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.

Atelectasis--an unusual and late complication of lung transplant

We report a previously unrecognized late complication of allograft lung transplantation - persistent recurrent atelectasis of the transplanted lung. The patient developed sudden, severe respiratory distress about 2 yr after a right lung transplant, because of acute atelectasis of her transplanted lung. Multiple transbronchial biopsies at the time revealed minimal inflammation and no evidence of rejection. She was treated with surfactant replacement therapy, and her collapsed lung fully expanded following surfactant installation. To eliminate the possibility of acquired deficiency of surfactant lipids or proteins, ultrastructural examination and immunostains for surfactant proteins were performed in a transbronchial lung biopsy. No deficiency of surfactant lipids or proteins was found. On ultrastructural examination of the lung biopsy, the number of Type II cells per alveolus and the number of lamellar bodies per square micron of Type II cell cross-sectional area was increased compared with an age-matched control. We conclude that synthesis of surfactant lipids and proteins was unimpaired and because of the patient's response to surfactant replacement therapy, that the increase in number of lamellar bodies could reflect a compensatory mechanism for a surfactant functional defect. The patient later developed breast carcinoma to which she succumbed. We raise the possibility that the functional surfactant defect is a hitherto unrecognized non-metastatic manifestation of malignancy.

Endoluminal graft repair for abdominal aortic aneurysms in high-risk patients and octogenarians: is it better than open repair?

OBJECTIVE

To analyze the short-term and midterm results of open and endoluminal repair of abdominal aortic aneurysms (AAA) in a large single-center series and specifically in octogenarians.

METHODS

Between January 1997 and October 2000, 470 consecutive patients underwent elective repair of AAA. Conventional open repair (COR) was performed in 210 patients and endoluminal graft (ELG) repair in 260 patients. Ninety of the patients were 80 years of age or older; of these, 38 underwent COR and 52 ELG repair.

RESULTS

Patient characteristics and risk factors were similar for both the entire series and the subgroup of patients 80 years or older. The overall complication rate was reduced by 70% or more in the ELG versus the COR groups. The postoperative death rate was similar for the COR and ELG groups in the entire series and lower (but not significantly) in the ELG 80 years or older subgroup versus the COR group. The 36-month rates of freedom from endoleaks, surgical conversion, and secondary intervention were 81%, 98.2%, and 88%, respectively.

CONCLUSION

The short-term and midterm results of AAA repair by COR or ELG are similar. The death rate associated with this new technique is low and comparable, whereas the complication rate associated with COR in all patients and those 80 years or older in particular is greater and more serious than ELG repair. Long-term results will establish the role of ELG repair of AAA, especially in elderly and high-risk patients.

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.

Pneumomediastinum and subcutaneous emphysema from pacemaker placement

Percutaneous insertion of permanent pacemaker leads through the subclavian vein is an alternative to the cephalic vein approach. A rare occurrence and successful conservative management of extensive pneumomediastinum and subcutaneous emphysema without concomitant pneumothorax resulting from permanent transvenous pacemaker insertion in an 80-year-old man with syncope and arrhythmia is reported.

Loss-of-function mutations reveal that the Drosophila nautilus gene is not essential for embryonic myogenesis or viability

nautilus (nau), the single Drosophila member of the bHLH-containing myogenic regulatory family of genes, is expressed in a subset of muscle precursors and differentiated fibers. It is capable of inducing muscle-specific transcription as well as myogenic transformation, and plays a role in the differentiation of a subset of muscle precursors into mature muscle fibers. In previous studies, the nau zygotic loss-of-function phenotype was determined using genetic deficiencies in which the gene is deleted. We note that this genetic loss-of-function phenotype differs from the loss-of-function phenotype determined using RNA interference (L. Misquitta and B. M. Paterson, 1999, Proc. Natl. Acad. Sci. USA 96, 1451-1456). The present study re-examines this loss-of-function phenotype using EMS-induced mutations that specifically alter the nau gene, and extends the genetic analysis to include the loss of both maternal and zygotic nau function. In brief, embryos lacking nau both maternally and zygotically are missing a distinct subset of muscle fibers, consistent with its apparent expression in a subset of muscle fibers. The muscle loss is tolerated, however, such that the loss of nau both maternally and zygotically does not result in lethality at any stage of development.

