bluuebunny/crossref_metadata_2025 huggingface dataset:
Resting energy expenditure in cryptogenic fibrosing alveolitis
Authors: Congleton J , Muers MF
Published: January 2003

A proportion of patients with chronic airflow limitation appear to have a raised resting energy expenditure (REE). This has been suggested as the reason for weight loss which may occur in these patients. A previous study found an increased REE in patients with interstitial lung disease of mixed aetiology. We were interested in studying REE in a more homogeneous group, with cryptogenic fibrosing alveolitis (CFA). Twenty patients with CFA were studied. They were compared with 18 controls matched for age, sex, weight and height. REE was measured by indirect calorimetry. Fat-free mass (FFM), was estimated by anthropometry. Patients had respiratory function tests performed, disability related to breathlessness was assessed by the activity section of the St George's Respiratory Questionnaire. Mean REE in the CFA group was not different from the control group: 5.20 (0.56) versus 5.12 (0.51) kj x h(-1) x kgFFM(-1). REE was elevated to greater than 110% of the value predicted by the Harris-Benedict equation in one CFA patient and in no control subjects. There was no correlation of REE with weight, pulmonary function tests, arterial oxygen saturation or activity score. The prevalence of a raised resting energy expenditure in cryptogenic fibrosing alveolitis patients with low transfer factor and relatively preserved vital capacity is low, and is less than that reported previously in a group of patients with interstitial lung disease of mixed aetiology.
Effects of single-dose zileuton on bronchial hyperresponsiveness in asthmatic patients treated with inhaled corticosteroids
Authors: Dekhuijzen PN , Bootsma GP , Wielders PL , van den Berg LR , Festen J , van Herwaarden CL
Published: January 2003

The aim of the study was to determine whether zileuton, an inhibitor of 5-lipoxygenase, attenuated bronchial hyperresponsiveness (BHR) in asthmatic subjects who had marked BHR during maintenance treatment with inhaled corticosteroids (ICS). In a randomized, double-blind, placebo-controlled, cross-over study, a challenge test with histamine (provocative concentration of histamine producing a 20% fall in forced expiratory volume in one second (FEV1) (PC20,Hist)) and with ultrasonically nebulized distilled water (UNDW) (provocative dose of UNDW producing a 20% fall in FEV1 (PD20,UNDW)) was performed in seven patients with asthma after intake of either 400 mg zileuton or placebo. All patients (mean age 33 yrs, mean FEV1 111% of predicted) had marked BHR, as indicated by a mean PD20,UNDW of 4.74 mL under treatment for at least 6 months with up to 800 microg ICS (mean 536 microg daily). On four different occasions, separated by at least 5 days, two UNDW and two histamine challenge tests were performed in random order 3 h after a morning dose of either zileuton or placebo. Neither zileuton nor placebo changed baseline airway calibre prior to provocation. Zileuton increased PC20,Hist from 0.99 to 5.64 mg x mL(-1) (2.1 doubling doses; p<0.03 compared to placebo), and increased PD20,UNDW from 3.10 to 9.31 mL (1.3 doubling doses; p<0.05 compared to placebo). In conclusion, a single dose of 400 mg zileuton attenuates bronchial hyperresponsiveness to histamine and ultrasonically nebulized distilled water in asthmatic patients with marked bronchial hyperresponsiveness during treatment with inhaled corticosteroids.
Comparison of addition of theophylline to inhaled steroid with doubling of the dose of inhaled steroid in asthma
Authors: Ukena D , Harnest U , Sakalauskas R , Magyar P , Vetter N , Steffen H , Leichtl S , Rathgeb F , Keller A , Steinijans VW
Published: January 2003

The anti-asthmatic effects of theophylline may supplement those of inhaled steroids in asthma. The aim of the present trial was to study how the addition of theophylline compares to doubling the dose of inhaled steroid in asthmatics who remain symptomatic on beclomethasone dipropionate (BDP) 400 microg x day(-1). The trial was designed as a randomized, double-blind, parallel-group study in several European countries. Sixty nine patients were treated for 6 weeks with theophylline plus BDP 400 microg x day(-1), compared to 64 patients treated with BDP 800 micro x day(-1). The mean+/-SD serum theophylline concentration was 10.1+/-4.2 mg x L(-1). Lung function measurements were made throughout the study and patients kept daily records of peak expiratory flow (PEF), symptoms and salbutamol usage. Forced expiratory volume in one second and PEF at week 6 were significantly increased by both treatments (p<0.01). PEF variability was reduced by about 30% in both groups. There were significant improvements in asthma symptoms and rescue medication use (p<0.001). There were no significant differences between the treatment groups. The study demonstrated clinical equivalence of theophylline plus beclomethasone dipropionate 400 microg x day(-1) and beclomethasone dipropionate 800 microg x day(-1) in patients whose asthma is not controlled on beclomethasone dipropionate 400 microg x day(-1). The results support the use of theophylline as a steroid-sparing agent. The combination of low-dose inhaled steroid plus theophylline is a suitable treatment for moderate asthma.
Inadequate antiasthma drug use in the north of Italy
Authors: Cerveri I , Zoia MC , Bugiani M , Corsico A , Carosso A , Piccioni P , Casali L , De Marco R
Published: January 2003

