Public Health Data Applications Using the CDC Tracking Network: Augmenting Environmental Hazard Information With Lower-Latency NASA Data.

Exposure to environmental hazards is an important determinant of health, and the frequency and severity of exposures is expected to be impacted by climate change. Through a partnership with the U.S. National Aeronautics and Space Administration, the U.S. Centers for Disease Control and Prevention's National Environmental Public Health Tracking Network is integrating timely observations and model data of priority environmental hazards into its publicly accessible Data Explorer (https://ephtracking.cdc.gov/DataExplorer/). Newly integrated data sets over the contiguous U.S. (CONUS) include: daily 5-day forecasts of air quality based on the Goddard Earth Observing System Composition Forecast, daily historical (1980-present) concentrations of speciated PM2.5 based on the modern era retrospective analysis for research and applications, version 2, and Moderate Resolution Imaging Spectroradiometer (MODIS) daily near real-time maps of flooding (MCDWD). Data integrated into the CDC Tracking Network are broadly intended to improve community health through action by informing both research and early warning activities, including (a) describing temporal and spatial trends in disease and potential environmental exposures, (b) identifying populations most affected, (c) generating hypotheses about associations between health and environmental exposures, and (d) developing, guiding, and assessing environmental public health policies and interventions aimed at reducing or eliminating health outcomes associated with environmental factors.

NASA GEOS Composition Forecast Modeling System GEOS-CF v1.0: Stratospheric Composition.

The NASA Goddard Earth Observing System (GEOS) Composition Forecast (GEOS-CF) provides recent estimates and 5-day forecasts of atmospheric composition to the public in near-real time. To do this, the GEOS Earth system model is coupled with the GEOS-Chem tropospheric-stratospheric unified chemistry extension (UCX) to represent composition from the surface to the top of the GEOS atmosphere (0.01 hPa). The GEOS-CF system is described, including updates made to the GEOS-Chem UCX mechanism within GEOS-CF for improved representation of stratospheric chemistry. Comparisons are made against balloon, lidar, and satellite observations for stratospheric composition, including measurements of ozone (O3) and important nitrogen and chlorine species related to stratospheric O3 recovery. The GEOS-CF nudges the stratospheric O3 toward the GEOS Forward Processing (GEOS FP) assimilated O3 product; as a result the stratospheric O3 in the GEOS-CF historical estimate agrees well with observations. During abnormal dynamical and chemical environments such as the 2020 polar vortexes, the GEOS-CF O3 forecasts are more realistic than GEOS FP O3 forecasts because of the inclusion of the complex GEOS-Chem UCX stratospheric chemistry. Overall, the spatial patterns of the GEOS-CF simulated concentrations of stratospheric composition agree well with satellite observations. However, there are notable biases-such as low NO x and HNO3 in the polar regions and generally low HCl throughout the stratosphere-and future improvements to the chemistry mechanism and emissions are discussed. GEOS-CF is a new tool for the research community and instrument teams observing trace gases in the stratosphere and troposphere, providing near-real-time three-dimensional gridded information on atmospheric composition.

Sub-City Scale Hourly Air Quality Forecasting by Combining Models, Satellite Observations, and Ground Measurements.

While multiple information sources exist concerning surface-level air pollution, no individual source simultaneously provides large-scale spatial coverage, fine spatial and temporal resolution, and high accuracy. It is, therefore, necessary to integrate multiple data sources, using the strengths of each source to compensate for the weaknesses of others. In this study, we propose a method incorporating outputs of NASA's GEOS Composition Forecasting model system with satellite information from the TROPOMI instrument and ground measurement data on surface concentrations. Although we use ground monitoring data from the Environmental Protection Agency network in the continental United States, the model and satellite data sources used have the potential to allow for global application. This method is demonstrated using surface measurements of nitrogen dioxide as a test case in regions surrounding five major US cities. The proposed method is assessed through cross-validation against withheld ground monitoring sites. In these assessments, the proposed method demonstrates major improvements over two baseline approaches which use ground-based measurements only. Results also indicate the potential for near-term updating of forecasts based on recent ground measurements.

