Lymphangioleiomyomatosis Diagnosis and Management: High-Resolution Chest Computed Tomography, Transbronchial Lung Biopsy, and Pleural Disease Management. An Official American Thoracic Society/Japanese Respiratory Society Clinical Practice Guideline.

BACKGROUND: Recommendations regarding key aspects related to the diagnosis and pharmacological treatment of lymphangioleiomyomatosis (LAM) were recently published. We now provide additional recommendations regarding four specific questions related to the diagnosis of LAM and management of pneumothoraces in patients with LAM. METHODS: Systematic reviews were performed and then discussed by a multidisciplinary panel. For each intervention, the panel considered its confidence in the estimated effects, the balance of desirable (i.e., benefits) and undesirable (i.e., harms and burdens) consequences, patient values and preferences, cost, and feasibility. Evidence-based recommendations were then formulated, written, and graded using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. RESULTS: For women who have cystic changes on high-resolution computed tomography of the chest characteristic of LAM, but who have no additional confirmatory features of LAM (i.e., clinical, radiologic, or serologic), the guideline panel made conditional recommendations against making a clinical diagnosis of LAM on the basis of the high-resolution computed tomography findings alone and for considering transbronchial lung biopsy as a diagnostic tool. The guideline panel also made conditional recommendations for offering pleurodesis after an initial pneumothorax rather than postponing the procedure until the first recurrence and against pleurodesis being used as a reason to exclude patients from lung transplantation. CONCLUSIONS: Evidence-based recommendations for the diagnosis and treatment of patients with LAM are provided. Frequent reassessment and updating will be needed.

A phase 3 trial of pirfenidone in patients with idiopathic pulmonary fibrosis.

BACKGROUND: In two of three phase 3 trials, pirfenidone, an oral antifibrotic therapy, reduced disease progression, as measured by the decline in forced vital capacity (FVC) or vital capacity, in patients with idiopathic pulmonary fibrosis; in the third trial, this end point was not achieved. We sought to confirm the beneficial effect of pirfenidone on disease progression in such patients. METHODS: In this phase 3 study, we randomly assigned 555 patients with idiopathic pulmonary fibrosis to receive either oral pirfenidone (2403 mg per day) or placebo for 52 weeks. The primary end point was the change in FVC or death at week 52. Secondary end points were the 6-minute walk distance, progression-free survival, dyspnea, and death from any cause or from idiopathic pulmonary fibrosis. RESULTS: In the pirfenidone group, as compared with the placebo group, there was a relative reduction of 47.9% in the proportion of patients who had an absolute decline of 10 percentage points or more in the percentage of the predicted FVC or who died; there was also a relative increase of 132.5% in the proportion of patients with no decline in FVC (P<0.001). Pirfenidone reduced the decline in the 6-minute walk distance (P=0.04) and improved progression-free survival (P<0.001). There was no significant between-group difference in dyspnea scores (P=0.16) or in rates of death from any cause (P=0.10) or from idiopathic pulmonary fibrosis (P=0.23). However, in a prespecified pooled analysis incorporating results from two previous phase 3 trials, the between-group difference favoring pirfenidone was significant for death from any cause (P=0.01) and from idiopathic pulmonary fibrosis (P=0.006). Gastrointestinal and skin-related adverse events were more common in the pirfenidone group than in the placebo group but rarely led to treatment discontinuation. CONCLUSIONS: Pirfenidone, as compared with placebo, reduced disease progression, as reflected by lung function, exercise tolerance, and progression-free survival, in patients with idiopathic pulmonary fibrosis. Treatment was associated with an acceptable side-effect profile and fewer deaths. (Funded by InterMune; ASCEND ClinicalTrials.gov number, NCT01366209.).

Official American Thoracic Society/Japanese Respiratory Society Clinical Practice Guidelines: Lymphangioleiomyomatosis Diagnosis and Management.