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.

Formation of supported membranes from vesicles

Using a combination of the quartz crystal microbalance and surface plasmon resonance techniques, we have studied the spontaneous formation of supported lipid bilayers from small (approximately 25 nm) unilamellar vesicles. Together these experimental methods measure the amount of lipid adsorbed on the surface and the amount of water trapped by the lipid. With this approach, we have, for the first time, been able to observe in detail the progression from the adsorption of intact vesicles to rupture and bilayer formation. Monte Carlo simulations reproduce the data.

Risk analysis for thoracoscopic lung volume reduction: a multi-institutional experience

OBJECTIVE

Most reports of thoracoscopic lung volume reduction (TLVR) are relatively small and early experiences from a single institution, factors which limit both the statistical validity and the applicability to the population at large. In order to address these shortcomings we undertook an analysis of the TLVR experience at five separate institutions to assess operative morbidity and identify predictors of mortality.

METHODS

Questionnaires were sent to four groups of surgical investigators at five institutions actively performing TLVR. Data was requested regarding preoperative, operative and postoperative parameters. Twenty-five potential predictors of mortality were analyzed and seven proved to be at least marginally significant (P<0.10). These parameters were entered into a stepwise logistic regression analysis to identify independent predictors.

RESULTS

The 682 patients (415 males, 267 females, mean age 64.0 years) underwent unilateral (410) or bilateral (272) TLVRs. Overall, operative mortality was 6% with half of the deaths resulting from respiratory causes. The remaining patients were discharged to home (88%), a rehabilitation facility (4%) or a ventilator facility (2%). There were 25 perioperative factors chosen representing clinically important indices such as spirometry, oxygenation, functional status, clinical and demographic variables. Univariate analysis identified seven variables as predictors of mortality (P<0.10) and these were entered into a stepwise logistic regression analysis. Only age, 6-min walk, gender (male 8%, female 3% mortality) and the procedure performed (unilateral 4.6%, bilateral 8%) were independent predictors while preoperative steroid therapy, preoperative oxygen administration, and time since smoking cessation dropped out of the model. The specific institution, learning curve (early vs. late experience), type of lung disease, spirometric indices and predicted maximum VO(2) were not significant predictors.

CONCLUSION

This experience suggests that unilateral and bilateral lung volume reduction procedure can be performed with acceptable morbidity and mortality. Although age, gender, exercise capacity and the procedure performed are all independent predictors of mortality, the risk of operative death did not appear excessive in this fragile patient subset.

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.

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.

Long-term survival after thoracoscopic lung volume reduction: a multiinstitutional review

BACKGROUND

It has been suggested that bilateral thoracoscopic lung volume reduction (BTLVR) yields significantly better long-term survival than unilateral thoracoscopic lung volume reduction (UTLVR).

METHODS

All perioperative data were collected at the time of the procedure. Follow-up data were obtained during office visits or by telephone.

RESULTS

A total of 673 patients underwent thoracoscopic LVR: 343 had either simultaneous or staged BTLVR and 330, UTLVR. As of July 1998, follow-up was available on 667 (99%) of the 673 patients with a mean follow-up of 24.3 months. The patients in the BTLVR group were significantly younger (62.6+/-8.0 years versus 65.4+/-8.1 years; p < 0.0001), had a higher preoperative arterial oxygen tension (69.7+/-12 mm Hg versus 65.3+/-11 mm Hg; p < 0.0001), and had a superior preoperative 6-minute walk performance (279.9+/-93.6 m [933+/-312 feet] versus 244.5+/-101.4 m [815+/-338 feet] p < 0.0001). There was no difference in the operative mortality rate between the two groups (UTLVR, 5.1%, and BTLVR, 7%). Actuarial survival rates for the UTLVR group at 1 year, 2 years, and 3 years were 86%, 75%, and 69%, respectively versus 90%, 81%, and 74%, respectively, for the BTLVR group (p = not significant).

