Study of pulmonary function tests in workers of rurally located flour mills

Background: Agro-based industrial works like flour milling are a significant component in the industrial arena of Kerala. In milling industry, dusts are produced in substantial quantities and inhalation of which can result in pulmonary impairment in workers. In such situations, spirometric evaluation can aid in the diagnosis and prognosis of pulmonary diseases. Aims and Objectives: The aims of this study were to assess the effect of flour dust on pulmonary function among flour mill workers and to study the variation in pulmonary function among workers according to duration of exposure and their working environment in the factory. Materials and Methods: A cross-sectional study was conducted in three wheat flour mills. Subjects were selected after proper exclusion and after getting informed consent. In the present study, 79 flour mill workers aged more than 20 years and employed for more than 1year, were considered and their FVC,FEV1,FEV1/FVC,PEFR and FEF25-75% values were assessed. The objective was to find out the effect of their duration of employment and exposure to dust on their spirometric parameters based on their type of job and age. These parameters were tested using a portable electronic spirometer in the factory premises. Results: The study showed no significant relation of these parameters with duration of employment and dust exposure. However, there was significant reduction in FVC and FEV1 with increasing age. Conclusion: Even though apparently normal PFT values are obtained in many subjects, these may be on the extremes of normal spectrum.

Study of spirometry parameters in suspected asthmatic children in a tertiary care hospital

Background: Asthma in children is difficult to diagnose due to inability of young children to successfully perform spirometry. However some parameters in the spirometry which are relatively effort independent can be very helpful in confirming the diagnosis of asthma. This study was conducted to find out the most commonly affected spirometry parameter in the suspected cases of childhood asthma.Methods: Total 56 children were studied between 7 to 18 years who came for outpatient visit or admitted in the paediatric ward and were clinically suspected to be asthmatic based on asthma predictive index. They were subjected to spirometry in our institute. Baseline and post bronchodilator values of spirometry parameters were studied and analysed using standard statistical tests.Results: Baseline Forced expiratory flow between 25% and 75% of vital capacity (FEF25-75%) was found to be the most commonly affected spirometry parameter in confirming the diagnosis of suspected asthmatics and correlated with the clinical diagnosis of childhood asthma.Conclusions: FEF25-75% can aid in confirming the diagnosis of suspected asthmatic children who are otherwise not treated as asthmatics and remain undiagnosed in view of not meeting the established spirometry criteria for asthma due to poor performance and ignorance of looking at this important and effort independent parameter.

Value of Exhaled Nitric Oxide and FEF(25–75) in Identifying Factors Associated With Chronic Cough in Allergic Rhinitis

PURPOSE: Chronic cough in allergic rhinitis (AR) patients is common with multiple etiologies including cough variant asthma (CVA), non-asthmatic eosinophilic bronchitis (NAEB), gastroesophageal reflux-related cough (GERC), and upper airway cough syndrome (UACS). Practical indicators that distinguish these categories are lacking. We aimed to explore the diagnostic value of the fraction of exhaled nitric oxide (FeNO) and forced expiratory flow at 25% and 75% of pulmonary volume (FEF(25–75)) in specifically identifying CVA and NAEB in these patients. METHODS: Consecutive AR patients with chronic cough were screened and underwent induced sputum, FeNO, nasal nitric oxide, spirometry, and methacholine bronchial provocation testing. All patients also completed gastroesophageal reflux disease questionnaires. RESULTS: Among 1,680 AR patients, 324 (19.3%) were identified with chronic cough, of whom 316 (97.5%) underwent etiology analyses. Overall, 87 (27.5%) patients had chronic cough caused by NAEB, 78 (24.7%) by CVA, 16 (5.1%) by GERC, and 81 (25.6%) by UACS. Patients with either NAEB or CVA (n = 165, in total) were further assigned to a common group designated as CVA/NAEB, because they both responded to corticosteroid therapy. Receiver operating characteristic curves of FeNO revealed obvious differences among CVA, NAEB, and CVA/NAEB (area under the curve = 0.855, 0.699, and 0.923, respectively). The cutoff values of FeNO at 43.5 and 32.5 ppb were shown to best differentiate CVA and CVA/NAEB, respectively. FEF(25–75) was significantly lower in patients with CVA than in those with other causes. A FEF(25–75) value of 74.6% showed good sensitivity and specificity for identifying patients with CVA. CONCLUSIONS: NAEB, CVA, and UACS are common causes of chronic cough in patients with AR. FeNO can first be used to discriminate patients with CVA/NAEB, then FEF(25–75) (or combined with FeNO) can further discriminate patients with CVA from those with CVA/NAEB.

Assessment of PEFR and FEF25-75 in Female SLE Patients and their Relationship with Duration of the Diseas.