BACKGROUND: Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease that primarily affects women. The purpose of these guidelines is to provide recommendations for the diagnosis and treatment of LAM. METHODS: Systematic reviews were performed to summarize evidence pertinent to our questions. The evidence was summarized and discussed by a multidisciplinary panel. Evidence-based recommendations were then formulated, written, and graded using the Grading of Recommendations, Assessment, Development, and Evaluation approach. RESULTS: After considering the panel's confidence in the estimated effects, the balance of desirable (i.e., benefits) and undesirable (i.e., harms and burdens) consequences of treatment, patient values and preferences, cost, and feasibility, recommendations were formulated for or against specific interventions. These included recommendations for sirolimus treatment and vascular endothelial growth factor D testing and recommendations against doxycycline and hormonal therapy. CONCLUSIONS: Evidence-based recommendations for the diagnosis and treatment of patients with LAM are provided. Frequent reassessment and updating will be needed.

All-cause mortality rate in patients with idiopathic pulmonary fibrosis. Implications for the design and execution of clinical trials.

RATIONALE: FVC has emerged as a standard primary endpoint in clinical trials evaluating novel therapies for patients with idiopathic pulmonary fibrosis (IPF). However, it has recently been proposed that all-cause mortality or a composite comprised of all-cause mortality and all-cause nonelective hospitalization be adopted as the standard primary endpoint for IPF clinical trials. OBJECTIVES: To conduct a comprehensive evaluation of mortality in three phase 3 clinical trials and evaluate the feasibility of mortality trials in patients with IPF. METHODS: The study population included 622 patients randomized to placebo in the CAPACITY studies evaluating pirfenidone (n = 347) or the INSPIRE study evaluating interferon-γ1b (n = 275). The Kaplan-Meier estimate of 2-year survival was fit to the exponential distribution and used to calculate sample size requirements for a mortality study with 90% power to detect a 25% reduction in all-cause mortality with a two-sided α of 0.05. Modeling analyses were used to assess the effects of selected variables on sample size and study design. MEASUREMENTS AND MAIN RESULTS: A total of 73 deaths occurred during the period of observation (mean duration of follow-up, 80.1 wk). The all-cause mortality rate was 6.6% at 1 year and 13.7% at 2 years. Based on the observed 2-year mortality rate, a total of 508 events would be required to detect a significant treatment benefit in a two-arm trial with 90% power to detect a 25% reduction in all-cause mortality. The estimated sample size for a trial enrolled over 3 years with a maximum follow-up period of 5 years is 2,582 patients. CONCLUSIONS: The all-cause mortality rate is relatively low in patients with IPF with mild to moderate impairment in lung function. Accordingly, the necessary size, duration, and cost of all-cause mortality trials in this population are substantial and likely prohibitive.

6-Minute walk distance is an independent predictor of mortality in patients with idiopathic pulmonary fibrosis.

6-min walk distance (6MWD) has recently been shown to be associated with the risk of mortality in patients with idiopathic pulmonary fibrosis (IPF); however, the independent contribution of 6MWD to the prediction of mortality risk has not been evaluated in a large, well-defined population of patients with IPF. A Cox proportional hazards model was used to characterise the relationship between risk factors of interest and all-cause mortality in IPF patients who completed a week 24 study visit in a clinical trial evaluating interferon γ-1b (n=748). Risk factors of interest included the independent predictors of mortality in the previously published clinical prediction model together with 6MWD and 24-week change in 6MWD. Baseline 6MWD <250 m was associated with a two-fold increase in the risk of mortality (hazard ratio 2.12, 95% CI 1.15-3.92) and a 24-week decline in 6MWD >50 m was associated with a nearly three-fold increase in mortality risk (hazard ratio 2.73; 95% CI 1.60-4.66). Inclusion of 6MWD data improved model discrimination compared with the original model (C-statistic 0.80 (95% CI 0.76-0.85) versus 0.75 (0.71-0.79)). Both 6MWD and change in 6MWD are independent predictors of mortality in patients with IPF. The addition of 6MWD to the clinical prediction model improves model discrimination compared with the original model.

Comprehensive assessment of the long-term safety of pirfenidone in patients with idiopathic pulmonary fibrosis.