CONCLUSIONS

Contrary to previous reports, survival after BTLVR was not superior to that after UTLVR even though the former group appeared to have a lower risk preoperatively because of younger age, higher arterial oxygen tension, more advantageous anatomy, and better functional status. Despite thoracoscopic LVR, the actuarial mortality rate approached 30% at 3 years, and this calls into question whether this procedure offers any survival advantage to patients with end-stage emphysema.

Current status of thoracoscopic lung volume reduction

Surgical therapy has recently been reintroduced for the treatment of emphysema, and a number of investigators have used video-assisted thoracic surgical (VATS) techniques to accomplish lung volume reduction. The published reports differ with regard to patient selection, preoperative preparation, operative approach, and surgical technique. The results of these reports are reviewed and compared. Thoracoscopic lung volume reduction appears to be a useful part of the surgeon's armamentarium in managing patients with severe pulmonary emphysema.

Endovascular stent grafts for aneurysmal and occlusive vascular disease

BACKGROUND

This report details our initial experience with two types of endovascular grafts- one for the treatment of infrarenal abdominal aortic aneurysms and the other for the treatment of iliac artery occlusive disease.

METHODS

An abdominal aortic aneurysm was repaired in 34 patients using 3 different types of Ancure endografts (Menlo Park, California). Control patients (n = 9) had a standard aneurysm repair. Patients with chronic lower extremity ischemia (n = 7) secondary to iliac artery occlusive disease were treated with a Hemobahn endograft (W. L. Gore & Associates, Flagstaff, Arizona).

RESULTS

Ancure graft deployment was achieved in 33 of 34 (97.1%) patients. Perioperative mortality for the Ancure and control group patients was 2.9% and 0%, respectively. Periprosthetic leaks were identified within 48 hours of deployment in 6 (18.2%) Ancure graft patients. All but 2 of the leaks resolved on serial follow-up. Additional endovascular procedures were required in 11 (32.4%) Ancure graft patients at the initial procedure or during follow-up to correct graft or arterial stenoses. Patients treated with an endovascular graft had significantly less blood loss and shorter hospital stays than control group patients. For Hemobahn patients, the technical success for graft deployment was 100%. There were no perioperative deaths. The ankle/brachial index increased from a mean of 0.52 preoperatively to 0.86 postoperatively (P = 0.004). One patient required a Wallstent in follow-up to correct a graft wrinkle. Angiography at 6 months demonstrated mild intimal hyperplasia in the stent graft in 5 of 6 patients.

CONCLUSIONS

These early results support the potential for endovascular grafts in the treatment of aneurysmal and occlusive vascular disease. Further modifications in the devices and deployment techniques are necessary to reduce the incidence of periprosthetic leaks, graft limb stenoses, and intimal hyperplasia.

A role for nautilus in the differentiation of muscle precursors

In the Drosophila embryo, nautilus is expressed in a subset of muscle precursors and differentiated fibers and is capable of inducing muscle-specific transcription, as well as myogenic transformation. In this study, we examine the consequences of nautilus loss-of-function on the development of the somatic musculature. Genetic and molecular characterization of two overlapping deficiencies, Df(3R)nau-9 and Df(3R)nau-11a4, revealed that both of these deficiencies remove the nautilus gene without affecting a common lethal complementation group. Individuals transheterozygous for these deficiencies survive to adulthood, indicating that nautilus is not an essential gene. These embryos are, however, missing a subset of muscle fibers, providing evidence that (1) some muscle loss can be tolerated throughout larval development and (2) nautilus does play a role in muscle development. Examination of muscle precursors in these embryos revealed that nautilus is not required for the formation of muscle precursors, but rather plays a role in their differentiation into mature muscle fibers. Thus, we suggest that nautilus functions in a subset of muscle precursors to implement their specific differentiation programs.

