Expiratory Flow Meter Research Articles

Algorithm for asthma diagnosis and management at Chitungwiza Central Hospital, Zimbabwe.

Introductionasthma is a chronic inflammatory and a heterogeneous condition of respiratory system whose pathogenesis is linked with variable structural changes. The clinical manifestation of asthma includes attacks of breathlessness, cough, chest tightness and wheezing. Provision of basic equipment and test for asthma diagnosis and access to essential medicines by asthmatic patients reduces morbidity and mortality rates. Significant progress has been made in the diagnosis and management of asthma in other countries but not in the health care delivery system in Zimbabwe. Therefore, the aim of this study was to develop algorithm for asthma diagnosis and management for Zimbabwe.Methodsa two stage Delphi model was used to collect data in order to develop an algorithm of asthma diagnosis and management. A baseline interview with 44 doctors was done to understand their experiences and knowledge regarding asthma diagnosis and management. We collected data using the KoBo Collect Toolbox installed on Android mobile phone and transferred the data to an Excel 2016 spreadsheet for cleaning. The data was qualitatively analysed and themes were constructed. These themes were further explored in stage two at an algorithm development workshop which was led by 4 medical expert panellists in order to develop consensus on the information to be included in the algorithms for asthma diagnosis and management. A total of 15 doctors and 30 nurses participated at the workshop.Resultsdoctors who attended the workshop described the challenges in asthma diagnosis and management that they experienced. These challenges were attributed to lack of basic equipment such as spirometers and Peak Expiratory Flow Meters and tests which included IgE tests, Skin Allergen Tests and RAST. Asthma diagnosis clinical history and management was based on the doctors' knowledge. The doctors indicated the need for refresher courses to update their knowledge on asthma diagnosis and enhance their diagnostic skills. A draft algorithm framework for asthma diagnosis was developed at the workshop and later refined by the core-research team. The final algorithm described in this paper was circulated for further contributions and endorsement by the asthma experts.Conclusionwe established the need for doctors to receive constant refresher courses on asthma diagnosis for upskilling. We recommend adoption by the Zimbabwe's Ministry of Health and Child Care of the asthma diagnostic algorithm we developed.

Comparative study of seasonal variability in peak expiratory flow rate amongst school children in rural and urban areas

Background: Peak Expiratory Flow (PEF) is a value test for lung function and can be conveniently measured by using relatively inexpensive and portable Peak Flow Meter, identifying and assessing the degree of airflow limitation of individuals. While PEFR is obviously related to factors like age, weight, height, race, gender, it may also be additionally affected by seasons and climate. The purpose of study being to observe seasonal variation in PEFR amongst school going children and to observe peak expiratory flow rate in school going children in urban and rural areas.Methods: This prospective and comparative study was carried out on total 600 children; with 300 each from rural and urban schools, of age group 10-14 years, both sexes. Peak expiratory flow meter was used for the measurements in the seasons of summer (April to June) and winter (December to February) of the year. The results thus obtained were compiled and analysed.Results: The mean PEFR value (Litres/min) during summers in the rural children was 243.50(S.D.=16.050) while during winters was 253.63(S.D.=16.934), highly significant (p<0.001); mean PEFR summers in the urban children was 241.50(S.D.=20.530)and during winters was 249.93(S.D.=21.685), again highly significant (p<0.001).In both rural and urban groups PEFR values increased with increase in height and weight of the children which was found to be highly significant (p<0.001). Girls representation proportion in rural vs urban schools being 49% vs 45%; whereas boys being 51% vs 55% respectively.Conclusions: Peak expiratory flow rate decreased during summer season of the year in both rural and urban school attending children. In both the groups PEFR values had a direct correlation with height and weight of the children. Rural schools showed more girl student representation than their urban counterparts indicating more awareness for girl child education amongst rural population.

Establishment of Reference Norms for Lung Function Parameters of Healthy Sri Lankan Tamils.