BACKGROUND AND OBJECTIVE: Pirfenidone is an oral antifibrotic agent that is approved in several countries for the treatment of idiopathic pulmonary fibrosis (IPF). We performed a comprehensive analysis of safety across four clinical trials evaluating pirfenidone in patients with IPF. METHODS: All patients receiving pirfenidone 2403 mg/day in the Phase 3 CAPACITY studies (Studies 004 and 006) and all patients receiving at least one dose of pirfenidone in one of two ongoing open-label studies in patients with IPF (Studies 002 and 012) were selected for inclusion. Safety outcomes were evaluated from baseline until 28 days after the last dose of study drug. RESULTS: A total of 789 patients were included in the analysis. The median duration of exposure to pirfenidone was 2.6 years (range, 1 week-7.7 years), and the cumulative total exposure was 2059 person exposure years (PEY). Gastrointestinal and skin-related events were the most commonly reported adverse events; these were almost always mild to moderate in severity, and rarely led to treatment discontinuation. Elevations (>3× upper limit of normal) in alanine aminotransferase (ALT) or aspartate aminotransferase (AST) occurred in 21/789 (2.7%) patients; the adjusted incidence of AST/ALT elevations was 1.7 per 100 PEY. CONCLUSIONS: This comprehensive analysis of safety in a large cohort of IPF patients receiving pirfenidone for a total of 2059 PEY demonstrates that long-term treatment with pirfenidone is safe and generally well tolerated.

Characteristics of patients with yellow nail syndrome and pleural effusion.

Yellow nail syndrome (YNS) can be associated with a pleural effusion (PE) but the characteristics of these patients are not well defined. We performed a systematic review across four electronic databases for studies reporting clinical findings, PE characteristics, and most effective treatment of YNS. Case descriptions and retrospective studies were included, unrestricted by year of publication. We reviewed 112 studies (150 patients), spanning a period of nearly 50 years. The male/female ratio was 1.2/1. The median age was 60 years (range: 0-88). Seventy-eight percent were between 41-80 years old. All cases had lymphoedema and 85.6% had yellow nails. PEs were bilateral in 68.3%. The appearance of the fluid was serous in 75.3%, milky in 22.3% and purulent in 3.5%. The PE was an exudate in 94.7% with lymphocytic predominance in 96% with a low count of nucleated cells. In 61 of 66 (92.4%) of patients, pleural fluid protein values were >3 g/dL, and typically higher than pleural fluid LDH. Pleurodesis and decortication/pleurectomy were effective in 81.8% and 88.9% of cases, respectively, in the treatment of symptomatic PEs. The development of YNS and PE occurs between the fifth to eighth decade of life and is associated with lymphoedema. The PE is usually bilateral and behaves as a lymphocyte-predominant exudate. The most effective treatments appear to be pleurodesis and decortication/pleurectomy.

Pirfenidone in patients with idiopathic pulmonary fibrosis (CAPACITY): two randomised trials.