Surface specific kinetics of lipid vesicle adsorption measured with a quartz crystal microbalance

We have measured the kinetics of adsorption of small (12.5-nm radius) unilamellar vesicles onto SiO2, oxidized gold, and a self-assembled monolayer of methyl-terminated thiols, using a quartz crystal microbalance (QCM). Simultaneous measurements of the shift in resonant frequency and the change in energy dissipation as a function of time provide a simple way of characterizing the adsorption process. The measured parameters correspond, respectively, to adsorbed mass and to the mechanical properties of the adsorbed layer as it is formed. The adsorption kinetics are surface specific; different surfaces cause monolayer, bilayer, and intact vesicle adsorption. The formation of a lipid bilayer on SiO2 is a two-phase process in which adsorption of a layer of intact vesicles precedes the formation of the bilayer. This is, to our knowledge, the first direct evidence of intact vesicles as a precursor to bilayer formation on a planar substrate. On an oxidized gold surface, the vesicles adsorb intact. The intact adsorption of such small vesicles has not previously been demonstrated. Based on these results, we discuss the capacity of QCM measurements to provide information about the kinetics of formation and the properties of adsorbed layers.

Simultaneous frequency and dissipation factor QCM measurements of biomolecular adsorption and cell adhesion

We have measured the energy dissipation of the quartz crystal microbalance (QCM), operating in the liquid phase, when mono- or multi-layers of biomolecules and biofilms form on the QCM electrode (with a time resolution of ca. 1 s). Examples are taken from protein adsorption, lipid vesicle adsorption and cell adhesion studies. Our results show that even very thin (a few nm) biofilms dissipate a significant amount of energy owing to the QCM oscillation. Various mechanisms for this energy dissipation are discussed. Three main contributions to the measured increase in energy dissipation are considered. (i) A viscoelastic porous structure (the biofilm) that is strained during oscillation, (ii) trapped liquid that moves between or in and out of the pores due to the deformation of the film and (iii) the load from the bulk liquid which increases the strain of the film. These mechanisms are, in reality, not entirely separable, rather, they constitute an effective viscoelastic load. The biofilms can therefore not be considered rigidly coupled to the QCM oscillation. It is further shown theoretically that viscoelastic layers with thicknesses comparable to the biofilms studied in this work can induce energy dissipation of the same magnitude as the measured ones.

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.

Drosophila myogenesis and insights into the role of nautilus

Several aspects of muscle development appear to be conserved between Drosophila and vertebrate organisms. Among these is the conservation of genes that are critical to the myogenic process, including transcription factors such as nautilus. From a simplistic point of view, Drosophila therefore seems to be a useful organism for the identification of molecules that are essential for myogenesis in both Drosophila and in other species. nautilus, the focal point of this review, appears to be involved in the specification and/or differentiation of a specific subset of muscle founder cells. As with several of its vertebrate and invertebrate counterparts, it is capable of inducing a myogenic program of differentiation reminiscent of that of somatic muscle precursors when expressed in other cell types. We therefore favor the model that nautilus implements the specific differentiation program of these founder cells, rather than their specification. Further analyses are necessary to establish the validity of this working hypothesis. Studies have revealed a critical role for Pax-3 in specifying a particular subset of myogenic cells, the progenitors of the limb muscles. These myogenic cells migrate from the somite into the periphery of the organism, where they differentiate. These myoblasts do not express MyoD or myf5 until they have arrived at their destination and begin the morphologic process of myogenesis (Bober et al., 1994; Goulding et al., 1994; Williams and Ordahl, 1994). They then begin to express these genes, possibly to put the myogenic plan into action. Thus, as with nautilus, MyoD and myf5 may be necessary for the manifestation of a muscle-specific commitment that has already occurred. By comparison with vertebrates, it was anticipated that the single Drosophila gene would serve the purpose of all four vertebrate genes. However, its restricted pattern of expression and apparent loss-of-function phenotype are inconsistent with this expectation. It remains to be determined whether nautilus functions in a manner similar to just one of the vertebrate genes. Since the myf5- and MyoD-expressing myoblasts are proliferative, the loss of one cell type appears to be compensated by proliferation of the remaining cell type. This apparent plasticity may obscure differences in mutant phenotype resulting from the loss of particular cells that express each of these genes. In Drosophila, by comparison, nautilus-expressing cells committed to the myogenic program undergo few, if any, additional cell divisions, and thus no other cells are available to compensate for the loss of nautilus. Therefore, the apparent differences between the Drosophila nautilus gene and its vertebrate counterparts may reflect, at least in part, differences in the developmental systems rather than differences in the function of the genes themselves.

