Parenchymal and airway diseases caused by asbestos.

PURPOSE OF REVIEW: The extensive industrial use of asbestos for many decades has been linked to development of benign and malignant pleuropulmonary disease. This review summarizes newer evidence and ongoing controversies that exist in the literature regarding asbestos-related parenchymal and airway diseases. RECENT FINDINGS: Asbestosis represents a significant respiratory problem despite the improvement in the workplace hygiene and a decrease in use of asbestos. The management of asbestosis remains challenging as currently there is no specific treatment. The role of asbestos exposure alone as a cause of chronic airway obstruction remains uncertain. The relationship between lung cancer and asbestos exposure alone and in combination with smoking has also been investigated. The benefit of screening for asbestos-related pleuropulmonary disease remains uncertain as does the use of computed tomography scanning for the purpose of screening. SUMMARY: Future studies will help clarify the clinical issues and shape screening strategies for asbestos-exposed individuals.

Patient satisfaction with physician-patient communication during telemedicine.

The quality of physician-patient communication is a critical factor in treatment outcomes and patient satisfaction with care. To date, few studies have specifically conducted an in-depth evaluation of the effect of telemedicine (TM) on physician-patient communication in a medical setting. Our objective was to determine whether physical separation and technology used during TM have a negative effect on physician-patient communication. In this noninferiority randomized clinical trial, patients were randomized to receive a single consultation with one of 9 physicians, either in person (IP) or via TM. Patients (n = 221) were recruited from pulmonary, endocrine, and rheumatology clinics at a Midwestern Veterans Administration hospital. Physician-patient communication was measured using a validated self-report questionnaire consisting of 33 items measuring satisfaction with visit convenience and physician's patient-centered communication, clinical competence, and interpersonal skills. Satisfaction for physician's patient-centered communication was similar for both consultation types (TM = 3.76 versus IP = 3.61), and noninferiority of TM was confirmed (noninferiority t-test p = 0.002). Patient satisfaction with physician's clinical competence (TM = 4.63 versus IP = 4.52) and physician's interpersonal skills (TM = 4.79 versus IP = 4.74) were similar, and noninferiority of TM was confirmed (noninferiority t-test p = 0.006 and p = 0.04, respectively). Patients reported greater satisfaction with convenience for TM as compared to IP consultations (TM = 4.41 versus IP = 2.37, noninferiority t-test p < 0.001). Patients were equally satisfied with physician's ability to develop rapport, use shared decision making, and promote patient-centered communication during TM and IP consultations. Our data suggest that, despite physical separation, physician-patient communication during TM is not inferior to communication during IP consultations.

An evaluation of patient-physician communication style during telemedicine consultations.

BACKGROUND: The quality of physician-patient communication is a critical factor influencing treatment outcomes and patient satisfaction with care. To date, there is little research to document the effect of telemedicine (TM) on physician-patient communication. OBJECTIVE: The objectives of this study are to measure and describe verbal and nonverbal communication during clinical TM consultations and to compare TM with in-person (IP) consultations in terms of the quality of physician-patient communication. METHODS: Veteran patients (n = 19) requiring pulmonary medicine consultations were enrolled into the study. The study group included 11 patients from the Iron Mountain Veterans Affairs Hospital (VAMC) remote site. Patients had individual TM consultations with a pulmonary physician at the Milwaukee VAMC hub site. A control group of 8 patients had IP consultations with a pulmonary physician at the Milwaukee VAMC. Video recordings of medical consultations were coded for patient-physician verbal and nonverbal communication patterns using the Roter Interaction Analysis System (RIAS). RESULTS: There were no differences in the length of TM consultations (22.2 minutes) and IP consultations (21.9 minutes). Analysis of visit dialogue indicated that the ratio of physician to patient talk was 1.45 for TM and 1.13 for IP consultations, indicating physician verbal dominance. Physicians were more likely to use orientation statements during IP consultations (P = .047). There were greater requests for repetition from patients during TM consultations (P = .034), indicating perceptual difficulties. CONCLUSIONS: The study findings indicate differences between TM and IP consultations in terms of physician-patient communication style. Results suggest that, when comparing TM and IP consultations in terms of physician-patient communication, TM visits are more physician centered, with the physician controlling the dialogue and the patient taking a relatively passive role. Further research is needed to determine whether these differences are significant and whether they have relevance in terms of health outcomes and patient satisfaction with care.