BACKGROUND: Idiopathic pulmonary fibrosis is a progressive and fatal lung disease with inevitable loss of lung function. The CAPACITY programme (studies 004 and 006) was designed to confirm the results of a phase 2 study that suggested that pirfenidone, a novel antifibrotic and anti-inflammatory drug, reduces deterioration in lung function in patients with idiopathic pulmonary fibrosis. METHODS: In two concurrent trials (004 and 006), patients (aged 40-80 years) with idiopathic pulmonary fibrosis were randomly assigned to oral pirfenidone or placebo for a minimum of 72 weeks in 110 centres in Australia, Europe, and North America. In study 004, patients were assigned in a 2:1:2 ratio to pirfenidone 2403 mg/day, pirfenidone 1197 mg/day, or placebo; in study 006, patients were assigned in a 1:1 ratio to pirfenidone 2403 mg/day or placebo. The randomisation code (permuted block design) was computer generated and stratified by region. All study personnel were masked to treatment group assignment until after final database lock. Treatments were administered orally, 801 mg or 399 mg three times a day. The primary endpoint was change in percentage predicted forced vital capacity (FVC) at week 72. Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, numbers NCT00287729 and NCT00287716. FINDINGS: In study 004, 174 of 435 patients were assigned to pirfenidone 2403 mg/day, 87 to pirfenidone 1197 mg/day, and 174 to placebo. In study 006, 171 of 344 patients were assigned to pirfenidone 2403 mg/day, and 173 to placebo. All patients in both studies were analysed. In study 004, pirfenidone reduced decline in FVC (p=0·001). Mean FVC change at week 72 was -8·0% (SD 16·5) in the pirfenidone 2403 mg/day group and -12·4% (18·5) in the placebo group (difference 4·4%, 95% CI 0·7 to 9·1); 35 (20%) of 174 versus 60 (35%) of 174 patients, respectively, had a decline of at least 10%. A significant treatment effect was noted at all timepoints from week 24 and in an analysis over all study timepoints (p=0·0007). Mean change in percentage FVC in the pirfenidone 1197 mg/day group was intermediate to that in the pirfenidone 2403 mg/day and placebo groups. In study 006, the difference between groups in FVC change at week 72 was not significant (p=0·501). Mean change in FVC at week 72 was -9·0% (SD 19·6) in the pirfenidone group and -9·6% (19·1) in the placebo group, and the difference between groups in predicted FVC change at week 72 was not significant (0·6%, -3·5 to 4·7); however, a consistent pirfenidone effect was apparent until week 48 (p=0·005) and in an analysis of all study timepoints (p=0·007). Patients in the pirfenidone 2403 mg/day group had higher incidences of nausea (125 [36%] of 345 vs 60 [17%] of 347), dyspepsia (66 [19%] vs 26 [7%]), vomiting (47 [14%] vs 15 [4%]), anorexia (37 [11%] vs 13 [4%]), photosensitivity (42 [12%] vs 6 [2%]), rash (111 [32%] vs 40 [12%]), and dizziness (63 [18%] vs 35 [10%]) than did those in the placebo group. Fewer overall deaths (19 [6%] vs 29 [8%]) and fewer deaths related to idiopathic pulmonary fibrosis (12 [3%] vs 25 [7%]) occurred in the pirfenidone 2403 mg/day groups than in the placebo groups. INTERPRETATION: The data show pirfenidone has a favourable benefit risk profile and represents an appropriate treatment option for patients with idiopathic pulmonary fibrosis. FUNDING: InterMune.

Getting the most from pleural fluid analysis.

Virtually, every pulmonary disease and most non-pulmonary diseases may be associated with a pleural effusion. The presence of a pleural effusion allows the clinician to 'diagnose' or narrow the differential diagnosis and aetiology of the fluid collection. However, pleural fluid analysis (PFA) in isolation rarely provides a definitive diagnosis. This review discusses the rationale for evaluating patients with a pleural effusion. If the clinician obtains a detailed history, performs a comprehensive physical examination, reviews pertinent blood tests, and evaluates the chest imaging findings prior to thoracentesis, there should be a high likelihood of establishing a firm clinical diagnosis based on the appropriate PFA. This manuscript reviews the clinical presentation, chest imaging findings, duration and natural course of specific pleural effusions to help narrow the range of pre-thoracentesis diagnoses. A diagnosis of transudative effusion confirms an imbalance in hydrostatic and oncotic pressures, normal pleura and a limited differential diagnosis, which is typically apparent from the clinical presentation. Exudates are the result of infections, malignancies, inflammation, impaired lymphatic drainage or the effects of drugs, and pose a greater diagnostic challenge. The differential diagnosis for a pleural exudate can be narrowed if LDH levels exceed 1000 IU/L, the proportion of lymphocytes is ≥80%, pleural fluid pH is <7.30 or there is pleural eosinophilia of >10%.

Ascertainment of individual risk of mortality for patients with idiopathic pulmonary fibrosis.

