Vascular Complications After A Multiligament Knee Reconstruction: A Case Report Highlighting the Role of Preoperative Imaging.

Vascular injuries are serious complications of multiligament knee injuries and can result in catastrophic outcomes. These injuries can range from intimal flaps with no compromise of the distal perfusion to a complete occlusion or transection requiring emergent vascular intervention. Several diagnostic tests including the measurement of the ankle-brachial index (ABI), conventional angiography and computed tomography angiography (CTA) are commonly used as diagnostic tools to identify vascular injuries in the context of a multiligament knee injury. In this report, the authors discuss the case of a patient with a normal ABI and palpable distal pulses on physical examination who developed limb ischemia after a multiligament knee reconstruction under tourniquet. The patient underwent emergent embolectomy and had a favorable postoperative outcome. During vascular exploration, there was no evidence of injury to the popliteal artery. Therefore, the two working diagnoses were that the patient had an intimal flap complicated by the development of a thrombus during surgery, or that the initial vascular injury was not detected by ABI and clinical examination. Therefore, intimal flaps in multiligament knee injuries can lead to limb threatening ischemia in the context of reconstructive knee surgery and are likely underdiagnosed with ABI assessment. The utilization of preoperative CTA may help identify these injuries in patients indicated for reconstructive surgeries.

Pharmacological Treatment of Degenerative Cervical Myelopathy: A Critical Review of Current Evidence.

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults, representing substantial morbidity and significant financial and resource burdens. Typically, patients with progressive DCM will eventually receive surgical treatment. Nonetheless, despite advancements in pharmacotherapeutics, evidence for pharmacological therapy remains limited. Health professionals from various fields would find interest in pharmacological agents that could benefit patients with mild DCM or enhance surgical outcomes. This review aims to consolidate all clinical and experimental evidence on the pharmacological treatment of DCM. We conducted a comprehensive narrative review that presents all pharmacological agents that have been investigated for DCM treatment in both humans and animal models. Riluzole exhibits effectiveness solely in rat models, but not in treating mild DCM in humans. Cerebrolysin emerges as a potential neuroprotective agent for myelopathy in animals but had contradictory results in clinical trials. Limaprost alfadex demonstrates motor function improvement in animal models and exhibits promising outcomes in a small clinical trial. Glucocorticoids not only fail to provide clinical benefits but may also lead to adverse events. Cilostazol, anti-Fas ligand antibody, and Jingshu Keli display promise in animal studies, while erythropoietin, granulocyte colony-stimulating factor and limaprost alfadex exhibit potential in both animal and human research. Existing evidence mainly rests on weak clinical data and animal experimentation. Current pharmacological efforts target ion channels, stem cell differentiation, inflammatory, vascular, and apoptotic pathways. The inherent nature and pathogenesis of DCM offer substantial prospects for developing neurodegenerative or neuroprotective therapies capable of altering disease progression, potentially delaying surgical intervention, and optimizing outcomes for those undergoing surgical decompression.

Bronchial Rheoplasty for Chronic Bronchitis: Results from a Canadian Feasibility Study with RheOx®.

Purpose: Chronic bronchitis (CB), a chronic obstructive pulmonary disease (COPD) phenotype defined by persistent mucus hypersecretion and cough, is associated with poor quality of life, exacerbations, and lung function impairment. Bronchial Rheoplasty (BR) delivers non-thermal pulsed electric fields to airway epithelium and submucosa. Preliminary studies demonstrated reduced airway goblet cell hyperplasia and symptom improvement in response to BR. This study aimed to further assess the safety and clinical feasibility of BR in the setting of CB. Patients and Methods: This 3-center, single-arm study evaluated the safety and feasibility of BR in Canadian patients. The major inclusion criteria were the sum of CAT first 2 questions (cough and mucus) ≥ 7 out of 10 and FEV1 ≥ 30% predicted. Right-sided airways were treated first; left, 1 month later. Serious adverse events (SAEs) were tabulated through 12 months. Outcomes were evaluated using the SGRQ and CAT. Results: Ten patients with CB were enrolled and followed for 12 months. The BR procedure was successful in all patients (mean age 69 ± 5.8 years, post-BD FEV1 77.1 ± 28.3, SGRQ 56.2 ± 8.8, CAT 25.4 ± 4.7). Only one SAE, a COPD exacerbation 13 days following the BR procedure, was considered device related. No additional SAEs occurred through 12 months, and 90% of the patients were CAT responders (≥ 2-point improvement) at 3 and 6 months. Similar results were observed in SGRQ. Conclusion: BR was safe and well-tolerated. Meaningful symptom improvement was observed through 12 months, suggesting BR may be a viable treatment option for patients with CB.

