BACKGROUND: Low spirometric forced vital capacity(FVC) in conjunction with a normal or high ratio of the forced expiratory volume at 1 second to the forced vital capacity(FEV1/FVC%) has traditionally been classified as a restrictive abnormality. However, the gold-standard diagnosis of a restrictive pulmonary impairment requires a measurement of the total lung capacity (TLC). This study was performed to determine the predictive value of spirometric measurements of the FVC for diagnosing a restrictivepulmonary abnormality. METHODS: Test results from 1,371 adult patients who undertook both spirometry and lung volume measurements on the same visit from January 1999 to December 2000 were enrolled in this study. The test values for the FVC, the TLC that was below 80% of predicted value, and a FEV1/FVC% that was below 70%, were classified as being abnormal. RESULTS: Of the 1,371 patients, 353 patients had a reduced a FVC. Of these patients, 186 patients had a reduced TLC. Therefore, the positive predictive value was 52.7%. Of the 196 patients with a normal FEV1/FVC% and a reduced FVC, 148(75.5%) patients had a lower TLC. Thirty eight (24.2%) patients out of 157 patients with a low FEV1/FVC% and a low FVC showed a restrictive defect. CONCLUSION: Spirometry is useful to rule out a restrictive pulmonary abnormality, but a restrictive pattern on the spirometry dose not mean there is a true restrictive disease. For the patients with a low FVC, TLC measurements are essential for diagnosing a restrictive pulmonary impairment.
Adult ; Diagnosis ; Forced Expiratory Volume ; Humans ; Lung Volume Measurements ; Plethysmography, Whole Body ; Respiratory Function Tests ; Spirometry* ; Total Lung Capacity ; Vital Capacity

Tuberculous spine has high incidence in children. Many cases of the tuberculous spine are complicated by deformities of the spine and disability such as paraplegia, cardio-plumonary dysfunction, and also early death. There are now several reports on the pulmonary dysfunction due to spinal deformities such as scoliosis and kyphoscoliosis, but there are few papers on the pulmonary function of patients with the tuberculous spine and kyphosis in children. This article is a report on the study of chest excursion in 70 kyphotic children and of the pulmonary function in 10 cases of severe kyphotic patients with collapsing tuberculous spine. The following results are obtained through the study: 1) Chest excursion was evidently diminished in the cases of moderate and severe thoracic, and severe lumbar involvement. The remainders were nearly within normal limits. 2) The study revealed that the chest excursion and the radiological kyphosis has a very gradually sloped negative correlation in thoracic involvement. 3) Pulmonary function in the severe kyphotics who had the curve over 50 degree were revealed as follows; a) Over 50 percent of the cases had diminished vital capacity. That is, over-all average was 67.7 percent of normal capacity. Especially inspiratory reserve volume was diminished, it was 63.7 percent of normal. Maximum breathing capacity was 68.8 percent of normal. b) Tidal volume, timed vital capacity, minute ventilation rate and O2 consumption were within normal limits or nearly normal.
Child ; Congenital Abnormalities ; Forced Expiratory Volume ; Humans ; Incidence ; Inspiratory Reserve Volume ; Kyphosis ; Paraplegia ; Respiration ; Scoliosis ; Spine ; Thorax ; Tidal Volume ; Ventilation ; Vital Capacity

A discussion on the causes and managing methods of the difference between the set tide volume and the actual delivered tide volume during the respiratory care, is given in the paper and to help doctors and nurses to handle respiratory therapy on the basis of related people-machine engineering science principle and experimental analysis.
Equipment Failure Analysis ; Humans ; Lung Volume Measurements ; Respiration, Artificial ; Tidal Volume ; Ventilators, Mechanical

BACKGROUNDNeural respiratory drive is usually measured during inspiration, even in patients with chronic obstructive pulmonary disease (COPD) in whom the primary physiological deficit is expiratory flow limitation. The purpose of the study was to test the hypothesis that inspiratory muscle neural respiratory drive could be used to assess expiratory load.

METHODSTen healthy young men, (26 ± 4) years old, were asked to expire through a tube immersed in water where an expiratory load was required. The load was judged by the depth of the tube in water and the different loads (0 cmH2O, 10 cmH2O, 20 cmH2O and 30 cmH2O) were randomly introduced. Each expiratory load lasted for 3 - 5 minutes and inspiration was unimpeded throughout. Diaphragm electromyogram (EMG) and transdiaphragmatic pressure were recorded by a catheter with 10 metal coils and two balloons. Incremental cycle exercise with and without an expiratory load at 30 cmH2O was also performed.

RESULTSNeural drive during expiratory loaded breathing was larger than during unloaded breathing but neural drive did not increase proportionally with increasing expiratory load; neural drive during expiratory loading at 0, 10, 20 and 30 cmH2O was (10.1 ± 3.1) µV, (16.7 ± 7.3) µV, (18.4 ± 10.7) µV and (22.9 ± 13.2) µV, respectively. Neural drive as a percentage of maximum at the end of exercise with or without load was similar ((57.4 ± 11.0)% max vs. (62.7 ± 16.4)% max, P > 0.05).