Background: Systemic Lupus Erythematosus (SLE) is an autoimmune disorder which affects multiple organs of human including lungs. Objectives: To assess PEFR and FEF25-75 in SLE patients and to correlate them with the duration of the disease. Method: This cross-sectional study was carried out in the Department of Physiology, BSMMU, Dhaka, from January 2010 to December 2010. A total number of 120 female subjects were selected, among which 30 were age and BMI matched apparently healthy subjects for comparison (control) and 90 were patients of SLE (study group). All the patients were matched for age, sex and BMI. Based on the duration of the disease, patients were subdivided into B1 (1-6 months), B2 (2-5 years) and B3 (6-10 years). Controls were selected from the community and the patients from the Out Patient Department (OPD) of SLE clinic, Department of Medicine, BSMMU, Dhaka. (PEFR) and FEF25-75 of all the subjects were measured by a Digital MicroDL spirometer. For statistical analysis Independent Sample ‘t’ test, One way ANOVA test and Pearson’s correlation coefficient test were performed as applicable. Results: The mean percentage of predicted values of lung function parameters in healthy female subjects were within normal ranges. The mean percentage of predicted values of PEFR and FEF25-75 were significantly lower in all study groups when compared to control. Again, the mean percentage of predicted values of PEFR and FEF25-75 were significantly lower in the patients of Group B3 compared to Group B2. Moreover, these comparisons were significantly lower when compared to Group B1. The differences of the mean percentage of predicted value of PEFR, FEF25-75 were non-significantly lower in Group B2 when compare to Group B1. In addition, FEF25-75 were positively correlated with duration of SLE in group B2 but negatively correlated in B3. On the other hand PEFR was negatively correlated with duration of SLE in both B2 and B3. All these values were statistically non-significant. Conclusion: These pulmonary functions decrease in SLE female and the reduction is inconsistently associated with duration of the disease.

Small Airway Impairment and Bronchial Hyperresponsiveness in Asthma Onset

PURPOSE: Our study tried to find a relationship between baseline FEF25-75% and airway hyperresponsiveness (AHR) and whether a greater FEF25-75% impairment may be a marker of a more severe hyperresponsiveness in subjects with normal FEV1 and FEV1/FVC and suggestive asthma symptoms. Besides, we tried to asses a FEF25-75% cut-off value to identify hyper-reactive subjects. METHODS: 4,172 subjects (2,042 M; mean age: 38.3+/-14.9; mean FEV1 % predicted: 100.5+/-12.7 and FEV1/FVC: 85.4+/-6.8) were examined after performing a methacholine (Mch) test. All subjects reported a symptom onset within 3 years before the test. Subjects with PD20400 microg were arbitrarily considered affected by moderate/severe and borderline AHR, respectively. RESULTS: PD20 values were 213 (IQR:86-557), 340 (IQR:157-872) and 433 (IQR:196-1032) microg in subjects with baseline FEF25-7570% respectively (P70%. The hyperreactive subjects percentage, was higher in those with FEF25-7570% (P70%) was a higher AHR risk factor, especially in subjects with moderate/severe AHR (OR: 2.18 [IQR:1.41-3.37]; P50 and 70% levels were similar both in normoreactive and hyperreactive subjects. CONCLUSIONS: At asthma onset, reduced baseline FEF25-75 values with normal FEV1 and FEV1/FVC may predict AHR. Detectable predictive cut-off values do not exist because even normoreactive subjects can show lower FEF25-75 values. Furthermore, a greater FEF25-75 reduction may be associated to a more severe AHR, suggesting a possible FEF25-75 role in the management of asthma when FEV1 and FEV1/FVC are normal.

FVC, FEV1, FEV1/FVC ratio and FEF25-75% in End-stage renal disease (ESRD) patients undergoing maintenance haemodialysis.

Background: End-stage renal disease causes multiple pulmonary complications and lung functions are decreased in ESRD patients undergoing maintenance haemodialysis. Objectives: To observe FVC, FEV1, FEV1/FVC ratio and FEF25-75% in ESRD patients undergoing maintenance haemodialysis to evaluate their lung functions status. Methods: This cross sectional study was carried out in the Department of Physiology, BSMMU, Dhaka, from July 2011 to June 2012. For this, 30 ESRD patients aged 25-55 years undergoing maintenance haemodialysis with less than 1 year duration were studied and 30 age, sex matched healthy subjects were taken as control. Patients were selected from the Nephrology department of BSMMU, Dhaka. FVC, FEV1, FEV1/FVC ratio and FEF25-75% were measured by a Digital Spirometer. For statistical analysis Independent Sample‘t’ test and One way ANOVA test were performed as applicable. Results: The mean percentage of predicted values of FVC, FEV1 and FEF25-75% were significantly lower in patients except FEV1/FVC ratio which was almost similar to control. 63.33% patients had restrictive and 36.67% patients had both restrictive and obstructive (small airway obstruction) feature. Conclusion: This study concluded that some pulmonary functions were markedly reduced in ESRD patients undergoing maintenance haemodialysis. In addition most of the patients were suffering from restrictive and some of them were affected with both obstructive and restrictive type of pulmonary disorders.