Polygenic inheritance and its interplay with smoking history in predicting lung cancer diagnosis: a French-Canadian case-control cohort.

BACKGROUND: The most near-term clinical application of genome-wide association studies in lung cancer is a polygenic risk score (PRS). METHODS: A case-control dataset was generated consisting of 4002 lung cancer cases from the LORD project and 20,010 ethnically matched controls from CARTaGENE. A genome-wide PRS including >1.1 million genetic variants was derived and validated in UK Biobank (n = 5419 lung cancer cases). The predictive ability and diagnostic discrimination performance of the PRS was tested in LORD/CARTaGENE and benchmarked against previous PRSs from the literature. Stratified analyses were performed by smoking status and genetic risk groups defined as low (<20th percentile), intermediate (20-80th percentile) and high (>80th percentile) PRS. FINDINGS: The phenotypic variance explained and the effect size of the genome-wide PRS numerically outperformed previous PRSs. Individuals with high genetic risk had a 2-fold odds of lung cancer compared to low genetic risk. The PRS was an independent predictor of lung cancer beyond conventional clinical risk factors, but its diagnostic discrimination performance was incremental in an integrated risk model. Smoking increased the odds of lung cancer by 7.7-fold in low genetic risk and by 11.3-fold in high genetic risk. Smoking with high genetic risk was associated with a 17-fold increase in the odds of lung cancer compared to individuals who never smoked and with low genetic risk. INTERPRETATION: Individuals at low genetic risk are not protected against the smoking-related risk of lung cancer. The joint multiplicative effect of PRS and smoking increases the odds of lung cancer by nearly 20-fold. FUNDING: This work was supported by the CQDM and the IUCPQ Foundation owing to a generous donation from Mr. Normand Lord.

Predictors of Episode-of-Care Costs for Ankle Fractures.

Ankle fractures are one of the most resource-consuming traumatic orthopedic injuries. Few studies have successfully evaluated the episode-of-care costs (EOCC) of common traumatic orthopedic injuries. The objective of this study was to determine the EOCC associated with the surgical management of ankle fractures. A retrospective cohort study of 105 consecutive patients who underwent open reduction internal fixation of an isolated ankle fracture at a Canadian Level-1 trauma center was conducted. Episode-of-care costs were generated using an activity-based costing framework. The median global episode-of-care cost for ankle fracture surgeries performed at the studied institution was $3,487 CAD [IQR 880] ($2,685 USD [IQR 616]). Patients aged 60 to 90 years had a significantly higher median EOCC than younger patients (p = .01). Supination-adduction injuries had a significantly higher median EOCC than other injury patterns (p = .01). The median EOCC for patients who underwent surgery within 10 days of their injury ($3,347 CAD [582], $2,577 USD [448]) was significantly lower than the cost for patients who had their surgery delayed 10 days or more after the injury ($3,634 CAD [776], $2,798 USD [598]) (p = .03). Patient sex, anesthesia type, ASA score and surgeon's fellowship training did not affect the EOCC. This study provides valuable data on predictors of EOCC in the surgical management of ankle fractures. Delaying simple ankle fracture cases due to operating time constraints can increase the total cost and burden of these fractures on the healthcare system. In addition, this study provides a framework for future episode-of-care cost analysis studies in orthopedic surgery.

Transbronchial Lung Cryobiopsy and Surgical Lung Biopsy: A Prospective Multi-Centre Agreement Clinical Trial (CAN-ICE).

