• Tuberculosis and Respiratory Diseases
• /
• 제67권4호
• /
• pp.311-317
• /
• 2009

Background: The methacholine bronchial provocation test is a useful tool for evaluating asthma in patients with normal or near normal baseline lung function. However, the sensitivity of this test is 82~92% at most. The purpose of this study is to evaluate the clinical usefulness of $FEF_{25-75%}$ in identification of airway hyperresponsiveness in patients with suspected asthmatic symptoms. Methods: One hundred twenty-five patients who experienced cough and wheezing within one week prior to their visiting the clinic were enrolled. Results: Sixty-four subjects showed no significant reduction of $FEV_{1}$ or $FEF_{25-75%}$ on the methacholine bronchial provocation test (Group I). In 24 patients, $FEF_{25-75%}$ fell more than 20% from baseline without a 20% fall of $FEV_{1}$ during methacholine challenge (Group II). All patients who had more than 20% fall of $FEV_{1}$ (n=37) also showed more than 20% of reduction in $FEF_{25-75%}$ (Group III). Baseline $FEV_{1}$/FVC (%) and $FEF_{25-75%}$ (L) were higher in group II than group III (81.51${\pm}$1.56% vs. 75.02${\pm}$1.60%, p<0.001, 3.25${\pm}$0.21 L vs. 2.45${\pm}$0.21 L, p=0.013, respectively). Group II had greater reductions of both $FEV_{1}$ and $FEF_{25-75%}$ than group I at 25 mg/mL of methacholine (p<0.001). The provocative concentration of methacholine causing a 20% fall in $FEF_{25-75%}$ in group II was about three-fold higher than that in group III. Conclusion: A 20% fall of $FEF_{25-75%}$ by methacholine provocation can be more sensitive indicator for detecting a milder form of airway hyperresponsiveness than $FEV_{1}$ criteria.

• 대한임상검사과학회지
• /
• 제36권2호
• /
• pp.199-204
• /
• 2004

Height has become one of the most important factors to determine the pulmonary function test index, and there is a high correlation between them, so that they have been utilized for evaluating pulmonary function test predictive value or nomogram. Therefore, we have tried to find out that difference and if there is any correlation and linear relationship between height and forced expiratory flow curve. There were a total of 163 subjects, male 93 and female 70. This study was done at the Department of Pulmonary Function Test of Jeon-Ju Presbyterian Hospital and we measured the index at the forced expiratory flow curve of FVC, $FEV_{1.0}$, $FEV_{1.0}$/FVC, $FEF_{25-75%}$, and $FEF_{200-1200m{\ell}}$. When we subjected the group of height more than 160cm, there were gradual increments at FVC(p<0.001), $FEV_{1.0}$(p<0.001), $FEF_{25-75%}$(p<0.05) and $FEF_{200-1200m{\ell}}$(p<0.001), but no changes at $FEV_{1.0}$/FVC in terms of forced expiratory flow curve index. We have analyzed the relationship between height and forced expiratory flow curve, there was a close relationship at FVC(r=0.670, p<0.01), $FEV_{1.0}$(r=0.491, p<0.01), $FEF_{25-75%}$ (r=0.175, p<0.05) and $FEF_{200-1200m{\ell}}$(r=0.370, p<0.01) but there was reciprocal relationship at $FEV_{1.0}$/FVC(r=-0.215, p<0.01). We have tried simple regression analysis to see if height affects forced expiratory flow curve index as a sector, and the result was $FVC(\ell)=0.0642{\times}height(cm)-7.2978$(p<0.01, $R^2=0.449$), $FEV_{1.0}(\ell)=0.0407{\times}height(cm)-4.2774$ (p<0.01, $R^2=0.2411$), $FEV_{1.0}/FVC(%)=-0.2892{\times}height(cm)+121.44$(p<0.01, $R^2=0.0464$), $FEF_{25-75%}(\ell/sec)=0.0176{\times}height(cm)-0.7876$(p<0.05, $R^2=0.0237$), $FEF_{200-1200m{\ell}}(\ell/sec)=0.0967{\times}height(cm)-11.037$(p<0.01, $R^2=0.1214$) this was approved statistically. According to this study, if height is taller than average, forced expiratory flow curve index were increased, there was a close relationship between height and forced expiratory flow curve, and there was a linear relationship as sector between height and forced expiratory flow curve index. Therefore, researches that study other factors such as sex, age, weight, body surface area, and obesity indexes other than height should be done to see if there are any further relationships.

