Relationship between FEV1 reduction and respiratory symptoms in the general population.

Obstructive airways diseases typically present with dyspnoea, cough and wheeze, and are defined by a reduced forced expiratory volume in one second (FEV1/forced vital capacity (FVC) ratio. Traditionally, however, the severity of chronic obstructive pulmonary disease is graded by the FEV1 % predicted rather than the FEV1/FVC ratio, whilst other potentially valid measures of FEV1 impairment, such as the absolute difference of FEV1 from predicted or the absolute level of FEV1, tend not to be used. The authors have therefore explored the relationship between these different measures of FEV1 impairment and chronic respiratory symptoms in a general population sample. FEV1 and FVC were measured and questionnaire data were obtained on cough, wheeze, shortness of breath and general self-reported breathing trouble in a cross-sectional survey of 2,633 adults aged 18-70 yrs from a district of Nottingham, UK. Odds ratios for each symptom were calculated for declining levels of absolute FEV1, FEV1 % pred, absolute difference of FEV1 from predicted, and FEV1/FVC ratio. They were plotted to display the shape and strength of these relationships before and after adjustment for each other measure. The odds of symptoms increased with declining levels of all FEV1 measures, particularly for wheeze and general breathing trouble. Although this study was not sufficiently powerful to detect significant differences between measures, these relationships were consistently strongest, before and after adjustment, for FEV1 % pred, particularly below a threshold of approximately 75%. The authors conclude that forced expiratory volume in one second % predicted appears to be the measure of airflow impairment most closely associated with chronic respiratory symptoms in the general population.     

Airway resistance in chronic heart failure measured by impulse oscillometry

BACKGROUND: Patients with chronic heart failure (CHF) complain of breathlessness and fatigue on exertion, have reduced peak oxygen consumption (pV(O(2))), and an increased ventilatory response to exercise (V(E)/V(CO(2)) slope). These limitations correlate with abnormalities of spirometry (forced expiratory volume in 1 second [FEV(1)] and forced ventilatory capacity [FVC]). Increased airway resistance by increasing the work of breathing might contribute to exercise intolerance in CHF. METHODS: Impulse oscillometry (IOS) measures airway resistance and lung compliance independently of respiratory muscle strength and patient compliance. Sound waves of varying frequencies are sent into the lungs and the amplitude and phase shift of the reflected waves give a measure of airway resistance (R) and reactance (X). Twenty-three CHF patients and 18 controls underwent peak exercise testing with metabolic gas analysis and had airway resistance assessment using the Jaeger (Würtzberg, Germany) IOS system. RESULTS: Patients had a lower pV(O(2)) (18.7 (4.0) v 39.2 (8.3) mL x kg x min; P < .0001), elevated V(E)/V(CO(2)) slope (41.6 (8.1) v 27.4 (2.9)), and lower FEV(1) (2.4 (0.4) v 3.2 (0.7) L/min; P = .0001) and FVC (3.3 (0.7) v 4.1 (1.1) L; P < .005) than controls. R and X correlated with spirometric abnormalities and were different between patients and controls (R at 5 Hz 0.44 (0.16) v 0.30 (0.15) kPa (L/s); P < .005 and X at 5 Hz -0.16 (0.08) v -0.09 (0.08) kPa (L/s); P < .05). R at 5 Hz correlated with pV(O(2)) (0.46; P = .0025) and V(E)/V(CO(2)) slope (0.43; P < .05). CONCLUSION: CHF patients have elevated airway resistance and reduced reactance measured with IOS compared with control subjects.     

