small (<1 µm), passing from the machine through the patient and to the detector without coalescence with respiratory aerosol, thereby unlikely to carry viral particles. More aerosol was generated in cough from patients with COVID-19 (n=8) than volunteers. CONCLUSIONS: In healthy volunteers, standard non-humidified CPAP is associated with less aerosol emission than breathing, speaking or coughing. Aerosol emission from the respiratory tract does not appear to be increased by HFNO. Although direct comparisons are complex, cough appears to be the main aerosol-generating risk out of all measured activities.
Subject(s)
COVID-19 , Aerosols , Humans , Oxygen , Respiratory System , SARS-CoV-2ABSTRACT
We investigated the predictors, aetiology and long-term outcomes of acute kidney injury (AKI) following urgent percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Acute kidney injury occurred in 198 (7.2%) of 2917 patients: 14.1% of AKI cases were attributed to cardiogenic shock and 5.1% were classified as atheroembolic renal disease (AERD). Significant risk factors for AKI included age (odds ratio [OR] 1.05, 95% confidence limits [CI] 1.03-1.06), diabetes (OR 1.73, 95% CI 1.20-2.47), hypertension (OR 1.43, 95% CI 1.03-2.00), heart failure (OR 3.01, 95% CI 1.58-5.57), femoral access (OR 1.50, 95% CI 1.03-2.15), cardiogenic shock (OR 2.03, 95% CI 1.19-3.37) and ST-elevation myocardial infarction (STEMI) (OR 3.89, 95% CI 2.80-5.47). One-year mortality after AERD was 44.4% and renal replacement therapy (RRT) requirement 22.2% (compared with mortality 33.3% and RRT requirement 7.4%, respectively, in all other AKI patients). Mortality at 1 year was associated with AKI (OR 4.33, 95% CI 2.89-6.43), age (OR 1.08, 95% CI 1.06-1.09), heart failure (OR 1.92, 95% CI 1.05-3.44), femoral access (OR 2.05, 95% CI 1.41-2.95) and cardiogenic shock (OR 3.63, 95% CI 2.26-5.77). Acute kidney injury after urgent PCI is strongly associated with worse outcomes. Atheroembolic renal disease has a poor outcome and a high likelihood of long-term RRT requirement.
Subject(s)
Acute Coronary Syndrome , Acute Kidney Injury , Percutaneous Coronary Intervention , Acute Coronary Syndrome/epidemiology , Acute Coronary Syndrome/therapy , Acute Kidney Injury/diagnosis , Acute Kidney Injury/epidemiology , Acute Kidney Injury/etiology , Contrast Media , Humans , Incidence , Percutaneous Coronary Intervention/adverse effects , Risk FactorsSubject(s)
Antiviral Agents/blood , COVID-19 Drug Treatment , COVID-19/blood , Hydroxychloroquine/blood , SARS-CoV-2/isolation & purification , Adult , Aged , Aged, 80 and over , Antiviral Agents/administration & dosage , Female , Humans , Hydroxychloroquine/administration & dosage , Male , Middle AgedABSTRACT
The longer-term consequences of SARS-CoV-2 infection are uncertain. Consecutive patients hospitalised with COVID-19 were prospectively recruited to this observational study (n=163). At 8-12 weeks postadmission, survivors were invited to a systematic clinical follow-up. Of 131 participants, 110 attended the follow-up clinic. Most (74%) had persistent symptoms (notably breathlessness and excessive fatigue) and limitations in reported physical ability. However, clinically significant abnormalities in chest radiograph, exercise tests, blood tests and spirometry were less frequent (35%), especially in patients not requiring supplementary oxygen during their acute infection (7%). Results suggest that a holistic approach focusing on rehabilitation and general well-being is paramount.
Subject(s)
COVID-19/therapy , Hospitalization/trends , Pandemics , SARS-CoV-2 , Adult , Aged , COVID-19/epidemiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , United Kingdom/epidemiologyABSTRACT
The use of thoracic CT for patients presenting with a unilateral pleural effusion is well established. However, there is no consensus with regard to the inclusion of the entire abdomen and pelvis in the initial imaging protocol. In this prospective UK-based study, 249 patients presenting with a unilateral effusion had a CT thorax/abdomen/pelvis performed. The prevalence of malignancy on thoracic CT was 56% (140/249). Clinically significant findings below the diaphragm were identified in 59 patients (24%). Integrating this approach into standard practice allows more rapid identification of the primary malignancy, upstaging lesions or alternative sites for biopsy.