• Journal of Chest Surgery
• /
• 제13권4호
• /
• pp.364-374
• /
• 1980

Twenty-two patients were selected for evaluation of pre-and postoperative pulmonary function. These patients were performed open cardiac surgery with the extracorporeal circulation from March 1979 to July 1980 at the Department of Thoracic and Cardiovascular Surgery, Kyungbook National University Hospital. Patients were classified with ventricular septal defect 5 cases, atrial septal defect 5 cases, tetralogy of Fallot 5 cases, mitral stenosis 4 cases, rupture of aneurysm of sinus Valsalva 1 case, left atrial myxoma I case, and aortic insufficiency 1 case. The pulmonary function tests were performed and listed: [1] respiratory rate, tidal volume [TV], and minute volume[MV], [2] forced vital capacity [FVC] and forced expiratory volume[FEV 0.5 & FEV 1.0], [3] forced expiratory flow [FEF 200-1200 ml & FEF 25-75%]. [4] Maximal voluntary ventilation [MVV], [5] residual volume [RV] and functional residual capacity[FRC], measured by a helium dilution technique. Respiratory rate increased during the early postoperative days and tidal volume decreased significantly. These values returned to the preoperative levels after postoperative 5-6 days. Minute volume decreased slightly, but essentially unchanged. Preoperative mean values of the forced vital capacity, functional residual capacity and total lung capacity decreased [63.2%, 87.2% & 77.3% predicted, respectively], and early postoperatively these values decreased further [19.6%, 76.0% & 38.0% predicted], but later progressively increased to the preoperative levels. In residual volume, there was no decline in the preoperative mean values [100.9% predicted] and postoperatively the value rather increased [106.3-161.7% predicted]. Forced expiratory volume [FEV 0.5 & FEV 1.0] and forced expiratory flow [FEF 200-1200 ml & FEF 25-75%] also revealed significant declines in the early postoperative period. There was no significant difference in values of the spirometric pulmonary function tests, such as FEF 1.O and FEF 25-75% between successful weaning group [17 cases] extubated within 24 hrs post-operatively and unsuccessful weaning group [5 cases] extubated beyond 24 hrs. Static compliance and airway resistance measured for the two cases during assisted ventilation, however, any information was not obtained. Long term follow-up pulmonary function studies were carried out for 8 cases in 9 months post-operatively. All of the results returned to the pre-operative or to normal predicted levels except FVC, FEV 1.0, and FEF 25-75% those showed minimal declines compared to the pre-operative figures.

