Use Of Peak Expiratory Flow Research Articles

Utility of Routine Spirometry Measures for Surveillance of Idiopathic Subglottic Stenosis

Because of the recurrent nature of idiopathic subglottic stenosis, routine follow-up is necessary for monitoring progression of stenosis. However, no easily accessible, standardized objective measure exists to monitor disease progression. To determine whether peak expiratory flow (PEF) can be used as a reliable and easily accessible biometric indicator of disease progression relative to other validated spirometry measures in patients with idiopathic subglottic stenosis. Prospectively collected data on PEF, expiratory disproportion index (EDI), and total peak flow (TPF) from 42 women with idiopathic subglottic stenosis without comorbid lower airway or parenchymal lung disease who were treated at a single tertiary referral center between 2014 and 2018 were analyzed. The mean follow-up period was 18.2 months (range, 2-40 months). Ten patients initially screened were not included in the analysis owing to comorbid glottic or supraglottic stenosis or nonidiopathic etiology. Measurements of PEF, EDI, and TPF were taken at preoperative visits and at all other visits. Forty-two women (mean age, 51.5 years; 98% white [n = 41]) met the inclusion criteria. The area under the curve for PEF was 0.855 (95% CI, 0.784-0.926). The optimal cutoff value was 4.4 liters per second (264 L/min), with a sensitivity and specificity of 84.4% and 82.0%, respectively. The area under the curve for EDI was 0.853 (95% CI, 0.782-0.925). For TPF, this was 0.836 (95% CI, 0.757-0.916). This study provides evidence supporting the use of PEF as a simple, efficient, and accessible way of monitoring progression of idiopathic subglottic stenosis and predicting receipt of surgical intervention. Sensitivity and specificity of PEF were comparable to those of the more complex measures of TPF and EDI.

Peak expiratory flow among healthy children aged 5-14 years in China.

Guidelines of the Global Initiative for Asthma recommend the use of peak expiratory flow (PEF) in the assessment and management of patients with asthma. However, normal PEF values for Chinese children have not been thoroughly investigated. This was a cross-sectional study of 3,169 healthy children aged 5-14 years from research centers in five cities of China: Guangzhou, Suzhou, Chengdu, Xi'an, and Beijing. We established pediatric reference values for PEF using a mini peak flow meter. PEF values recorded by the mini peak flow meter were compared with those obtained using a spirometer. Height was the biometric variable with greatest correlation to PEF for both sexes. Significant differences were noted between males and females. The regression equation for boys was calculated as PEF =4.39× height (cm) -300.48 (R2 =0.76, P<0.001); for girls, this equation was PEF =4.13× height (cm) -278.04 (R2 =0.72, P<0.001). PEF values for Chinese children according to age were close to those of Irish, Turkish, and British children but were lower than those of children in Greece; PEF values according to height were similar to those of Turkish and Danish children but lower than values for children in Ireland. We established normal PEF values and developed predictive equations using linear regression analysis for Chinese children aged 5-14 years, while Greece and Ireland references were inappropriate for Chinese children.

How Well Does CAPTURE Translate?: An Exploratory Analysis of a COPD Case-Finding Method for Spanish-Speaking Patients