Rationale: Transbronchial cryobiopsy (TBCB) for the diagnosis of interstitial lung disease (ILD) has shown promising results, but prospective studies with matched surgical lung biopsy (SLB) have yielded conflicting results. Objectives: We aimed to assess within- and between-center diagnostic agreement between TBCB and SLB at both the histopathologic and multidisciplinary discussion (MDD) levels in patients with diffuse ILD. Methods: In a multicenter prospective study, we performed matched TBCB and SLB in patients referred for SLB. After a blinded review by three pulmonary pathologists, all cases were reviewed by three independent ILD teams in an MDD. MDD was performed first with TBCB, then with SLB in a second session. Within-center and between-center diagnostic agreement was evaluated using percentages and correlation coefficients. Measurements and Main Results: Twenty patients were recruited and underwent contemporaneous TBCB and SLB. Within-center diagnostic agreement between TBCB-MDD and SLB-MDD was reached in 37 of the 60 (61.7%) paired observations, resulting in a Cohen's κ value of 0.46 (95% confidence interval [CI], 0.29-0.63). Diagnostic agreement increased among high-confidence or definitive diagnoses on TBCB-MDD (21 of 29 [72.4%]), but not significantly, and was more likely among cases with SLB-MDD diagnoses of idiopathic pulmonary fibrosis than fibrotic hypersensitivity pneumonitis (13 of 16 [81.2%] vs. 16 of 31 [51.6%]; P = 0.047). Between-center agreement for cases was markedly higher for SLB-MDD (κ = 0.71 [95% CI, 0.52-0.89]) than TBCB-MDD (κ = 0.29 [95% CI, 0.09-0.49]). Conclusions: This study demonstrated moderate TBCB-MDD and SLB-MDD diagnostic agreement for ILD, while between-center agreement was fair for TBCB-MDD and substantial for SLB-MDD. Clinical trial registered with www.clinicaltrials.gov (NCT02235779).

Wait Times and Survival in Lung Cancer Patients across the Province of Quebec, Canada.

Lung cancer is the leading cause of cancer death worldwide, with a five-year survival of 22% in Canada. Guidelines recommend rapid evaluation of patients with suspected lung cancer, but the impact on survival remains unclear. We reviewed medical records of all patients with newly diagnosed lung cancer in four hospital networks across the province of Quebec, Canada, between 1 February and 30 April 2017. Patients were followed for 3 years. Wait times for diagnosis and treatment were collected, and survival analysis using a Cox regression model was conducted. We included 1309 patients, of whom 39% had stage IV non-small cell lung cancer (NSCLC). Median wait times were, in general, significantly shorter in patients with stage III-IV NSCLC or SCLC. Surgery was associated with delays compared to other types of treatments. Median survival was 12.9 (11.1-15.7) months. The multivariate survival model included age, female sex, performance status, histology and stage, treatment, and the time interval between diagnosis and treatment. Longer wait times had a slightly protective to neutral effect on survival, but this was not significant in the stage I-II NSCLC subgroup. Wait times for the diagnosis and treatment of lung cancer were generally within targets. The shorter wait times observed for advanced NSCLC and SCLC might indicate a tendency for clinicians to act quicker on sicker patients. This study did not demonstrate the detrimental effect of longer wait times on survival.

Tracking the rise of United States foreign military training: IMTAD-USA, a new dataset and research agenda.

Training other countries' armed forces is a go-to foreign policy tool for the United States and other states. A growing literature explores the effects of military training, but researchers lack detailed data on training activities. To assess the origins and consequences of military training, as well as changing patterns over time, this project provides a new, global dataset of US foreign military training. This article describes the scope of the data along with the variables collected, coding procedures, and spatial and temporal patterns. We demonstrate the added value of the data in their much greater coverage of training activities, showing differences from both existing datasets and aggregate foreign military aid data. Reanalyzing prior research findings linking US foreign military training to the risk of coups d'état in recipient states, we find that this effect is limited to a single US program representing a small fraction of overall US training activities. The data show comprehensively how the United States attempts to influence partner military forces in a wide variety of ways and suggest new avenues of research.

Outcomes Following Surgical Lung Biopsy for Interstitial Lung Diseases: A Monocenter Experience.

BACKGROUND: Surgical lung biopsy (SLB) is considered in the investigation of interstitial lung diseases (ILDs) when a complete clinical evaluation and a multidisciplinary discussion (MDD) do not allow the clinician to make a confident diagnosis. Owing to the risk of the procedure, an appropriate assessment of the risk/benefit ratio prior to the intervention is recommended. We aimed to assess the postoperative outcomes and diagnostic yield of SLB for the investigation of ILD in a tertiary care institution. METHODS: We conducted a retrospective cohort study of consecutive subjects who underwent a SLB for the investigation of ILD in our center from 2009 to 2020. The postoperative mortality and complications rates as well as the diagnostic yield of the procedure were assessed. RESULTS: Of the 1,805 patients newly investigated for ILD in our center from 2009 to 2020, 71 (3.93%) underwent a SLB. At days 30 and 90, the mortality rates were 0 and 2.8%, whereas 4.3 and 7.6% patients experienced an acute ILD exacerbation, respectively. In addition, 4 (5.8%) patients experienced infectious complications and 5 (7.0%) presented prolonged air leaks (all within 30 days). A definite pathological diagnosis was made in 47 (66.2%) patients. Following postoperative MDD, a confident diagnosis was made in 61 patients (85.9%) and resulted in a change of therapy in 49 (69.0%) patients. CONCLUSION: SLB for the diagnosis of unclassifiable ILDs is associated with low mortality but significant morbidity. However, it results in a confident diagnosis and a change in therapy in the majority of patients.

