The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
M R Miller - One of the best experts on this subject based on the ideXlab platform.
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Peak Expiratory Flow profiles delivered by pump systems limitations due to wave action
American Journal of Respiratory and Critical Care Medicine, 2000Co-Authors: M R Miller, Barrie Jones, Yong Xu, Philip H QuanjerAbstract:Pump systems are currently used to test the performance of both spirometers and Peak Expiratory Flow (PEF) meters, but for certain Flow profiles the input signal (i.e., requested profile) and the output profile can differ. We developed a mathematical model of wave action within a pump and compared the recorded Flow profiles with both the input profiles and the output predicted by the model. Three American Thoracic Society (ATS) Flow profiles and four artificial Flow-versus-time profiles were delivered by a pump, first to a pneumotachograph (PT) on its own, then to the PT with a 32-cm upstream extension tube (which would favor wave action), and lastly with the PT in series with and immediately downstream to a mini-Wright Peak Flow meter. With the PT on its own, recorded Flow for the seven profiles was 2.4 ± 1.9% (mean ± SD) higher than the pump's input Flow, and similarly was 2.3 ± 2.3% higher than the pump's output Flow as predicted by the model. With the extension tube in place, the recorded Flow was 6.6...
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gas compression in lungs decreases Peak Expiratory Flow depending on resistance of Peak Flowmeter
Journal of Applied Physiology, 1997Co-Authors: O F Pedersen, T F Pedersen, M R MillerAbstract:Pedersen, O. F., T. F. Pedersen, and M. R. Miller. Gas compression in lungs decreases Peak Expiratory Flow depending on resistance of Peak Flowmeter. J. Appl. Physiol. 83(5): 1517–1521, 1997.—It ha...
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Peak Expiratory Flow conclusions and recommendations of a working party of the european respiratory society
The European respiratory journal. Supplement, 1997Co-Authors: Philip H Quanjer, M R Miller, I Gregg, O F PedersenAbstract:The use of Peak Flow meters has been widely adopted for monitoring patients with asthma. The Working Party of the European Respiratory Society (ERS) has solely addressed technical and physiological issues relating to Peak Expiratory Flow (PEF) (Flow describes the rate of change of volume (volume rate), so that Flow rate is equivalent to volume acceleration. Hence, PEF should be used in preference to Peak Expiratory Flow rate (PEFR)). Monitoring schemes, or comparison of PEF with other indices, such as the forced Expiratory volume in one second (FEV1), do not form part of these recommendations. Measurements of PEF are of value in identifying airFlow limitation. The correlation between airFlow and symptoms is variable, some patients being poor perceivers of changes in airway patency, whereas others quickly perceive small changes [1‐6]. Recording the PEF is, therefore, of value in clinical practice where it can be helpful in monitoring the progress of airFlow limitation and the effects of treatment, and in epidemiological and occupational studies for identifying the presence of airFlow limitation, assessing its severity and variation. Various types of instrument can be used to measure PEF, including pneumotachometers, spirometers, turbines and anemometers. By far the most suitable and commonly used instruments in clinical practice are Flow meters which measure PEF only and, hence, may be referred to as Peak Flow meters. Since they are massproduced, they are relatively inexpensive; furthermore, they are portable and do not require electrical power for their operation. Most handheld Peak Flow meters employ the principle of a variable orifice to measure airFlow indirectly. The pressure exerted by a forced expiration causes a diaphragm or vane to move and, in so doing, to open a progressively larger area of the orifice. The point at which no further movement of the diaphragm occurs depends on the maximal pressure and, hence, on the Peak Expiratory Flow that has been generated.
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Peak Expiratory Flow and the resistance of the mini wright Peak Flow meter
European Respiratory Journal, 1996Co-Authors: O F Pedersen, Torben Riis Rasmussen, Oyvind Omland, Torben Sigsgaard, P H Quanjer, M R MillerAbstract:The purpose of this study was to examine whether the resistance of the Peak Flow meter influences its recordings. One hundred and twelve subjects, (healthy nonsmokers and smokers and subjects with lung diseases) performed three or more Peak Expiratory Flow (PEF) manoeuvres through a Fleisch pneumotachograph with and without a mini-Wright Peak Flow meter added in random order as a resistance in series. The results were as follows. In comparison with a pneumotachograph alone, Peak Flow measured with an added mini-Wright meter had a smaller within-test variation, defined as the difference between the highest and second highest values of PEF in a series of blows. The mean (SE) variation was 14 (1.3) L.min-1 and 19 (1.5) L.min-1 with and without meter added, respectively. In comparison with the pneumotachograph alone, the addition of the mini-Wright meter caused PEF to be underread, especially at high Flows. The difference (PEF with meter minus PEF without meter) = -0.064 (average PEF) -8 L.min-1; R2 = 0.13. The mean difference was -7.8 (1.1) %, and increased numerically for a given PEF, when maximal Expiratory Flow when 75% forced vital capacity remains to be exhaled (MEF75%FVC) decreased. The reproducibility criteria for repeated measurements of Peak Flow are more appropriately set at 30 L.min-1 than the commonly used 20 L.min-1, because a within-test variation of less than 30 L.min-1 was achieved in 76% of the subjects without PEF meter inserted and in 88% with meter inserted, with no difference between healthy untrained subjects and patients. The resistance of the Peak Expiratory Flow meter causes less variation in recordings but reduces Peak Expiratory Flow, especially at high values and when the Peak is large as compared with the rest of the maximal Expiratory Flow-volume curve.