This study tested the properties of a Spanish translation of CAPTURE (COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk) with selective use of peak expiratory flow (PEF). This study comprised analyses of data from the Spanish-speaking cohort of the cross-sectional, case-control study used to develop CAPTURE. Translation procedures included forward and backward translation, reconciliation, and cognitive interviewing to assure linguistic and cultural equivalence, yielding CAPTURE-S. Spanish-speaking participants were recruited through one center and designated as case subjects (clinically significant COPD: FEV1≤ 60%predicted and/or at risk of COPD exacerbation) or control subjects (no or mild COPD). Subjects completed a questionnaire booklet that included 44 candidate items, the COPD Assessment Test (CAT), and the modified Medical Research Council (mMRC) dyspnea question. PEF and spirometry were also performed. The study included 30 participants (17 case subjects and 13 control subjects). Their mean (± SD) age was 62.6 (11.49) years, and 33%were male. CAPTURE-S scores were significantly correlated with PEF (r= -0.78), the FEV1/FVC ratio (r= -0.74), FEV1 (r= -0.69), FEV1 %predicted (r= -0.69), the CAT score (r= 0.70), and the mMRC dyspnea question (r= 0.59) (P< .0001), with significantly higher scores in case subjects than in control subjects (t= 6.16; P< .0001). PEF significantly correlated with FEV1 (r= 0.89), FEV1 %predicted (r= 0.79), and the FEV1/FVC ratio (r= 0.75) (P< .0001), with significantly lower PEF in case subjects than in control subjects (t= 5.08; P< .0001). CAPTURE-S score+ PEF differentiated case subjects and control subjects with a sensitivity of 88.2%and a specificity of 92.3%. CAPTURE-S with selective use of PEF seems to be useful for identifying Spanish-speaking patients in need of diagnostic evaluation for clinically significant COPD who may benefit from initiation of COPD treatment. ClinicalTrials.gov; No.: NCT01880177; URL: www.clinicaltrials.gov.

Los Angeles phonospirometry technique: creating a normogram that correlates with peak expiratory flow measurements in children

Objective: Measurement of peak expiratory flow (PEF) is recommended in the assessment of patients with asthma. However, the use of PEF involves multiple barriers, which have limited its use. Phonospirometry, as assessed by a novel Los Angeles phonospirometry technique, has shown good correlation to standard PEF measurements in a pilot study on symptomatic patients with asthma. We sought to develop a normogram for phonospirometry, and to validate the PEF normogram. Methods: A convenience sample of asymptomatic children ages 3–17 years old was approached for participation in the Emergency Department. Sample size calculations determined that at least 30 children per age group (n = 450) were needed. Children were asked to perform PEF measurements and phonospirometry, measured as the length of time (in s) the child was able to chant “lalala” in a single breath. Results: 510 children were enrolled. Spearman's rho between PEF and phonospirometry was 0.722. Phonospirometry correlated with both age and height, with a spearman rho of 0.697 and 0.696, respectively. This was slightly lower than the correlation of PEF with age and height with spearman rhos of 0.877 and 0.902, respectively. A normogram was developed for phonospirometry based on age and height. Conclusions: This study determined normal value ranges for the Los Angeles phonospirometry technique for age and height, and also showed that the technique has good correlation with PEF. This technique may be used to assess a pediatric patient with an acute asthma exacerbation.

Correlation of a Unique “Los Angeles” Phonospirometry Technique with Peak Expiratory Flows in Children with Asthma

Background. Measurement of peak expiratory flow (PEF) is recommended as part of the assessment of patients with asthma. However, there are multiple barriers in the use of PEF, even for older pediatric patients. Objective. Phonospirometry, as measured by the Los Angeles (LA) technique, was assessed and compared with standard PEF measurements in patients with asymptomatic and symptomatic asthma. Methods. A convenience sample of patients with asthma aged 8–17 years was enrolled from visits in the Allergy/Immunology Clinic and in the Emergency Department of Children’s Hospital Los Angeles. The phonospirometry technique was demonstrated, and the length of time the patient repeated the syllable “lah” continuously with the same breath was measured. After a brief interval of time to recover, the patient performed conventional PEF measurement. Results. Using the first observation for each patient in our study, the Pearson correlation coefficient between phonospirometry and PEF was r = 0.67, p = .0016 for asymptomatic asthma patients and r = 0.77, p < .0001 for symptomatic asthma patients. Analysis of the first and last measurements of the symptomatic asthma patients who had multiple measurements revealed a Pearson correlation coefficient between phonospirometry and PEF at first measurement r = 0.69, p = .0008 and at the last measurement r = 0.76, p < .0001. Conclusions. Using the LA technique, phonospirometry was shown to have a linear correlation with PEF in pediatric patients with asymptomatic and symptomatic asthma. It is simple and easily reproducible, as well as cross-cultural. This novel technique shows promise to aid the assessment of patients with acute asthma exacerbations.