A multicentre survey of prevalence, determinants and management of asthma (the European Community Respiratory Health Survey (ECRHS)) has shown that the ratio of subjects declaring current use of antiasthmatic drugs to those reporting asthma attacks in the previous 12 months was particularly low (0.54) in the north of Italy. In this study, we used a standardized clinical interview to gather a more detailed insight into the issue of asthma undertreatment in the north of Italy. A total of 1,104 subjects were interviewed, 116 of whom had been defined as asthmatic by the family doctor. Fifty subjects had current asthma and 66 had a history of previous asthma. A considerable percentage (26%) of subjects with current asthma were not being treated with antiasthmatic therapy. Even when only patients with severe asthma were considered, the percentage of untreated patients was still high (21%). Forty two per cent of subjects used inhaled beta2-agonists alone, 28% inhaled steroids plus beta2-agonists, 2% inhaled steroids alone and 2% other drugs. Only 19% of the asthmatics on treatment, 85% of whom had more severe asthma, received daily treatment. Only 65% of the subjects who had received antiasthmatic drug prescriptions declared they had taken all the drugs prescribed; this percentage was 74% when respiratory symptoms were worsening. Of the patients with past asthma, 18% had taken antiasthmatic drugs. Most of these patients were those who had had more severe asthma. In conclusion, antiasthmatic drugs are underused in the north of Italy, at least in part due to low compliance.
Investigations on the renin-angiotensin system in acute severe asthma
Authors: Ramsay SG , Dagg KD , McKay IC , Lipworth BJ , McSharry C , Thomson NC
Published: January 2003

The renin-angiotensin system is activated in acute severe asthma. The precise mechanism of activation is at present unknown, but may involve, beta2-agonists, catecholamines or proteases released in airway inflammation. This study aims to identify potential factors involved in the activation of the renin-angiotensin system in acute asthma. Forty asthmatics with severe exacerbations of asthma, assessed by measurement of peak expiratory flow rate (mean (SD) 35 (18)% predicted), oxygen saturation (94 (4)%) and pulse rate (108 (16) beats x min(-1)) were recruited. Nineteen (48%) asthmatics had elevated plasma angiotensin II levels (median (interquartile range) 10.9 (4.3-23.5) pg x mL(-1) (normal range 3-12 pg x mL(-1))) and 10 (25%) had elevated plasma renin concentration (22.0 (10.0-50.0) microU x mL(-1) (normal range 9-50 microU x mL(-1))). Plasma renin and angiotensin II correlated strongly, implying renin-dependent angiotensin II formation. No correlation was found between plasma salbutamol, adrenaline, nor-adrenaline, endothelin-1, histamine, eosinophilic cationic protein, serum angio-tensin-converting enzyme (ACE) activity, total immunoglobulin E (IgE), urea and electrolytes, indicators of the severity of the attack, atopic status, blood pressure and renin or angiotensin II levels. We conclude that although a subpopulation of asthmatics appear to have raised renin and angiotensin II during attacks of acute, severe asthma, the mechanism of activation of the renin-angiotensin system remains unclear.
Lack of correlation between bronchoconstrictor response and bronchodilator response in a population-based study
Authors: Douma WR , de Gooijer A , Rijcken B , Schouten JP , Koeter GH , Weiss ST , Postma DS
Published: January 2003