• Journal of Chest Surgery
• /
• 제25권11호
• /
• pp.1169-1179
• /
• 1992

To determine the period and degree of full recovery of postoperative pulmonary function, the author performed seiral pulmonry function test with spirometry at preoperative period and 1st, 2nd, 3rd, 4th, 6th and 8th postoperative week in 64 patients who underwent chest surgery form 1990. 1. to 1990. 8. at Dep. of Thoracic & Cardiovascular surgery, Pusan National University Hospitcal, Pusan, Korea 28 patients underwent lung resection[Group A], 14 patients mediastinal and other thoracic surgery[Group B], and 22 patients heart surgery with cardiopulmonary bypass[Group C]. Al of them recovered normally and discharged without any complications. Their serial changes of pulmonary function test were compaired and its results was as follows; l. Over all mean recovery time of restrictive ventilatory function tests[ie, VC, ERV, IC, FEF1, FVC, FEF200-1200, MVV] were 4th & 6th postoperative week, and that of obstructive ventilatory function tests[ie., EFE25-75%, Vmax50] were 2nd postoperative week. 2. In patient who underwent lung resection surgery[Group A], FEF1 recovered in 4th~6th postoperative week and its ratio to preoperative value was 70% in pneumonectomy, and 75% in lobectomy. FVC recovered in 4th~6th postoperative week and its ratio to preoperative value was 65% in pneumonectomy, and 80% in lobectomy. MVV was recovered in 4th~8th postoperative week and recovery ratio was 80%, FEF200-1200 was recovered at 4th~6th postoperative week and its recovery ratio was 70%, FEF25-75% and Vmax50 was recovered in 2nd~4th postoperative week and recovered nearly to preoperative level. 3. In patient who underwent mediastinal and other thoracic surgery[Group B], FEV1 and FVC and recovered in 4th~6th postoperative week and the recovery ratio of FVC in blebectomy was 90%. MVV reached preoperative level in 4th~8th postoperative week. FEF200-1200, FEF25-75% and Vmax50 were recovered in 2nd~4th postoperative week and the recovery of FEF25-75% and Vmax50 in blebectomy was prominant. 4. In patient who underwent heart surgery[Group C], FEV1 and FVC were recovered in 4th~6th postoperative week. The recover ratio of FEF25-75% and Vmax50 was delaied to 6th~8th postoperative week From the above results we concluded that the recovery time of posoperative restrictive ventilatory disorder was 4th postoperative week and pulmonary complication would possibly occure during that period. So more intensive observations will be needed.

• Tuberculosis and Respiratory Diseases
• /
• 제71권3호
• /
• pp.188-194
• /
• 2011

Background: When patients with chronic respiratory symptoms have a normal spirometry result, it is not always easy to consider bronchial asthma as the preferential diagnosis. Forced expiratory flow between 25% and 75% of vital capacity ($FEF_{25{\sim}75%}$) is known as a useful diagnostic value of small airway diseases. However, it is not commonly used, because of its high individual variability. We evaluated the pattern of bronchodilator responsiveness (BDR) and the correlation between $FEF_{25{\sim}75%}$ and BDR in patients with suspicious asthma and normal spirometry. Methods: Among patients with suspicious bronchial asthma, 440 adult patients with a normal spirometry result (forced expiratory volume in one second [$FEV_1$]/forced vital capacity [FVC] ${\geq}70%$ & $FEV_1%$ predicted ${\geq}80%$) were enrolled. We divided this group into a positive BDR group (n=43) and negative BDR group (n=397), based on the result of BDR. A comparison was carried out of spirometric parameters with % change of $FEV_1$ after bronchodilator (${\Delta}FEV_1%$). Results: Among the 440 patients with normal spirometry, $FEF_{25{\sim}75%}%$ predicted were negatively correlated with ${\Delta}FEV_1%$ (r=-0.22, p<0.01), and BDR was positive in 43 patients (9.78%). The means of $FEF_{25{\sim}75%}%$ predicted were $64.0{\pm}14.5%$ in the BDR (+) group and $72.9{\pm}20.8%$ in the BDR (-) group (p<0.01). The negative correlation between $FEF_{25{\sim}75%}%$ predicted and ${\Delta}FEV_1%$ was stronger in the BDR (+) group (r=-0.38, p=0.01) than in the BDR (-) group (r=-0.17, p<0.01). In the ROC curve analysis, $FEF_{25{\sim}75%}$ at 75% of predicted value had 88.3% sensitivity and 40.3% specificity for detecting a positive BDR. Conclusion: BDR (+) was not rare in patients with suspicious asthma and normal spirometry. In these patients, $FEF_{25{\sim}75%}%$ predicted was well correlated with BDR.