Atmospheric implications of large C2-C5 alkane emissions from the U.S. oil and gas industry.

Emissions of C2-C5 alkanes from the U.S. oil and gas sector have changed rapidly over the last decade. We use a nested GEOS-Chem simulation driven by updated 2011NEI emissions with aircraft, surface and column observations to 1) examine spatial patterns in the emissions and observed atmospheric abundances of C2-C5 alkanes over the U.S., and 2) estimate the contribution of emissions from the U.S. oil and gas industry to these patterns. The oil and gas sector in the updated 2011NEI contributes over 80% of the total U.S. emissions of ethane (C2H6) and propane (C3H8), and emissions of these species are largest in the central U.S. Observed mixing ratios of C2-C5 alkanes show enhancements over the central U.S. below 2 km. A nested GEOS-Chem simulation underpredicts observed C3H8 mixing ratios in the boundary layer over several U.S. regions and the relative underprediction is not consistent, suggesting C3H8 emissions should receive more attention moving forward. Our decision to consider only C4-C5 alkane emissions as a single lumped species produces a geographic distribution similar to observations. Due to the increasing importance of oil and gas emissions in the U.S., we recommend continued support of existing long-term measurements of C2-C5 alkanes. We suggest additional monitoring of C2-C5 alkanes downwind of northeastern Colorado, Wyoming and western North Dakota to capture changes in these regions. The atmospheric chemistry modeling community should also evaluate whether chemical mechanisms that lump larger alkanes are sufficient to understand air quality issues in regions with large emissions of these species.

Pulmonary alveolar proteinosis in association with household exposure to fibrous insulation material.

We report the case of a 35-year-old woman who developed pulmonary alveolar proteinosis requiring multiple lavage treatments, in association with household exposure to ventilation system dust comprised at least partially by a cellulose fire-resistant fibrous insulation material. Scanning electron microscopy with energy-dispersive x-ray analysis documented the presence of spectral peaks consistent with the insulation material in transbronchial biopsy tissue. The patient showed symptomatic improvement once exposure to the insulation material had ceased. We believe that this case demonstrates an unusual association with pulmonary alveolar proteinosis. This case emphasizes the broad differential diagnosis for this histologic injury pattern and the need to thoroughly investigate environmental exposures in patients with unexplained pulmonary disease.

Severe ischemic injury to the proximal airway following lung transplantation. Immediate and long-term effects on bronchial cartilage. Multi-Organ Transplant Group.

Ischemia due to interruption of the bronchial circulation has been recognized as a cause of immediate postoperative anastomotic dehiscence in lung and heart-lung transplant recipients. Since patients do not ordinarily survive such major ischemic insults, the long-term effects of airway ischemia and the differentiation of these effects from those of transplant rejection and infection have not been clearly defined. We describe a patient who suffered extensive airway ischemia, necrosis, and subsequent diffuse airway stenosis. Loss of the bronchial circulation with variable ischemia may be a major cause of late airway abnormality responsible for significant morbidity and mortality in transplant recipients.

Pulmonary alveolar proteinosis in a painter with elevated pulmonary concentrations of titanium.

We present the case of a professional painter who developed pulmonary alveolar proteinosis (PAP) with severe respiratory failure. He required total bilateral pulmonary lavage on two separate occasions, 3 months apart. Quantitative analysis of particles found in lung tissues obtained by open lung biopsies demonstrated the presence of titanium (60-129 million particles of titanium per cm3 of lung tissue). This report extends previous results from animal studies that demonstrated development of alveolar proteinosis in rats following exposure to titanium. It has been proposed that the overwhelming impairment of the normal clearance mechanisms of the lung by particles of titanium is one of the possible mechanisms responsible for the development of this lung disease. We suggest that a similar mechanism occurred in our patient and that titanium should be recognized as a potential cause of PAP in humans.

The use of endoscopic argon plasma coagulation in airway complications after solid organ transplantation.