Pulmonary telemedicine--a model to access the subspecialist services in underserved rural areas.

BACKGROUND: To describe the use of videoconference telemedicine for providing outpatient pulmonary consultation to a remote, underserved clinic site. METHODS: Analysis of data from the Milwaukee Veteran Affairs Medical Center (VAMC) pulmonary telemedicine clinic. Pulmonary physicians at the Milwaukee VAMC provide outpatient consultations with the use of videoconference technology to patients located at the Iron Mountain VAMC in Iron Mountain, MI (346 km or 215 miles from Milwaukee). Data on demographics, referral patterns, access to care, consultation process, and outcomes are presented. RESULTS: A total of 314 patients (684 visits) received telemedicine consultations between January 1, 1998 and December 31, 2004. Common reasons for referral were abnormal radiology (38%), chronic obstructive pulmonary disease (COPD) (26%), and dyspnea (13%). Physical exam was performed by the telemedicine registered nurse or respiratory therapists in 90% of visits. Common diagnoses were COPD (29%), benign pulmonary nodule (11%), bronchial asthma (6%), and lung cancer (6%). Telemedicine consultation resulted in a change in management for 41% of patients. Only 8% of patients required an in-person clinic visit at Milwaukee VAMC following a telemedicine visit. Telemedicine saved patients 473,340 km or 294,120 miles of travel over the study period. CONCLUSIONS: The provision of subspecialty services using telemedicine to a remote underserved rural population provides improved patient access to subspecialty care. Physicians are able to rely on medical history and radiology to manage patients across a broad spectrum of complex pulmonary conditions with the assistance of a non-physician health care provider at the remote site.

The effect of inhaled nitric oxide and oxygen on the hydroxylation of salicylate in rat lungs.

Inhaled nitric oxide (iNO) is used as a selective pulmonary vasodilator, and often under conditions when a high fraction of inspired oxygen is indicated. However, little is known about the potential toxicity of iNO therapy with or without concomitant oxygen therapy. NO can combine with superoxide (O2-) to form peroxynitrite (ONOO-), which can in turn decompose to form hydroxyl radical (OH.). Both OH. and ONOO- are involved in various forms of lung injury. To begin evaluation of the effect of iNO under either normoxic or hyperoxic conditions on OH. and/or ONOO- formation, rats were exposed for 58 h to either 21% O2, 21% O2 + 10 parts per million (ppm) NO, 21% O2 + 100 ppm NO, 50% O2, 90% O2, 90% O2 + 10 ppm NO, or 90% O2 + 100 ppm NO. We used a salicylate hydroxylation assay to detect the effects of these exposures on lung OH. and/or ONOO- formation measured as the appearance of 2,3-dihydroxybenzoic acid (2,3-DHBA). Exposure to 90% O2 and 90% O2 + 100 ppm NO resulted in significantly (p < 0.05) greater lung wet weight (1.99 +/- 0.14 g and 3.14 +/- 0.30 g, respectively) compared with 21% O2 (1.23 +/- 0.01 g). Exposure to 21% O2 + 100 ppm NO led to 2.5 times the control (21% O2 alone) 2,3 DHBA formation (p < 0.05) and exposure to 90% O2 led to 2.4 times the control 2,3-DHBA formation (p < 0.05). However, with exposure to both 90% O2 and 100 ppm NO, the 2,3-DHBA formation was no greater than the control condition (21% O2). Thus, these results indicate that, individually, both the hyperoxia and the 100 ppm NO led to greater salicylate hydroxylation, but that the combination of hyperoxia and 100 ppm NO led to less salicylate hydroxylation than either did individually. The production of OH. and/or ONOO- in the lung during iNO therapy may depend on the ratio of NO to O2.

Effects of ozone on lung function and lung diseases.

Ozone (O3) is an air pollutant produced by sunlight-driven reactions involving the oxides of nitrogen and volatile organic compounds. The population of many large metropolitan areas in the US is exposed to high levels of O3, particularly in the summer months. Individuals exposed to O3 levels in human experiments at higher than common ambient levels develop reversible reductions in lung function often associated with symptoms, such as airway hyperreactivity and lung inflammation. Animal models have helped characterize potential mechanisms of lung injury from O3 exposure. Defining the adverse effects of chronic exposure to ambient levels of O3 on lung function and disease have been challenging, in part due to the presence of co-pollutants, such as particulate matter. The US Environmental Protection Agency's 1997 revised standard for O3 (0.08 ppm averaged over 8 hours) is designed to provide better protection to susceptible individuals. The revised standard is being implemented following the failure of court challenges.