PEFR and FEF 25-75 in Rheumatoid Arthritic Female and their Relationships with Duration of the Disease.

Background: Rheumatoid Arthritis (RA) is a chronic, progressive multisystemic inflammatory disorder of unknown etiology affecting approximately 1% of the population. Pulmonary involvement is a frequent extraarticular manifestation in rheumatoid arthritis. Objective: To observe PEFR, FEF 25-75 in female patients of RA in order to find out their relationships with duration of the disease. Methods: This cross-sectional study was carried out in the Department of Physiology, BSMMU, Dhaka, between January and December 2009 on 90 RA female patients of 30-50 years age (Group B). For comparison, 30 age and BMI matched apparently healthy subjects (Group A) were also studied. According to the duration of disease, RA patients were subdivided into B1 (newly diagnosed), B2 (3-5 years) and B3 (6- 10 years). They were selected from the Out Patient Department of Physical Medicine of Bangabandhu Sheikh Mujib Medical University, Dhaka. PEFR, FEF25-75 of all the subjects were measured by a digital MicroDL spirometer. Results were expressed as percentage of predicted value. For statistical analysis One-Way ANOVA, Unpaired Student’s ‘t’ test and Pearson’s correlation coefficient test were performed. Results: The mean percentage of predicted values of these lung function parameters in the healthy female subjects and newly diagnosed (B1) RA patients were within normal ranges. The mean percentage of predicted values of both the spirometric variables were significantly lower in B3 compared to those in B2 (PEFR p<0.001, FEF25-75 p<0.001), B1 (PEFR p<0.05, FEF25-75 p<0.02) and A(PEFR p<0.05, FEF25- 75 p<0.01). Again the same parameters were significantly lower in B2 in comparison to those of B1 (PEFR p<0.001, FEF25-75 p<0.05) and A (PEFR p<0.001, FEF25-75 p<0.05). In addition both the ventilatory variables had significant (p<0.001) negative correlation with durations of disease. Conclusion: This study reveals that pulmonary functions may be lower in patients with RA and their lung function is inversely related to the duration of disease.

PEFR and FEF25-75 in type 2 diabetes mellitus and their relationships with its duration.

Background: Diabetes mellitus is a major public health problem with increasing incidence worldwide and long term complications of various organs including lungs. The magnitude of the complications of this disease is related to its duration. Objective: To observe PEFR and FEF25-75 in type 2 diabetic male and their relationship with duration of the disease. Methods: This cross sectional study was carried out in the Department of Physiology, BSMMU, Dhaka, from 1st July 2007 to 30th June 2008 on 60 type 2 diabetic, non smoker, male of 40-60 years old. For comparison, 30 age, BMI and socioeconomic status matched apparently healthy non diabetic subjects were also studied. Based on the duration of disease, diabetic patients were divided into B1 (5-10 years) and B2 (10-20 years). PEFR and FEF25-75 of all the subjects were measured by an electronic spirometer. Data were analyzed by One way ANOVA, Unpaired Student’s ‘t’ and Pearson’s correlation coefficient tests. Results: The mean percentage of predicted values of PEFR and FEF25-75 in non diabetic male were within normal ranges. But, both the parameters were significantly (p<0.001) lower in both the groups of type 2 diabetic male compared to those of non diabetic male. Again, the PEFR and FEF25-75 were lower in the patients of longer duration compared to those of shorter duration but the differences were not significant. However, PEFR was negatively correlated and FEF25-75 was positively correlated with shorter duration of diabetes and the relationships were nonsignificant. On the other hand, both the parameters were negatively correlated with longer duration of diabetes while only PEFR showed significant (p<0.01) relationship. Conclusion: The PEFR and FEF25-75 may be lower in type 2 diabetic male, which are inversely related to the duration of the disease.