Alteration in breathing pattern with progression of chronic obstructive pulmonary disease

We examined the relationship between breathing pattern and severity of disease in patients with chronic obstructive pulmonary disease (COPD). Resting breathing pattern was recorded for 45 min using the respiratory inductance plethysmograph (RIP) in 22 patients with stable COPD. Six subjects (moderate group) had FEV1 25 to 50% predicted, 8 subjects (severe group) had FEV1 less than 25% predicted, and 8 subjects (respiratory failure group) had FEV1 less than 25% predicted and were hypoxemic. Seven of the subjects with respiratory failure were also hypercapnic. Subjects with respiratory failure were studied with and without supplemental O2. All subjects were studied in the seated position. There were no significant differences in breathing pattern between the moderate and severe groups. Tidal volume (VT) was 120 ml lower in the severe group, but breathing frequency (f) was slightly elevated, allowing minute ventilation (VI) to be maintained. The respiratory failure group demonstrated a significant decrease in VT compared with that in the moderate group and a significant decrease in VT/TI as compared with both moderate and severe groups; TI was unchanged in subjects with respiratory failure, and, as f did not increase significantly, VI was decreased. Acute relief of hypoxemia had no effect on breathing pattern in respiratory failure. Variability was assessed by comparing the coefficients of variation for each timing component. There was no difference in intraindividual variability of breathing pattern between all groups. These results suggest that changes in ventilatory control as reflected by breathing pattern are to some extent independent of mechanical abnormalities.     

The maintenance of total ventilatory requirements through a chronic bronchopleural cutaneous fistula

In patient with a chronic post-tuberculous bronchopleural cutaneous fistula (BPCF), minute ventilation, dead space, flow rates, arterial blood gas tensions, and oxygen consumption were measured during mouth breathing and after 30 min of steady-state breathing solely through the BPCF. Despite a 390-ml (18%) decrease in dead space when breathing took place through the BPCF, there were no significant changes in minute ventilation or respiratory rate. BPCF breathing was also associated with an increase in airways resistance as reflected by a 300-ml (35%) decrease in the FEV1 and a 16% decrease in the FEV1/FVC ratio. The increased resistance resulted in a 20 ml/min (18%) increase in oxygen consumption. Arterial blood gas tensions remained constant. We conclude that although ventilatory efficiency was not improved, this patient was able to satisfy his total minute ventilatory requirements, for the 30-min period, solely through BPCF breathing.     

Static lung volumes in patients with Cushing's disease.

OBJECTIVE: Numerous clinical manifestations have been described in association with Cushing's syndrome. There are no eligible data on pulmonary function tests in Cushing's disease (CD). We aimed to asses pulmonary function tests including spirometry in a series of patients with active CD. MATERIALS AND METHODS: This cross-sectional study comprised 10 patients with Cushing's disease (F/M, 9/1). The forced expiratory volume in 1st second (FEV1), the forced vital capacity (FVC), the FEV1/FVC ratio and the forced expiratory flow over the middle half of the FVC (FEF 25-75%) values and predicted values were determined by spirometry. RESULTS: Mean age, height, weight, body mass index were 36.7+/-12.6 yrs (range 22-63 years), 156.9+/-8.4 cm, 74.1+/-10.7 kg, 29.6+/-3.8 kg/m(2), respectively. Spirometric abnormalities (impairment of FEV1, FVC, FEV1/FVC and FEF 25-75 values) were not detected, and there were no significant differences compared to reference values. Disease duration and cortisol concentrations by HDDSTs were negatively correlated with predicted FEV1/FVC values and the percentage of predicted FEV1 ratios, respectively. DISCUSSION: The lung volume and ventilatory performance by spirometry were not disturbed in patients with endogenous hypercostisolism due to Cushing's disease.     

Can schoolchildren provide valid answers about their respiratory health experiences in questionnaires? Implications for epidemiological studies

