OBJECTIVE: To study the percentage of the measured values of the main pulmonary ventilation function parameters in their predicted values based on Zapletal equation among healthy children aged 5-14 years in Kunming, China, and to provide a basis for accurate judgment of pulmonary ventilation function in clinical practice. METHODS: A total of 702 healthy children aged 5-14 years (352 boys and 350 girls) from Kunming were enrolled. The Jaeger spirometer was used to measure the nine indices:forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), maximal mid-expiratory flow (MMEF), forced expiratory flow at 25% of forced vital capacity (FEF25), forced expiratory flow at 50% of forced vital capacity (FEF50), forced expiratory flow at 75% of forced vital capacity (FEF75), peak expiratory flow (PEF), and maximal voluntary ventilation (MVV). The values obtained from the Zapletal equation of predicted values provided by the spirometer were used as the predicted values of children, and the percentage of measured values in predicted values was calculated. RESULTS: In the 702 children, the percentages of the measured values of the main pulmonary ventilation function parameters PEF, FVC, FEV1, FEV1/FVC, and MVV in their predicted values fluctuated from 102% to 114%, 94% to 108%, 98% to 113%, 98% to 107%, and 141% to 183% respectively. As for the main airway velocity parameters, the percentages of the measured values of FEF25, FEF50, FEF75, and MMEF in their predicted values fluctuated from 98% to 116%, 85% to 102%, 71% to 98%, and 83% to 100% respectively. The percentages of the measured values of PEF, FVC, FEV1, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in their predicted values had the lower limits of normal of 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively. CONCLUSIONS There are differences between pulmonary ventilation function parameter levels and normal values provided by Zapletal equation in healthy children aged 5-14 years in Kunming. As for the pulmonary ventilation function parameters of PEF, FVC, FEV, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in these children, the lower limits of normal of measured values in predicted values may be determined as 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively.
Adolescent ; Child ; Child, Preschool ; China ; Female ; Forced Expiratory Volume ; Humans ; Lung/physiology* ; Male ; Pulmonary Ventilation ; Reference Values ; Vital Capacity

Background: Neural respiratory drive (NRD) using diaphragm electromyography through an invasive transesophageal multi-electrode catheter can be used as a feasible clinical physiological parameter in patients with chronic obstructive pulmonary disease (COPD) to provide useful information on the treatment response. However, it remains unknown whether the surface diaphragm electromyogram (EMGdi) could be used to identify the deterioration of clinical symptoms and to predict the necessity of hospitalization in acute exacerbation of COPD (AECOPD) patients. Methods: COPD patients visiting the outpatient department due to acute exacerbation were enrolled in this study. All patients who were subjected to EMGdi and classical parameters such as spirometry parameters, arterial blood gas analysis, COPD assessment test (CAT) score, and the modified early warning score (MEWS) in outpatient department, would be treated effectively in the outpatient or inpatient settings according to the Global Initiative for Chronic Obstructive Lung Disease guideline. When the acute exacerbation of the patients was managed, all the examination above would be repeated. Results: We compared the relationships of admission-to-discharge changes (Δ) in the normalized value of the EMGdi, including the change of the percentage of maximal EMGdi (ΔEMGdi%max) and the change of the ratio of minute ventilation to the percentage of maximal EMGdi (ΔVE/EMGdi%max) with the changes of classical parameters. There was a significant positive association between ΔEMGdi%max and ΔCAT, ΔPaCO, and ΔpH. The change (Δ) of EMGdi%max was negatively correlated with ΔPaO/FiOin the course of the treatment of AECOPD. Compared with the classical parameters including forced expiratory volume in 1 s, MEWS, PaO/FiO, the EMGdi%max (odds ratio 1.143, 95% confidence interval 1.004-1.300) has a higher sensitivity when detecting the early exacerbation and enables to predict the admission of hospital in the whole cohort. Conclusions The changes of surface EMGdi parameters had a direct correlation with classical measures in the whole cohort of AECOPD. The measurement of NRD by surface EMGdi represents a practical physiological biomarker, which may be helpful in detecting patients who should be hospitalized timely.
Diaphragm ; physiopathology ; Electromyography ; methods ; Forced Expiratory Volume ; physiology ; Hospitalization ; Humans ; Pulmonary Disease, Chronic Obstructive ; metabolism ; physiopathology ; Spirometry ; Vital Capacity ; physiology

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

OBJECTIVETo probe the clinical application and value of dual source CT quantification volume imaging to forecast lung cancer patients' postoperative pulmonary function changing.