The objective of the study was to describe a safe and effective treatment option for endobronchial complications after solid organ transplantation. A retrospective analysis was performed in a tertiary-care university hospital. The use of bronchoscopic argon plasma coagulation (APC) for the treatment of endobronchial lesions was studied in five solid organ transplant recipients. Four patients presented with variable degrees of endobronchial obstruction, and one patient presented with massive hemoptysis. Two of the patients with endobronchial obstruction were double lung transplant recipients who developed anastomotic strictures. The strictures were opened with endobronchial stents but became obstructed again by inflammatory granulation tissue overgrowth through the stent mesh. APC was used to maintain airway patency. One kidney transplant recipient developed pulmonary zygomycosis with secondary obstruction of the left main bronchus because of granulation tissue growth through endobronchial stents. Airway patency was reestablished with several treatments with APC. Another kidney transplant recipient developed subglottic and tracheal papillomatosis that was effectively removed with APC. A heart transplant recipient was referred with recurrent massive hemoptysis refractory to bronchial artery embolization. The bleeding was caused by hemorrhagic polypoid lesions, which were completely ablated by APC. Bronchoscopic use of the argon plasma coagulator is a safe and simple technique that can be used effectively to treat endobronchial pathology in solid organ transplant patients.

Pulmonary hypertension in chronic obstructive pulmonary disease. Multivariate analysis.

The severity of pulmonary hypertension was evaluated by right cardiac catheterization in 89 patients with stable chronic obstructive pulmonary disease, both at rest and during maximum treadmill exercise. Thirty-one patients were found to have pulmonary hypertension at rest, defined as a mean pulmonary arterial pressure of 20 mm Hg or more. Although the remaining 58 patients had normal mean pulmonary arterial pressure at rest, three developed pulmonary hypertension during exercise (mean pulmonary arterial pressure greater than or equal to 35 mm Hg). Multiple anthropometric, spirometric, radiographic, and gas-exchange variables were analyzed and correlated with the hemodynamic data to define their value in predicting mean pulmonary arterial pressure. While arterial oxygen pressure (PaO2) at maximum exercise was the variable most highly correlated with resting mean pulmonary arterial pressure (r = -0.67), stepwise multiple linear regression analysis indicated that measurement of the diameter of the right descending pulmonary artery and arterial carbon dioxide tension (PaCO2) also contributed to the prediction of mean pulmonary arterial pressure. Spirometric indices of airflow obstruction, hyperinflation, and the diffusing capacity of the lung for carbon monoxide correlated poorly with the severity of pulmonary hypertension and consequently were not useful predictors of mean pulmonary arterial pressure. The threshold criteria of a PaO2 less than 60 mm Hg or a PaCO2 more than 40 mm Hg were reasonably accurate for a diagnosis of pulmonary hypertension. These arterial blood gas criteria were superior to the spirometric and radiographic variables examined in predicting pulmonary hypertension prior to the development of clinically overt cor pulmonale.

Bronchiolitis obliterans in recipients of single, double, and heart-lung transplantation.

Thirty-two recipients of single, double, or heart-lung transplantation followed-up for at least 3 months posttransplant were retrospectively reviewed to assess the frequency, predictors, and risk factors associated with the development of bronchiolitis obliterans (BO). A clinical definition for the diagnosis of BO was made using the following criteria: persistent and progressive decline in FEF25-75, associated with normal results of cytologic and microbiologic studies for significant pathogens in bronchoalveolar lavage fluid, with a normal chest radiograph. This was correlated with histologic diagnosis and patient outcome. Sixteen (50%) of the patients developed BO, and this was associated with a 56% mortality. All but 1 patient with histologic BO had a clinical diagnosis of BO made (often months) prior to diagnostic biopsy. No patients with normal histologic findings had a clinical diagnosis of BO. More than 3 episodes of histologically documented acute rejections in any 12-month period were eventually associated with a 100% incidence of BO. Cytomegalovirus occurred with greater frequency in patients with BO, and in most cases, preceded or occurred concomitantly with the diagnosis of acute rejection or BO.