To evaluate the relative validity of information on children's respiratory experience given by different informants, we examined and compared the relationship between low ventilatory function (defined as more than 1 standard deviation below the corresponding mean) and schoolchildren's respiratory symptoms or illnesses reported separately by the children and their parents, using a standard respiratory questionnaire. A total of 1,963 children aged 8-12 years from 12 primary schools in three districts of Hong Kong provided parent-completed and self-completed questionnaires, as well as acceptable spirometric measurements. Prevalence of low forced expiratory volume ratio (FEV1/FVC) and low forced expiratory flow rate between 25-75% of FVC (FEF25-75) were higher among those with either parent or child-reported symptoms/illnesses. Child-reported cough and phlegm performed better than the corresponding parent-reported symptoms in predicting low FEV1/FVC. The contrary was true for wheezing and bronchitis. For low FEF25-75, parent-reported wheezing, asthma, and bronchitis performed better, while the opposite was true for cough. Subgroup analysis by age showed that for older children (age 10 or above), child-reported symptoms/illnesses performed better in general in the prediction of low FEV1/FVC. On the other hand, parent-reported symptoms/illnesses seemed to have an advantage over child-reported ones in predicting low FEF25-75. Subgroup analysis by sex did not reveal any clear pattern. Overall, there was little difference between respiratory illness experiences reported by schoolchildren and their parents in terms of their associations with low ventilatory function. In a population-based study in which schoolchildren are subjects, it would be appropriate for respiratory questionnaires to be administered to the children themselves, especially if they have reached age 10. By doing so, higher response rates, and perhaps also better yields of correct information, may be obtained.     

Inspiratory flow reserve in boys with Duchenne muscular dystrophy

Patients with advanced muscular dystrophy frequently develop ventilatory failure. Currently respiratory impairment usually is assessed by measuring vital capacity and the mouth pressure generated during a maximal inspiratory maneuver (PI,max), neither of which directly measures ventilatory capacity. We assessed inspiratory flow reserve in 26 boys [mean (SD) age 12.8 (3.8) years] with Duchenne muscular dystrophy (DMD) without ventilatory failure and in 28 normal boys [mean (SD) age 12.6 (1.9) years] by analyzing the ratio between the largest inspiratory flow during tidal breathing (V'I,max(t)) and during a forced vital capacity maneuver (V'I,max(FVC), (V'I,max(t)/V'I,maxFVC). We have compared this ratio with the forced vital capacity FVC and PI,max measured at functional residual capacity. Mean PI,max was -90(30)cmH2O, average 112% (range 57-179%) of predicted values in control boys and -31(11)cmH2O, average 40% predicted values in DMD boys (control vs DMD, P < 0.001). FVC was reduced in DMD boys [59(20)% predicted values vs 86(10)% predicted values in controls, P < 0.01]. Absolute V'I,max(FVC) was strongly related to FVC in both control and DMD boys; V'I,max(FVC) (expressed as FVC. s(-1)) was not related to PI,max in either group. The mean V'I,max(t)/V'I,max(FVC); ratio was higher in DMD 0.22 (0.08) than in controls 0.12 (0.03) (P < 0.001) indicating a reduction in inspiratory flow reserve in DMD. Inspiratory flow reserve was within the normal range in 8 of 19 DMD patients with PI,max less than 50% of predicted values. We conclude that measurement of inspiratory flow reserve (V'I,max(t)/V'I,maxFVC ratio) provides a simple and direct assessment of dynamic inspiratory muscle function which is not replicated by static measurement of PI,max or vital capacity and might be useful in assessment of respiratory impairment in boys with Duchenne muscular dystrophy. Follow-up studies are required to establish whether measures of inspiratory flow reserve are of clinical value in predicting subsequent ventilatory failure.     

The prognosis of respiratory failure in patients with tuberculous destroyed lung.