METHODSBetween June 2012 and June 2013, there were 233 patients (121 male patients and 112 female patients, with a mean age of (53 ± 16) years) who accepted the thoracoscope lobectomy or unilateral holo-lungs pneumonectomy accepted pulmonary function test before and after 3 months of the surgery. CT scan was conducted at both inspiration phase and expiration phase before the surgery and the lung volume of the single lobe, the pixel exponential distribution histogram, and the average lung density were measured after CT scan. The discrepancy and correlation between the preoperative lung volume accepted by CT and preoperative, postoperative pulmonary function index were compared.

RESULTSThe CT volume scan showed that average lung density of the superior part at decubitus position is -(870 ± 22) HU, the inferior part was -(767 ± 16) HU (t = 3.13, P < 0.01). The volume ratio of the right upper lobe, right middle lobe, right lower lobe, left upper lobe, left lower lobe were 20.5%, 10.3%, 23.1%, 24.6%, 21.5%, whole-right lung was 53.9% and whole-left was 46.1%. There were high correlation between CT volume index and preoperative routine pulmonary function index such as total lung capacity, forced vital capacity (FVC), forced expiratory volume in the first second (FEV(1)), residual volume, and FEV(1)/FVC. The highest correlation coefficient were 0.92, 0.76, 0.70, 0.85, 0.56 (t = 3.14, 3.05, 2.86, 3.09, 2.68; all P < 0.01). The highest correlation coefficient for the postoperative pulmonary function index were 0.87, 0.68, 0.75, 0.81, -0.64 (t = 3.10, 2.85, 3.05, 3.02, 2.79; all P < 0.01).

CONCLUSIONSIt is feasible to use dual source CT quantification volume imaging to predict lung cancer patients' postoperative pulmonary function alteration, which can provide precise predictive value of these patients. CT quantification volume imaging technology has important clinical application value.

Adult ; Aged ; Female ; Forced Expiratory Volume ; physiology ; Humans ; Lung ; physiology ; Lung Neoplasms ; physiopathology ; surgery ; Male ; Middle Aged ; Pneumonectomy ; Postoperative Period ; Prospective Studies ; Respiratory Function Tests ; Tidal Volume ; physiology ; Tomography, X-Ray Computed ; methods ; Vital Capacity ; physiology

OBJECTIVETo propose a new method for acquiring pulmonary function parameters based on measurement of volume changes of thoracic impedance.

METHODSWe studied the relationship between the volume changes of thoracic impedance and pulmonary function parameters during forced breathing based on bioimpedance measurement, and developed an instrument for measuring thoracic impedance. Using this instrument and a MRI spirolab III lung function test instrument, both based on flowmeter measurement, we measured such pulmonary function parameters including forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), and peak expiratory flow in 10 healthy volunteers and compared the measurement results.

RESULTSThe differences in the parameters measured using the two instruments were all within two folds of the positive and negative standard deviations of the average values, demonstrating good consistency in the measurement between the two methods.

CONCLUSIONSThe measurement results of the bioimpedance-based instrument we developed show good consistency with those by the commercially available pulmonary function test instrument.

Adult ; Electric Impedance ; Forced Expiratory Volume ; Humans ; Peak Expiratory Flow Rate ; Respiratory Function Tests ; methods ; Thorax ; physiology ; Vital Capacity ; Young Adult

OBJECTIVETo establish predictive equations of lung function for adults in urban areas in north China.

METHODSA survey was conducted in 600 male and 600 female healthy adults in the urban areas in north China. Five flow-volume test parameters were measured including forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). Stepwise multiple regression was carried out to establish the predicative equations for the parameters for male and female adults separately. The predicted values from these equations and those from other commonly used equations (such as ECCS equation and Knudson equation) were compared with the actual measurements in pulmonary function tests.

RESULTSFour flow-volume test parameters, namely FVC, FEV1, 25% forced expiratory flow (FEF25%), and FEF75%, showed obvious differences between the male and female adults, while FEV1/FVC was not correlated with gender. Multiple regression analysis showed that FVC, FEV1, FEF25% and FEF75% were positively correlated with height and negatively with age, and FEV1/FVC was negatively correlated with both height and age. The parameters were not affected by body weight. The predicted values from our equations were closer to the actual measurements than those calculated from other equations.

CONCLUSIONThe equations we established are more appropriate than the generally used equations for predicting lung functions in adults in north China urban areas.