Bronchodilator and bronchoconstrictor responsiveness have been considered physiological opposites in patients with obstructive airways disease. Provocation challenges have been replaced by bronchodilator tests in the assessment of cases of severe airways obstruction. The aim of this study was to examine the relationship between bronchoconstrictor and bronchodilator responsiveness, and their supposed interchangeability, in a general population. From the Vlagtwedde-Vlaardingen follow-up study, 101 adults were recruited (mean (SD) age 55 (11) yrs, 67 males and 34 females, and 31 were smokers). All completed a questionnaire on airways symptoms. Bronchoconstrictor and bronchodilator responsiveness were assessed with cumulative dose-response curves, using histamine and terbutaline, respectively. Thus, it was possible to relate histamine sensitivity of the airways (the concentration of histamine, at which forced expiratory volume in one second (FEV1) falls by 10% (PC10)) to the maximal bronchodilator response (delta FEV1) and the sensitivity to the bronchodilator (cumulative dose of inhaled terbutaline at which FEV1 increases by 10% (RD10)). Subjects with a bronchoconstrictor response (PC10 < or = 16 mg x mL(-1); n=38) had more respiratory symptoms than those without (n=63) (40 versus 21%) and also lower baseline FEV1 values (90 versus 96% predicted), but had comparable bronchodilator responsiveness. Subjects with a bronchodilator response (delta FEV1 > or = 9% of the predicted value; n=13) did not differ from those without (n=88) for all parameters, including symptoms, allergy and pulmonary function. In those with a bronchoconstrictor response, there was a weak but significant correlation between the PC10 and RD10 (rho=-0.32), but not between PC10 and delta FEV1. This study suggests that bronchoconstrictor and bronchodilator responsiveness are not highly correlated, even in subjects with airways obstruction. Symptoms were associated with the presence of a bronchoconstrictor, but not a bronchodilator, response. We conclude that bronchoconstrictor and bronchodilator responsiveness are two different phenotypic markers that are not interchangeable in epidemiological studies.
Dependence of human respiratory thermal washout on extrathoracic airway conditions
Authors: Kaufman JW
Published: January 2003

Thermal washout curves have been proposed as noninvasive tools for analysing lower airway dimensions and pulmonary blood flow, but how upper airway heat transfer affects these washout curves is unclear. The present study was designed to compare extrathoracic and tracheobronchial contributions to thermal washout curves. Respiratory frequency, air ambient temperature, and body core temperature (tc) were varied in six male subjects before and after immersion in cold (1.1 degrees C) water for up to 2 h under three conditions: 1) control: ambient temperature (tamb) = 25 degrees C, rectal temperature change (delta tre) = 0 degrees C; 2) pre-immersion: tamb = 4 degrees C, delta tre = 0 degrees C; and 3) post-immersion: tamb = 25 degrees C, delta tre = -0.7 degrees C. Both peak expiratory nasal (tpn) and oral (tpo) airstream temperatures were measured. Each subject was tested twice. Expiratory tpo was generally higher than tpn in all conditions. Increasing breathing rates lowered tpn and tpo in the control and cold air environments. Orifice temperatures, which are presumed to reflect upper airway blood temperatures, correlated with both tpn and tpo. Lowering tc had no effect on washout curves during quiet breathing and affected only tpn during rapid breathing. The results suggest that while tracheobronchial conditions may contribute to thermal washout curves, extrathoracic conditions predominate. Strong correlations between orifice temperatures, peak expiratory nasal temperatures and peak expiratory oral temperature demonstrate the dominant role of upper airway heat exchange in determining thermal washout curves.
Bronchiectasis: an orphan disease with a poorly-understood prognosis
Authors: Keistinen T , Saynajakangas O , Tuuponen T , Kivela SL
Published: January 2003

The prognosis and risk factors for bronchiectasis are at present poorly known. The aim of this study was to examine the long-term prognosis and cause of death in this disease. The National Hospital Discharge Register was used to search for patients aged 35-74 yrs, with newly-diagnosed bronchiectasis in the period 1982-1986. Each of the 842 patients identified was matched with an asthmatic patient and a patient with chronic obstructive pulmonary disease (COPD), who were of the same age and sex and who had been treated in hospital at the same time. The use of hospital services by these subjects was examined up to the end of 1992, and mortality to the end of 1993. The prognosis for the bronchiectatic patients treated in hospital was better than that for the COPD patients but poorer than that for the asthmatics; the risk of death being 1.25 (95% confidence interval (95% CI) 1.15-1.36) for the COPD patients and 0.79 (95% CI 0.71-0.87) for the asthmatics, relative to the bronchiectatic patients. Bronchiectasis was the main cause of death in 13% of bronchiectatic patients, the risk of death being increased by a factor of 1.21 in the presence of asthma as the main secondary diagnosis, by 1.31 with COPD, by 1.35 with tuberculosis and its sequelae, and by 1.32 with some other secondary diagnosis, as compared with cases for which no secondary diagnosis was indicated. The fact that the prognosis for bronchiectatic patients is poorer than that for asthmatics points to a continued need for focused care and follow-up, particularly in the presence of additional illnesses.
Potentiative effects of neutral proteinases in an inflamed lung: relationship of neutrophil procollagenase (proMMP-8) to plasmin, cathepsin G and tryptase in bronchiectasis in vivo
Authors: Sepper R , Konttinen YT , Buo L , Eklund KK , Lauhio A , Sorsa T , Tschesche H , Aasen AO , Sillastu H
Published: January 2003