SETTING: The medical intensive care unit of a tertiary referral hospital. OBJECTIVE: To determine the prognosis of patients whose lungs are damaged by previous and/or present tuberculosis infection and who have subsequently been presented with acute respiratory failure requiring mechanical ventilation. DESIGN: A consecutive series of 38 patient cases with retrospective data analysis. RESULTS: Pulmonary function test results for tests performed within the previous year were made available in 21 of the 38 cases (55%). These showed a mean (+/- SD) forced vital capacity (FVC) of 1.52 +/- 0.46 L (41.0 +/- 14.5% predicted), a forced expiratory volume/second (FEV1) of 0.77 +/- 0.18 L (29.3 +/- 13.6% predicted), and an FEV1/FVC ratio of 55.1 +/- 16.2%. The acid-fast bacilli (AFB) positive group had a significantly higher mortality and more severe lung destruction when compared with the AFB-negative group. Patients with positive AFB were significantly more hypocapnic than those with negative AFB (6.4 +/- 2.7 vs. 9.3 +/- 3.9 kPa, P = 0.020). In multivariate analysis, the level of PaCO2 on admission was identified as the only significant prognostic index (OR 0.76, 95%CI 0.60-0.96). CONCLUSION: Patients with positive AFB smears or cultures may have higher mortality rates than those with negative AFB in the tuberculosis destroyed lung patients with acute respiratory failure. A higher PaCO2 measurement could indicate a better survival rate in this group of patients.     

Noninvasive ventilation in cystic fibrosis patients with acute or chronic respiratory failure.

The experience of using noninvasive ventilation (NIV) in 113 adult cystic fibrosis (CF) patients with chronic respiratory failure, during episodes of acute deterioration in respiratory function is reported. The patients aged 15-44 yrs were divided into three groups. Group A consisted of 65 patients (median forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) 0.7/1.4 L) who were on a lung transplant waiting list. Group B consisted of 25 patients (median FEV1/FVC 0.7/1.4 L) who were being evaluated for lung transplantation. Group C consisted of 23 patients (median FEV1/FVC 0.6/1.2 L) who were not being considered for lung transplantation. The mean duration of NIV support for groups A, B and C was 61 (range: 1-600) days, 53 (1-279) days and 45 (0.5-379) days respectively. Twenty-three patients in group A subsequently received lung transplantation and 12 of these patients had a median survival of 39 months postsurgery. Thirty-nine patients died and three awaited transplantation. Five patients in group B received a transplant four of whom survived; thirteen patients died and seven awaited transplantation. Twenty patients in group C died. Noninvasive ventilation improved hypoxia but failed to correct hypercapnia in these cystic fibrosis patients. Noninvasive ventilation is useful in the treatment of acute episodes of respiratory failure in cystic fibrosis patients with end-stage lung disease who have been accepted, or are being evaluated, for lung transplantation. For these patients, there is a possibility of prolonging life if they are successfully treated for their acute episode of respiratory failure until transplantation. In this group, treatment is not merely prolonging the process of dying.     

Functional implications of BAL in the presence of restrictive or obstructive lung disease

Most of the complications associated to bronchoscopy are related to changes of the respiratory function during or after its performance. Prevention of complications should be achieved by understanding the effects of bronchoscopic procedures and their relation to the pulmonary function deterioration. Previous studies regarding the functional impairment caused by bronchoalveolar lavage (BAL) were mostly limited by the presence of interferent factors such as sedative drugs. Furthermore, it is not clear whether or not patients with different ventilatory disturbances present the same functional response to bronchoscopy and BAL. The aim of this study was to determine the additional effects of BAL over the respiratory function deterioration related to bronchoscopy in patients with different respiratory function profiles (normal, restrictive and obstructive). Forty patients submitted to bronchoscopy without premedication were divided into four groups: group I-normal pulmonary function submitted to basic bronchoscopy; group II-bronchoscopy in combination with BAL, subdivided according to pulmonary function: group IIa (normal function), group IIb (restrictive ventilatory disturbances) and group IIc (obstructive ventilatory disturbances). Spirometry was made before and after the bronchoscopic procedure. Baseline hemoglobin saturation was compared to the lowest level during the procedure. Functional worsening caused by the procedure was observed with a decrease in forced vital capacity (FVC), forced expiratory volume in the first second (FEV(1)) and Hemoglobin saturation in all groups. Comparison between groups showed no significant difference regarding the changes in FVC (P=0.8324), FEV(1) (P=0.6952) and hemoglobin saturation (P=0.5044). We conclude that standardized BAL, like the one used in our study, does not result in an increased risk for ventilatory impairment compared to bronchoscopy itself, independently of the presence of previous respiratory disease.     