P S Burge - One of the best experts on this subject based on the ideXlab platform.
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effect of Peak Expiratory Flow data quantity on diagnostic sensitivity and specificity in occupational asthma
European Respiratory Journal, 2004Co-Authors: W Anees, P F G Gannon, V Huggins, C F A Pantin, P S BurgeAbstract:Serial Peak Expiratory Flow records are recommended in the first-line investigation of suspected occupational asthma. The effects of sequentially reducing the numbers of working weeks, consecutive days at work and readings taken per day on diagnostic sensitivity and specificity were investigated, using good quality Peak Expiratory Flow records from 81 workers with independently confirmed occupational asthma and 60 asthmatics without occupational exposure. Sensitivity was 81.8% for records of 4 weeks' duration and 70% for those of 2 weeks' duration (specificity 93.8 and 82.4% respectively). The sensitivity fell to 56.7% if there were only 2 consecutive workdays in each work period. Although best at 8 readings x day(-1), sensitivity and specificity were acceptable with four daily readings (82.4 and 87%). The effect of defining a record as being of adequate quality if it was of > or = 2.5 weeks' duration, with > or = 4 readings x day(-1) and > or = 3 consecutive workdays in each work period, was tested in records not used in the initial data reduction process. The sensitivity and specificity respectively of adequate records were 78.1 and 91.8 versus 63.6 and 83.3% for inadequate records. Peak Expiratory Flow records for the diagnosis of occupational asthma should be interpreted with caution if they do not satisfy the suggested minimum data quantity criteria.
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effect of Peak Expiratory Flow data quantity on diagnostic sensitivity and specificity in occupational asthma
European Respiratory Journal, 2004Co-Authors: W Anees, P F G Gannon, V Huggins, C F A Pantin, P S BurgeAbstract:Serial Peak Expiratory Flow records are recommended in the first-line investigation of suspected occupational asthma. The effects of sequentially reducing the numbers of working weeks, consecutive days at work and readings taken per day on diagnostic sensitivity and specificity were investigated, using good quality Peak Expiratory Flow records from 81 workers with independently confirmed occupational asthma and 60 asthmatics without occupational exposure. Sensitivity was 81.8% for records of 4 weeks' duration and 70% for those of 2 weeks' duration (specificity 93.8 and 82.4% respectively). The sensitivity fell to 56.7% if there were only 2 consecutive workdays in each work period. Although best at 8 readings·day−1, sensitivity and specificity were acceptable with four daily readings (82.4 and 87%). The effect of defining a record as being of adequate quality if it was of ≥2.5 weeks' duration, with ≥4 readings·day−1 and ≥3 consecutive workdays in each work period, was tested in records not used in the initial data reduction process. The sensitivity and specificity respectively of adequate records were 78.1 and 91.8 versus 63.6 and 83.3% for inadequate records. Peak Expiratory Flow records for the diagnosis of occupational asthma should be interpreted with caution if they do not satisfy the suggested minimum data quantity criteria. This study was funded by the European Chemical Industry Council, Brussels, Belgium. W. Anees is also supported by a grant from the Colt foundation, Havant, UK.
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Development of an expert system for the interpretation of serial Peak Expiratory Flow measurements in the diagnosis of occupational asthma. Midlands Thoracic Society Research Group.