Role of Methacholine PC20 in FEF(25-75%) for the Diagnosis of Bronchial Asthma / 결핵및호흡기질환

BACKGROUND: The methacholine bronchial provocation test is a useful tool for evaluating asthma in patients with normal or near normal baseline lung function. However, the sensitivity of this test is 82~92% at most. The purpose of this study is to evaluate the clinical usefulness of FEF(25-75%) in identification of airway hyperresponsiveness in patients with suspected asthmatic symptoms. METHODS: One hundred twenty-five patients who experienced cough and wheezing within one week prior to their visiting the clinic were enrolled. RESULTS: Sixty-four subjects showed no significant reduction of FEV1 or FEF(25-75%) on the methacholine bronchial provocation test (Group I). In 24 patients, FEF(25-75%) fell more than 20% from baseline without a 20% fall of FEV1 during methacholine challenge (Group II). All patients who had more than 20% fall of FEV1 (n=37) also showed more than 20% of reduction in FEF(25-75%) (Group III). Baseline FEV1/FVC (%) and FEF(25-75%) (L) were higher in group II than group III (81.51+/-1.56% vs. 75.02+/-1.60%, p<0.001, 3.25+/-0.21 L vs. 2.45+/-0.21 L, p=0.013, respectively). Group II had greater reductions of both FEV1 and FEF(25-75%) than group I at 25 mg/mL of methacholine (p<0.001). The provocative concentration of methacholine causing a 20% fall in FEF(25-75%) in group II was about three-fold higher than that in group III. CONCLUSION: A 20% fall of FEF(25-75%) by methacholine provocation can be more sensitive indicator for detecting a milder form of airway hyperresponsiveness than FEV1 criteria.

The Effect of Body Mass Index, Fat Percentage, and Fat-free Mass Index on Pulmonary Function Test: With Particular Reference to Parameters Derived from Forced Expiratory Volume Curve / 결핵

BACKGROUND: Sex specific cross sectional reference values for the lung function indices usually employ a linear model with a term for age and height. The purpose of this study was to determine the effects of the body mass index (BMI), the fat percentage of the body mass and the fat-free mass index (FFMI) on the forced expiratory volume curve. METHOD: Between January 2000 and December 2001, a total of 300 subjects, 150 men and 150 women (mean age : 45+/-13 years), with a normal lung function were enrolled in the study sample. This study measured the FEV1, FVC and FEF25-75% from the forced expiratory volume curve by a spirometer and the body composition by a bioelectrical impedance method in all subjects. Multiple regression analysis was used in order to examine the effects of the body composition on the parameters derived from the forced expiratory volume curve. RESULT: After adjusting for age, the BMI and Fat percentage improved the descriptions of the FVC (p<0.05, r2=0.491) and FEV1 (p<0.05, r2=0.654) in women. In contrast, the FFMI contributed significantly to the FVC (p<0.05, r2=0.432) and FEV1 (p<0.05, r2=0.567) in men. The FEF25-75% correlated with the fat percentage in women (p<0.05, r2=0.337). CONCLUSION: These results suggest that the BMI, the fat percentage and the FFMI are significant determinants of the forced expiratory volume curve. The pulmonary function test, when considering the BMI, the fat percentage and the FFMI, might be useful in clinical applications.

Evaluation of the Severity in Patients with Bronchial Asthma Using FEF25-75%

PURPOSE: Spirometry, because of its simplicity and reproducibility, has been used to evaluate pulmonary function in childhood asthma. We investigated whether FEF25-75% is the most sensitive parameter among other spirometric parameters in the diagnosis of pulmonary function and airway obstruction. METHODS: This study included 32 children with asthma. We recorded values of spirometry(FVC, FEV1, PEFR, and FEF25-75%) before and after symptomatic improvement and compared them. The values were recorded as a percent of the predicted normal value. RESULTS: The FEV1 value before and after symptomatic improvement was 71.7+/-15.6% and 83.8+/-12.8%, respectively; PEFR was 75.4+/-18.3% and 85.0+/-16.0%; and FEF25-75% was 60.8+/-17.9% and 81.5+/-16.3%. According to symptomatic improvement, FEF25-75% improved more than the other spirometric parameters. Of the 40 cases of spitometric measurement before symptomatic improvement, abnormal FEV1, PEFR, FEF25-75% values were observed in 25, 17 and 28 cases, respectively. There was statistically significant difference between FEF25-75% and PEFR(P=0.005), but not between FEF25-75% and FEV1(P=0.091). After symptomatic improvement, abnormal FEV1, PEFR, and FEF25-75% values were observed in 14, 12 and 9 cases, respectively. There was statistically significant difference between FEF25-75% and FEV1(P=0.044) but not between FEF25-75% and PEFR (P=0.097). The cases of normalized values with symptomatic improvement, 11 in FEV1, 7 in PEFR and 19 in FEF25-75%. CONCLUSION: FEF25-75% showed the most improvement rate before and after symptomatic improvement. FEF25-75% was helpful in the assessment of treatment effectiveness and reversible bronchial responsiveness. However, this study did not suggest that FEF25-75% is the most sensitive measurement of airway obstruction.