Subject(s)
Pleural Effusion/diagnostic imaging , Tomography, X-Ray Computed/methods , Aged , Aged, 80 and over , Diagnosis, Differential , Female , Humans , Male , Pleural Effusion, Malignant/diagnostic imaging , Prospective Studies , United KingdomABSTRACT
Malignant pleural effusion is common and causes disabling symptoms such as breathlessness. Treatments are palliative and centred around improving symptoms and quality of life but an optimal management strategy is yet to be universally agreed. A novel pump system, allowing fluid to be moved from the pleural space to the urinary bladder, may have a role for the management of recurrent malignant pleural effusion. We hereby describe the first animal study using this device and the results of the first application in patients.
Subject(s)
Catheters, Indwelling , Implants, Experimental , Pleural Effusion, Malignant/therapy , Urinary Bladder , Animals , Disease Models, Animal , Dyspnea/etiology , Female , Humans , Middle Aged , Pleural Effusion, Malignant/complications , Prosthesis Failure , Prosthesis Implantation/methods , Recurrence , SwineABSTRACT
Rationale: Parapneumonic effusions have a wide clinical spectrum. The majority settle with conservative management but some progress to complex collections requiring intervention. For decades, physicians have relied on pleural fluid pH to determine the need for chest tube drainage despite a lack of prospective validation and no ability to predict the requirement for fibrinolytics or thoracic surgery.Objectives: To study the ability of suPAR (soluble urokinase plasminogen activator receptor), a potential biomarker of pleural fluid loculation, to predict the need for invasive management compared with conventional fluid biomarkers (pH, glucose, and lactate dehydrogenase) in parapneumonic effusions.Methods: Patients presenting with pleural effusions were prospectively recruited to an observational study with biological samples stored at presentation. Pleural fluid and serum suPAR levels were measured using the suPARnostic double-monoclonal antibody sandwich ELISA on 93 patients with parapneumonic effusions and 47 control subjects (benign and malignant effusions).Measurements and Main Results: Pleural suPAR levels were significantly higher in effusions that were loculated versus nonloculated parapneumonic effusions (median, 132 ng/ml vs. 22 ng/ml; P < 0.001). Pleural suPAR could more accurately predict the subsequent insertion of a chest tube with an area under the curve (AUC) of 0.93 (95% confidence interval, 0.89-0.98) compared with pleural pH (AUC 0.82; 95% confidence interval, 0.73-0.90). suPAR was superior to the combination of conventional pleural biomarkers (pH, glucose, and lactate dehydrogenase) when predicting the referral for intrapleural fibrinolysis or thoracic surgery (AUC 0.92 vs. 0.76).Conclusions: Raised pleural suPAR was predictive of patients receiving more invasive management of parapneumonic effusions and added value to conventional biomarkers. These results need validation in a prospective multicenter trial.
Subject(s)
Chest Tubes/statistics & numerical data , Fibrinolytic Agents/therapeutic use , Pleural Effusion/metabolism , Receptors, Urokinase Plasminogen Activator/metabolism , Thoracentesis/statistics & numerical data , Thoracic Surgical Procedures/statistics & numerical data , Aged , Aged, 80 and over , C-Reactive Protein/metabolism , Case-Control Studies , Conservative Treatment , Enzyme-Linked Immunosorbent Assay , Exudates and Transudates/metabolism , Female , Glucose/metabolism , Humans , Hydrogen-Ion Concentration , L-Lactate Dehydrogenase/metabolism , Leukocyte Count , Male , Middle Aged , Neutrophils , Pleural Effusion/etiology , Pleural Effusion/therapy , Pleural Effusion, Malignant/metabolism , Pneumonia/complications , Prognosis , Proteins/metabolism , Receptors, Urokinase Plasminogen Activator/bloodSubject(s)
Doxycycline/therapeutic use , Granuloma/pathology , Lymphocytosis/diagnosis , Pleural Effusion/pathology , Sarcoidosis, Pulmonary/diagnostic imaging , Biopsy, Needle , Diagnosis, Differential , Female , Follow-Up Studies , Granuloma/diagnostic imaging , Humans , Immunohistochemistry , Middle Aged , Pleural Effusion/diagnostic imaging , Pleural Effusion/drug therapy , Radiography, Thoracic/methods , Sarcoidosis, Pulmonary/drug therapy , Sarcoidosis, Pulmonary/pathology , Severity of Illness Index , Treatment OutcomeABSTRACT
Introduction: One of the most debilitating symptoms of malignant pleural mesothelioma (MPM) is dyspnoea caused by pleural effusion. MPM can be complicated by the presence of tumour on the visceral pleura preventing the lung from re-expanding, known as trapped lung (TL). There is currently no consensus on the best way to manage TL. One approach is insertion of an indwelling pleural catheter (IPC) under local anaesthesia. Another is video-assisted thoracoscopic partial pleurectomy/decortication (VAT-PD). Performed under general anaesthesia, VAT-PD permits surgical removal of the rind of tumour from the visceral pleura thereby allowing the lung to fully re-expand. Methods and analysis: MesoTRAP is a feasibility study that includes a pilot multicentre, randomised controlled clinical trial comparing VAT-PD with IPC in patients with TL and pleural effusion due to MPM. The primary objective is to measure the SD of visual analogue scale scores for dyspnoea following randomisation and examine the patterns of change over time in each treatment group. Secondary objectives include documenting survival and adverse events, estimating the incidence and prevalence of TL in patients with MPM, examining completion of alternative forms of data capture for economic evaluation and determining the ability to randomise 38 patients in 18 months. Ethics and dissemination: This study was approved by the East of England-Cambridge Central Research Ethics Committee and the Health Research Authority (reference number 16/EE/0370). We aim to publish the outputs of this work in international peer-reviewed journals compliant with an Open Access policy. Trial registration: NCT03412357.