Occupational and environmental medicine, 1999Co-Authors: P S Burge, P F G Gannon, C F A Pantin, D. T. Newton, P. Bright, John Belcher, J. Mccoach, David R Baldwin, C. B. S. G. BurgeAbstract:If asthma is due to work exposures there must be a relation between these exposures and the asthma. Asthma causes airway hyperresponsiveness and obstruction; the obstruction can be measured with portable meters, which usually measure Peak Expiratory Flow, or sometimes forced Expiratory volume in 1 second (FEV1). These can be measured serially (for instance 2 hourly) over several weeks at and away from work. Once occupational asthma develops, the asthma will be induced by many non-specific triggers common to non-occupational asthma. The challenge is to identify changes in Peak Expiratory Flow due to work among other non-occupational causes. Standard statistical tests have been found to be insensitive or non-specific, principally because of the variable period for deterioration to occur after exposure, and the sometimes prolonged time for recovery to occur, such that days away from work may initially have lower measurements than days at work. A computer assisted diagnostic aid (Oasys) has been developed to separate occupational from non-occupational causes of airFlow obstruction. Oasys-2 is based on a discriminant analysis, and achieved a sensitivity of 75% and a specificity of at least 94%; therefore Peak Expiratory Flow monitoring combined with Oasys-2 analysis is better to confirm than to exclude occupational asthma. A neural network version in development has improved on this. Both have been based on expert interpretation of Peak Flow measurements plotted as daily maximum, mean, and minimum, with the first reading at work taken as the first reading of the day. Oasys has been evaluated with independent criteria against measurements made in a wide range of occupational situations. Oasys is sufficiently developed to be the initial method for the confirmation, although less so for exclusion of occupational asthma.
Pedro Gonzalezsantos - One of the best experts on this subject based on the ideXlab platform.
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asthma self management education program by home monitoring of Peak Expiratory Flow
American Journal of Respiratory and Critical Care Medicine, 1995Co-Authors: Jose M Ignaciogarcia, Pedro GonzalezsantosAbstract:A prospective controlled trial of home monitoring of Peak Expiratory Flow rate (PEFR) was conducted to determine the usefulness of an objective measure of lung function in association with an education program and a medication self-management plan in reducing morbidity in adult patients with asthma. Thirty-five patients managed themselves, using Peak Flow readings as the basis for the therapeutic plan coupled with educational intervention, whereas 35 control patients used symptoms and spirometric data for following physicians' treatment plans. After a 6-mo study period, patients in the experimental group showed statistically significant improvements in morbidity parameters (days lost from work, acute asthma attacks, days on antibiotic therapy, physician consultations, and emergency room admissions for asthma), increases in FVC, FEV1, and FEV1/FVC, mean PEFR and mean morning PEFR, decrease in percentage of the mean PEFR amplitude, and a reduction in the use of inhaled beta-agonists, oral theophylline, and ...
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asthma self management education program by home monitoring of Peak Expiratory Flow
American Journal of Respiratory and Critical Care Medicine, 1995Co-Authors: Jose M Ignaciogarcia, Pedro GonzalezsantosAbstract:A prospective controlled trial of home monitoring of Peak Expiratory Flow rate (PEFR) was conducted to determine the usefulness of an objective measure of lung function in association with an education program and a medication self-management plan in reducing morbidity in adult patients with asthma. Thirty-five patients managed themselves, using Peak Flow readings as the basis for the therapeutic plan coupled with educational intervention, whereas 35 control patients used symptoms and spirometric data for following physicians' treatment plans. After a 6-mo study period, patients in the experimental group showed statistically significant improvements in morbidity parameters (days lost from work, acute asthma attacks, days on antibiotic therapy, physician consultations, and emergency room admissions for asthma), increases in FVC, FEV1, and FEV1/FVC, mean PEFR and mean morning PEFR, decrease in percentage of the mean PEFR amplitude, and a reduction in the use of inhaled beta-agonists, oral theophylline, and oral prednisone. Although improvements in some of these parameters were also found in the control group, they did not reach the levels of significance obtained in the experimental group. The personal use of an objective measure of lung function in association with a medication self-management plan leads to improvement in the patient's condition.
O F Pedersen - One of the best experts on this subject based on the ideXlab platform.
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gas compression in lungs decreases Peak Expiratory Flow depending on resistance of Peak Flowmeter
Journal of Applied Physiology, 1997Co-Authors: O F Pedersen, T F Pedersen, M R MillerAbstract:Pedersen, O. F., T. F. Pedersen, and M. R. Miller. Gas compression in lungs decreases Peak Expiratory Flow depending on resistance of Peak Flowmeter. J. Appl. Physiol. 83(5): 1517–1521, 1997.—It ha...