Adult ; Age Factors ; Body Height ; Body Weight ; China ; Female ; Forced Expiratory Volume ; Humans ; Lung ; physiology ; Male ; Middle Aged ; Predictive Value of Tests ; Reference Values ; Regression Analysis ; Respiratory Function Tests ; methods ; Sex Factors ; Spirometry ; statistics & numerical data ; Urban Population ; Vital Capacity

BACKGROUNDIt has been stated that preoperative pulmonary function tests are essential to assess the surgical risk in patients with scoliosis. Arterial blood gas tests have also been used to evaluate pulmonary function before scoliotic surgery. However, few studies have been reported. The aim of this study was to investigate the roles of preoperative arterial blood gas tests in the surgical treatment of scoliosis with moderate or severe pulmonary dysfunction.

METHODSThis study involved scoliotic patients with moderate or severe pulmonary dysfunction (forced vital capacity < 60%) who underwent surgical treatment between January 2002 and April 2010. A total of 73 scoliotic patients (23 males and 50 females) with moderate or severe pulmonary dysfunction were included. The average age of the patients was 16.53 years (ranged 10 - 44). The demographic distribution, medical records, and radiographs of all patients were collected. All patients received arterial blood gas tests and pulmonary function tests before surgery. The arterial blood gas tests included five parameters: partial pressure of arterial oxygen, partial pressure of arterial carbon dioxide, alveolar-arterial oxygen tension gradient, pH, and standard bases excess. The pulmonary function tests included three parameters: forced expiratory volume in 1 second ratio, forced vital capacity ratio, and peak expiratory flow ratio. All five parameters of the arterial blood gas tests were compared between the two groups with or without postoperative pulmonary complications by variance analysis. Similarly, all three parameters of the pulmonary function tests were compared.

RESULTSThe average coronal Cobb angle before surgery was 97.42° (range, 50° - 180°). A total of 15 (20.5%) patients had postoperative pulmonary complications, including hypoxemia in 5 cases (33.3%), increased requirement for postoperative ventilatory support in 4 (26.7%), pneumonia in 2 (13.3%), atelectasis in 2 (13.3%), pneumothorax in 1 (6.7%), and hydrothorax in 1 (6.7%). No significant differences in demographic characteristics or perioperative factors (P > 0.05) existed between the two groups with or without postoperative pulmonary complications. According to the variance analysis, there were no statistically significant differences in any parameter of the arterial blood gas tests between the two groups.

CONCLUSIONSNo significant correlation between the results of the preoperative arterial blood gas tests and postoperative pulmonary complications existed in scoliotic patients with moderate or severe pulmonary dysfunction. However, the postoperative complications tended to increase with the decrease of partial pressure of arterial oxygen in the arterial blood gas tests.

Adolescent ; Adult ; Female ; Forced Expiratory Volume ; physiology ; Humans ; Lung ; physiology ; Male ; Oxygen ; blood ; Postoperative Complications ; Preoperative Care ; Respiratory Function Tests ; Retrospective Studies ; Scoliosis ; surgery ; Vital Capacity ; physiology ; Young Adult

BACKGROUNDThe respiratory system changes with age and a better understanding of the changes contribute to detect and prevent respiratory dysfunctions in old population. The purpose of this study was to observe age-associated changes of pulmonary function parameters in healthy young adults and the elderly.

METHODSA cross-sectional study was conducted among 600 male and female subjects aged 19 to 92 years. The subjects were divided into three groups by age: young adult (19 - 39 years), middle-aged adult (40 - 59 years), and the elderly (≥ 60 years). The pulmonary function was measured with routine examination methods and 13 parameters including vital capacity (VC), residual volume (RV), functional residual capacity (FRC), total lung capacity (TLC), RV/TLC, forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), FEV(1)/FVC, peak expiratory flow (PEF), forced expiratory flow at 25% of FVC exhaled (FEF(25)), forced expiratory flow at 50% of FVC exhaled (FEF(50)), diffusion capacity of the lung for carbon monoxide (D(L)CO), and specific diffusion capacity of CO (KCO) were collected and analyzed. Changes in pulmonary function parameters among the pre-elderly and elderly subjects, especially the aging influence on FEV(1)/FVC and RV were studied further.

RESULTSTen pulmonary function parameters including VC, FVC, FEV(1), FEV(1)/FVC, PEF, FEF(25), FEF(50), TLC, D(L)CO and KCO decreased significantly with age in both male and female subjects (P < 0.01). RV and RV/TLC were increased with age (P < 0.01). FRC remained stable during aging. Except FRC, the linear relationship was significant between age and other pulmonary function parameters. In the pre-elderly and elderly subjects, RV had a non-significantly increasing tendency with age (P > 0.05), and FEV(1)/FVC did not change significantly with age (P > 0.05).