CONCLUSIONNeural respiratory drive measured at inspiration does not accurately quantify expiratory load either at rest or during exercise.

Adult ; Electromyography ; Exercise ; Humans ; Lung Volume Measurements ; Male ; Respiration ; Respiratory Muscles ; innervation ; Tidal Volume

Atelectasis can impair arterial oxygenation and decrease lung compliance. However, the effects of atelectasis on endotoxemic lungs during ventilation have not been well studied. We hypothesized that ventilation at low volumes below functional residual capacity (FRC) would accentuate lung injury in lipopolysaccharide (LPS)-pretreated rats. LPS-pretreated rats were ventilated with room air at 85 breaths/min for 2 hr at a tidal volume of 10 mL/kg with or without thoracotomy. Positive end-expiratory pressure (PEEP) was applied to restore FRC in the thoracotomy group. While LPS or thoracotomy alone did not cause significant injury, the combination of endotoxemia and thoracotomy caused significant hypoxemia and hypercapnia. The injury was observed along with a marked accumulation of inflammatory cells in the interstitium of the lungs, predominantly comprising neutrophils and mononuclear cells. Immunohistochemistry showed increased inducible nitric oxide synthase (iNOS) expression in mononuclear cells accumulated in the interstitium in the injury group. Pretreatment with PEEP or an iNOS inhibitor (1400 W) attenuated hypoxemia, hypercapnia, and the accumulation of inflammatory cells in the lung. In conclusion, the data suggest that atelectasis induced by thoracotomy causes lung injury during mechanical ventilation in endotoxemic rats through iNOS expression.
Animals ; Blood Pressure ; Carbon Dioxide/blood ; Cardiac Output ; Combined Modality Therapy ; Endotoxemia/*complications/immunology/pathology ; Functional Residual Capacity ; Immunohistochemistry ; Leukocytes, Mononuclear/pathology ; Lipopolysaccharides/pharmacology ; Lung/enzymology/pathology/physiopathology ; Lung Compliance ; Lung Volume Measurements ; Male ; Neutrophils/pathology ; Nitric Oxide Synthase Type II/metabolism ; Oxygen/blood ; Positive-Pressure Respiration/*adverse effects ; Pulmonary Atelectasis/*etiology/pathology/*therapy ; Rats ; Rats, Sprague-Dawley ; Thoracotomy/*adverse effects

Breath Tests ; methods ; Child ; Humans ; Infant ; Lung Diseases ; diagnosis ; physiopathology ; Lung Volume Measurements ; Maximal Voluntary Ventilation ; Respiratory Function Tests ; Tidal Volume

OBJECTIVE: To measure and compare the quantitative parameters of the lungs and airways in Korean never-smokers and current or former smokers (“ever-smokers”). MATERIALS AND METHODS: Never-smokers (n = 119) and ever-smokers (n = 45) who had normal spirometry and visually normal chest computed tomography (CT) results were retrospectively enrolled in this study. For quantitative CT analyses, the low attenuation area (LAA) of LAA(I-950), LAA(E-856), CT attenuation value at the 15th percentile, mean lung attenuation (MLA), bronchial wall thickness of inner perimeter of a 10 mm diameter airway (Pi10), total lung capacity (TLC(CT)), and functional residual capacity (FRC(CT)) were calculated based on inspiratory and expiratory CT images. To compare the results between groups according to age, sex, and smoking history, independent t test, one way ANOVA, correlation test, and simple and multiple regression analyses were performed. RESULTS: The values of attenuation parameters and volume on inspiratory and expiratory quantitative computed tomography (QCT) were significantly different between males and females (p < 0.001). The MLA and the 15th percentile value on inspiratory QCT were significantly lower in the ever-smoker group than in the never-smoker group (p < 0.05). On expiratory QCT, all lung attenuation parameters were significantly different according to the age range (p < 0.05). Pi10 in ever-smokers was significantly correlated with forced expiratory volume in 1 second/forced vital capacity (r = −0.455, p = 0.003). In simple and multivariate regression analyses, TLC(CT), FRC(CT), and age showed significant associations with lung attenuation (p < 0.05), and only TLC(CT) was significantly associated with inspiratory Pi10. CONCLUSION: In Korean subjects with normal spirometry and visually normal chest CT, there may be significant differences in QCT parameters according to sex, age, and smoking history.
Female ; Forced Expiratory Volume ; Functional Residual Capacity ; Humans ; Lung* ; Male ; Reference Values ; Respiratory Function Tests ; Retrospective Studies ; Smoke ; Smoking ; Spirometry ; Thorax ; Tomography, X-Ray Computed ; Total Lung Capacity ; Vital Capacity

BACKGROUNDObstructive sleep apnea is strongly associated with obesity, particularly abdominal obesity common in centrally obese males. Previous studies have demonstrated that intra-abdominal pressure (IAP) is increased in morbid obesity, and tracheal traction forces may influence pharyngeal airway collapsibility. This study aimed to investigate that whether IAP plays a role in the mechanism of upper airway (UA) collapsibility via IAP-related caudal tracheal traction.