Spirometry and Peak Expiratory Flow Rate (PEFR) are important measurements in diagnosing and monitoring of COPD and asthma. Ethnic specific reference equations are necessary in interpretation of these parameters. However, equations for Sri Lankan Tamil adults are not available. This study aims to establish reference equations for lung function parameters of Sri Lankan Tamils. A descriptive cross sectional study was carried out in all 5 districts of Northern Sri Lanka. Participants were selected by cluster sampling. Base line data were obtained by a questionnaire. Height, sitting height, weight, arm span, mid arm circumference, and chest expansion were measured. Respiratory functions were assessed by a calibrated spirometer (Cosmed Micro Quark, Italy) and Wright compatible peak expiratory flow meter. Means, and standard deviations for Vital Capacity (VC), Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), FEV1%, Peak Expiratory Flow Rate (PEFR) and for other forced expiratory parameters of 775 males and 687 females were determined. Lung function parameters have significant (p < 0.05) positive correlations with most of the anthropometric measures. Age had a significant (p < 0.05) negative correlation with lung function parameters in adults >20 years and positive correlation (p < 0.05) in 14–20 years group. Step wise multiple regression analysis was used to determine the prediction equations. Also equations based on age, height and age, arm span were derived. Age, height based equations were retested in the same population. Predicted values by the developed equations had better agreement than that of GLI 2012 equations. This can be useful in assessing the respiratory function in Sri Lankan Tamil population as there are no already existing equations.

Correlation between PEFR and regional body fat in the middle aged male subjects – A cross sectional study

Introduction: Obesity and its related pulmonary morbidities have become global epidemic. Association between altered pulmonary functions and its relation with distribution of fat percentage in the body is analysed in our study. Material and Methods: Inclusion Criteria : Male subjects in the age group of 35-45 years with BMI between 18.5-30 kg/m2. Exclusion Criteria: Diabetics, hypertensives, a lcoholics, smokers and subjects with any other recent illness. BC 601 TANITA Bioimpedence analyser was used to measure visceral fat and subcutaneous fat. PEFR (Peak expiratory flow rate) was measured using Wrights peak expiratory flow meter. BMI was calculated from height and weight of the subjects. Results: Pearson correlation was applied. PEFR showed significant negative correlation with visceral fat and subcutaneous fat with r value of -0.576 and - 0.409 respectively. PEFR showed only mild negative correlation with BMI with r value - 0.203 when compared to regional fat. Conclusion: Visceral fat and subcutaneous fat remains a better predictor than BMI in assessing the obesity related morbidity of lung functions. Keywords: Body Mass Index, Peak Expiratory Flow Rate, Subcutaneous fat, Visceral fat.

Effect of Obesity on Asthma Severity in Urban School Children of Kanpur, India: An Analytical Cross-Sectional Study.

The prevalence of both Obesity and Asthma is increasing worldwide. Various epidemiological data has linked obesity with the development and severity of asthma in children. The aim of this study was to assess if any relationship exists between obesity and asthma in children. The study population included school children aged 5 to 18years. A total of 320 asthma cases and 300 controls were included in our study. Association analysis of obesity and asthma based on epidemiological basis was measured. Out of 320 cases, 61 children were found to have moderate persistent asthma. Out of 61 moderate persistent asthma cases, 50 children were selected randomly and divided into two groups. Group I included 25 obese moderate persistent asthmatics and Group II included 25 non-obese moderate persistent asthmatics. Forced expiratory volume in one second (FEV1), Forced vital capacity (FVC), Forced expiratory flow (FEF25-75%), Peak expiratory flow (PEF) were measured with spirometry and Peak expiratory flow meter. Statistical analysis was done by Odds ratio and p value. Out of 320 cases, 97 were obese and 223 were non-obese. Out of 300 controls, 46 were obese and 254 were non-obese. Exposure rate for cases and controls were 30.31% and 15.33% respectively. Odds ratio was 2.40. χ2 value was 19.56 with p value < 0.05.FEV1, FVC, FEF25-75%, PEF for Group-1 were 66.3 ± 9.9, 63.5 ± 4.2, 54.2 ± 5.7, 67.4 ± 8.4 respectively and FEV1, FVC, FEF25-75%, PEF for Group-2 were 74.07 ± 3.5, 77.4 ± 7.2, 60.1 ± 2.1, 71.6 ± 2.4 respectively and p values were < 0.001, < 0.001, < 0.001, < 0.05 respectively which is statistically significant. Children who are obese are more likely to develop severe asthma than those who were not obese.