CONCLUSIONTotal pulmonary function was declined with advancing age, but FRC was stable, and the increasing tendency of RV and decreasing tendency of FEV(1)/FVC obviously slowed down in the pre-elderly and elderly subjects.

Adult ; Age Factors ; Aged ; Aged, 80 and over ; Aging ; physiology ; Cross-Sectional Studies ; Female ; Forced Expiratory Volume ; Functional Residual Capacity ; Humans ; Lung ; physiology ; Male ; Middle Aged ; Vital Capacity ; Young Adult

PURPOSE: For patients with neuromuscular disease, air stacking, which inflates the lungs to deep volumes, is important for many reasons. However, neuromuscular patients with severe glottic dysfunction or indwelling tracheostomy tubes cannot air stack effectively. For these patients, we developed a device that permits deep lung insufflations substituting for glottic function. MATERIALS AND METHODS: Thirty-seven patients with bulbar-innervated muscle weakness and/or tracheostomies were recruited. Twenty-three had amyotrophic lateral sclerosis, and 14 were tetraplegic patients due to cervical spinal cord injury. An artificial external glottic device (AEGD) was used to permit passive deep lung insufflation. In order to confirm the utility of AEGD, vital capacity, maximum insufflation capacity (MIC), and lung insufflation capacity (LIC) with AEGD (LICA) were measured. RESULTS: For 30 patients, MICs were initially zero. However, with the use of the AEGD, LICA was measurable for all patients. The mean LICA was 1,622.7+/-526.8 mL. Although MIC was measurable for the remaining 7 patients without utilizing the AEGD, it was significantly less than LICA, which was 1,084.3+/-259.9 mL and 1,862.9+/-248 mL, respectively (p<0.05). CONCLUSION: The AEGD permits lung insufflation by providing deeper lung volumes than possible by air stacking.
Adult ; Aged ; Female ; Forced Expiratory Flow Rates/physiology ; Humans ; Insufflation/*instrumentation/methods ; Male ; Middle Aged ; Neuromuscular Diseases/*physiopathology/therapy ; *Ventilators, Mechanical ; Vital Capacity/physiology ; Young Adult

The aim of this study is to develop backpropagation neural networks (BPNN) for better prediction of ventilatory function in children and adolescents. Nine hundred and ninety-nine healthy children and adolescents (500 males and 499 females) aged 10-18 years, all of the Han Nationality, were selected from Inner Mongolia Autonomous Region, and their heights, weights, and ventilatory functions were measured respectively by means of physical examination and spirometric test. Using the approaches of BPNN and stepwise multiple regression, the prediction models and equations for forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow (PEF), forced expiratory flow at 25% of forced vital capacity (FEF25%), forced expiratory flow at 50% of forced vital capacity (FEF50%), maximal mid-expiratory flow (MMEF) and forced expiratory flow at 75% of forced vital capacity (FEF75%) were established. Through analyzing mean squared difference (MSD) and correlation coefficient (R) of the ventilatory function indexes, the present study compared the results of BPNN, linear regression equation based on this work (LR's equation), prediction equations based on the studies of Ip et al. (Ip's equation) and Zapletal et al. (Zapletal's equation). The results showed, regardless of sex, the BPNN prediction models appeared to have smaller MSD and higher R values, compared with those from the other prediction equations; and the LR's equation also had smaller MSD and higher R values compared with those from Ip's and Zapletal's equations. The coefficients of variance (CV) for FEF50%, MMEF and FEF75% were higher than those of the other ventilatory function parameters, and their increasing percentages of R values (ΔR, relative to R values by LR's equation) derived by BPNN were correspondingly higher than those of the other indexes. In sum, BPNN approach for ventilatory function prediction outperforms the traditional regression methods. When CV of a certain ventilatory function parameter is higher, the superiority of BPNN would be more significant compared with traditional regression methods.
Adolescent ; Child ; China ; Female ; Forced Expiratory Volume ; physiology ; Forecasting ; Humans ; Lung ; physiology ; Male ; Neural Networks (Computer) ; Peak Expiratory Flow Rate ; physiology ; Pulmonary Ventilation ; physiology ; Reference Values ; Sampling Studies ; Vital Capacity ; physiology