Increased gelatinolytic activity in bronchoalveolar lavage fluid in stable lung transplant recipients

Proteolytic enzymes have been proposed to play a role in the pathogenesis of various inflammatory pulmonary diseases accompanied by parenchymal remodeling. To assess the role of inflammatory cells and proteolytic enzymes in the development of chronic allograft rejection after lung transplantation, bronchoalveolar lavage fluid (BALF) samples from clinically stable lung transplant (LT) recipients (i.e., without evidence of active infection or rejection), heart transplant (HT) recipients, and healthy volunteers (NL) were analyzed for total white blood cell (WBC) count and differential cell count, along with gelatinolytic/type IV collagenolytic activity. The LT group displayed a significantly increased total WBC count, neutrophil count, and percent neutrophils compared with the NL group, confirming the presence of inflammation. Furthermore, gelatin zymography revealed a significant increase in activity of the 72 and 92 kD gelatinases in the LT group compared with the NL group. A positive correlation existed between neutrophil counts and the increase in proteolytic activity. Immunosuppressive therapy did not account for the findings, since no significant difference in cell counts or proteolytic activity existed between the NL and HT control groups. These findings, together with those of others that relate chronic lung allograft dysfunction to an increase in BALF neutrophils and collagen matrix remodeling, collectively indicate that up-regulated proteolytic activity may have a role in chronic rejection after lung transplantation.

Thoracoscopic lung volume reduction surgery reduces dyspnea and improves exercise capacity in patients with emphysema

Improved ventilation and exercise capacity follows thoracoscopic lung volume reduction surgery (TLVRS) in patients with severe emphysema. This improvement could be related to changes in inspiratory and expiratory flows following surgery, with consequent improvement in dyspnea indices. Changes in inspiratory/expiratory flows at rest and exercise and their relation to subjective improvement in dyspnea after TLVRS are not well known. We studied 25 patients with severe emphysema who underwent unilateral TLVRS performed in well-defined zones with decreased perfusion in nuclear medicine lung scans. Early follow-up after surgery (4.2 +/- 0.8 mo) showed significant improvements in exercise tolerance: The distance covered over a 6 min walk test increased from 934 +/- 297 to 1,071 +/- 241 ft (p = 0.01). Exercise tolerance using a bicycle ergometer showed increased exercise endurance from 4.43 +/- 1.7 to 5.71 +/- 1.8 min (p < 0.001). The maximum workload tolerated increased from 37 +/- 19 to 52 +/- 21 W (p < 0.01) and VO2 max changed from 9.7 +/- 2 to 11.8 +/- 3 (ml.kg)/min (p < 0.01). This increment was achieved by generating significantly larger minute ventilation (VE), from 24 +/- 11 to 29 +/- 10 L/min, reached through larger tidal volumes (increasing from 951 +/- 330 to 1,145 +/- 367 ml), while maintaining the same maximum respiratory rates. Increased VE was also accompanied by significant increases in both average inspiratory and expiratory flows measured during exercise: from 0.89 +/- 0.41 L/s to 1.06 +/- 0.08 L/s, and from 0.77 +/- 0.37 to 0.90 +/- 0.32 L/s respectively (p < 0.01). The parallel increment in flows resulted in constant T1/Ttot relationship. These functional changes correlated with increased inspiratory flows at rest measured with pulmonary function tests (forced inspiratory volume in one s [FIV1], expiratory flows [FVC, FEV1], and increased maximum voluntary ventilation [MVV]) following the surgically induced reduction in residual volume (RV). These objective changes occurred parallel to improved dyspnea indices. The Baseline Focal Score was 3.36 +/- 1.47 and the Transition Focal Score was 6.12 +/- 0.7. The objectively measured variables at rest that best correlated with subjective improvement in dyspnea were the change in MVV, change in resting arterial PaO2, and change in FEV1 following TLVRS. Exercise variables did not have significant correlation with subjective markers indicating improvement in dyspnea, with the exception of the change in Dyspneic Index [(VE/MVV)100] at maximum exercise.