We attempted to study the possible relationships between neutrophil-type procollagenase/pro-matrix metalloproteinase (MMP-8) and the serine proteinases plasmin, cathepsin G and tryptase in bronchiectasis. The presence of the plasmin/plasminogen system and plasmin-, cathepsin G- and tryptase-like activities were compared to the activity of endogenously activated MMP-8 in bronchoalveolar lavage (BAL) fluid in 38 bronchiectasis patients and in 14 healthy controls by means of immunohistochemistry, Western-blot and substrate-based functional assays. In contrast to cathepsin G- and tryptase-like activities, the plasmin/plasminogen activator system in BAL fluid was observed to have a relatively weak activation stage and no correlation with disease severity. Neither plasmin-like activities nor concentrations of plasminogen activators from the bronchiectatic patients differed significantly from the values of healthy controls. Immunolocation of plasminogen activator inhibitor-1 showed a marked, but not significant, increase in bronchiectatic lung as compared to controls. In contrast to cathepsin G- and tryptase-like activities, with their strong and significant correlation with endogenously activated collagenase (r=0.9; p=0.0001; and r=0.6; p=0.03, respectively), no correlations were observed between plasmin-like and endogenously activated collagenase (r=0.3; p=0.2) in bronchiectasis. These findings suggest that cathepsin G- and tryptase-like activities may act as potent pro-matrix metalloproteinase-8 activators in patients with bronchiectasis, whereas the plasminogen activator/plasmin cascade was shown to be down-regulated.
Co-morbidity contributes to predict mortality of patients with chronic obstructive pulmonary disease
Authors: Antonelli Incalzi R , Fuso L , De Rosa M , Forastiere F , Rapiti E , Nardecchia B , Pistelli R
Published: January 2003

The aim of this study was to assess the prognostic role of co-morbidity in severe chronic obstructive pulmonary disease (COPD). A cohort of 270 COPD patients, mean (+/-SD) age 67+/-9 yrs, consecutively discharged from a University Hospital after an acute exacerbation was studied. Mean (+/-SD) forced expiratory volume in one second (FEV1) was 34+/-16% of predicted and FEV1/forced vital capacity (FVC) was 40.5+/-13.8%. The most common co-morbid diseases were: hypertension (28%), diabetes mellitus (14%), and ischaemic heart disease (10%). Clinical, electrocardiogram (ECG), and respiratory function data taken at the time of discharge were collected from the clinical records. The Charlson's index was used to quantify co-morbidity. Follow-up was conducted by means of telephone calls. Multivariate survival analysis was used to identify the independent predictors of death. The median survival of the cohort was 3.1 yrs. Death was predicted by the following variables: age (hazard rate (HR) 1.04; 95% confidence intervals (95% CI) 1.02-1.05), ECG signs of right ventricular hypertrophy (HR 1.76; 95% CI 1.30-2.38), chronic renal failure (HR 1.79; 95% CI 1.05-3.02), ECG signs of myocardial infarction or ischaemia (HR 1.42; 95% CI 1.02-1.96), FEV1 < 590 mL (HR 1.49; 95% CI 0.97-2.27). A score based upon these variables predicted mortality at 5 yrs with a sensitivity of 63% and a specificity of 77%. Selected co-morbid diseases and electrocardiogram signs of right ventricular hypertrophy play a major prognostic role in advanced chronic obstructive pulmonary disease. The clinical assessment of patients with chronic obstructive pulmonary disease should include these important and easily measurable variables.
Out-patient rehabilitation improves activities of daily living, quality of life and exercise tolerance in chronic obstructive pulmonary disease
Authors: Bendstrup KE , Ingemann Jensen J , Holm S , Bengtsson B
Published: January 2003