Asthma in Patients with Persistent Cough: A Cross-Sectional Analysis from a Primary Care Center in Karachi

Objective: To determine the frequency and risk factors of asthma among patients having persistent cough attending primary care center in a tertiary care hospital of Karachi, Pakistan. Methods: This cross-sectional study was conducted from June 2017 till May 2018 in a Primary Health Care Center Sikanderabad, Karachi. All patients coming to Primary Health Care Center above 5 years of age, presenting with cough for more than eight weeks were consecutively enrolled. Chest was examined and the patients underwent Peak Expiratory Flow Meter Test (PEF). If PEF was found 12% post bronchodilation was labeled asthmatic. Results: Out of 150 subjects, mean age of the patients was 27.65 ±19.53 years. There were 78 (52%) females and 72 (48%) males. Frequency of cough, sputum, wheeze, and dyspnea was observed in 120 (80%), 21 (14%), 62 (41.3%), and 56 (37.3%) respectively. There were 44 (29.3%) asthmatic. The odds of asthma were 4.55 times signiicantly higher among smokers (aOR: 4.55, 95% CI: 1.62-12.79, p-value 0.004) and 3.14 times significantly higher among patients with dyspnea (aOR: 3.14, 95% CI: 1.27-7.74, pvalue 0.013). MRC dyspnea score showed that among 44 asthmatic patients with dyspnea, grade 1 was found higher (n=33, 75%) followed by grade 2 (n=7, 16%), while grade 0 and grade 3 in 2 (5%) patients each. Conclusion: The finding of this research showed aconsiderable number of patients with asthma. Smoking and dyspnea found important risk factors for asthma.

Comparison between Emergency Severity Index plus peak flow meter and Emergency Severity Index in the dyspneic patients with chronic obstructive pulmonary disease: A randomized clinical trial

IntroductionIt is unclear whether the Emergency Severity Index (ESI) can identify high-risk patients with Chronic Obstructive Pulmonary Disease (COPD). This study aims to compare the mistriage rates of the ESI plus the Peak Expiratory Flowmeter (PEF) approach and ESI approach among dyspneic patients with COPD. MethodsThis study was a randomized clinical trial conducted between July and October 2018. We randomly assigned COPD patients with dyspnea to the ESI + PEF or ESI groups. Triage levels, disposition rates, number of resources used, and time to first physician contact were compared in patients admitted to the Intensive Care Unit (ICU), the Pulmonary Care Unit (PU), or discharged from the ED. Reliability of the ESI was evaluated by using the interobserver agreement (Kappa). ResultsSeventy COPD patients were equally assigned to the ESI + PEF and ESI groups. The under-triage rates were 11.42% and 0%, the over-triage rates were 31.42% and 2.85% in the ESI and ESI + PEF groups, respectively. The triage levels of the patients admitted to the ICU (2 vs. 3), the PU (2 vs. 4), or discharged from the ED (3 vs. 2) were significantly different between the ESI + PEF and ESI groups. ConclusionsAddition of PEF to the ESI provides a more accurate method for triaging COPD patients compared to ESI alone. We recommend using PEF for the triage of COPD patients in the ED.

Particulate matters and gaseous pollutants in indoor environment and Association of ultra-fine particulate matters (PM1) with lung function.

