Peak expiratory flow (PEF) is a portable, reliable, and inexpensive method for lung function assessment. PEF can reflect expiratory airflow limitation and its variability can document reversibility, which provides an objective basis for the diagnosis of asthma in children. Short-term PEF monitoring can be an important aid in the management of acute asthma exacerbations, identification of possible triggers, and assessment of response to treatment. Long-term PEF monitoring can assist in the assessment of asthma control and warning of acute exacerbations, and this is useful for children with severe asthma. This article reviews the measurements, influencing factors, interpretation, and application of PEF, and its role in the diagnosis and management of asthma in children, to provide references for the clinical application of PEF in children.
Asthma/therapy* ; Child ; Humans ; Peak Expiratory Flow Rate ; Respiratory Function Tests

OBJECTIVES: The aim of this study was to evaluate pulmonary function in patients with mandibular fractures and to determine the pattern of pulmonary functions in these patients.MATERIALS AND METHODS: This was a cross-sectional study of pulmonary functions in Nigerian non-smoking patients with isolated mandibular fractures managed at our health institution from December 2015 to June 2017. Forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), peak expiratory flow rate (PEFR), and ratio of FEV₁ to FVC (FEV₁/FVC) were measured for all participants using a portable spirometer just before treatment. The pulmonary indices were compared with the predicted reference values for Nigerians to determine the respiratory pattern.RESULTS: Forty participants consisting of six females (15.0%) and thirty-four males (85.0%) with a female to male ratio of 1:5.7 were included in this study. The mean patient age was 34.5±13.1 years (range, 17–63 years). The mean FVC, FEV₁, FEV₁/FVC, and PEFR were 3.8±1.2 L, 3.0±1.0 L, 74.3%±13.8%, and 5.2±2.2 L/s, respectively. Comparison of data with predicted values revealed that 17 subjects (42.5%) had normal pulmonary function pattern while 23 subjects (57.5%) had features suggestive of obstructive and restrictive pulmonary function patterns.CONCLUSION: Isolated mandibular fractures presented with abnormal pulmonary function pattern.
Airway Obstruction ; Cross-Sectional Studies ; Female ; Forced Expiratory Volume ; Humans ; Male ; Mandibular Fractures ; Peak Expiratory Flow Rate ; Reference Values ; Spirometry ; Vital Capacity

BACKGROUND: Despite growing concern over occupational exposure to particulate matter (PM) such as grain dust and diesel exhaust, information about the exposure level and health implications among workers in small-scale milling enterprises in developing countries like Nigeria has not been adequately documented. The purpose of this study was to assess the level of exposure to grain dust and diesel exhaust and effect on lung function among grain millers in food markets in Ibadan metropolis, Nigeria. METHODS: The study adopted descriptive cross-sectional design with a comparative approach. Sixteen grain milling shops each were randomly selected from two major food markets in Ibadan metropolis for indoor PM₁₀ and PM(2.5) monitoring. Seventy-two respondents each were proportionately selected from grain millers and shop owners for forced expiratory volume in one second and peak expiratory flow rate tests. RESULTS: The PM(2.5) concentrations for both market locations ranged between 1,269.3 and 651.7 μg/m³, while PM₁₀ concentrations were between 1,048.2 and 818.1 μg/m³. The recorded concentrations exceeded the World Health Organization guideline limit of 50 μg/m³ and 25 μg/m³ for PM(2.5) and PM₁₀, respectively. As compared with control group (2.1 L), significantly lower forced expiratory volume in one second value (1.61 L) was observed among the exposed group (p < 0.05). Likewise, significantly lower peak expiratory flow rate value (186.7 L/min) was recorded among the exposed group than the control group (269.51 L/min) (p < 0.05). CONCLUSION: Exposure to grain dust and diesel exhaust accentuated respiratory disorders with declines in lung functions amongst grain millers. Improved milling practices and engaging cleaner milling facilities should be adopted to minimize exposure and related hazards.
Developing Countries ; Dust ; Forced Expiratory Volume ; Lung ; Nigeria ; Occupational Exposure ; Particulate Matter ; Peak Expiratory Flow Rate ; Surveys and Questionnaires ; Vehicle Emissions ; World Health Organization

OBJECTIVE: We investigated the opinions of experts to identify problems and prepare an improvement plan when applying the Korean Triage and Acuity Scale (KTAS) to pediatric patients in the emergency department. METHODS: The experts comprised 15 researchers at a pediatric emergency center designated by the Ministry of Health and Welfare and research team members of the Korean Society of Pediatric Emergency Medicine. The first survey was an open-ended question about the problems, application results, and remedies of applying KTAS to children through e-mail. The problems were categorized by topic, and degree of agreement was presented using a 9-point Likert scale. RESULTS: In the first survey, 67% of experts participated and 18 problems were identified. In the second survey, 73% of experts participated and eight problems were identified in four categories, validity, reliability, feasibility and other opinions. All experts pointed out that resources were not considered during pediatric triage in the KTAS. Ninety-one percent of experts said that peak expiratory flow rate measurement and Glasgow Coma Scale evaluation were unlikely to be feasible. Moreover, 91% experts were concerned that the triage level could be distorted if KTAS was interlocked with medical costs. Eighty-two percent of the respondents pointed to the high triage result of febrile children and the difference in pain score between the evaluators, etc. CONCLUSION: Based on the problems pointed out by experts and the reality of Korea's emergency departments, it is necessary to consider revision of KTAS for children.
Child ; Delphi Technique ; Electronic Mail ; Emergencies ; Emergency Medicine ; Emergency Service, Hospital ; Glasgow Coma Scale ; Humans ; Peak Expiratory Flow Rate ; Surveys and Questionnaires ; Triage