Respiratory function after esophagectomy for patients with esophageal cancer

BACKGROUND/AIMS: Postoperative respiratory hypofunction sometime ruins quality of life of patients with esophageal cancer. From 1993, we introduced transhiatal esophagectomy without thoracotomy as a less invasive surgery to prevent postoperative respiratory complications for patients who have relatively early stage of esophageal cancer and have preoperative respiratory complication, or who are older in age. In this study, postoperative long-term evaluation of respiratory functions of patients with esophageal cancer who underwent esophagectomy was performed. METHODOLOGY: Among the patients with esophageal cancer who underwent esophagectomy in our hospital between 1993 and 1995, we selected 13 patients who underwent transhiatal esophagectomy (transhiatal group) and 9 patients who underwent transthoracic esophagectomy (transthoracic group). Conventional respiratory function tests (VC, vital capacity; FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; FEV1/FVC, ratio of FEV1 to FVC; PEF, peak expiratory flow) were compared between the two groups at 3, 6, and 12 months after operation. RESULTS: In the transhiatal group, postoperative average values of VC, FVC, and FEV1 recovered 92%, 98%, and 93% of preoperative average values at 6 months after operation, while in the transthoracic group, the average values of VC, FVC, and FEV1 were still 78%, 78%, and 72% of preoperative average values at 6 months after operation. Postoperative respiratory complications were detected in 4 patients (transhiatal: 2 and transthoracic: 2). The recovery rates of VC, FVC, FEV1, FEV1/FVC, and PEF at 6 months after operation of these 4 patients were not different from those of 18 patients without postoperative respiratory complications. CONCLUSIONS: In patients treated with transthoracic esophagectomy, postoperative respiratory hypofunctions continued over 6 months after surgery. However, postoperative respiratory complications may not be related with the long-term postoperative respiratory hypofunction in patients with esophageal cancer.     

Non-invasive assessment of respiratory muscle strength in patients with previous poliomyelitis

In patients with poliomyelitis, respiratory failure requiring ventilatory support may occur during the acute illness. Some patients continue to require long-term nocturnal ventilatory support; others are weaned but subsequently require support because of a late deterioration in ventilatory function. OBJECTIVES: To assess the sensitivity of sniff nasal inspiratory pressure (SNIP) to post-poliomyelitis respiratory muscle weakness and to assess the relationship between the respiratory muscle strength and the need for ventilatory support in patients with previous poliomyelitis (post-polio patients). METHODS: Respiratory muscle strength was measured in 50 post-polio patients. Tests included forced vital capacity (FVC), maximum inspiratory and expiratory pressures (MIP and MEP), and SNIP. RESULTS: Twenty-one patients used non-invasive nocturnal ventilatory support (NIV group) compared to 29 on no support (non-NIV group). The percentage predicted FVC was significantly lower in the NIV group compared to the non-NIV group (P=0.01). Similarly, the percentage predicted MIP was significantly lower in NIV group (P=0.007). Low SNIP values (both absolute value and percentage predicted) were associated with the need for ventilatory support (P<0.001). Of the patients requiring no support, those who had been ventilated during the acute episode of poliomyelitis had a significantly lower SNIP than those who had never been ventilated (P=0.04). CONCLUSIONS: Post-polio patients who are currently on nocturnal ventilation have significantly lower FVC, MIP and SNIP compared to currently non-ventilated patients. Non-ventilated patients who were ventilated during the acute episode of poliomyelitis have significantly weaker respiratory muscle strength than patients who were never ventilated. This study indicates that SNIP is more sensitive to post-polio respiratory muscle weakness than other non-invasive tests. Thus measurement of SNIP is a valuable tool for monitoring the progression of respiratory muscle weakness due to previous poliomyelitis and this can be applied to other neuromuscular disorders.     