RATIONALE: Several predictors of mortality in patients with idiopathic pulmonary fibrosis have been described; however, there is a need for a practical and accurate method of quantifying the prognosis of individual patients. OBJECTIVES: Develop a practical mortality risk scoring system for patients with idiopathic pulmonary fibrosis. METHODS: We used a Cox proportional hazards model and data from two clinical trials (n = 1,099) to identify independent predictors of 1-year mortality among patients with idiopathic pulmonary fibrosis. From the comprehensive model, an abbreviated clinical model comprised of only those predictors that are readily and reliably ascertained by clinicians was derived. Beta coefficients for each predictor were then used to develop a practical mortality risk scoring system. MEASUREMENTS AND MAIN RESULTS: Independent predictors of mortality included age, respiratory hospitalization, percent predicted FVC, 24-week change in FVC, percent predicted carbon monoxide diffusing capacity, 24-week change in percent predicted carbon monoxide diffusing capacity, and 24-week change in health-related quality of life. An abbreviated clinical model comprising only four predictors (age, respiratory hospitalization, percent predicted FVC, and 24-wk change in FVC), and the corresponding risk scoring system produced estimates of 1-year mortality risk consistent with observed data (9.9% vs. 9.7%; C statistic = 0.75; 95% confidence interval, 0.71­0.79). CONCLUSIONS: The prognosis for patients with idiopathic pulmonary fibrosis may be accurately determined using four readily ascertainable predictors. Our simplified scoring system may be a valuable tool for determining prognosis and guiding clinical management. Additional research is needed to validate the applicability and accuracy of the scoring system.

Forced vital capacity in patients with idiopathic pulmonary fibrosis: test properties and minimal clinically important difference.

RATIONALE: Forced vital capacity (FVC) is an established measure of pulmonary function in idiopathic pulmonary fibrosis (IPF). Evidence regarding its measurement properties and minimal clinically important difference (MCID) in this population is limited. OBJECTIVES: To assess the reliability, validity, and responsiveness of FVC and estimate the MCID in patients with IPF. METHODS: The study population included all 1,156 randomized patients in two clinical trials of IFN-γ1b. FVC and other measures of functional status were measured at screening or baseline and 24-week intervals thereafter. Reliability was assessed based on two proximal measures of FVC, validity was assessed based on correlations between FVC and other measures of functional status, and responsiveness was assessed based on the relationship between 24-week changes in FVC and other measures of functional status. Distribution-based and anchor-based methods were used to estimate the MCID. MEASUREMENTS AND MAIN RESULTS: Correlation of percent-predicted FVC between measurements (mean interval, 18 d) was high (r = 0.93; P < 0.001). Correlations between FVC and other parameters were generally weak, with the strongest observed correlation between FVC and carbon monoxide diffusing capacity (r = 0.38; P < 0.001). Correlations between change in FVC and changes in other parameters were slightly stronger (range, r = 0.16-0.37; P < 0.001). Importantly, 1-year risk of death was more than twofold higher (P < 0.001) in patients with a 24-week decline in FVC between 5% and 10%. The estimated MCID was 2-6%. CONCLUSIONS: FVC is a reliable, valid, and responsive measure of clinical status in patients with IPF, and a decline of 2-6%, although small, represents a clinically important difference.

Six-minute-walk test in idiopathic pulmonary fibrosis: test validation and minimal clinically important difference.

RATIONALE: The 6-minute-walk test (6MWT) is a practical and clinically meaningful measure of exercise tolerance with favorable performance characteristics in various cardiac and pulmonary diseases. Performance characteristics in patients with idiopathic pulmonary fibrosis (IPF) have not been systematically evaluated. OBJECTIVES: To assess the reliability, validity, and responsiveness of the 6MWT and estimate the minimal clinically important difference (MCID) in patients with IPF. METHODS: The study population included all subjects completing a 6MWT in a clinical trial evaluating interferon gamma-1b (n = 822). Six-minute walk distance (6MWD) and other parameters were measured at baseline and at 24-week intervals using a standardized protocol. Parametric and distribution-independent correlation coefficients were used to assess the strength of the relationships between 6MWD and measures of pulmonary function, dyspnea, and health-related quality of life. Both distribution-based and anchor-based methods were used to estimate the MCID. MEASUREMENTS AND MAIN RESULTS: Comparison of two proximal measures of 6MWD (mean interval, 24 d) demonstrated good reliability (coefficient = 0.83; P < 0.001). 6MWD was weakly correlated with measures of physiologic function and health-related quality of life; however, values were consistently and significantly lower for patients with the poorest functional status, suggesting good construct validity. Importantly, change in 6MWD was highly predictive of mortality; a 24-week decline of greater than 50 m was associated with a fourfold increase in risk of death at 1 year (hazard ratio, 4.27; 95% confidence interval, 2.57- 7.10; P < 0.001). The estimated MCID was 24-45 m. CONCLUSIONS: The 6MWT is a reliable, valid, and responsive measure of disease status and a valid endpoint for clinical trials in IPF.