The purpose of this study was to investigate the effects on activities of daily living, quality of life, and exercise tolerance of a comprehensive out-patient rehabilitation programme for patients with moderate-to-severe chronic obstructive pulmonary disease. In this randomized and controlled trial, the main outcome measures were Activities of Daily Living (ADL) score, York Quality of Life Questionnaire (YQLQ) score, Chronic Respiratory Disease Questionnaire (CRDQ) score, 6 min walking distance (6MWD), forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). The rehabilitation programme included physical training, occupational therapy, education, and smoking cessation therapy, and lasted for 12 weeks. The patients were evaluated at entry, halfway through, and at the end of the programme. Follow-up was at 24 weeks. Forty seven patients were recruited, and 16 in each group completed the trial. There were significant differences in the improvements in ADL and CRDQ between the control and the treatment groups at 12 and 24 weeks, and at 24 weeks, respectively. At 6, 12 and 24 weeks, improvements in the 6MWD were 21.6 versus 79.8, 36.1 versus 113.1 and 21.4 versus 96.2 for control and treatment groups, respectively (p<0.004). A correlation matrix showed only ADL and 6MWD to be significantly correlated; the matrix was also used to validate the translated questionnaires. The programme required 124 staff-hours in total. An inexpensive, comprehensive out-patient rehabilitation programme can produce long-term improvement in activities of daily living, quality of life, and exercise tolerance in patients with moderate-to-severe chronic obstructive pulmonary disease.
Peak exercise response in relation to tissue depletion in patients with chronic obstructive pulmonary disease
Authors: Baarends EM , Schols AM , Mostert R , Wouters EF
Published: January 2003

In several studies a correlation between body weight and peak exercise capacity has been found in patients with chronic obstructive pulmonary disease (COPD). In the present study a thorough analysis of the relationship between body composition and peak exercise performance was executed in 62 patients with clinically stable COPD. This was based on the hypothesis that particularly muscle mass, as the largest constituent of both fat-free mass (FFM) and body cell mass, is related to exercise capacity. Body composition was assessed using deuterium and bromide dilution techniques, to measure total body water (TBW) and extracellular water. From these measurements FFM:TBW/0.73, the ratio of ECW/intracellular water (ICW) and ICW-index (ICW/height2) were calculated. Peak exercise performance was measured using an incremental cycle ergometry test. The transfer factor of the lung for carbon monoxide (TL,CO) intrathoracic gas volume (ITGV), maximal expiratory and inspiratory mouth pressure, forced expiratory volume in one second (FEV1), FFM-index (FFM/height2), body mass index (weight/height2) and ICW-index correlated strongly (p<0.01) to peak oxygen consumption (V'O2). The ratio ECW/ICW correlated only weakly, but significantly, with peak V'O2 (r=-0.25, p<0.05). Stepwise regression analysis demonstrated that FFM-index and TL,CO explained 53% of the variation in peak V'O2. The results of this study furthermore indicate that severe FFM depletion is related to a blunted tidal volume response to peak exercise, a decreased peak oxygen pulse and an early anaerobic metabolism in patients with COPD. Depletion of muscle mass, measurable by assessment of fat-free mass, significantly effects peak oxygen consumption, ventilatory response, the oxygen pulse and anaerobic energy metabolism in patients with chronic obstructive pulmonary disease.
Evaluation of a movement detector to measure daily activity in patients with chronic lung disease
Authors: Schonhofer B , Ardes P , Geibel M , Kohler D , Jones PW
Published: January 2003

This study was designed to evaluate the performance of movement detectors (pedometers) in measuring daily activity of patients with chronic lung disease. Three groups of subjects were studied: group 1: 25 patients with stable nonhypercapnic chronic obstructive pulmonary disease (COPD) (forced expiratory volume in one second (FEV1) = 47+/-9% predicted) studied twice, one month apart; group 2: 25 patients with chronic respiratory failure studied before and three months after nasal nocturnal mechanical ventilation; and group 3: 25 normal healthy subjects studied once. The median level of activity in the healthy subjects (group 3) was three times greater than in either group of patients (groups 1 and 2). Activity levels were not correlated with age, sex or employment status. The repeatability of the activity counts in the nonhypercapnic COPD patients was high (intraclass correlation coefficient=0.94) and in these patients activity correlated significantly with FEV1 (r=0.54, p=0.006). In the respiratory failure patients, daytime arterial carbon dioxide pressure (Pa,CO2) improved following nasal nocturnal mechanical ventilation (NMV) (pre NMV: 8.5+/-1.2 kPa; post NMV: 6.2+/-0.5 kPa), health status improved (p<0.004) and daily movement count doubled (p<0.0001). This increase correlated with change in Pa,CO2 (r-0.53, p=0.006), but not with improved health status. We conclude that motion detectors may provide repeatable measures of daily activity that are related to physiological impairment and improvement following treatment. Activity counts appear to be complementary to estimates of exercise limitation obtained using health questionnaires.
Effects of inspiratory flow waveforms on arterial blood gases and respiratory mechanics after open heart surgery
Authors: Polese G , Lubli P , Poggi R , Luzzani A , Milic-Emili J , Rossi A
Published: January 2003