Clinical correlations and pulmonary function at 8 years of age after severe neonatal respiratory failure

OBJECTIVES: The aim of this study was to determine the pulmonary sequelae of severe neonatal respiratory failure. STUDY DESIGN: This was a multicenter, prospective study. Fifty-four survivors of neonatal respiratory failure (oxygenation indices >25 on two occasions), completed pulmonary function testing at 8 years of age. Thirty-one (57%) received extracorporeal membrane oxygenation (ECMO). Pulmonary outcome was based on spirometry and lung volume data. Pulmonary outcome for each diagnostic and treatment group is reported as mean and as percent predicted. Individually subjects were also classified based on spirometry, as either normal, obstructed (defined as forced expiratory volume (FEV(1)) in 1 sec:forced vital capacity (FVC) of <80 % predicted, or with reduced FVC (FCV of <80% predicted) with normal FEV(1)/FVC. Risk for adverse outcome was determined using univariate analysis. RESULTS: Mean FVC, FEV(1) and FEV(25-75) were reduced in the total cohort. The reduction was greatest in the subgroup with CDH and the group treated with ECMO. Assessed individually, 54% of subjects had normal spirometry and lung volumes, 19% airflow obstruction, and 27% reduced FVC. Poorer pulmonary outcome was linked to ECMO, congenital diaphragmatic hernia (CDH), birth weight for gestational age <10th percentile, duration of hospitalization, or need for prolonged supplemental oxygen. CONCLUSION: Neonates with severe respiratory failure due to CDH or needing ECMO and small for gestation are at increased risk of poorer pulmonary outcome and require close follow-up.     

双水平气道正压治疗慢性阻塞性肺疾病合并呼吸衰竭的临床疗效分析

目的观察双水平气道正压(BiPAP)无创机械通气(NIV)治疗慢性阻塞性肺疾病(COPD)合并呼吸衰竭的临床疗效。方法选择成都市第六人民医院呼吸内科2016年1月至2018年12月收治的120例COPD合并呼吸衰竭患者作为研究对象,将其随机分为2组,对照组(n=60)给予常规药物治疗+鼻导管低流量吸氧治疗,试验组(n=60)给予常规药物治疗+BiPAP联合NIV治疗;观察试验组和对照组患者治疗前和治疗后7 d的心率(HR)、呼吸频率(RR)、酸碱值(pH值)、动脉血二氧化碳分压(PaCO2)、动脉血氧分压(PaO2)、动脉血氧饱和度(SaO2),肺功能指标包括用力肺活量(FVC)、第1秒用力呼气容积(FEV1)、第1秒用力呼气容积占预计值百分比(FEV1%pred)、急性生理功能与慢性健康评分表Ⅱ(APACHEⅡ)、血气改善时间和住院时间,统计试验组和对照组患者治疗前的并发症发生情况。结果试验组和对照组患者治疗前的HR、RR、pH值、PaCO2、PaO2、SaO2、FVC、FEV1、FEV1%pred、APACHEⅡ比较,差异无统计学意义(t=1.306、1.041、1.058、1.140、1.026、1.260、1.021、1.274、1.165、1.529,P值均>0.05),但治疗后组间HR、RR、pH值、PaCO2、PaO2、SaO2、FVC、FEV1、FEV1%pred、APACHEⅡ各项指标比较,差异有统计学意义(t=3.254、3.985、3.052、4.162、3.262、5.124、3.544、3.127、5.251、3.184,P值均<0.05);试验组和对照组患者的血气改善时间、住院时间、并发症发生率比较,差异有统计学意义(t=3.658、5.187,χ2=26.359,P值均<0.05)。结论BiPAP NIV可以有效治疗COPD合并呼吸衰竭,但需注意加强针对性护理干预,降低相关并发症发生风险。     