Malignant pleural mesothelioma: Comparison of surgery-based trimodality therapy to medical therapy at two tertiary academic institutions.

OBJECTIVES: Medical management based on palliative chemotherapy is currently the standard of care in malignant pleural mesothelioma (MPM). Median survival of 12-16 months has been reported with modern chemotherapy regimens with or without anti-angiogenic agents. Multimodality therapy incorporating cytoreductive surgery, systemic chemotherapy and radiotherapy has been offered for years to fit patients with early-stage disease, but its role remains debated. Our objective was to compare overall survival in patients offered multimodality therapy in a specialized clinic setting in London, UK to that of patients offered exclusively medical treatment at another academic institution in Quebec, Canada. MATERIALS AND METHODS: We retrospectively compared the survival rates of 2 separate cohorts of patients treated consecutively: Cohort 1 (n = 106) received multimodality therapy including systemic chemotherapy, extended pleurectomy/decortication (P/D) and prophylactic radiotherapy in London (United Kingdom) between 2009 and 2016, while Cohort 2 (n = 98) received medical treatment at the Quebec Heart and Lung Institute (Canada) during the same period. RESULTS: In Cohort 1, all patients but two completed trimodality therapy. In cohort 2, 51 % received palliative care only and 40 % received systemic chemotherapy. Median survival was 32 months vs 10 months in Cohort 1 and Cohort 2, respectively (hazard ratio with age, gender, pathology and TNM staging as covariates: 3.81; 95 % CI: 2.67-5.45; p < 0.0001). Similar results were obtained in sensitivity analyses, after excluding those who received best supportive care only and in a propensity score-matched analysis. CONCLUSION: Aggressive therapy of MPM using cancer-directed surgery, systemic chemotherapy and prophylactic radiotherapy may provide a significant survival benefit in selected patients.

Risk Perception Among a Lung Cancer Screening Population.

BACKGROUND: A successful lung cancer screening program requires a patient cohort at sufficient risk of developing cancer who are willing to participate. Among other factors, a patient's lung cancer risk perception may inform their attitudes toward screening and smoking cessation programs. RESEARCH QUESTION: This study analyzed data from the Pan-Canadian Early Detection of Lung Cancer (PanCan) Study to address the following questions: Which factors are associated with the perception of lung cancer risk? Is there an association between risk perception for lung cancer and actual calculated risk? Is there an association between risk perception for lung cancer and the intent to quit smoking? Are there potential targets for lung cancer screening awareness? STUDY DESIGN AND METHODS: The PanCan study recruited current or former smokers aged 50 to 75 years who had at least a 2% risk of developing lung cancer over 6 years to undergo low-dose screening CT. Risk perception and worry about lung cancer were captured on a baseline questionnaire. Cumulative logistic regression analysis was used to assess the relationship between baseline risk variables and both lung cancer risk perception and worry. RESULTS: Among the 2,514 individuals analyzed, a higher perceived risk of lung cancer was positively associated with calculated risk (P = .032). Younger age, being a former smoker, respiratory symptoms, lower FEV1, COPD, and a family history of lung cancer were associated with higher perceived risk. Conversely, a consistent relationship between calculated risk and worry was not identified. There was a positive association between risk perception and lung cancer worry and reported intent to quit smoking. INTERPRETATION: Individuals' lung cancer risk perception correlated positively with calculated risk in a screening population. Promotion of screening programs may benefit from focusing on factors associated with higher risk perception; conversely, harnessing worry seemingly holds less value.

Division of an Iliac Crest Bone Biopsy Specimen to Allow Histomorphometry, Immunohistochemical, Molecular Analysis, and Tissue Banking: Technical Aspect and Applications.