Outcome of the native lung after single lung transplant. Multiorgan Transplant Group.

Twenty-one long-term survivors of single lung transplant since 1987 have been followed from 7 to 81 months. Posttransplant complications unique to the native lung and their impact on patient outcome are reported. In 7 of 21 recipients of single lung transplant, clinical complications in the native lung developed, including infection, pulmonary infarction, and severe ventilation-perfusion mismatching. Impact on the patient has ranged from little effect (prolongation of hospital or ICU stay) to recurrent severe infections, the need for surgical intervention, and a possible contribution to the recurrence of original disease--giant cell interstitial pneumonitis. The remaining native lung can be a source of significant complications following single lung transplant. Pretransplant diagnoses other than uncomplicated idiopathic pulmonary fibrosis seem to be most frequently associated with compromise of function or risk of infection arising from the native lung.

Right ventricular function in patients with severe COPD evaluated for lung transplantation. Lung Transplant Group.

Right ventricular function was measured in ten patients with severe COPD (mean FEV1 = 0.48 +/- 0.2 L/s) as part of an evaluation for single lung transplant (SLT). Right ventricular ejection fraction (RVEF) was determined by two methods: first-pass radionuclide scan by multigated acquisition (MUGA) and by using a fast thermistor tipped RVEF/volumetric pulmonary artery catheter. None of the patients had clinical evidence of active right heart failure, although mild resting pulmonary hypertension (mean pulmonary artery pressure [PAP] = 24 +/- 4 mm Hg) that worsened with minimal exercise (mean PAP = 39 +/- 11 mm Hg) was present. There was a significant difference in RVEF measured by the two methods (mean MUGA RVEF = 57 +/- 10%, mean catheter RVEF = 27 +/- 8%; p < 0.00005). RVEF determined by both methods was correlated with hemodynamic and gas exchange variables obtained during rest and at maximal exercise. There were significant, yet inverse, correlations between RVEF measured by catheter and cardiac index measured during exercise (CIex), as well as with exercise pulmonary vascular resistance index (PVRI). There were no significant correlations found between MUGA RVEF and any gas exchange or hemodynamic variables. Significant correlations were found with the catheter-measured right ventricular end-diastolic volume (RVEDV) and CIex (r = 0.9 p < 0.005), with maximal oxygen consumption during exercise (VO2max) (r = 0.86 p < 0.0025), with exercise stroke volume index (SVI) (r = 0.76 p < 0.01), and exercise central venous pressure (CVP) (r = 0.62 p < 0.05). Echocardiographic studies revealed right ventricular dilatation and mild tricuspid regurgitation (TR) in all patients. The strong correlation between RVEDV, CIex, and VO2max supports the concept that in these patients, as long as there is no clinical evidence of right heart failure (resting CVP still within normal limits), those with the largest RVEDVs use the Frank Starling principle to their best advantage to remain more functional.(ABSTRACT TRUNCATED AT 400 WORDS)

Histopathologic diagnosis made in lung tissue resected from patients with severe emphysema undergoing lung volume reduction surgery.