OBJECTIVE: The head-tilt/chin-lift (HT/CL) is a simple, routinely used maneuver to open the upper airway. Changes in the peak expiratory flow rate (PEFR) before and after the HT/CL maneuver have not been evaluated among conscious volunteers who are regarded as a control cohort.METHODS: Sixty healthy 20-year-old volunteers (30 males and 30 females) were enrolled. The supine position was defined as the position at which the ear-eye line was at a 10° angle to the horizontal. The HT/CL position was defined as the position at which the ear-eye line was at a 25° angle to the horizontal. PEFR was measured using a hand-held device with the subject in the supine position (pre-PEFR) and HT/CL position (post-PEFR), respectively. One set was defined as these two measurements. Five sets of measurements were performed on each subject (300 sets). The set with the maximal and minimal difference between pre-PEFR and post-PEFR were excluded from the analysis. We used a paired t-test to compare the mean pre-PEFR and post-PEFR values for the entire group and subgroups divided by sex, height, body weight, body mass index and response status.RESULTS: Overall, 360 measurements (180 sets) were analyzed. The mean pre-PEFR and post-PEFR were 316.1±87.6 and 346.5±94.7 L/min, respectively. Further, significant differences were observed for sex, height, body weight, and body mass index. In 10 subjects, post-PEFR was lower than pre-PEFR.CONCLUSION: PEFR increased by 9.6% after the HT/CL maneuver in young conscious subjects, but some subjects showed decreased PEFR after the HT/CL maneuver.
Airway Management ; Body Height ; Body Mass Index ; Body Weight ; Cohort Studies ; Humans ; Male ; Peak Expiratory Flow Rate ; Supine Position ; Volunteers ; Young Adult

OBJECTIVE: To investigate the relationship between peak cough flow (PCF), pulmonary function tests (PFT), and severity of dysphagia in patients with ischemic stroke. METHODS: This study included patients diagnosed with ischemic stroke, who underwent videofluoroscopic swallowing study (VFSS), PCF and PFT from March 2016 to February 2017. The dysphagia severity was assessed using the videofluoroscopic dysphagia scale (VDS). Correlation analysis of VDS, PFT and PCF was performed. Patients were divided into three groups based on VDS score. One-way ANOVA of VDS was performed to analyze PCF, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and age among the different groups. RESULTS: The correlation coefficients of VDS and PCF, VDS and FVC, and VDS and FEV1 were -0.836, -0.508, and -0.430, respectively, all of which were statistically significant at the level of p < 0.001. The one-way ANOVA indicated statistically significant differences in PCF, FVC, FEV1, and age among the VDS groups. Statistically significant differences in VDS and age were observed between aspiration pneumoia and non-aspiration pneumonia groups. CONCLUSION: Coughing is a useful factor in evaluating the risk of aspiration in dysphagia patients. Evaluation of respiratory and coughing function should be conducted during the swallowing assessment of patients with ischemic stroke.
Cough* ; Deglutition ; Deglutition Disorders* ; Forced Expiratory Volume ; Humans ; Peak Expiratory Flow Rate ; Pneumonia ; Respiratory Function Tests ; Stroke* ; Vital Capacity

OBJECTIVETo investigate the changes of pulmonary function and fractional exhaled nitric oxide (FeNO) in the standardized treatment of bronchial asthma in children.

METHODSA total of 254 children who were newly diagnosed with acute exacerbation of bronchial asthma were selected as asthma group, and they were divided into two subgroups: asthma with concurrent rhinitis and asthma without concurrent rhinitis. All patients received the standardized management and treatment for one year. The pulmonary function parameters included forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), maximal mid-expiratory flow (MMEF), and mid-expiratory flow at 25%, 50%, and 75% of vital capacity (MEF25, MEF50, and MEF75). The FeNO levels were measured before treatment and at 3, 6, 9, and 12 months after treatment. Another 62 healthy children were selected as the control group, and the pulmonary function and FeNO levels were measured only once.