Perioperative management of lung volume reduction patients

Over the last 2 to 3 years, surgical lung volume reduction via sternotomy or thoracoscopy has been widely explored as an alternative to improve dyspnea, exercise tolerance, and lung mechanics in patients with severe emphysema. In this article, the authors describe the intra- and postoperative management of patients with severe airflow obstruction who undergo this procedure. Anesthesia techniques, extubation, ventilatory management, and overall medical and surgical care are reviewed. The most common postoperative complications also are reviewed, and management of these complications is discussed.

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.

Effects of long-term infusion of prostacyclin (epoprostenol) on echocardiographic measures of right ventricular structure and function in primary pulmonary hypertension. Primary Pulmonary Hypertension Study Group

BACKGROUND

Right heart failure is an important cause of morbidity and mortality in primary pulmonary hypertension. In a recent prospective, randomized study of severely symptomatic patients, treatment with prostacyclin (epoprostenol) produced improvements in hemodynamics, quality of life, and survival. This article describes the echocardiographic characteristics of participants in this trial; the relationship of echocardiographic variables to hemodynamic parameters, exercise capacity, and quality of life; and the echocardiographic changes associated with prostacyclin therapy.

METHODS AND RESULTS

The 81 patients enrolled in this multicenter trial were randomized to treatment with a long-term infusion of prostacyclin in addition to conventional therapy (n = 41) or conventional therapy alone (n = 40) for 12 weeks. Echocardiograms and assessments of hemodynamics, exercise capacity, and quality of life were performed before and after the treatment phase. On baseline evaluation, patients had marked right ventricular dilatation and dysfunction, abnormal septal curvature, and significant tricuspid regurgitation with a high regurgitant velocity. Pericardial effusions were common. More pronounced abnormalities in right heart structure and function were associated with higher pulmonary arterial and mean right atrial pressures, lower cardiac index, and impaired exercise capacity but had no predictable relationship to quality-of-life indicators. The 12-week infusion of prostacyclin had beneficial effects on right ventricular size, curvature of the interventricular septum, and maximal tricuspid regurgitant jet velocity.

CONCLUSIONS

The echocardiographic manifestations of severe primary pulmonary hypertension reflect abnormalities in hemodynamics and exercise capacity. Prostacyclin has beneficial effects on right heart structure and function that may contribute to the clinical improvement and prolonged survival observed with this drug.

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.

Misexpression of nautilus induces myogenesis in cardioblasts and alters the pattern of somatic muscle fibers

nautilus (nau), one member of the myogenic regulatory family of bHLH-encoding genes, is expressed in a subset of muscle precursors and differentiated fibers in the Drosophila embryo. To elucidate the role of nautilus in myogenesis, we have misexpressed it using the GAL4-targeted system. We find that ectopic expression results in lethality throughout Drosophila development. We analyzed the effects of embryonic expression in mesodermal tissues that include the cardioblasts of the dorsal vessel as well most, if not all, of the presumptive somatic muscle precursors. Immunohistochemical staining for muscle MHC revealed abnormalities that include an absence of cardial cells, coincident with the appearance of novel muscle fibers adjacent to the dorsal vessel. Moreover, many cardioblasts express increased levels of muscle-specific genes such as myosin, actin 57B, and Mlp60A, a protein that is restricted to the somatic, visceral, and pharyngeal muscles. These data suggest that the missing cardial cells have been transformed into cells with properties similar to those of the somatic muscles. In addition, ubiquitous expression of nautilus in somatic muscle cells of these embryos resulted in muscle pattern defects. Specifically, muscles that do not normally express nautilus were frequently absent, and novel fibers were observed in positions reminiscent of nau-expressing muscles. These data imply that nautilus can alter the developmental program of muscle precursors. In summary, we suggest that nautilus induces myogenic differentiation in vivo when ectopically expressed in developing cardioblasts and may affect the myogenic differentiation program of specific muscle fibers.