The clinical usefulness of inspiratory flow pattern manipulation during mechanical ventilation remains unclear. The aim of this study was to investigate the effects of different inspiratory flow waveforms, i.e. constant, sinusoidal and decelerating, on arterial blood gases and respiratory mechanics, in mechanically ventilated patients. Eight patients recovering after open heart surgery for valvular replacement and/or coronary bypass were studied. The ventilator inspiratory flow waveform was changed according to a randomized sequence, keeping constant the other variables of the ventilator settings. We measured arterial blood gases, flow, volume and pressure at the proximal (airway opening pressure (Pao)) and distal (Ptr) ends of the endotracheal tubes before and after 30 min of mechanical ventilation with each inspiratory flow waveform. We computed breathing pattern, respiratory mechanics (pressures and dynamic elastance) and inspiratory work, which was then partitioned into its elastic and resistive components. We found that: 1) arterial oxygen tension (Pa,O2) and arterial carbon dioxide tension (Pa,CO2) were not affected by changes in the inspiratory flow waveform; and 2) peak Pao and Ptr were highest with sinusoidal inspiratory flow, whilst mean Pao and Ptr and total work of breathing were least with constant inspiratory flow, mainly because of a concomitant decrease in resistive work during constant flow inflation. The effects of the inspiratory flow profile on Pao, Ptr and total inspiratory work performed by the ventilator were mainly due to the resistive properties of the endotracheal tubes. We conclude that the ventilator inspiratory flow waveform can influence patients' respiratory mechanics, but has no impact on arterial oxygen and arterial carbon dioxide tension.
Maximal respiratory pressures in adult Chinese, Malays and Indians
Authors: Johan A , Chan CC , Chia HP , Chan OY , Wang YT
Published: January 2003

Maximal static inspiratory and expiratory mouth pressures (PI,max and PE,max, respectively) enable the noninvasive measurement of global respiratory muscle strength. The aim of this study was primarily to obtain normal values of PI,max and PE,max for adult Chinese, Malays and Indians and, secondarily, to study their effect on lung volumes in these subjects. Four hundred and fifty two healthy subjects (221 Chinese, 111 Malays, 120 Indians) were recruited. Measurements of PI,max from residual volume (RV), PE,max from total lung capacity (TLC) and forced vital capacity (FVC) were obtained in the seated position. There were significant ethnic differences in PI,max and PE,max measurements obtained in males, and FVC measurements in both males and females. Chinese males had higher PI,max values (mean (+/-SD) 88.7+/-32.5 cmH2O) and higher PE,max values (113.4+/-41.5) than Malay males (PI,max 74.0+/-22.7 cmH2O, PE,max 94.7+/-23.4 cmH2O). Chinese males had higher PE,max than Indian males (PI,max = 83.7+/-30.0 cmH2O, PE,max 98.4+/-29.2 cmH2O). There were no significant differences among Chinese females (PI,max 53.6+/-2.3 cmH2O, PE,max 68.3+/-24.0 cmH2O), Malay females (PI,max 50.7+/-18.3 cmH2O, PE,max 63.6+/-21.6 cmH2O) and Indian females (PI,max 50.0+/-15.2 cmH2O, PE,max 60.7+/-20.4 cmH2O). In both sexes, the Chinese had a higher FVC compared with Malays and Indians. After adjusting for age, height and weight, race was still a determinant for PE,max in males, and FVC in both sexes. The FVC only correlated weakly with PI,max and PE,max in both sexes. Ethnic differences in respiratory muscle strength, and lung volumes, occur among Asians. However, respiratory muscle strength does not explain the differences in lung volumes in healthy Asian subjects.
Short-term effects of nasal proportional assist ventilation in patients with chronic hypercapnic respiratory insufficiency
Authors: Ambrosino N , Vitacca M , Polese G , Pagani M , Foglio K , Rossi A
Published: January 2003

