OBJECTIVETo investigate the differential value of inhaled volume and exhaled volume in anesthesia mice, and its effect on the pressure change inside of plethysmograph.

METHODSPressure and temperature in head chamber of double-chamber plethysmograph were tested when mice were placed in the body chamber. The differential values of inhaled volume and exhaled volume of mice were calculated.

RESULTThe baseline pressure in head chamber increased with temperature rising within 12 minutes, then went down though temperature remained high. The inhaled volumes of 8 mice were (0.2842 + or - 0.0173)ml,and the differential value of inhaled volume and exhaled volume was (0.0012 + or - 0.0002)ml.

CONCLUSIONThe inhaled volume is larger than exhaled volume, which makes pressure baseline of plethysmograph decreased. The differential value may be generated from respiratory quotient.

Animals ; Exhalation ; physiology ; Inhalation ; physiology ; Mice ; Plethysmography ; Pressure ; Temperature ; Tidal Volume ; Vital Capacity ; physiology

BACKGROUNDPulmonary problems often occur in patients with early-onset scoliosis (EOS). However, lung function in patients with EOS after growing rod surgery has not been documented. The aim of this study was to investigate lung function after the treatment for EOS with growing rod and its possible correlative factors.

METHODSEight patients with EOS were treated with growing rod surgery at Peking Union Medical College Hospital from September 2002 to September 2009. Four patients had finished the final fusion surgery (group 1), and the other 4 (group 2) were in the process of periodic lengthening. Preoperative forced vital capacity (FVC), ratio of FVC to predicted FVC, forced expiratory volume in 1 second (FEV1), ratio of FEV1 to predicted FEV1, and radiographic measurements of Cobb's angle and C7-S1 distance were recorded. Lung function changes and correlations between lung function changes and radiographic changes (Cobb's angle and C7-S1 distance) were analyzed.

RESULTSIn group 1, FVC and FEV1 both increased. FVC showed a significant difference (P = 0.01), but FEV1 did not (P = 0.05). In group 2, FVC and FEV1 also increased, and both showed a significant difference (P = 0.04 and P = 0.02, respectively). Ratio of FVC to predicted FVC and ratio of FEV1 to predicted FEV1 changed similarly and did not show statistical differences in the 2 groups. There were no significant correlations between lung function changes and radiographic changes (Cobb's angle and C7-S1 distance) (P = 0.10 and P = 0.41, respectively).

CONCLUSIONSLung function increases after growing rod surgery in patients with EOS. Lung function changes do not correlate with Cobb's angle changes or C7-S1 distance changes.

Child ; Female ; Forced Expiratory Volume ; physiology ; Humans ; Male ; Orthopedic Procedures ; adverse effects ; Scoliosis ; physiopathology ; surgery ; Vital Capacity ; physiology

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

OBJECTIVESTo compare the difference in pulmonary function between Caucasians and Chinese and assess the best reference values of pulmonary function for Chinese adults.

METHODSValues for pulmonary function were predicted by tests on 4773 Chinese healthy subjects (male: 2560, female: 2213, aged 15-78 years) in six parts (north, northeast, northwest, east, southwest and south) of China. Prediction equations of the European Community for Steel and Coal (ECSC), other equations for overseas Chinese or for Caucasians were also selected. The regression coefficients of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, total lung capacity (TLC) and residual volume (RV) were summarized.

RESULTSECSC predictions were closer to the Chinese ones than other selected equations. Comparison with ECSC predictions showed that on average the values for FVC, FEV1 were 5.3% smaller in Chinese males and 3.3% smaller in Chinese females, with the maximal differences in south China and the minimal differences in North China. RV and TLC in Chinese were lower than in Caucasians (males 4.8%, 5.5%, respectively; females 8.7% and 6.0%, respectively). Conversion factors were given for adjusting ECSC equations to fit Chinese.

CONCLUSIONSFor predicting values of pulmonary function in Chinese, we suggest to use the equations reported here. Alternatively, ECSC regression equations may be used with appropriate conversion factors.

Adolescent ; Adult ; Aged ; Female ; Forced Expiratory Volume ; Humans ; Lung ; physiology ; Male ; Middle Aged ; Reference Values ; Regression Analysis ; Total Lung Capacity ; Vital Capacity

Adult ; Female ; Forced Expiratory Volume ; Humans ; Lung ; physiology ; Malaysia ; Male ; Occupations ; Respiration ; Singapore ; United Kingdom ; Vital Capacity

OBJECTIVETo assess the possibility of using spirometrically controlled computed tomography (CT) to test pulmonary ventilation function.

METHODSSpiral CT scans under the control of a spirometer were performed on 30 healthy adults. Spiral CT scan was performed at 50% vital capacity (VC) with an 8 mm slice thickness. Mean attenuation values and pixel index (PI) of lung regions were evaluated with semiautomatic evaluation software.

RESULTSThere were significant differences in PI values between four pixel intervals.

CONCLUSIONSSpirometrically controlled spiral CT with semiautomatic evaluation software is an accurate and reproducible method of measuring lung density and PI, which has the possibility of indicating pulmonary ventilation function.

Adult ; Female ; Humans ; Lung ; diagnostic imaging ; physiology ; Male ; Middle Aged ; Respiratory Function Tests ; Spirometry ; Tomography, X-Ray Computed ; Vital Capacity

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

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

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

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