Real-time particulate matters (PM1, PM2.5, PM4, PM7, PM10, and TSP) with AEROCET 531S (USA), gaseous pollutants (NO2 and TVOC) with Aeroquel 500 gas sampler (NZ) were measured from the indoor air of houses at four residential locations in Dhaka, Bangladesh. PM10 samples were collected on quartz filters with a dual channel dust sampler (IPM-FDS 2510, India) for selected trace metal determination from five houses of Dhaka. Respiratory function of the occupants was assessed by using a peak expiratory flow meter (Rossmax PF 120). Mean PM1, PM2.5, and PM10 concentrations were 46.1 ± 13.4, 76.0 ± 16.2, and 203.9 ± 44.8μgm-3, respectively. Higher enrichment factors of Pb, Zn, and Ni were found for traffic, industrial, and constructional activities. The correlation between indoor and outdoor PM2.5 (R2 = 0.42) and ratios (I/O < 1) suggesting indoor air was effected by outdoor air. The concentration of NO2 (0.076 ± 0.007ppm) and TVOC (90.0 ± 46.0ppm) was found above than other studies. The average total hazard ratio (THR) in Dhaka was 9.06 and has the highest exposure to air pollutants (PM2.5, PM10, NO2) in Khilkhet (THR 10.1) residents. A negative association between ultra-fine particles (PM1) and peak flow rate measurements of the residents living in these houses indicates that inhalations of ultra-fine particles has great influence on the reduced lung efficiency.

Effect of lower respiratory tract infections on peak expiratory flow rate in children admitted to Rajarajeshwari medical college hospital, Bangalore, Karnataka, India

Background: Peak expiratory flow rate is the simplest , cost effective and easily available test to assess the respiratory function. PEFR is measured by a peak expiratory flow meter. Measurement of PEFR is most commonly used for asthmatic patients. To evaluate the effect of lower respiratory tract infection on peak expiratory flow rate in children. Methods: PEFR were measured in eighty children suffering from LRTI by peak flow meter . Height and weight were measured. PEFR was compared with the normal charts. mean PEFR was calculated and predicted percentage of PEFR was calculated.Results: Mean PEFR in pneumonia , para pneumonic effusion, bronchiectasis, and bronchitis was 187.2 , 187.6, 171.85 and 173.1 respectively. Mean PEFR was maximally reduced in bronchiectasis and bronchitis. Mean PEFR was reduced in female children in comparison to males with LRTI. PEFR was decreased more in children with severe clinical presentation and with malnutrition.Conclusions: In this study , most common LRTI was pneumonia followed by parapneumonic effusion. PEFR was maximally reduced in bronchiectasis and bronchitis. Undernourished children were more affected.

Association between Individual Indoor PM2.5 Exposure and Peak Expiratory Flow Rate in Schoolchildren.

Background: PM2.5 exposure is known to have adverse effect on respiratory function in children. However, most of the previous studies were based on the ecological evaluation of outdoor exposure. The aim of the present study is to examine the association between individually monitored indoor PM2.5 concentration and peak expiratory flow rate (PEFR).Methods: We recruited 30 9-year-old children to conduct a panel study. Each child&amp;#8217;s PM2.5 exposure was measured using indoor air quality station equipped with light-scattering particle sensor. The indoor air quality stations were installed at the children&amp;#8217;s classrooms and each child&amp;#8217;s bedroom at their homes. We calculated daily mean concentration for each child according to the time spent at each place. PEFR was measured using peak expiratory flow meter at their class rooms (during week days) and homes (during weekend) between 8 and 9 AM for 6 consecutive days. We measured the children&amp;#8217;s heights and weights to calculate the body mass index (BMI), and a questionnaire was administered to obtain information on covariates. We constructed mixed linear model to examine the association adjusting for age (months), sex, BMI, environmental tobacco smoke exposure and monthly average household income.Result: A total of 115 observations were included in the present analysis. The daily average PM2.5 concentrations were between 38.6&amp;#177;11.6 and 67.3&amp;#177;15.8 &amp;#956;g/m3. The daily average PEFRs were between 266.1&amp;#177;48.57 and 276.2&amp;#177;48.86 L/min. The regression coefficient of PEFR (L/min) for the increment of 10 &amp;#956;g/m3 of daily mean concentration of PM2.5 was -2.27 (SE: 0.14, P-value: 0.098).Conclusion: We observed marginally significant adverse association between individually monitored PM2.5 concentration and PEFR in 9-year-old children.

Asthma knowledge, care, and outcome during pregnancy: The QAKCOP study.