Proportional assist ventilation (PAV) has recently been proposed as a mode of synchronized partial ventilatory support. This study evaluates the short-term effects of nasal PAV on arterial blood gases in stable patients with chronic hypercapnia. Forty two patients (30 with chronic obstructive pulmonary disease (COPD) and 12 with restrictive chest wall disease (RCWD) due to kyphoscoliosis) underwent a 1 h run of nasal PAV. Randomly, two levels of assistance were performed: 1) PAV was set at a level corresponding to volume assist (VA) and flow assist (FA) at 80% of the individual values of elastance (Ers) and resistance (Rrs) obtained with the "runaway" method; and 2) VA and FA were set at a value corresponding to the difference between the patients' individual Ers and Rrs and normal values of Ers and Rrs. Arterial blood gases and dyspnoea (by visual analogue scale (VAS)) were evaluated in all patients during unsupported ventilation and 60 min of PAV. PAV was well tolerated and resulted in significant improvement in arterial oxygen tension (Pa,O2), arterial carbon dioxide tension (Pa,CO2) (6.8+/-0.8 to 7.4+/-1.4 and 7.2/-0.9 to 6.8+/-0.9 kPa, respectively) and VAS (29+/-23 to 20+/-18%). The effects of PAV were not different in the two groups of diseases nor in the two groups of settings. Different settings of nasal proportional assist ventilation are well tolerated and may improve gas exchange and dyspnoea in patients with stable hypercapnic respiratory insufficiency.
Domiciliary nasal intermittent positive pressure ventilation in severe COPD: effects on lung function and quality of life
Authors: Perrin C , El Far Y , Vandenbos F , Tamisier R , Dumon MC , Lemoigne F , Mouroux J , Blaive B
Published: January 2003

The aim of this study was to determine the effect of domiciliary nasal intermittent positive pressure ventilation (NIPPV) on lung function and quality of life in hypercapnic patients with chronic obstructive pulmonary disease (COPD). Fourteen hypercapnic COPD patients in a stable clinical condition were evaluated in a prospective study of domiciliary NIPPV plus long-term oxygen therapy. Baseline data obtained during a 4 week run-in period were compared with measurements at the end of the 6 month study period. Spirometric parameters, arterial blood gas tensions, and quality of life were assessed. Quality of life was measured using the St George's Respiratory Questionnaire (SGRQ) and the French version of the Nottingham Health Profile (FVNHP). All patients completed 6 months of domiciliary NIPPV. Gastro-intestinal inflation was reported by eight patients. Daytime arterial oxygen tension and arterial carbon dioxide tension, improved after therapy. During the NIPPV study period, the total SGRQ score and impacts score both improved significantly; significant improvements were also noted in the total FVNHP score and the physical mobility, emotional reactions, and energy component scores. Domiciliary nasal intermittent positive pressure ventilation combined with long-term oxygen therapy has been found to improve blood gases in spontaneous ventilation, as well as the quality of life of patients with chronic obstructive pulmonary disease.
Daytime mechanical ventilation in chronic respiratory insufficiency
Authors: Schonhofer B , Geibel M , Sonneborn M , Haidl P , Kohler D
Published: January 2003

Chronic respiratory insufficiency (CRI) is associated with nocturnal hypoventilation. Treatment with noninvasive mechanical ventilation (NIMV) performed overnight relieves symptoms of hypoventilation and improves daytime blood gases in CRI. In order to test whether the efficacy of NIMV depends on it being applied during sleep, we conducted a prospective case-controlled study comparing daytime mechanical ventilation (dMV) in awake patients with nocturnal mechanical ventilation (nMV) given in equal quantities. We enrolled 34 clinically stable patients (age 56.1+/-12.1 yrs, 20 females, 14 males) with CRI due to restrictive lung and chest wall disorders and neuromuscular disease. Using a prospective case-control design, matched subjects were allocated alternately to dMV and nMV. After 1 month of NIMV there was considerable symptomatic improvement in both dMV and nMV patients. There were no significant differences between groups in the improvement in daytime arterial carbon dioxide tension (Pa,CO2) (dMV from 7.5+/-0.6 to 5.7+/-0.6 kPa; nMV from 7.2+/-0.5 to 5.8+/-0.5 kPa, p<0.0001) and during the unassisted spontaneous night-time ventilation in terms of transcutaneous Pa,CO2 (dMV from 8.4+/-1.2 to 6.6+/-0.7 kPa; nMV from 8.2+/-1.2 to 6.8+/-0.5 kPa, p<0.0001). We conclude that in many respects, when compared to nocturnal mechanical ventilation, daytime mechanical ventilation in awake patients is equally effective at reversing chronic respiratory insufficiency. Since long-term safety issues were not addressed in this study, we recommend that nocturnal mechanical ventilation should remain the modality of choice for noninvasive mechanical ventilation.
Influence of noninvasive positive pressure ventilation on inspiratory muscle activity in obese subjects
Authors: Pankow W , Hijjeh N , Schuttler F , Penzel T , Becker HF , Peter JH , von Wichert P
Published: January 2003