Subject(s)
Lung Neoplasms/surgery , Mesothelioma/surgery , Pleural Effusion, Malignant/surgery , Pleural Neoplasms/surgery , Pleurodesis/methods , Thoracic Surgery, Video-Assisted/methods , Adult , Catheters, Indwelling , Clinical Trials, Phase III as Topic , England/epidemiology , Feasibility Studies , Female , Humans , Lung Neoplasms/complications , Lung Neoplasms/mortality , Male , Mesothelioma/complications , Mesothelioma/mortality , Mesothelioma, Malignant , Multicenter Studies as Topic , Observational Studies as Topic , Pilot Projects , Pleural Effusion, Malignant/etiology , Pleural Effusion, Malignant/mortality , Pleural Neoplasms/complications , Pleural Neoplasms/mortality , Pleurodesis/adverse effects , Pleurodesis/instrumentation , Randomized Controlled Trials as Topic , Sample Size , Survival Analysis , Thoracic Surgery, Video-Assisted/adverse effects , Thoracic Surgery, Video-Assisted/instrumentation , Treatment OutcomeABSTRACT
PURPOSE: Malignant pleural mesothelioma (MPM) has a high symptom burden and poor survival. Evidence from other cancer types suggests some benefit in health-related quality of life (HRQoL) with early specialist palliative care (SPC) integrated with oncological services, but the certainty of evidence is low. METHODS: We performed a multicentre, randomised, parallel group controlled trial comparing early referral to SPC versus standard care across 19 hospital sites in the UK and one large site in Western Australia. Participants had newly diagnosed MPM; main carers were additionally recruited. INTERVENTION: review by SPC within 3 weeks of allocation and every 4 weeks throughout the study. HRQoL was assessed at baseline and every 4 weeks with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30. PRIMARY OUTCOME: change in EORTC C30 Global Health Status 12 weeks after randomisation. RESULTS: Between April 2014 and October 2016, 174 participants were randomised. There was no significant between group difference in HRQoL score at 12 weeks (mean difference 1.8 (95% CI -4.9 to 8.5; p=0.59)). HRQoL did not differ at 24 weeks (mean difference -2.0 (95% CI -8.6 to 4.6; p=0.54)). There was no difference in depression/anxiety scores at 12 weeks or 24 weeks. In carers, there was no difference in HRQoL or mood at 12 weeks or 24 weeks, although there was a consistent preference for care, favouring the intervention arm. CONCLUSION: There is no role for routine referral to SPC soon after diagnosis of MPM for patients who are cared for in centres with good access to SPC when required. TRIAL REGISTRATION NUMBER: ISRCTN18955704.