Effect of unilateral pulmonary vagotomy on respiratory control in man

We studied the breathing pattern and pulmonary function at rest, and ventilatory responses to progressive hypoxia and hypercapnia in 7 awake patients who had undergone esophageal-carcinoma resection with sectioning of the right pulmonary vagal branch by lymphadenectomy. Twelve control patients, who had received the same surgery without vagotomy, were also studied by the same protocol. Two months after the operation, both patient groups demonstrated substantial depressions in FVC and FEV1.0, and slight augmentations in breathing frequency, minute ventilation, and occlusion pressure at 0.2s (P0.2) at rest. In the vagotomized group, the occlusion pressure responses to hypercapnia (delta P0.2/delta PaCO2) and hypoxia (delta P0.2/delta SaO2) in terms of response curve slope increased from 1.3 +/- 1.2 to 1.9 +/- 1.1 cm H2O/Torr and from 0.29 +/- 0.19 to 0.88 +/- 0.53 cm H2O/% (p less than 0.05), respectively. Contrary to the vagotomized patients, the nonvagotomized control group exhibited no significant changes in ventilatory chemosensitivities. Furthermore, when comparing the control and vagotomized groups, postoperative ventilatory chemosensitivity responses in terms of both hypercapnic and hypoxic occlusion pressure responses were significantly higher in the latter. We suggest that (1) due to the development of the substantial mechanical limitation in pulmonary functions, the Hering-Breuer inflation reflex became activated after surgery, and (2) a diminished Hering-Breuer reflex effect to inhibit the respiratory centers by unilateral vagotomy may have resulted in augmented ventilatory chemosensitivities.     

The interaction of ageing and lung disease

This article explores the structural and physiological changes that occur in the ageing lung, and the impact that lung disease and other co-morbidities may have on it. The major changes associated with ageing are reduced lung elasticity, respiratory muscle strength and chest wall compliance, all of which may be influenced by impaired lung growth in early childhood and adolescence. The resultant reduction in diffusing capacity may not be relevant in a fit older adult, but co-morbidities may interact to cause breathlessness and impairments in quality of life. Lung function declines with age, but forced vital capacity (FVC) begins to decline later than forced expiratory volume in 1?s (FEV(1)) and at a slower rate. This results in a natural fall in the FEV(1)/forced vital capacity (FVC) ratio which may result in overdiagnosis of chronic obstructive pulmonary disease, and hence the need to ensure the FEV(1) is less than 80% before confirming the diagnosis. As older adults probably have a diminished response to hypoxia and hypercapnia, they become more vulnerable to ventilatory failure during high-demand states such as heart failure and pneumonia and therefore to possible poorer outcomes. Poor nutritional status is likely to be an important factor, as is cognitive impairment. It is important to assess older patients using a range of clinical and physiological parameters rather than on the basis of age per se which is a poor predictor of outcome.     

Weaning from mechanical ventilation by long-term nasal positive pressure ventilation in two patients with acute respiratory distress syndrome associated with pneumococcal sepsis

Only few data concerning weaning by nasal positive pressure ventilation (NPPV) are available, and successful weaning by using NPPV in patients with acute respiratory distress syndrome (ARDS) and severe complications has not yet been described. Two cases with ARDS and both preexisting thoracopulmonary disease (infundibulum abnormality and suspected COPD) and associated complications (recurrent sepsis, acute renal failure, need for lobectomy, severe malnutrition) could not be weaned by invasive ventilatory techniques. Both patients presented with rapid shallow breathing and PaCO(2) values >60 mm Hg during intermittent trials of spontaneous breathing, although the primary pathology and associated complications had been resolved. Patients were successfully adapted on NPPV in a stepwise approach after 93 days and 67 days of invasive ventilation. In one patient withdrawal from NPPV was possible after 2 months. In the other patient the duration of daily ventilation could be significantly reduced from 18 to 6 h/day after 9 months on NPPV. Therefore, patients with ARDS who cannot be weaned by invasive ventilatory strategies might be removed successfully from invasive mechanical ventilation by using NPPV even when there are preexisting thoracopulmonary disease and major complications during invasive ventilation.     