Asthma is the most common chronic medical condition affecting pregnancy. Optimizing asthma management in pregnancy is paramount for the well-being of both the mother and the baby. The primary objectives of this study were to assess patient’s knowledge about asthma, the level of asthma care, and fetal and maternal outcomes among pregnant asthmatic women in this wealthy country with tremendous improvement in maternal and fetal health care. The secondary objective was to identify barriers to asthma control. This was a cross-sectional, face-to-face, prospective study of 80 pregnant women with physician-diagnosed asthma. About 56% of patients reported worsening of their asthma control during pregnancy, of which 52.3% felt this worsening in the third trimester. About 65% of patients had uncontrolled asthma during their pregnancy, and inhaler technique was incorrect in 64.4%. Only 38% of patients knew the difference between controller and reliever asthma medications, 12.7% of patients had received written asthma action plan, 17% had a spirometry done in the previous 5 years, and 3.8% had peak expiratory flow meter at home. The main reasons for uncontrolled asthma were lack of knowledge about right asthma medications in 30% and fear of side effects of inhaled corticosteroids in 19% of patients. No financial reason was reported. Significant associations between total number of pregnancies, poor perception of asthma medications, asthma exacerbation during delivery and poor asthma control were observed. Preeclampsia and congenital anomalies occurred at higher rates than previously reported among general population in this country. The tremendous improvements in maternal health care and socioeconomic status do not seem to be a barrier to the globally recognized poor asthma care in pregnancy. Important strategies are much needed.

Analysis of agreement between peak expiratory flow meters and comparison of reference values

Abstract Introduction: The peak expiratory flow (PEF) is a practical method that evaluates the caliber of the proximal airways. The ease in handling and the low cost of portable PEF meters made their use frequent. However, few studies have examined the correlation between the different equipment and compared their reference values. Objective: Analyze the correlation of three portable meters of PEF and check if the reference values are applicable in the studied population. Methods: 168 healthy individuals, of both genders, ranging in age from 20 to 80 years, had their PEF measured in Mini-Wright®, Assess® and AirZone® and the values obtained were compared to those predicted by Leiner et al. (1963) and Nunn and Gregg (1989). Statistical analysis was performed by the Kolmogorov-Smirnov tests, ANOVA, Wilcoxon test, Spearman correlation and analysis of agreement of Bland-Altman (p&lt; 0.05). Results: There was significant difference in the values of PEF obtained between the Mini-Wright® and Assess® meters in both genders, between the AirZone® and Assess® only in men and between the Mini-Wright® and AirZone® only in women. The predicted values in the three meters have overestimated the obtained in both genders; there was no correlation between the values obtained from three meters due to the great variation of agreement limits and large interindividual variation. Conclusion: The values obtained in the three meters are not interchangeable and the predicted values were unsuitable for the sample.

Evaluation of spirometry in asthmatic children

Background:The use of spirometry in the assessment of children with asthma is taking on new importance with the realization that considerable airway obstruction may exist in the absence of clinically detectable abnormalities. Hence this study was planned to evaluate, forced expired volume in 1 second (FEV1), forced vital capacity (FVC), the forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) and Peak Expiratory Flow rates (PEFR) in asthmatic children aged 6-12 years. The objective of the study was to determine prevalence of asthma according to clinical classification and identify common trigger factors and to determine which is more sensitive between FEV1, FVC, FEV1/FVC, FEF 25-75 and PEFR in different age groups.Methods: The present study was conducted among 60 patients of age group 6 to 12 years with asthma. Forced vital capacity (FVC), Forced expiratory volume in 1 second (FEV1), Ratio of forced expiratory volume in 1 second and forced vital capacity (FEV1/FVC), PEFR and Forced expiratory flow between 25-75% were recorded. Data was analyzed using chi-square test, Karl Pearson’s correlation coefficient. Level of significance was set at 5%. All p values less than 0.05 were treated as significant.Results:In Age and Sex wise correlation with classification of asthma, a male preponderance was seen in all the age groups i.e. between 6-8 years, 9-10 years and 11-12 years. Mosquito coils were the most common indoor agents to trigger an asthmatic accounting for nearly 80%. Amongst the outdoor triggers, exacerbation of symptoms during the cold weather accounted for 90 % followed by variation during festivals like Diwali, dust, pollution, exercise and insects. Comparison of Pre and Post bronchodilator FEF 25-75 values have shown a high statistical significance.Conclusions:Parents need to be educated regarding certain modifiable factors that can improve the prognosis. Pulmonary Function tests should be performed as a routine office procedure. Peak expiratory flow meter is a handy instrument. In all children above 6 years of age suspected to have asthma, this test should be performed before beginning therapy.