STUDY OBJECTIVES: This study reports histopathologic findings in a group of emphysema patients who underwent thoracoscopic lung volume reduction surgery (75) or sternotomy (five) with the purpose to induce functional improvement and relief of dyspnea. Immediate outcome and complications were correlated to histologic patterns. DESIGN: Histopathologic material obtained in lung volume reduction surgery in 80 consecutive patients was analyzed. Thirty patients who had other histopathologic diagnoses in addition to emphysema were grouped and compared with 50 patients found to have emphysema exclusively. Postoperative outcome and preoperative lung function variables were compared. MEASUREMENTS AND RESULTS: All patients had severe obstructive lung disease and significant air trapping preoperatively documented by pulmonary function testing. All had severe exertional dyspnea. All had chest radiographs, CT, and nuclear medicine lung scans consistent only with emphysema. All portions of resected lung tissue were weighed, lung volume was estimated, and routine histopathologic studies were made. Thirty patients (37.5%) had unsuspected findings such as interstitial fibrosis, noncaseating granulomatosis, chronic inflammation, and unsuspected neoplasia (three carcinomas, one carcinoid). Retrospective review of imaging studies in these patients failed to show infiltrative processes. The average lung weight resected in this group was significantly heavier (65+/-18 g) compared with the other group (56+/-13 g), although both had the same estimated lung volume. Average number of days requiring chest tubes and length of hospitalization was also significantly higher (12.8+/-19 vs 6.4+/-5 days with chest tubes and 17.4+/-22 vs 8.5+/-6 days of hospitalization, respectively). None of the preoperative pulmonary function tests variables were different between the two groups. Serious postoperative complications were more frequent in these patients compared with those who showed only emphysema. CONCLUSIONS: A significant portion of patients diagnosed as having severe emphysema will have other unsuspected histologic findings. When subjected to lung volume reduction surgery, this subgroup will have more serious complications and longer periods of air leaks, requiring longer hospitalization time. Retrospective review of imaging studies and preoperative pulmonary function tests used to select patients for lung volume reduction failed to identify this subgroup.

Myocardial stress. Exercise versus sleep in patients with COPD.

Epidemiologic investigation has revealed that patients with pulmonary disease are at increased risk of dying during the early morning hours. To provide a pathophysiologic explanation for these excessive nocturnal mortality statistics, we tested the hypothesis that episodes of arterial O2 desaturation during sleep can produce as severe a stress on the maintenance of myocardial O2 balance as maximal exercise in patients with chronic obstructive pulmonary disease (COPD). Thirty-one subjects with COPD underwent both overnight sleep and treadmill exercise study to their dyspnea-limited maximum. During both activities, systemic blood pressure was directly recorded and myocardial oxygen consumption (MVO2) estimated from the pulse rate (HR) - systolic blood pressure (SBP) product. Arterial O2 content (CaO2) was calculated from hemoglobin concentration and arterial O2 saturation (SaO2) measured by ear oximetry. Using these data and the Fick principle, myocardial blood flow (MBF) was continuously estimated during both exercise and sleep. During sleep, mean SaO2 was 88 +/- 7 percent while the average of the lowest SaO2 recorded for each subject was 71 +/- 14 percent. Episodes of nocturnal oxyhemoglobin desaturation produced consistent elevations in SBP frequently accompanied by an increase in HR. Because this hemodynamic response resulted in increased MVO2 at precisely the times when arterial O2 contents were low, high demands for MBF were generated. The average of the highest individual values for MBF during sleep was 244 +/- 144 (ml/100 g LV/min). This value was not significantly different from the value of MBF = 281 +/- 91 (ml/100 g LV/min) determined for maximal exercise. This finding suggests that the demand for coronary blood flow during episodes of nocturnal hypoxemia can be transiently as great as during maximal exercise in patients with COPD.

Mixed (neutrophil-rich) interstitial pneumonitis in biopsy specimens of lung allografts: a clinicopathologic evaluation.

STUDY OBJECTIVES: Mixed interstitial pneumonitis (MIP), defined herein as a diffuse neutrophil-rich inflammatory infiltrate within the interstitial tissues, is an uncommon finding that is not a standard manifestation of acute or chronic rejection. This study examines the clinical significance of MIP in lung allograft recipients at St. Louis University Hospital. DESIGN: We retrospectively reviewed surgical pathology reports from a selected 50-month period, and identified MIP reported in 13 transbronchial biopsy specimens in lung transplant recipients, representing 4.7% of all lung allograft biopsy specimens seen during this 4-year period. Biopsy specimens with MIP were examined to confirm the presence of a neutrophil-rich interstitial infiltrate and other associated histopathologic findings. The culture results, cytopathologic findings, and clinical charts of the affected patients were also reviewed. MEASUREMENTS AND RESULTS: The detection of MIP at some point in a patient's posttransplant course was found to be associated with a significantly shorter (p < 0.01) survival, when compared to lung allograft recipients who did not show this finding. A total of seven lung allograft recipients (23% of total) showed MIP at some point in their posttransplant course. Four of the seven (57%) were actively smoking following lung transplantation, compared to 0 of 22 patients who did not show MIP. Six of the 13 MIP biopsy specimens were associated with positive cultures. In no case did MIP coexist with the conventional histologic patterns of acute or chronic rejection. MIP also did not correlate with levels of immunosuppressive therapy or with the incidence of rejection at other times in the patients' posttransplant courses. CONCLUSIONS: We found no evidence that MIP represents an unusual form of acute or chronic rejection. Instead, it appears to represent a response to acute injury, similar to other injury patterns (hyaline membranes, organizing pneumonia) in transplant recipients. Exposure to tobacco smoke is likely to have played a role in the development of MIP in at least some cases. Because patients with MIP had a significantly shorter posttransplant survival, MIP may usefully identify lung allograft recipients at risk for an adverse outcome.