METHODSAn abdominal wall lifting (AWL) system and graded CO2pneumoperitoneum pressure was applied to four supine, anesthetized Guizhou miniature pigs and its effects on tracheal displacement (TD) and airflow dynamics of UA were studied. Individual run data in 3 min obtained before and after AWL and obtained before and after graded pneumoperitoneum pressure were analyzed. Differences between baseline and AWL/graded pneumoperitoneum pressure data of each pig were examined using a Student's t-test or analysis of variance.

RESULTSApplication of AWL resulted in decreased IAP and significant caudal TD. The average displacement amplitude was 0.44 mm (P < 0.001). There were three subjects showed increased tidal volume (TV) (P < 0.01) and peak inspiratory airflow (P < 0.01); however, the change of flow limitation inspiratory UA resistance (Rua) was not significant. Experimental increased IAP by pneumoperitoneum resulted in significant cranial TD. The average displacement amplitude was 1.07 mm (P < 0.001) when IAP was 25 cmH2O compared to baseline. There were three subjects showed reduced Rua while the TV increased (P < 0.01). There was one subject had decreased TV and elevated Rua (P < 0.001).

CONCLUSIONSDecreased IAP significantly increased caudal TD, and elevated IAP significantly increased cranial TD. However, the mechanism of UA collapsibility appears primarily mediated by changes in lung volume rather than tracheal traction effect. TV plays an independent role in the mechanism of UA collapsibility.

Airway Resistance ; physiology ; Animals ; Female ; Lung Volume Measurements ; Obesity, Morbid ; physiopathology ; Sleep Apnea, Obstructive ; physiopathology ; Swine ; Tidal Volume ; physiology ; Trachea ; physiology

PURPOSE: Changes in the curvature of the vertebral columns of elderly women with increasing age causes various side effects and disorders. Therefore, this study was conducted to evaluate the effectiveness of the 8-figure scapular brace to improve pulmonary function and balance ability based on lung capacity and foot pressure by increasing the vertebral curvature. METHODS: Seventeen elderly women with a forward head posture were selected. Women were asked to wear the 8-figure scapular brace and the forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were measured, as were changes in foot pressure. Measurements were conducted three times each and the mean values were used for subsequent analyses. For static evaluation, we used the paired t-test to identify differences between pre and post values. RESULTS: There was no significant difference in FEV1 and FVC before and after use of the brace (p>0.05); however, there was a significant decrease in forefoot pressure and an increase in rearfoot pressure following application of the brace (p < 0.05). CONCLUSION: Application of the 8-figure scapular brace to correct vertebral curvature in elderly women influenced pressure distribution change from immediate effect body arrange of cervical and thoracic. However, wearing the 8-figure scapular brace may interfere with expansion of the chest and therefore respiratory muscle activity. Accordingly, it is necessary to apply appropriate treatment when wearing a scapular brace and to allow a sufficient intervention period while also providing therapeutic interventions such as posture correction or respiration training.
Aged* ; Braces* ; Female ; Foot* ; Forced Expiratory Volume ; Head* ; Humans ; Lung Volume Measurements ; Posture* ; Respiration ; Respiratory Muscles ; Spine ; Thorax ; Vital Capacity

Since pulmonary function testing was first described by Hutchinson in 1846, this technic has been developed by many physiologists and applied to clinical fields for eviluation of cardiopulmonary status in order to improve diagnosis and treatment of cardiopulmonary diseases. The normal values of the lung volumes and capacities, maximal midexpiratory flow, maximal breathing capacity and forced expiratory volume and time in 120 (male-60, female-60) normal Korean adults by using a Gaensler-Collins bronchospirometer are presented. The results were as follows: 1. The vital capacity of the normal Korean adult was 4191+/-451ml. for males and 2685+/-375 ml. for females. 2. The ratio of inspiratory capacity to vital capacity for males was 66+/- 9% and for females 70+/- 7%, but that of expiratory reserve volume to vital capacity for males was 34+/-9% and for females was 30+/-7%. The ratio of inspiratory capacity to vital capacity of normal Korean adults is slightly lower than that of whites, while that of expiratory reserve volume to vital capacity of normal Korean adults is slightly higher than that of whites. 3. The maximal breathing capacity of males was 95+/- 171/min. and that of females 61+/-141/min. 4. The maxima mid-expiratory flow for males was 266+/- 711/min. and for females 176+/- 421 /min. The maximal mid-expiratory time of males was 0. 497+/- 0.145 second and that of females 0. 479+/- 0. 128 second.
Adult* ; Diagnosis ; Expiratory Reserve Volume ; Female ; Forced Expiratory Volume ; Humans ; Inspiratory Capacity ; Lung ; Male ; Maximal Voluntary Ventilation ; Reference Values ; Respiratory Function Tests ; Vital Capacity