• 비파괴검사학회지
• /
• 제24권5호
• /
• pp.532-537
• /
• 2004

전자기장을 유도하는 원리를 기초로 한 새로운 비파괴탐상법인 FEF법을 개발하였다. 이 탐상법은 전자기장을 유도하는 유도선과 이를 감지하는 감지부로 구성되어 있고, 비접촉 방식으로 탐상을 실시한다. 본 연구는 알루미늄합금, 스테인레스강과 인코넬 합금강의 재료에 방전 가공한 결함에 대하여 결함 검출 및 결함 깊이에 대한 평가를 실시하였다. 결함이 없는 영역에서의 측정전압은 lift-off에 의존한다. 결함영역에서 탐촉자가 결함에 가까이 접근할수록 전압은 증가하고, 결함위치에서 최고전압으로 측정되며, 이 최고치는 결함의 깊이에 따라 변화한다. 각 재료에 대한 전압분포 같은 경향으로 측정된다.

• Tuberculosis and Respiratory Diseases
• /
• 제42권3호
• /
• pp.332-341
• /
• 1995

연구목적: 폐쇄성 기도 질환자에서 기관지 확장제에 대한 반응의 평가는 그 반응의 가역성 유무에 따라 진단, 치료 그리고 예후 판단에 도움이 된다. 기관지 확장제 반응 지표는 폐쇄성 기도 질환자에서 기관지 확장 반응을 보다 예민하게 찾아낼 수 있어야 하고 폐쇄 정도에 따라 그 예만도가 일정하여야 하며, 그리고 처음 FEV1값에 크게 좌우되지 않아야 폐쇄성 기도 질환자에서 효과적으로 기관지 확장제 반응을 평가할 수 있다. 방법: 영남대학교 의과대학 부속병원 내과를 내원하여 폐쇄성 기도질환자로 진단받은 환자 75명을 대상으로 하여 fenoterol 흡입전과 흡입후 10분에 각각 폐기능 검사(2800 Autobox plethysmograph Gould electronics)를 시행하였으며, 이들 중 가역 반응을 보인 환자들을 처음 $FEV_1$(% pred)값에 따라 중증군, 중등증군, 경증군으로 나누어, American Thoracic Society에서 정한 가역성반응의 기준에 따라 기관지 가역 반응을 나타내는 5가지 지표($FEV_1$, FVC, $FEF_{25\sim75%}$, Isovolume $FEF_{25\sim75%}$, sGaw)들에서 그 예민도를 조사하였고 그리고 폐쇄성 기도 질환자 75명에서 $FEV_1$으로 가역반응을 나타내는 4가지 지표인 absolute, % initial, % predicted, %possible으로 구분하여 처음 $FEV_1$값에 대한 의존도를 조사하였다. 결과: 가역 반응의 예민도 조사에서 전체적으로 Isovolume $FEF_{25\sim75%}$와 sGaw에서 58.0%, 60.0%로 가장 높았고 유량속도의 변화를 이용한 지표 중에서는 FVC가 54.0%로 가장 높았다. 중증군에서는 FVC, Isovolume $FEF_{25\sim75%}$, sGaw에서 61.5% 였고, 중등증군에서는 Isovolume $FEF_{25\sim75%}$와 sGaw에서 각각 56.3% 였으며 경증군에서는 $FEV_1$과 sGaw에서 62.5% 그리고 Isovolume $FEF_{25\sim75%}$와 FVC에서 50.0%였다. 처음 $FEV_1$값에 대한 의존도 조사에서는 처음 $FEV_1$값을 측정된 $FEV_1$값(L)로 나타낼 때 처음 $FEV_1$값과 absolute, % initial, % predicted, % possible 각각에서의 상관계수 r은 0.15, -0.22(p<0.05), 0.02, 0.24(p<0.05)였으며, 처음 $FEV_1$값을 $FEV_1$, % predicted로 나타낼 때 처음 $FEV_1$값과 absolute, % initial, % predicted, % possible 각각에서의 상관계수 r은 0.06, -0.28(p<0.05), 0.08, 0.39(p<0.05) 였다. 결론: 이상의 결과에서 폐쇄성 기도 질환에서 기관지 확장반응의 가역성을 나타내는 5가지 판정 지표들 중 처음 폐쇄정도와 관계없이 폐용적의 변화를 고려한 지표(Isovolume $FEF_{25\sim75%}$, sGaw)들에서 가역반응의 예민도가 높았으며, $FEV_1$으로 가역반응을 니타내는 4가지 지표중에서 처음 $FEV_1$값에 의존도가 가장 낯은 지표는 % predicted 였고, 처음 $FEV_1$값과 상관관계를 가지는 지표는 % initial과 % possible 이었다.