Anesthetic management of patients undergoing unilateral video-assisted lung reduction for treatment of end-stage emphysema

OBJECTIVES

Nonanatomic resection of peripheral areas of lung is being performed via sternotomy for the treatment of end-stage emphysema. Recent technologic advances have allowed the resection of lung tissue using video-assisted thoracic surgery (VATS) techniques. The study was performed to document the physiologic changes that occur during unilateral VATS lung reduction in hopes of determining appropriate monitoring and intraoperative management strategies.

DESIGN

Prospective trial of unilateral VATS lung reduction.

SETTING

Tertiary care university hospital.

PARTICIPANTS

Twenty patients with end-stage emphysema.

INTERVENTIONS

Participants underwent unilateral VATS lung reduction.

MEASUREMENTS AND MAIN RESULTS

Invasive hemodynamic monitoring was performed using radial and pulmonary artery catheters. Hemodynamic and respiratory gas exchange data were collected at four intraoperative points: (1) supine, two-lung ventilation; (2) lateral decubitus, two-lung ventilation; (3) lateral decubitus, one-lung ventilation, and (4) end of surgery, supine, two-lung ventilation. Data were compared with that collected at the first point. Patients tolerated lengthy surgical procedures and remained hemodynamically stable with no episodes of hypoxemia requiring treatment. Extubation was tolerated by 19 of 20 patients at the conclusion of surgery without further requirement of mechanical ventilation.

CONCLUSIONS

VATS lung reduction under general anesthesia with one-lung ventilation is well tolerated. Permissive hypercapnia was well tolerated by all patients. Early extubation can be routinely accomplished in these patients.

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.

Flow cytometric analysis of lung lymphocytes in lung transplant recipients

Lung transplantation is an accepted therapeutic modality in end-stage lung disease. Presently, histologic examination of tissue by transbronchial biopsy remains as the definitive diagnostic procedure for determining rejection. To begin addressing the usefulness of flow cytometric analysis of bronchoalveolar lavage fluid (BALF) in acute lung rejection, we prospectively studied the expression of markers on lymphocytes from BALF samples removed from 10 lung and heart-lung transplant recipients and compared their pattern with that of BALF lymphs obtained from normal volunteers (Norm) and nonrejecting heart transplant recipients (HT) who were receiving similar immunosuppressive regimens. Compared with both Norm and HT subjects, CD4+ lymphocytes in the BALF of lung transplant recipients was significantly reduced. A greater percentage of the CD4+ lymphocytes in nonrejecting lung transplant subjects also expressed the interleukin-2 receptor, but only during the early post-transplant period, suggesting possible reactivity to persistent donor cells. However, the CD8+ lymphocytes were increased only in lung transplant recipients undergoing acute lung rejection. We conclude that the immunologic milieu is indeed altered in the transplanted lung. Further studies in lung transplant recipients are required to evaluate the role of flow cytometry in the early detection of acute lung rejection.

A comparison of continuous intravenous epoprostenol (prostacyclin) with conventional therapy for primary pulmonary hypertension

BACKGROUND

Primary pulmonary hypertension is a progressive disease for which no treatment has been shown in a prospective, randomized trial to improve survival.

METHODS

We conducted a 12-week prospective, randomized, multicenter open trial comparing the effects of the continuous intravenous infusion of epoprostenol (formerly called prostacyclin) plus conventional therapy with those of conventional therapy alone in 81 patients with severe primary pulmonary hypertension (New York Heart Association functional class III or IV).