The evaluation of bone complications in chronic kidney disease (CKD) often requires a bone biopsy, the analysis of which can refine the diagnosis of bone defects. Bone histomorphometry performed on sections of the iliac crest biopsy remains the reference procedure for the quantitative assessment of bone health in CKD patients, whereas immunohistochemistry and other molecular biology analyses are indispensable tools for studying the disrupted signaling pathways. Traditionally, the whole iliac crest biopsy was included in methyl-methacrylate (MMA) and was exclusively used for bone histomorphometry to describe static, dynamic, and structural parameters. Therefore, further molecular analysis of the bone tissue or the need for tissue banking would require a second biopsy to be made, because inclusion in MMA prevents the extraction of good-quality nucleic acids. In this work, we describe a simple approach to divide a single iliac crest bone biopsy into multiple parts. This allows for simultaneous assessments of histology, immunohistochemistry, biomolecular analysis, and tissue banking while preserving the same bone surface area for histomorphometry. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Chronic obstructive pulmonary disease prevalence and prediction in a high-risk lung cancer screening population.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an underdiagnosed condition sharing risk factors with lung cancer. Lung cancer screening may provide an opportunity to improve COPD diagnosis. Using Pan-Canadian Early Detection of Lung Cancer (PanCan) study data, the present study sought to determine the following: 1) What is the prevalence of COPD in a lung cancer screening population? 2) Can a model based on clinical and screening low-dose CT scan data predict the likelihood of COPD? METHODS: The single arm PanCan study recruited current or former smokers age 50-75 who had a calculated risk of lung cancer of at least 2% over 6 years. A baseline health questionnaire, spirometry, and low-dose CT scan were performed. CT scans were assessed by a radiologist for extent and distribution of emphysema. With spirometry as the gold standard, logistic regression was used to assess factors associated with COPD. RESULTS: Among 2514 recruited subjects, 1136 (45.2%) met spirometry criteria for COPD, including 833 of 1987 (41.9%) of those with no prior diagnosis, 53.8% of whom had moderate or worse disease. In a multivariate model, age, current smoking status, number of pack-years, presence of dyspnea, wheeze, participation in a high-risk occupation, and emphysema extent on LDCT were all statistically associated with COPD, while the overall model had poor discrimination (c-statistic = 0.627 (95% CI of 0.607 to 0.650). The lowest and the highest risk decile in the model predicted COPD risk of 27.4 and 65.3%. CONCLUSIONS: COPD had a high prevalence in a lung cancer screening population. While a risk model had poor discrimination, all deciles of risk had a high prevalence of COPD, and spirometry could be considered as an additional test in lung cancer screening programs. TRIAL REGISTRATION: (Clinical Trial Registration: ClinicalTrials.gov, number NCT00751660 , registered September 12, 2008).

Trial marketing in the Pan-Canadian Early Detection of Lung Cancer Study.

BACKGROUND: Recruitment to clinical trials is suboptimal, increasing costs, and delaying the potential implementation of clinical advances. Among other barriers, the lack of marketing experience among trialists may limit recruitment. In this observational study, in the context of the Pan-Canadian Early Detection of Lung Cancer Trial, we assessed the value of a motivational survey of study participants in planning a tailored advertising campaign and analysed the value of individual components of advertising in generating telephone calls to the study and recruited subjects. METHODS: The Pan-Canadian Early Detection of Lung Cancer Trial was a single arm study assessing risk modelling for lung cancer screening by low-dose computed tomography scan and autofluorescence bronchoscopy. Individuals were recruited to eight sites across Canada without a central marketing plan. On contact with the study, individuals reported how they heard about the study according to a predefined list. One site, the Juravinski Cancer Centre, worked with a marketing expert to develop a survey to assess participant motivations, source of study awareness, and personal habits. The survey was used to develop a media campaign for recruitment. Media events were collected from all sites. The primary analysis assessed the number of telephone contacts and recruited subjects associated with various media factors. Individual print media characteristics were assessed for their effect on recruitment. RESULTS: At all sites, 7059 individuals contacted the study, and 2537 were eligible and recruited. Among 52 individuals completing the Juravinski Cancer Centre survey, motivation included concern for personal risk of lung cancer (71%), followed by desire to contribute to a cure (67%), followed by personal knowledge of a person with lung cancer (50%). Most reported hearing of the study from the newspaper (58%) despite no print ad yet being distributed. With survey input, a newsprint campaign was executed. The number of media events varied by site (median: 13, range: 3-28). Among all recruits, 56.4% reported referral by newspaper followed by family/friend (14%). Telephone contacts and recruited subjects per event varied significantly by site, while unpaid media events appeared superior to paid events. Print media characteristics associated with increased telephone contacts and recruitment included use of a rational appeal (vs a mixed rational-emotional), less use of white space, and larger headline font. CONCLUSION: A survey of trial candidates provides useful information regarding personal motivation, media use, and lifestyle. Unpaid media events appear superior in generating recruitment, while print media may be superior to radio and television in selecting eligible recruits. The utility of individual print media characteristics appears to differ from the commercial advertising literature. Further research on marketing in clinical trials is encouraged to improve recruitment ( ClinicalTrials.gov registration: NCT00751660, https://clinicaltrials.gov/ct2/show/NCT00751660 ).