Hemodynamics and gas exchange after single lung transplantation and unilateral thoracoscopic lung reduction.

BACKGROUND: Single lung transplantation and recently thoracoscopic lung reduction (TLR) have become surgical alternatives to manage emphysema. We report here early outcomes of 10 single lung transplant (SLT) recipients with severe emphysema compared with 10 patients treated with unilateral TLR. METHODS: Ten consecutive recipients of (SLT) and 10 patients undergoing unilateral TLR were studied. Both groups had measurements of preoperative pulmonary function and arterial blood gases. Hemodynamic measurements were made by use of a right ventricular ejection fraction/volumetric pulmonary artery catheter during and immediately after surgery in both groups to compare hemodynamic and gas exchange response in each procedure. Pulmonary function tests were repeated 3 months and 1 year after surgery. Complications and functional outcome are reported. RESULTS: Both groups had the same severity of obstructive disease (mean forced expiratory volume in 1 second = 20% +/- 5% for the SLT group and 23% +/- 9% for the TLR group) and similar patterns of right ventricular dysfunction. During operation, SLT recipients showed worse hypercapnia and pulmonary hypertension than TLR subjects when ventilation and perfusion to the operative lung were interrupted. Patients undergoing TLR only had interrupted ventilation, which was transiently reversed when severe hypoventilation or hypoxemia occurred. All patients undergoing TLR were extubated immediately after surgery. SLT recipients were extubated an average of 42 hours later. Pulmonary function testing performed 3 months after surgery showed improvement in both groups. SLT recipients showed larger improvements in airflow but comparable improvements in forced vital capacity. Both groups achieved similar improvements in gas exchange. This trend continued a year after surgery. Patients undergoing TLR were not subjected to complications of immunosuppressive therapy or exposed to opportunistic infections. CONCLUSIONS: Early results show TLR as an acceptable alternative to SLT in carefully selected patients with the same severity of obstructive lung disease. Long-term follow-up studies are needed to establish long-term differences in functional outcome and development of complications. TLR may be an option for patients with severe dyspnea related to emphysema who do not meet criteria for transplantation.

Outcome of bedside percutaneous tracheostomy with bronchoscopic guidance.

OBJECTIVE: To determine the morbidity and mortality of percutaneous dilational tracheostomy with bronchoscopic guidance when performed by medical intensivists. DESIGN: A retrospective analysis. SETTING: A tertiary care university hospital. PATIENTS: Fifty consecutive patients who underwent percutaneous dilational tracheostomy for prolonged mechanical ventilation. INTERVENTION: Bedside percutaneous dilational tracheostomy with bronchoscopic guidance. RESULTS: Seventeen women and 33 men with a mean age of 62 +/- 17 years. Operative mortality was 0 with four (8%) operative complications. Complications included one posterior tracheal abrasion, one anterior tracheal laceration, one episode of endobronchial hemorrhage requiring bronchoscopy, and one pneumothorax. Thirty-day mortality was 28% and overall mortality was 40%. All deaths were related to the patients' underlying disease. CONCLUSIONS: Percutaneous dilational tracheostomy with bronchoscopic guidance is a safe procedure when performed by experienced medical intensive care personnel in tertiary care institutions. Bronchoscopy helps to reduce the risk of major complications and aids in the management of minor complications.