RESULTS

Exercise capacity was improved in the 41 patients treated with epoprostenol (median distance walked in six minutes, 362 m at 12 weeks vs. 315 m at base line), but it decreased in the 40 patients treated with conventional therapy alone (204 m at 12 weeks vs. 270 m at base line; P < 0.002 for the comparison of the treatment groups). Indexes of the quality of life were improved only in the epoprostenol group (P < 0.01). Hemodynamics improved at 12 weeks in the epoprostenol-treated patients. The changes in mean pulmonary-artery pressure for the epoprostenol and control groups were -8 percent and +3 percent, respectively (difference in mean change, -6.7 mm Hg; 95 percent confidence interval, -10.7 to -2.6 mm Hg; P < 0.002), and the mean changes in pulmonary vascular resistance for the epoprostenol and control groups were -21 percent and +9 percent, respectively (difference in mean change, -4.9 mm Hg/liter/min; 95 percent confidence interval, -7.6 to -2.3 mm Hg/liter/min; P < 0.001). Eight patients died during the study, all of whom had been randomly assigned to conventional therapy (P = 0.003). Serious complications included four episodes of catheter-related sepsis and one thrombotic event.

CONCLUSIONS

As compared with conventional therapy, the continuous intravenous infusion of epoprostenol produced symptomatic and hemodynamic improvement, as well as improved survival in patients with severe primary pulmonary hypertension.

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.

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)

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.

Methods of drawing blood samples through central venous catheters in pediatric patients undergoing bone marrow transplant: results of a national survey

PURPOSE/OBJECTIVES

To describe methods of drawing blood samples from central venous catheters (CVCs) currently in use in pediatric bone marrow transplant (BMT) units, the rationale for method selection, and concerns of clinicians related to those methods.

DESIGN

Descriptive survey.

SETTING

National.

SAMPLE

34 pediatric BMT units (median = 8 beds) in hospitals ranging in size from 48 to 1,100 beds (median = 530).

METHODS

A mailed questionnaire was completed by a designated member of the BMT nursing staff.

MAIN RESEARCH VARIABLES

Type of blood drawing method, volume of blood drawn, rationale for using a specific method and volume, and clinician concerns regarding drawing procedure.

FINDINGS

The majority of the BMT units use the discard method of blood drawing (i.e., prior to drawing the required volume of blood for testing, a sample of blood is withdrawn and discarded). Discard volumes ranged from 0.5 ml-10 ml. The most frequently cited concerns were risk of infection, blood loss, and accuracy of laboratory values.

CONCLUSIONS

The concerns of the respondents and the lack of empiric studies mandate that research determine the safest method of drawing blood samples through CVCs in a pediatric BMT population.

IMPLICATIONS FOR NURSING PRACTICE

Concern regarding current practice exists, but minimal data are available to assist nurses in determining safe and appropriate methods for withdrawing blood through CVCs. A prospective, randomized study of the three methods currently being used with a large sample can provide the information necessary to establish quality practice guidelines.

Giant cell interstitial pneumonitis. Disease recurrence in the transplanted lung

Recurrence of the original disease in the transplanted organ is well reported in renal transplant recipients. There have been no previously fully documented cases of recurrence of the original disease after lung transplantation. We report a patient who underwent single-lung transplant in 1990 for end-stage respiratory failure secondary to biopsy-proved giant cell interstitial pneumonitis (GIP). There was no further industrial exposure. Surveillance bronchoscopies and biopsies post-transplant demonstrated eosinophils and giant cells in the bronchoalveolar lavage of both lungs, and in biopsies of the transplanted organ. Two years after successful transplantation the patient deteriorated and underwent open lung biopsy, which demonstrated not only bronchiolitis obliterans but also the classic features of GIP. There was no evidence of inorganic particles in the transplanted lung. Autopsy confirmed the presence of numerous giant cells characteristic of GIP with associated fibrosis throughout the transplanted lung. Although tungsten and other inorganic particles were again demonstrated in the native lung, there was no evidence of tungsten particles in the transplanted lungs. We believe that this case documents recurrence of the original disease after lung transplantation. The absence of unusual inorganic particles in the transplanted lung in the face of the classic picture of GIP is highly suggestive of an autoimmune mechanism for this occupation-associated disease. The appropriateness of transplant in the management of this lung disease should be reviewed further.

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.