Use of peak expiratory flow for assessing bronchodilator responsiveness

Lung function in 1686 adult patients was measured before, and 15 minutes after, salbutamol inhalation. Bronchodilator responsiveness (BDR) was defined as a 12% improvement over baseline in either FEV1 or FVC, along with an absolute volume increment of 200 ml. Peak expiratory flow (PEF) change, both absolute and relative to baseline, was also calculated (DeltaPEF and DeltaPEF%, respectively). Change in PEF significantly correlated with change in FEV1. However, DeltaPEF and DeltaPEF% had poor discrimination in identifying BDR, with all specific cutoff values for DeltaPEF and DeltaPEF% having low or moderate sensitivity, specificity and predictive values.

Peak expiratory flow as a predictor of subsequent disability and death in community-living older persons.

To determine whether peak expiratory flow (PEF), when expressed by a validated method using standardized residual (SR) percentile, is associated with subsequent disability and death in older persons. Prospective cohort study. New Haven, Connecticut. Seven hundred fifty-four initially nondisabled, community-living persons aged 70 and older. PEF was assessed at baseline along with chronic conditions and smoking history. The onset of persistent disability in activities of daily living (ADLs), continuous mobility disability, and death were ascertained during monthly interviews over a 5-year period. Participants' mean age was 78.4, 63.7% had a smoking history, and 17.4% reported chronic lung disease. The incidence rates per 100 person-months were 1.00 (95% confidence interval (CI)=0.90-1.12) for ADL disability, 0.80 (95% CI=0.70-0.93) for mobility disability, and 0.44 (95% CI=0.38-0.51) for death. At a PEF less than 10(th) SR percentile, identifying nearly one-quarter of the cohort, hazard ratios (HRs) adjusted for multiple confounders, including age, smoking, and chronic lung disease, demonstrated a greater risk of ADL disability (HR=1.79, 95% CI=1.23-2.62), mobility disability (HR=1.89, 95% CI=1.15-3.10), and death (HR=2.31, 95% CI=1.29-4.12). In an elderly cohort, it was found that low PEF, when expressed as an SR percentile, is independently associated with subsequent disability and death. These results support the use of PEF as a potentially valuable risk assessment tool in community-living older persons.

Increasing the Use of Anti-Inflammatory Agents for Acute Asthma in the Emergency Department: Experience with an Asthma Care Map

Acute asthma is a common emergency department (ED) presentation and variation in its management is well recognized. The present study examined the use of an asthma care map (ACM) in one Canadian ED to improve adherence to acute asthma guidelines, emphasizing the use of systemic corticosteroids (SCSs) and inhaled corticosteroids (ICSs). Three time periods were studied: the 15 months before ACM introduction (PRE), the 15 months following a three-month introduction of the ACM (POST(1)) and the 18 months after POST(1) (POST(2)). Randomly selected patient charts from each period were included from patients who were 18 to 60 years of age and presented with a primary diagnosis of acute asthma. A priori criteria were established to determine the degree of completion and success of the ACM. Primary outcomes included documentation, use of SCSs in the ED, and prescription of SCSs and ICSs at ED discharge. A total of 387 patient charts were included (PRE, n=150; POST(1), n=150; POST(2), n=87). Patient characteristics in the three groups were similar; however, patients in POST(1) and POST(2) showed higher use of newer agents than those in the PRE group. Overall, more women (n=209; 54%) than men were seen; the mean age was 32.4 years. The care map was used in 67% of cases during POST(1) and 70% during POST(2). The use of peak expiratory flow (PEF) was high during the PRE, POST(1) and POST(2) periods (91%, 89% and 91%, respectively); however, documentation of other markers of severity increased in the POST periods. Use of SCSs occurred earlier (P<0.01) and more often (57% PRE, 68% POST(1) and 75% POST(2); P<0.01) in the POST(1,2) periods than the PRE period. There was a significant increase in use of SCSs on discharge (55% PRE, 66% POST(1) and 69% POST(2); P<0.05), and prescription of ICSs significantly increased (24% PRE, 45% POST(1) and 61% POST(2); P<0.001) in the POST(1,2) periods. Discharge without any corticosteroids decreased over the three periods (32% PRE, 21% POST(1) and 17% POST(2); P<0.05). The length of stay in the ED increased over the study periods (181 min PRE, 209 min POST(1) and 265 min POST(2); P<0.01) and admissions were infrequent (9% PRE, 13% POST(1) and 6% POST(2); P=0.50). The present study provides evidence that the standardized ED ACM was widely accepted, improved chart documentation, improved some aspects of ED care and increased prescribing of discharge preventive medications.