Cost effectiveness of telemedicine for the delivery of outpatient pulmonary care to a rural population.

The objective of this study was to determine the cost effectiveness of outpatient pulmonary subspecialty consultations via telemedicine. A decision-analytic model was used to compare the cost effectiveness of providing outpatient telemedicine pulmonary consultations with alternative treatment methods. Model options included: (1) telemedicine, (2) routine care (patients travel from a remote site to the hub site to receive care), and (3) on-site care (patients receive care at the remote site). Cost and effectiveness data from the Milwaukee and Iron Mountain Veterans Affairs Medical Centers (VAMC) telepulmonary program were collected for a period of 1 year. The cost-effectiveness analysis was conducted from a societal perspective. Average and incremental cost-effectiveness ratios were calculated together with sensitivity analysis. Telemedicine was found to be more cost effective ($335 per patient/year) compared to routine care ($585 per patient/year) and on-site care ($1,166 per patient/year). Sensitivity analysis revealed that cost effectiveness of telemedicine was sensitive to changes in the values for the number of patients, probability of successful telemedicine consultation, telemedicine equipment cost, utility of telemedicine, and percentage effort assigned to the on-site pulmonary physician. Telemedicine is a cost-effective alternative for the delivery of outpatient pulmonary care for rural populations with limited access to subspecialty services. Cost effectiveness of telemedicine is related to three major factors: cost sharing, i.e., adequate patient volume and sharing of telemedicine infrastructure amongst various clinical users; effectiveness of telemedicine in terms of patient utility and successful clinical consultations; and indirect cost savings accrued by decreasing cost of patients' lost productivity.

L-Arginine uptake and metabolism following in vivo silica exposure in rat lungs.

Pulmonary inflammation increases nitric oxide (NO) production via inducible nitric oxide synthase (iNOS). This study was performed to determine some of the factors that affect the availability of the NOS substrate, L-arginine (L-arg), in the intact lung subjected to silica-induced inflammation. Nitrate production, as an index of NO production, was significantly greater in silica-exposed lungs (53.5 +/- 12.1 nmol/90 min) compared with controls (22.5 +/- 5.1 nmol/90 min, P < 0.05). This was accompanied by greater (P < 0.0001) 90-min [(3)H]L-arg uptake (62 +/- 3% control, 82 +/- 1% silica), a significantly (P < 0.005) increased permeability-surface area product for L-arg (0.28 +/- 0.05 ml/min control, 0.63 +/- 0.07 ml/min silica), and a significantly (P < 0.001) increased urea production (1.16 +/- 0.08 micromol/90 min control, 1.77 +/- 0.06 micromol/90 min silica). There was no difference in eNOS protein between groups and eNOS mRNA was not detectable in either group, whereas silica exposure resulted in the appearance of both iNOS protein and mRNA. Silica exposure increased CAT-1 and CAT-2 mRNA approximately 8-fold compared with controls. We conclude that the increase in NO production in silica-exposed lungs was associated with increased L-arg uptake from the vasculature, presumably resulting from increased CAT-1 and CAT-2, and by increased L-arg metabolism via arginase.

Vocal cord closure pressure during volitional swallow and other voluntary tasks.

Our goal was to determine and compare vocal cord (VC) closure pressure and its associated intratracheal pressure during several physiological events such as swallowing, coughing, straining, and phonation. We studied 11 healthy subjects (age 41 +/- 2 years) with no current or previous history of laryngeal or pulmonary diseases. VC closure pressure during the above-mentioned tasks was studied using a concurrent manometric and endoscopic technique. VC closure pressure during dry swallows averaged 298 +/- 23 mm Hg, while intratracheal pressures exhibited a biphasic pattern ranging from -4 +/- 0.5 to +6 +/- 0.8 mm Hg. Average VC closure pressure during cough was 280 +/- 20 mm Hg, during straining/valsalva maneuver it averaged 330 +/- 45 mm Hg, during phonation it produced an initial rapidly rising spike like pressure (222 +/- 25 mm Hg) followed by a sustained minimally positive pressure during continued phonation of two tested vowel sounds (15-25 mm Hg). Between-group comparison showed that for all studied tasks, the in-' tercordal pressures were significantly higher than those of respective intratracheal pressures (p < 0.05). The vocal cords generate closure pressures that vary depending on the performed function.