Unilateral video-assisted thoracic surgical lung reduction.

BACKGROUND: Lung reduction has been demonstrated to be a promising treatment for end-stage emphysema when performed on both lungs via sternotomy. The role for a thoracoscopic approach has not yet been determined. METHODS: Unilateral video-assisted thoracic surgical lung reduction was performed on 50 patients for the treatment of end-stage emphysema. There were 34 men and 16 women with a mean age of 61.5 years (range, 31 to 78 years). Emphysema was secondary to smoking in 45 patients (90%), and alpha 1-antitrypsin deficiency in 5 patients (10%), 4 of whom had smoked in the past. Lung reduction was performed unilaterally using a thoracoscope and a stapled resection without the routine use of bovine pericardium. The side to be operated on and site of resection were determined preoperatively by examination of the perfusion and computed tomographic scans of the lungs. The average amount of lung removed was 59 +/- 15 g (range, 29 to 111 g). RESULTS: Morbidity included prolonged air leak in 15 patients (30%), bleeding in 3 (6%), pneumonia requiring reintubation in 3 (6%), myocardial infarction in 1 (2%), and perforated ulcer in 1 (2%). Seven patients (14%) required a second thoracic procedure for management of these complications. Two patients died, for an operative mortality of 4%. Follow-up obtained between 1 and 3 months in 25 patients revealed significant improvement in forced expiratory volume in 1 second (0.71 to 0.95 L; p < 0.001), forced vital capacity (2.24 to 2.58 L; p < 0.01), and oxygen tension (59 to 67 mm Hg; p < 0.01). The improvement in functional capacity as measured by 6-minute walk approached statistical significance (771 to 923 ft; p = 0.06). CONCLUSIONS: Significant subjective improvement in dyspnea has been noted in 41 of 48 hospital survivors (85%). For patients with end-stage emphysema, unilateral video-assisted thoracic surgical lung reduction appears to be a preferable alternative to standard medical management.

Comparison of clinical results for unilateral and bilateral thoracoscopic lung volume reduction.

BACKGROUND: It is widely believed that bilateral thoracoscopic lung volume reduction (BTLVR) yields superior results when compared with unilateral thoracoscopic lung volume reduction (UTLVR) with regard to spirometry, functional capacity, oxygenation and quality of life results. METHODS: To address these issues, we compared the results of patients undergoing UTLVR (N = 338 patients) and BTLVR (N = 344 patients) from 1993 to 1998 at five institutions. Follow-up data were available on 671 patients (98.4%) between 6 and 12 months after surgery, and a patient self-assessment was obtained at a mean of 24 months. RESULTS: It was found that BTLVR provides superior improvement in measured postoperative percent change in FEV1 (L) (UTLVR 23.3% +/- 55.3 vs BTLVR 33% +/- 41, p = 0.04), FVC(L) (10.5% +/- 31.6 vs 20.3% +/- 34.3, p = 0.002) and RV(L) (-13% +/- -22 vs -22% +/- 17.9, p = 0.015). BTLVR also provides a slight improvement over UTLVR in patient's perception regarding improved quality of life (UTLVR 79% vs BTLVR 88%, p = 0.03) and dyspnea relief (71% vs 61%, p = 0.03). There was no difference in mean changes in PO2 (mm Hg) (UTLV 4.5 +/- 12.3 vs BTLVR 4.9 +/- 13.3, p = NS), 6-minute walk (UTLVR 26% +/- 66.1 vs BTLVR 31% +/- 59.6, p = NS) or decreased oxygen utilization (UTLVR 78% vs BTLVR 74%, p = NS). CONCLUSIONS: These data suggest that both UTLVR and BTLVR yield significant improvement, but the results of BTLVR seem to be superior with regard to spirometry, lung volumes, and quality of life.