Clinical value of low attenuation area ratio and lung volume on CT in evaluating severity of spirometric abnormality / 上海交通大学学报（医学版）

Objective • To explore the clinical value of the ratio of low attenuation areas (LAA%) and lung volume calculated according to chest CT in evaluating the severity of spirometric abnormality. Methods • The patients who underwent chest CT scan and lung function test at the same time from January 2010 to July 2014 in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine were retrospectively enrolled. LAA% and lung volume were calculated by Myrian software. The correlation analysis was performed between post-bronchodiation forced expiratory volume in 1 second (FEV1) or its percentage of predicted value (FEV1%pred) and LAA% or lung volume. Multi-variable models for post-bronchodiation FEV1 and FEV1%pred were developed based on LAA%, lung volume, gender, height, and weight. The ROC curves were depicted and the diagnostic values of LAA%, lung volume, and models were compared. The cut points were chosen according to Younden indexes and specificity. Results • A total of 1 150 patients were included in summarization group. LAA% was negatively correlated with post-bronchodiation FEV1 and FEV1%pred. Lung volume was positively correlated with post-bronchodiation FEV1. The regression models of post-bronchodiation FEV1 and FEV1%pred were FEV1=-2.700+0.111×lung volume-0.216×ln (LAA%+0.1)-0.025×age+0.154×gender+0.034×height and FEV1%pred=65.582+4.014×lung volume-7.508×ln (LAA%+0.1)-10.264×gender, respectively. The regression model performed better than LAA% and lung volume in estimating the degree of post-bronchodiation FEV1 decrease. LAA% and the regression model performed better than lung volume in estimating the degree of post-bronchodiation FEV1%pred decrease. The sensitivity was 75.6% and the specificity was 90.6% in estimating post-bronchodiation FEV1%pred1.61% as the criteria. The sensitivity was 58.9% and the specificity was 81.4% in estimating post-bronchodiation FEV1<1 L by using the value of regression model<1.76. Conclusion • The regression models of post-bronchodiation FEV1 and FEV1%pred were obtained based on lung volume and LAA% on chest CT. LAA% and lung volume can roughly estimate the severity of spirometric abnormality.

Pulmonary Function Impairment in Female Workers Exposed to Environments with Varied Ambient Air Pollution in the Central Business Area of Lusaka-Zambia.

Aims: To determine the lung function of cleaners exposed to particulate matter of aerodynamic diameter less than 2.5 micrometer (PM2.5) in the streets and offices in Lusaka, Zambia. Study Design: This was a cross sectional study between two groups. Place and Duration of Study: Lusaka city, central business area, between June and August 2014. Methodology: The study included women between 18-50 years of age who had been working as street or office cleaners for 6 months or more. Males and individuals in both groups who used to smoke or were currently smokers, as well as those with a history of respiratory related illnesses or had cardiopulmonary conditions were excluded from the study. The cleaners were interviewed to get information on socio-demographic characteristics and other information using a structured interview schedule. The participants’ lung volumes, forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and their ratio (FEV1/FVC) were measured using a MRI spirobank G spirometer. On the day of the interview, PM2.5 in their work environment was sampled using a personal aerosol monitor (SIDEPAK AM510). Results: Out of the 90 participants, 45 were street sweepers and 45 were office cleaners. More street sweepers had impaired lung function (FEV1/FVC) 15(75%) than office cleaners 5(25%) p=0.01. FEV1 was also significantly different among street sweepers 12(70.6%) and office cleaners 5(29.4%) p=0.05. PM2.5 measurements revealed significantly high levels of exposure among street sweepers (p=0.001). Participants with impaired lung function (p=.005) and those with reduced FEV1percent predicted were exposed to significantly high concentrations of PM2.5 (p=0.012). Conclusion: Exposure to high PM2.5 concentration is associated with pulmonary function impairment and reduced FEV1 % predicted among cleaners.

THE UNDERUSE OF SPIROMETERY IN ROUTINE MEDICAL PRACTICE FOR DIAGNOSIS AND MANAGEMENT OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS IN KARACHI, PAKISTAN

Introduction: Spirometry is important in the diagnosis and management of chronic obstructive pulmonary disease (COPD), yet it is a common clinical observation that it is underused though the extent is unclear. This survey aims to examine the use of spirometry in the diagnosis and management of COPD patients in districts of, Karachi. Material and Methods: It is a cross-sectional survey involving four clinic settings: hospital-based respiratory specialist clinic, hospital-based mixed medical specialist clinic, general outpatient clinic (primary care), and tuberculosis and chest clinic. Thirty physician-diagnosed COPD patients were randomly selected from each of the four clinic groups. All of them had a forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio less than 0.70 and had been followed up at the participating clinic for at least 6 months for COPD treatment. Results: Of the 120 COPD patients, there were 111 males and mean post-bronchodilator FEV1 was 46.2% predicted. Only 22 patients (18.3%) had spirometry done during diagnostic workup, and 64 patients (53.3%) had spirometry done ever. Conclusion: We conclude that spirometry is underused in general but especially by non-respiratory physicians and family physicians in the management of COPD patients. More effort at educating the medical community is urgently needed.