Intrapleural therapy.

Numerous intrapleural therapies have been adopted to treat a vast array of pleural diseases. The first intrapleural therapies proposed focused on the use of fibrinolytics and DNase to promote fluid drainage in empyema. Numerous case series and five randomized controlled trials have been published to determine the outcomes of fibrinolytics in empyema treatment. In the largest randomized trial, the use of streptokinase had no reduction in mortality, decortication rates or hospital days compared with placebo in the treatment of empyema. Criticism over study design and patient selection may have potentially affected the outcomes in this study. The development of dyspnoea is common in the setting of malignant pleural effusions. Pleural fluid evacuation followed by pleurodesis is often attempted. Numerous sclerosing agents have been studied, with talc emerging as the most effective agent. Small particle size of talc should be avoided because of increased systemic absorption potentiating toxicity, such as acute lung injury. Over the past several years, the use of chronic indwelling pleural catheters have emerged as the preferred modality in the treating a symptomatic malignant pleural effusion. For patients with malignant-related lung entrapment, pleurodesis often fails due to the presence of visceral pleural restriction; however, chronic indwelling pleural catheters are effective in palliation of dyspnoea. Finally, the use of staphylococcal superantigens has been proposed as a therapeutic model for the treatment of non-small lung cancer. Intrapleural instillation of staphylococcal superantigens increased median survival by 5 months in patients with non-small cell lung cancer with a malignant pleural effusion.

Effect of interferon gamma-1b on survival in patients with idiopathic pulmonary fibrosis (INSPIRE): a multicentre, randomised, placebo-controlled trial.

BACKGROUND: Idiopathic pulmonary fibrosis is a fatal disease for which no effective treatment exists. We assessed whether treatment with interferon gamma-1b improved survival compared with placebo in patients with idiopathic pulmonary fibrosis and mild-to-moderate impairment of pulmonary function. METHODS: 826 patients with idiopathic pulmonary fibrosis were enrolled from 81 centres in seven European countries, the USA, and Canada. Patients were randomly assigned (double-blind) in a 2:1 ratio to receive 200 microg interferon gamma-1b (n=551) or equivalent placebo (n=275) subcutaneously, three times per week. Eligible patients were aged 40-79 years, had been diagnosed in the past 48 months, had a forced vital capacity of 55-90% of the predicted value, and a haemoglobin-corrected carbon monoxide diffusing capacity of 35-90% of the predicted value. The primary endpoint was overall survival time from randomisation measured at the second interim analysis, when the proportion of deaths had reached 75% of those expected by the study conclusion. This study is registered with ClinicalTrials.gov, number NCT00075998. FINDINGS: At the second interim analysis, the hazard ratio for mortality in patients on interferon gamma-1b showed absence of minimum benefit compared with placebo (1.15, 95% CI 0.77-1.71, p=0.497), and indicated that the study should be stopped. After a median duration of 64 weeks (IQR 41-84) on treatment, 80 (15%) patients on interferon gamma-1b and 35 (13%) on placebo had died. Almost all patients reported at least one adverse event, and more patients on interferon gamma-1b group had constitutional signs and symptoms (influenza-like illness, fatigue, fever, and chills) than did those on placebo. Occurrence of serious adverse events (eg, pneumonia, respiratory failure) was similar for both treatment groups. Treatment adherence was good and few patients discontinued treatment prematurely in either group. INTERPRETATION: We cannot recommend treatment with interferon gamma-1b since the drug did not improve survival for patients with idiopathic pulmonary fibrosis, which refutes previous findings from subgroup analyses of survival in studies of patients with mild-to-moderate physiological impairment of pulmonary function. FUNDING: InterMune.

Pleural fluid analysis in chylous pleural effusion.