A Rare Complication: Development of an Aspergilloma after Endobronchial Coil Placement in a COPD Patient.

Endobronchial coils are a relatively novel endoscopic lung volume reduction modality that aims to increase functional capacity in chronic obstructive pulmonary disease (COPD) patients. Two major trials have studied the safety and efficacy of this therapy, but long-term safety has not been studied. Adverse events reported are mainly periprocedural pneumothoraces and early bacterial infectious complications. We report the case of a patient with severe emphysema (Global Initiative for Chronic Obstructive Lung Disease stage IV COPD) who developed endobronchial coil-associated aspergillomas 3 years after coil placement.

Improving Lung Function in Severe Heterogenous Emphysema with the Spiration Valve System (EMPROVE). A Multicenter, Open-Label Randomized Controlled Clinical Trial.

Rationale: Less invasive, nonsurgical approaches are needed to treat severe emphysema.Objectives: To evaluate the effectiveness and safety of the Spiration Valve System (SVS) versus optimal medical management.Methods: In this multicenter, open-label, randomized, controlled trial, subjects aged 40 years or older with severe, heterogeneous emphysema were randomized 2:1 to SVS with medical management (treatment) or medical management alone (control).Measurements and Main Results: The primary efficacy outcome was the difference in mean FEV1 from baseline to 6 months. Secondary effectiveness outcomes included: difference in FEV1 responder rates, target lobe volume reduction, hyperinflation, health status, dyspnea, and exercise capacity. The primary safety outcome was the incidence of composite thoracic serious adverse events. All analyses were conducted by determining the 95% Bayesian credible intervals (BCIs) for the difference between treatment and control arms. Between October 2013 and May 2017, 172 participants (53.5% male; mean age, 67.4 yr) were randomized to treatment (n = 113) or control (n = 59). Mean FEV1 showed statistically significant improvements between the treatment and control groups-between-group difference at 6 and 12 months, respectively, of 0.101 L (95% BCI, 0.060-0.141) and 0.099 L (95% BCI, 0.048-0.151). At 6 months, the treatment group had statistically significant improvements in all secondary endpoints except 6-minute-walk distance. Composite thoracic serious adverse event incidence through 6 months was greater in the treatment group (31.0% vs. 11.9%), primarily due to a 12.4% incidence of serious pneumothorax.Conclusions: In patients with severe heterogeneous emphysema, the SVS shows significant improvement in multiple efficacy outcomes, with an acceptable safety profile.Clinical trial registered with www.clinicaltrials.gov (NCT01812447).

Simplified Criteria Using Pleural Fluid Cholesterol and Lactate Dehydrogenase to Distinguish between Exudative and Transudative Pleural Effusions.

BACKGROUND: An important part of the investigation of pleural effusion is the identification of markers that help separate exudate from transudate. OBJECTIVES: The purposes of this study were to compare the accuracy of published and new sets of criteria to distinguish between exudative and transudative pleural effusions, and to determine whether serum biochemical analysis is necessary. METHODS: An externally validated cohort study was performed. Pleural effusions were determined to be transudative or exudative on the basis of an assessment of the medical record by two clinicians blinded to biochemical results. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and area under the receiver operating characteristic curve were determined for each proposed combination of criteria. RESULTS: Pleural fluid analysis was available for 311 thoracenteses in the main cohort and for 112 thoracenteses in the validation cohort. The best sensitivity (97% [95% CI 94-99]) and negative likelihood ratio (0.04 [95% CI 0.02-0.08]) for identifying exudative effusions were observed with criteria combining pleural fluid lactate dehydrogenase greater than 0.6 the upper limit of normal serum lactate dehydrogenase and pleural fluid cholesterol greater than 1.04 mmol/L (40 mg/dL). The overall diagnostic accuracy was similar to Light's criteria. Findings were similar in the validation cohort. CONCLUSIONS: Our proposed criteria using simultaneously pleural fluid lactate dehydrogenase and pleural fluid cholesterol can identify an exudate with a sensitivity and an overall diagnostic accuracy similar to Light's criteria. It avoids simultaneous blood sampling, thus reducing patient discomfort and potential costs.