Guiding Inspiratory Flow: Development of the In-Check DIAL G16, a Tool for Improving Inhaler Technique.

Portable inhalers are divisible into those that deliver medication by patient triggering (pMDIs: a gentle slow inhalation) and those that use the patient's inspiratory effort as the force for deaggregation and delivery (DPIs: a stronger deeper inspiratory effort). Patient confusion and poor technique are commonplace. The use of training tools has become standard practice, and unique amongst these is an inspiratory flow meter (In-Check) which is able to simulate the resistance characteristics of different inhalers and, thereby, guide the patient to the correct effort. In-Check's origins lie in the 1960s peak expiratory flow meters, the development of the Mini-Wright peak flow meter, and inspiratory flow assessment via the nose during the 1970s–1980s. The current device (In-Check DIAL G16) is the third iteration of the original 1998 training tool, with detailed and ongoing assessments of all common inhaler resistances (including combination and breath-actuated inhaler types) summarised into resistance ranges that are preset within the device. The device works by interpolating one of six ranges with the inspiratory effort. Use of the tool has been shown to be contributory to significant improvements in asthma care and control, and it is being advocated for assessment and training in irreversible lung disease.

Peak expiratory flow rate of primary school children in high and low air pollution level areas

Background Chronic inhalation of air pollutants may causebronchoconstriction, bronchiolitis, and edema of airway, thus alterlung volume. To measure the lung volume, a simple lung functiontest, the peak expiratory flow rate (PEFR), can provide a feature oflung volume in liters/minute.Objective The purpose of this study was to measure PEFR val-ues of primary school children in a high air pollution level area(Medan) and compare the results with the PEFR values of those ina low air pollution level area (Tebing Tinggi).Methods A cross sectional study was conducted on primary schoolchildren (10-12 years of age) during May-July 2000 in Medan andTebing Tinggi. Data were obtained by questionnaires. Physical ex-amination included age, sex, height, weight, and PEFR value. PEFRvalues were measured by Mini Wright peak expiratory flow meter(MPFM) from three blows. The highest volume was taken as thePEFR value. Statistical analysis was done by t-test and p&lt;0.05was considered significant.Results There were 212 primary school children eligible for thisstudy; 107 came from the high air pollution level area and 105from the low air pollution level area. The PEFR values did not dif-fer significantly between the two groups (p&gt;0.05)Conclusion PEFR values in a high air population level area werenot statistically different compared with those in low air pollutionlevel area

Pattern of morbidity among female textile workers in Puducherry, South India

International Journal of Medicine and Public Health,2016,6,3,140-143.DOI:10.5530/ijmedph.2016.3.9Published:August 2016Type:Original ArticlePattern of morbidity among female textile workers in Puducherry, South IndiaPunitha Kumary P, Subitha L, and Gautam Roy Punitha Kumary. P*, Subitha L, Gautam Roy Department of Community Medicine, PSG Institute of Medical Science and Research, Peelamedu, Coimbatore- 641 004, Tamil Nadu, INDIA. Abstract:Introduction: The Indian textile industry is one of the largest in the world and accounts for 21% of the total employment generated in the Indian economy. The current burden of occupational health diseases is estimated to be around 18 million cases. Objectives: To study the pattern of diseases which are common among textile workers. Methods: A descriptive study was conducted among 179 women working in a textile industry in Puducherry. After obtaining informed consent, data was collected using a structured questionnaire. This was followed by systemic examination of Sensory systems (visual acuity testing using Snellen’s chart, hearing tests using Tuning fork), Respiratory system (using Peak Expiratory Flow Meter) and Musculoskeletal system (Straight leg raising test and others). Data was analyzed using SPSS version 19:IBM. Results: 70% of the participants belonged to the age group 21-40 years and more than half of the women were employed for 5-9 yrs. One fourth of the subjects had complaints of musculoskeletal problems such as joint pain, myalgia and chronic low backache. Respiratory infections and other complaints were also reported. Nearly 40% of the study subjects had myopia, 3% had abnormality in hearing and Peak Expiratory Flow Rate was reduced in 53% of cases. Conclusion: The present study shows that myopia is common among the workers, along with abnormal lung function, which indicates a need for, preplacement and periodic medical examination to rule out ophthalmic and pulmonary morbidities. Keywords:Female textile workers, Morbidity pattern, Pondicherry, South India, Visual problemsView:PDF (421.52 KB)