RESULTSDuring one year of standardized treatment, FEV1, PEF, MMEF, MEF25, MEF50, and MEF75 gradually increased, and FeNO levels gradually decreased (P<0.05). Indicators of large airway function, such as FEV1 and PEF, almost returned to normal after 6 months of treatment; indicators of small airway function, such as MMEF, MEF25, MEF50, and MEF75 almost returned to normal after 9 months of treatment; there were no significant differences in the above indices between the asthma group and the control group after one year of treatment (P>0.05). However, the asthma group had a significantly higher FeNO levels than the control group after one year of treatment (P<0.05). The asthmatic patients with concurrent rhinitis had significantly higher FeNO levels than those without concurrent rhinitis before treatment and 3 months after treatment (P<0.05). Before treatment, there was a significant negative correlation between FeNO levels and pulmonary function parameters (P<0.05).

CONCLUSIONSWith the standardized treatment of bronchial asthma in children, pulmonary function parameters gradually increase and FeNO levels gradually decrease. The recovery of large airway function occurs earlier than the recovery of small airway function. Furthermore, the effect of rhinitis on airway responsiveness should be noted.

Asthma ; physiopathology ; therapy ; Breath Tests ; Child ; Female ; Forced Expiratory Volume ; Humans ; Lung ; physiopathology ; Male ; Maximal Midexpiratory Flow Rate ; Nitric Oxide ; analysis ; Rhinitis ; physiopathology

BACKGROUND: Tasks involved in traditional charcoal production expose workers to various levels of charcoal dust and wood smoke. This study aimed to identify specific tasks influencing lung function and respiratory symptoms. METHODS: Interviews, direct observation, and task/symptom checklists were used to collect data from 50 charcoal-production workers on 3 nonwork days followed by 11 workdays. The peak expiratory flow rate (PEFR) was measured four times per day. RESULTS: The PEFR was reduced and the prevalence of respiratory symptoms increased over the first 6–7 workdays. The PEFR increased until evening on nonwork days but not on workdays. Loading the kiln and collecting charcoal from within the kiln markedly reduced the PEFR and increased the odds of respiratory symptoms. CONCLUSION: Tasks involving entry into the kiln were strongly associated with a short-term drop in the PEFR and the occurrence of respiratory symptoms, suggesting a need for the use of protective equipment and/or the operation of an effective kiln ventilation system.
Charcoal ; Checklist ; Dust ; Lung* ; Peak Expiratory Flow Rate ; Prevalence ; Smoke ; Ventilation ; Wood

BACKGROUNDStudies of interleukin (IL)-4 and IL-6 in the exhaled breath condensate (EBC) of asthmatic patients are limited. This study was to determine the effect of inhaled corticosteroid (ICS) treatment on IL-4 and IL-6 in the EBC of asthmatic patients.

METHODSIn a prospective, open-label study, budesonide 200 μg twice daily by dry powder inhaler was administered to 23 adult patients with uncontrolled asthma (mean age 42.7 years) for 12 weeks. Changes in asthma scores, lung function parameters (forced expiratory volume in 1 s [FEV1], peak expiratory flow [PEF], forced expiratory flow at 50% of forced vital capacity [FEF50], forced expiratory flow at 75% of forced vital capacity, maximum mid-expiratory flow rate) and the concentrations of IL-4 and IL-6 in EBC were measured.

RESULTSBoth asthma scores and lung function parameters were significantly improved by ICS treatment. The mean IL-4 concentration in the EBC was decreased gradually, from 1.92 ± 0.56 pmol/L before treatment to 1.60 ± 0.36 pmol/L after 8 weeks of treatment (P < 0.05) and 1.54 ± 0.81 pmol/L after 12 weeks of treatment (P < 0.01). However, the IL-6 concentration was not significantly decreased. The change in the IL-4 concentration was correlated with improvements in mean FEV1, PEF and FEF50 values (correlation coefficients -0.468, -0.478, and -0.426, respectively).

CONCLUSIONSThe concentration of IL-4 in the EBC of asthmatic patients decreased gradually with ICS treatment. Measurement of IL-4 in EBC could be useful to monitor airway inflammation in asthmatics.

Administration, Inhalation ; Adult ; Asthma ; drug therapy ; physiopathology ; Breath Tests ; Budesonide ; administration & dosage ; Female ; Forced Expiratory Volume ; Humans ; Interleukin-4 ; analysis ; Interleukin-6 ; analysis ; Male ; Middle Aged ; Peak Expiratory Flow Rate ; Prospective Studies

The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC > or = 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD.
Aged ; Dyspnea/diagnosis/physiopathology ; Exercise Test ; Exercise Tolerance ; Female ; Forced Expiratory Flow Rates/physiology ; Forced Expiratory Volume ; Humans ; Lung/*physiopathology ; Male ; Middle Aged ; Prognosis ; Pulmonary Disease, Chronic Obstructive/*diagnosis/mortality/physiopathology ; Pulmonary Emphysema/*diagnosis/mortality/physiopathology ; Republic of Korea ; Residual Volume/*physiology ; Respiratory Function Tests ; Surveys and Questionnaires ; Total Lung Capacity/*physiology ; Vital Capacity ; Walking/physiology