Subject(s)
Lung Neoplasms/rehabilitation , Mesothelioma/rehabilitation , Palliative Care/organization & administration , Pleural Neoplasms/rehabilitation , Quality of Life , Aged , Caregivers/psychology , Female , Humans , Male , Mesothelioma, Malignant , Patient Compliance , Psychometrics , Referral and Consultation/organization & administration , Time Factors , United Kingdom , Western AustraliaSubject(s)
Neurilemmoma/complications , Pleural Effusion/etiology , Pleural Neoplasms/complications , Adult , Humans , Male , Neurilemmoma/diagnostic imaging , Neurilemmoma/pathology , Pleural Effusion/diagnostic imaging , Pleural Neoplasms/diagnostic imaging , Pleural Neoplasms/pathology , Positron Emission Tomography Computed TomographyABSTRACT
INTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare cancer with a heterogeneous prognosis. Prognostic models are not widely utilized clinically. Classification and regression tree (CART) analysis examines the interaction of multiple variables with a given outcome. METHODS: Between 2005 and 2014, all cases with pathologically confirmed MPM had routinely available histological, clinical, and laboratory characteristics recorded. Classification and regression tree analysis was performed using 29 variables with 18-month survival as the dependent variable. Risk groups were refined according to survival and clinical characteristics. The model was then tested on an external international cohort. RESULTS: A total of 482 cases were included in the derivation cohort; the median survival was 12.6 months, and the median age was 69 years. The model defined four risk groups with clear survival differences (p < 0.0001). The strongest predictive variable was the presence of weight loss. The group with the best survival at 18 months (86.7% alive, median survival 34.0 months, termed risk group 1) had no weight loss, a hemoglobin level greater than 153 g/L, and a serum albumin level greater than 43 g/L. The group with the worst survival (0% alive, median survival 7.5 months, termed risk group 4d) had weight loss, a performance score of 0 or 1, and sarcomatoid histological characteristics. The C-statistic for the model was 0.761, and the sensitivity was 94.5%. Validation on 174 external cases confirmed the model's ability to discriminate between risk groups in an alternative data set with fair performance (C-statistic 0.68). CONCLUSIONS: We have developed and validated a simple, clinically relevant model to reliably discriminate patients at high and lower risk of death using routinely available variables from the time of diagnosis in unselected populations of patients with MPM.
Subject(s)
Decision Trees , Lung Neoplasms/diagnosis , Mesothelioma/diagnosis , Pleural Neoplasms/diagnosis , Aged , Cohort Studies , Female , Humans , Lung Neoplasms/mortality , Lung Neoplasms/pathology , Male , Mesothelioma/mortality , Mesothelioma/pathology , Mesothelioma, Malignant , Models, Statistical , Pleural Neoplasms/mortality , Pleural Neoplasms/pathology , PrognosisABSTRACT
Primary spontaneous pneumothorax (PSP) affects young healthy people with a significant recurrence rate. Recent advances in treatment have been variably implemented in clinical practice. This statement reviews the latest developments and concepts to improve clinical management and stimulate further research.The European Respiratory Society's Scientific Committee established a multidisciplinary team of pulmonologists and surgeons to produce a comprehensive review of available scientific evidence.Smoking remains the main risk factor of PSP. Routine smoking cessation is advised. More prospective data are required to better define the PSP population and incidence of recurrence. In first episodes of PSP, treatment approach is driven by symptoms rather than PSP size. The role of bullae rupture as the cause of air leakage remains unclear, implying that any treatment of PSP recurrence includes pleurodesis. Talc poudrage pleurodesis by thoracoscopy is safe, provided calibrated talc is available. Video-assisted thoracic surgery is preferred to thoracotomy as a surgical approach.In first episodes of PSP, aspiration is required only in symptomatic patients. After a persistent or recurrent PSP, definitive treatment including pleurodesis is undertaken. Future randomised controlled trials comparing different strategies are required.
Subject(s)
Pneumothorax/diagnosis , Pneumothorax/epidemiology , Pneumothorax/surgery , Advisory Committees , Antiperspirants , Humans , Pleurodesis , Practice Guidelines as Topic , Recurrence , Smoking/adverse effects , Societies, Medical , Talc/therapeutic use , Thoracic Surgery, Video-Assisted , ThoracotomyABSTRACT
BACKGROUND: The minimal important difference (MID) is essential for interpreting the results of randomised controlled trials (RCTs). Despite a number of RCTs in patients with malignant pleural effusions (MPEs) which use the visual analogue scale for dyspnea (VASD) as an outcome measure, the MID has not been established. METHODS: Patients with suspected MPE undergoing a pleural procedure recorded their baseline VASD and their post-procedure VASD (24 hours after the pleural drainage), and in parallel assessed their breathlessness on a 7 point Likert scale. FINDINGS: The mean decrease in VASD in patients with a MPE reporting a 'small but just worthwhile decrease' in their dyspnea (i.e. equivalent to the MID) was 19mm (95% CI 14-24mm). The mean drainage volume required to produce a change in VASD of 19mm was 760ml. INTERPRETATION: The mean MID for the VASD in patients with a MPE undergoing a pleural procedure is 19mm (95% CI 14-24mm). Thus choosing an improvement of 19mm in the VASD would be justifiable in the design and analysis of future MPE studies.