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Peak Expiratory Flow conclusions and recommendations of a working party of the european respiratory society
The European respiratory journal. Supplement, 1997Co-Authors: Philip H Quanjer, M R Miller, I Gregg, O F PedersenAbstract:The use of Peak Flow meters has been widely adopted for monitoring patients with asthma. The Working Party of the European Respiratory Society (ERS) has solely addressed technical and physiological issues relating to Peak Expiratory Flow (PEF) (Flow describes the rate of change of volume (volume rate), so that Flow rate is equivalent to volume acceleration. Hence, PEF should be used in preference to Peak Expiratory Flow rate (PEFR)). Monitoring schemes, or comparison of PEF with other indices, such as the forced Expiratory volume in one second (FEV1), do not form part of these recommendations. Measurements of PEF are of value in identifying airFlow limitation. The correlation between airFlow and symptoms is variable, some patients being poor perceivers of changes in airway patency, whereas others quickly perceive small changes [1‐6]. Recording the PEF is, therefore, of value in clinical practice where it can be helpful in monitoring the progress of airFlow limitation and the effects of treatment, and in epidemiological and occupational studies for identifying the presence of airFlow limitation, assessing its severity and variation. Various types of instrument can be used to measure PEF, including pneumotachometers, spirometers, turbines and anemometers. By far the most suitable and commonly used instruments in clinical practice are Flow meters which measure PEF only and, hence, may be referred to as Peak Flow meters. Since they are massproduced, they are relatively inexpensive; furthermore, they are portable and do not require electrical power for their operation. Most handheld Peak Flow meters employ the principle of a variable orifice to measure airFlow indirectly. The pressure exerted by a forced expiration causes a diaphragm or vane to move and, in so doing, to open a progressively larger area of the orifice. The point at which no further movement of the diaphragm occurs depends on the maximal pressure and, hence, on the Peak Expiratory Flow that has been generated.
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Peak Expiratory Flow and the resistance of the mini wright Peak Flow meter
European Respiratory Journal, 1996Co-Authors: O F Pedersen, Torben Riis Rasmussen, Oyvind Omland, Torben Sigsgaard, P H Quanjer, M R MillerAbstract:The purpose of this study was to examine whether the resistance of the Peak Flow meter influences its recordings. One hundred and twelve subjects, (healthy nonsmokers and smokers and subjects with lung diseases) performed three or more Peak Expiratory Flow (PEF) manoeuvres through a Fleisch pneumotachograph with and without a mini-Wright Peak Flow meter added in random order as a resistance in series. The results were as follows. In comparison with a pneumotachograph alone, Peak Flow measured with an added mini-Wright meter had a smaller within-test variation, defined as the difference between the highest and second highest values of PEF in a series of blows. The mean (SE) variation was 14 (1.3) L.min-1 and 19 (1.5) L.min-1 with and without meter added, respectively. In comparison with the pneumotachograph alone, the addition of the mini-Wright meter caused PEF to be underread, especially at high Flows. The difference (PEF with meter minus PEF without meter) = -0.064 (average PEF) -8 L.min-1; R2 = 0.13. The mean difference was -7.8 (1.1) %, and increased numerically for a given PEF, when maximal Expiratory Flow when 75% forced vital capacity remains to be exhaled (MEF75%FVC) decreased. The reproducibility criteria for repeated measurements of Peak Flow are more appropriately set at 30 L.min-1 than the commonly used 20 L.min-1, because a within-test variation of less than 30 L.min-1 was achieved in 76% of the subjects without PEF meter inserted and in 88% with meter inserted, with no difference between healthy untrained subjects and patients. The resistance of the Peak Expiratory Flow meter causes less variation in recordings but reduces Peak Expiratory Flow, especially at high values and when the Peak is large as compared with the rest of the maximal Expiratory Flow-volume curve.
J A Jellicoe - One of the best experts on this subject based on the ideXlab platform.
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transcutaneous electrical nerve stimulation after thoracotomy pain relief and Peak Expiratory Flow rate a trial of transcutaneous electrical nerve stimulation
Anaesthesia, 2007Co-Authors: J F Stubbing, J A JellicoeAbstract:Summary Forty patients scheduled to undergo thoracotomy were randomly allocated to receive either transcutaneous electrical nerve stimulation with intramuscular papaveretum (20 patients) or intramuscular papaveretum alone (20 patients) for postoperative pain relief. Total intramuscular analgesic requirements in the first 24 hours, time to satisfactory transfer to oral analgesia, antiemetic requirements and length of stay in hospital postoperatively were noted. Peak Expiratory Flow rate was compared pre-and postoperatively in the two groups. Use of nerve stimulation did not significantly alter the requirements for analgesia although there was a reduction in postoperative nausea and vomiting in the nerve stimulation group. There was no difference between the two groups with respect to changes in Peak Expiratory Flow rate.