Smart phone‐based peak expiratory flow meter

The design and performance of a smart-phone-based device, called AudioFlow, that measures and records peak expiratory flow (PEF) is presented. PEF is a measure used by asthma sufferers to monitor their asthma conditions. The device is comprised of a custom 3D printed airtube and a minimal number of electronic components that communicate with a smartphone via a custom app. A pressure-dependent frequency signal generated when the user blows into the tube is sent to a smartphone app via the headphone jack. The custom designed app reads the signal and converts the frequency to a flow rate, which is displayed for the user to see and logged for condition tracking. The device has been validated with a commercial gas flow meter and is ready for human subject testing.

Reference Values for Peak Expiratory Flow Meter in Chinese Aged 4 to 80 Year

Reference Values for Peak Expiratory Flow Meter in Chinese Aged 4 to 80 Year

Study of PEFR in urban lower and middle class high school children at Bangalore, India

Background: Peak expiratory flow rate (PEFR) recording is an essential measure in the management and evaluation of asthmatic children. The PEFR can be measured by a simple instrument-peak expiratory flow meter. The aim of this study was to determine the normal PEFR in Urban lower and middle class high school children at Bangalore, India. Methods: The PEFR was measured in 1000 healthy urban school children living in Bangalore, India using the mini-wright peak flow meter. All measurements were obtained in a standing position and the best out of three trials was recorded. Anthropometric measurements, weight, height, and mid-upper-arm circumference (MAC) were recorded, and body surface area (BSA) and body mass index (BMI) were calculated. Results: Positive correlation was seen between age, height, weight and PEFR. The regression equations for PEFR were determined for boys and girls separately. The boys had higher values than the girls at all heights. The prediction equation for PEFR based on height was PEFR = 3.64 height (cm)-257.86 (R=0.47, R 2 =0.22) for female; PEFR = 4.7 height (cm)-346.51 (R=0.62, R 2 =0.38) for male. Conclusions: PEFR is a reliable measurement, which can be used routinely and regularly in urban areas for assessment of airway obstruction and prediction formula derived for use in this population.

Effects of fast expiration exercises without pressure on the respiratory muscle strength of healthy subjects.

[Purpose] The aim of this investigation was to determine the effects of 4 weeks of fast expiration exercises performed without pressure on respiratory muscle strength. [Subjects and Methods] Respiratory muscle strength of the training group that performed fast expiration exercises (n=12) was compared with that of a control group that performed no exercises (n=12). The fast expiration exercises were performed using a peak expiratory flow meter device and consisted of 20 fast expiration exercises performed 3 times per week for 4 weeks. Maximal expiratory and inspiratory pressures were evaluated as respiratory muscle strength using a spirometer pre- and post- intervention. [Results] There were significant increases in maximal expiratory pressure from 76.9 ± 29.1 to 96.1 ± 37.5 cmH2O and maximal inspiratory pressure from 80.8 ± 36.6 to 95.3 ± 37.6 cmH2O in the training group, but there was no significant difference in respiratory muscle strength between pre- and post-intervention in the control group. [Conclusion] Fast expiration exercises may be beneficial for increasing respiratory muscle strength. The findings of this study should be considered when prescribing a variation of the expiratory muscle strength training, as part of a pulmonary rehabilitation program.