OBJECTIVES: Chyle is a noninflammatory, lymphocyte-predominant fluid that may cause a pleural effusion as a consequence of thoracic duct leakage into the pleural space. Although chyle is reported to have protein concentrations in the transudative range, chylous effusions are typically exudative, as defined by the standard criteria. We hypothesized that chylous effusions from a thoracic duct leak alone have low lactate dehydrogenase (LDH) concentrations due to the absence of inflammation and are lymphocyte-predominant, protein-discordant exudates. Consequently, pleural effusions that do not meet these criteria but with triglyceride concentrations of > 110 mg/dL or are positive for chylomicrons should be associated with other diagnoses contributing to pleural fluid formation. STUDY DESIGN: Retrospective. METHODS: The pleural fluid analyses of 876 consecutive thoracenteses were reviewed. All cases with a triglyceride concentration of > 110 mg/dL or the presence of chylomicrons were retrieved. The effusions were then classified as transudates, concordant exudates, protein-discordant exudates, and LDH-discordant exudates, and according to lymphocyte predominance (> 50%). The causes of these pleural effusions were determined after the review of the medical record. RESULTS: Twenty-two pleural effusions had elevated triglyceride concentrations and/or were positive for chylomicrons. Eleven effusions were lymphocyte-predominant, protein-discordant exudates, and two of these were associated with chylous ascites. The remaining effusions were transudates (n = 7) or concordant exudates (n = 4); all were associated with conditions known to cause pleural effusion apart from chyle leakage. CONCLUSION: Chylous effusions caused solely by conditions known to cause chylothorax were lymphocyte-predominant, protein-discordant exudates. Protein concentrations in the transudative range or elevated LDH concentrations were associated with a coexisting condition that may impact the management of these chylous effusions.

The value of pleural fluid analysis.

Pleural fluid analysis in isolation may have clinical value. To have the greatest diagnostic impact, the clinician must formulate a prethoracentesis diagnosis based on the clinical presentation, blood tests, and radiographic imaging. With this approach, a definitive or confident clinical diagnosis can be expected in up to 95% of patients. The information in this report should allow the clinician to achieve this goal.

Lipid pleural effusions.

Traditionally, a lipid pleural effusion has been described as milky or turbid appearing. However, lipid effusions may have varied presentations making a diagnosis by appearance problematic. Distinguishing between a chylothorax and a cholesterol effusion, the 2 types of lipid effusions, is essential. A chylothorax develops after injury or obstruction of the thoracic duct, leading to a chyle leak into the pleural space that is characterized by an increased triglyceride concentration and the presence of chylomicrons. In contrast, a cholesterol effusion is a long-standing effusion associated with an elevated cholesterol concentration, usually greater than 250 mg/dL, a thick pleural rind, and represents a form of lung entrapment.

Chronic dyspnea and severe obstruction after pneumonectomy: postpneumonectomy syndrome.

Postpneumonectomy syndrome is a rare complication secondary to postsurgical anatomic changes in the pneumonectomy space. Patients present with marked dyspnea on exertion secondary to airflow limitation from proximal airway compression and overdistention of the remaining lung because of mediastinal shift. Postpneumonectomy syndrome is treated by surgical repositioning of the mediastinum. Knowledge of the clinical and radiological features will enable prompt diagnosis and appropriate treatment.

Common problems in critically ill obstetric patients, with an emphasis on pharmacotherapy.

Pharmacological treatment of critically ill obstetric patients can be especially challenging due to the complexity of caring for 2 patients, with a paucity of research to support practice. This review will provide practitioners with primary recommendations for management of the critical illnesses most commonly encountered in pregnancy and will discuss the scientific and clinical merit of these recommendations.

Seat belt-induced chylothorax: a cause of idiopathic chylothorax?

Chylothoraces are associated with multiple etiologies including non-Hodgkin lymphoma and surgical trauma, representing 50% and 25% of all chylothoraces, respectively. Intrathoracic operations such as repair of coarctation of the aorta and esophagectomy are commonly associated with surgical trauma. Idiopathic chylothoraces may account for up to 15% of all chylothoraces. When a thorough evaluation finding is negative, further history to identify possible blunt, nonpenetrating trauma to the chest is warranted.