Evaluation of physician and patient compliance with the use of peak flow meters in commercial insurance and Oregon health plan asthmatic populations

Home use of peak expiratory flow (PEF) meters is recommended by NIH management guidelines for patients with moderate to severe asthma. To evaluate whether differences in physician PEF meter prescription patterns and patient compliance rates with PEF meter use exist between populations of commercially insured and Oregon Health Plan (OHP) patients. A prospective, case-series study was conducted at the Bay Clinic Coos Bay, Oregon. Volunteers responded to a short survey. Patient asthma severity was evaluated by responses to the following questions: (1) frequency of shortness of breath per week, (2) daily and weekly frequency of albuterol rescue inhaler use, and (3) other prescription medications used. Additional questions included: (1) possession of a PEF meter, (2) physician instruction of meter use, (3) patient compliance with instructions, and (4) type of medical insurance. Using NIH asthma stratification guidelines, only respondents with moderate to severe asthma were included in this study. Respondents were age restricted to between 6 and 60 years. Incomplete surveys were not accepted. Ninety-six surveys were received and 54 accepted. Only 24 (44%) of the 54 respondents with moderate to severe asthma had a PEF meter. Nineteen (79%) used it according to physician instructions. Of the 29 patients reporting to have commercial insurance, 18 (62%) had a PEF meter and 15 (83%) used it as prescribed. Of the 21 asthmatic patients with OHP coverage, only 5 (24%) P = .007 had a peak flow meter and 4 (80%) used it as prescribed. We conclude physician prescription compliance of peak flow meters for asthma monitoring falls short of the NIH guidelines. When a PEF meter is prescribed, patients will likely use it regardless of their medical insurance. Significant differences exist in physician compliance with PEF meter prescription between populations of commercially insured and OHP patients. More study is necessary to further understand this divergence in care delivery.

Asthma education for Swedish primary care physicians--a study on the effects of "academic detailing" on practice and patient knowledge.

To assess the effect of an intervention on general practitioners' (GPs) knowledge about the diagnosis and treatment of asthma, including the prescribing of anti-asthmatic drugs, and asthmatic patients' knowledge about their disease. The study took place in the south-west region of Stockholm County. In the area where the intervention took place (area 1), 44 GPs at 21 health centres were visited by a clinical pharmacologist and a pharmacist presenting oral and written information. The basic messages were: (1) the central role of inhaled glucocorticoids; (2) the use of peak expiratory flow (PEF) meters; and (3) the use of reversibility tests. In the control area (area 2), there were 19 GPs at nine health centres. The GPs knowledge about the intervention message was evaluated by a questionnaire pre- and post-intervention. The ratios of prescribed inhaled be beta-adrenoceptor agonists to inhaled glucocorticoids were determined. At the 26 local pharmacies, all asthmatic patients who presented a prescription for anti-asthmatic drugs, issued at the 30 health centres, were given a questionnaire before and after the intervention regarding their knowledge of asthma and its treatment. GPs in area 1 showed significantly more knowledge about item numbers 2 and 3 in the above-described intervention message than did the GPs in the control area 2. The data on prescriptions showed lower ratios of beta-adrenoceptor agonists to glucocorticoids in area 1 than in area 2. The difference, however, between area 1 and area 2 was not significant. After the GP intervention, the patients' knowledge about asthma had increased in area 1, as assessed by the questionnaire filled in by the patients. However, there was no significant difference from that in area 2. The study shows differences between the intervention and control areas regarding the knowledge and practice of GPs after the intervention. We found changes in knowledge, attitudes and actual practice, the latter being measured by the prescriptions.