• Clinical and Experimental Pediatrics
• /
• 제55권9호
• /
• pp.330-336
• /
• 2012

Purpose: Fractional exhaled nitric oxide (FeNO) and forced expiratory flow between 25% and 75% of vital capacity ($FEF_{25-75}$) are not included in routine monitoring of asthma control. We observed changes in FeNO level and $FEF_{25-75}$ after FeNO-based treatment with inhaled corticosteroid (ICS) in children with controlled asthma (CA). Methods: We recruited 148 children with asthma (age, 8 to 16 years) who had maintained asthma control and normal forced expiratory volume in the first second ($FEV_1$) without control medication for ${\geq}3$ months. Patients with FeNO levels >25 ppb were allocated to the ICS-treated (FeNO-based management) or untreated group (guideline-based management). Changes in spirometric values and FeNO levels from baseline were evaluated after 6 weeks. Results: Ninety-three patients had FeNO levels >25 ppb. These patients had lower $FEF_{25-75}$ % predicted values than those with FeNO levels ${\leq}25$ ppb (P<0.01). After 6 weeks, the geometric mean (GM) FeNO level in the ICS-treated group was 45% lower than the baseline value, and the mean percent increase in $FEF_{25-75}$ was 18.7% which was greater than that in other spirometric values. There was a negative correlation between percent changes in $FEF_{25-75}$ and FeNO (r=-0.368, P=0.001). In contrast, the GM FeNO and spirometric values were not significantly different from the baseline values in the untreated group. Conclusion: The anti-inflammatory treatment simultaneously improved the FeNO levels and $FEF_{25-75}$ in CA patients when their FeNO levels were >25 ppb.

• 대한임상검사과학회지
• /
• 제41권3호
• /
• pp.135-139
• /
• 2009

Pulmonary function test has been know to be greatly affected by body indices, such as sex, age, height, body weight, body surface area (BSA) and body mass index (BMI), so hat this study was focused to see the relationship between body index and flow-volume curves. Subjects were 156 (male 90, female 66) and they were examined for pulmonary function test in terms of body index and correlation/multiple regression analysis of flow-volume curves at Presbyterian Medical Center from March to August, 2009. The followings results after analyzing the correlation between body index and flow-volume curves. Although flow-volume curve FEF25-75% showed close correlation with age, body weight, and body surface area, but not with body mass index. In addition, multiple regression analysis was performed to see how each body index affects flow-volume curve FEF25-75%, and FEF25-75% dispersion was explained as 74.5% with age only, 94.2% with age and height, and 96% with age, height, and sex. Therefore, sex, age and height that are mainly used for predictive formular of pulmonary function test and nomogram were important factors for pulmonary function test itself, and further study must be done for other body index.

• Tuberculosis and Respiratory Diseases
• /
• 제38권4호
• /
• pp.379-383
• /
• 1991

To evaluate the effect of intensive training on ventilatory functions in soccer players, comparisons of various ventilatory parameters were made before and after 5-5.5 months of intensive training. The subjects were 15 members of a university soccer team with mean age and career of 19.9 and 8.3 years, respectively. Ventilatory parameters studied were those obtained by the analyses of forced expiratory volume and maximal expiratory flow-volume curves, as well as spirometric measurements of VC and MVV. After intensive training, volume parameters, such as VC, FVC and $FEV_{1&3}$ as well as flow parameters, effort-dependent and effort-independent, such as MVV, FEF200-1200, FEF25-75%, PEF, FEF25%, FEF50%, FEF75% showed significant increase. However, when the observed values of flow parameters were volume-adjusted to FVC, the differences before and after intensive training became insignificant. This suggests that enhanced ventilatory functions in soccer players after intensive training are primarily due to increase in FVC caused by increase in respiratory musle strength.