Improvement of “irreversible” airway obstruction by thiazinamium (Multergan®)

Thiazinamium (Multergan®, 50 mg intramuscularly) improved lung function (forced expiratory volume in one second [FEV_1.0]; forced vital capacity [FVC]) within one hour after injection in 11 men (average age 66.4 years) with chronic cough, phlegm, and dyspnea, and with severe ventilatory function loss (average FEV_1.0, 42.5% of predicted values; average FVC, 64.6%) due to prolonged exposure (≥28 years) to dust of soft hemp in industry. The increase of FEV_1.0 and of FVC after thiazinamium was significantly greater than that observed after isoproterenol inhalation in the same subjects. The acute effect of thiazinamium, which lasted at least six hours, was maintained over a one-month period of daily injections. Oral administration of 200 mg thiazinamium had little effect on FEV_1.0 and FVC. The results suggest that "irreversible" airway obstruction may be more amenable to drug treatment than is often thought.     

Pulmonary involvement in inflammatory bowel disease

AIM:To determine the relationship of pulmonary abnormalities and bowel disease activity in inflammatory bowel disease(IBD).METHODS:Thirty ulcerative colitis(UC)and nine Crohn’s disease patients,and 20 control subjects were enrolled in this prospective study.Detailed clinical information was obtained.Extent and activity of the bowel disease were established endoscopically.Each patient underwent pulmonary function tests and high-resolution computed tomography(HRCT).Blood samples for measurement of C-reactive protein(CRP),erythrocyte sedimentation rate(ESR),angiotensin converting enzyme and total IgE were delivered by the patients.RESULTS:Ten(25.6%)patients had respiratory symptoms.A pulmonary function abnormality was present in 22 of 39 patients.Among all patients,the most prevalent abnormalities in lung functions were a decrease in forced expiratory volume in 1 s(FEV1),FEV1/forced vital capacity(FVC),forced expiratory flow(FEF)25%-75%,transfer coefficient for carbon monoxide(DLCO),DLCO/alveolar volume.Increased respiratory symptoms score was associated with high endoscopic activity index in UC patients.Endoscopic and clinical activities in UC patients were correlated with FEV1,FEV1/FVC,and FEF 25%-75%.Smoking status,duration of disease and medication were not correlated with pulmonary physiological test results,HRCT abnormalities,clinical/endoscopic disease activity,CRP,ESR or total IgE level or body mass index.CONCLUSION:It is important that respiratory manifestations are recognized and treated early in IBD.Otherwise,they can lead to destructive and irreversible changes in the airway wall.     

BiPAP呼吸机治疗COPD急性呼吸衰竭的疗效

目的　探讨 (鼻 )面罩双水平气道正压通气 (Bi PAP)治疗在慢性阻塞性肺部疾病 (COPD)急性呼吸衰竭的治疗作用。方法　 5 2例 COPD急性加重合并呼吸衰竭患者应用 Bi PAP呼吸机辅助通气治疗 ,记录通气治疗前及通气治疗 2 h、2 4 h条件下患者的血气分析及第一秒用力肺活量 (FEV1 )、用力肺活量 (FVC)。结果　治疗前二氧化碳分压 (Pa CO2 ) (76± 15 ) mm Hg,肺功能 FVC(1.2 8± 0 .2 0 ) L ;治疗后 Pa CO2 (4 0± 9) mm Hg,FVC(1.32± 0 .2 0 )L,二者无显著性差异 (P>0 .0 5 )。而治疗前动脉血氧分压 (Pa O2 ) (4 8± 12 ) mm Hg,FEV1 (0 .6 7± 0 .0 7) L,治疗后Pa O2 (88± 16 ) mm Hg,FEV1 (0 .85± 0 .2 0 ) L,二者有显著差异 (P<0 .0 5 )。结论　应用 Bi PAP呼吸机辅助通气治疗COPD急性呼吸衰竭可提高 Pa O2 ,降低 Pa CO2 ,改善肺功能。