Noninvasive positive pressure ventilation (NPPV) can improve ventilation in obese subjects during the postoperative period after abdominal surgery. Compared to nasal continuous positive airway pressure (nCPAP), NPPV was superior in correcting blood gas abnormalities both during the night-time and during the daytime in a subgroup of patients with the obesity hypoventilation syndrome (OHS). However, as it is unknown, if and to what extent NPPV can unload the respiratory muscles in the face of the increased impedance of the respiratory system in obesity, this is what was investigated. Eighteen obese subjects with a body mass index > or = 40 kg x m(-2) were investigated during the daytime, which included five healthy controls (simple obesity (SO)), seven patients with obstructive sleep apnoea (OSA) and six patients with the obesity hypoventilation syndrome (OHS). Assisted PPV was performed with bi-level positive airway pressure (BiPAP), applied via a face mask. Inspiratory positive airway pressure (IPAP) was set to 1.2 or 1.6 kPa and expiratory positive airway pressure (EPAP) was set to 0.5 kPa. Inspiratory muscle activity was measured as diaphragmatic pressure time product (PTPdi). Comparison of spontaneous breathing with BiPAP ventilation showed no significant difference in breathing pattern, although there was a tendency towards an increase in tidal volume (VT) in all three groups and a decrease in respiratory frequency (fR) in patients with OSA and OHS. End-tidal carbon dioxide (PET,CO2) with BiPAP was unchanged in SO and OSA, but was decreased in OHS. In contrast, inspiratory muscle activity was reduced by at least 40% in each group. This was indicated by a decrease in PTPdi with BiPAP 1.2/0.5 kPa from mean+/-SD 39+/-5 to 20+/-9 kPa x s (p<0.05) in SO, from 42+/-7 to 21+/-8 kPa x s (p<0.05) in OSA, and from 64+/-20 to 38+/-17 kPa x s (p<0.05) in OHS. With BiPAP 1.6/0.5 kPa, PTPdi was further reduced to 17+/-6 kPa x s in SO, and to 17+/-6 kPa x s in OSA, but not in OHS (40+/-22 kPa x s). We conclude that noninvasive assisted ventilation unloads the inspiratory muscles in patients with gross obesity.
Fibre types in skeletal muscles of chronic obstructive pulmonary disease patients related to respiratory function and exercise tolerance
Authors: Satta A , Migliori GB , Spanevello A , Neri M , Bottinelli R , Canepari M , Pellegrino MA , Reggiani C
Published: January 2003

This study aimed to investigate the relationship between skeletal muscle, fibre type composition, functional respiratory impairment and exercise tolerance in patients with moderate to severe chronic obstructive pulmonary disease (COPD). A group of 22 COPD patients and 10 healthy control subjects were studied. In COPD patients, vital capacity (VC) and forced expiratory volume in one second (FEV1) were reduced to 79% and 51%, respectively. Diffusion indices (transfer factor of the lung for carbon monoxide (TL,CO) and carbon monoxide transfer coefficient (KCO)) were also reduced. Arterial oxygen tension (Pa,O2) was normal or slightly altered. A maximal exercise test was performed and anaerobic threshold was calculated. Muscle samples from vastus lateralis were obtained by needle biopsy. Myosin heavy chain (MHC) and light chain (MLC) isoforms were separated by gel electrophoresis and quantified by densitometry. MHC isoforms were considered as molecular markers of fibre types. The proportion of the fast MHC-2B isoform was increased in COPD patients. TL,CO, KCO, VC and FEV1 were positively correlated with slow MHC isoform content. TL,CO and KCO were also negatively correlated with the content of the fast MHC-2B isoform. No correlation was found between exercise parameters and MHC isoform composition. The co-ordinated expression between MHC and MLC isoforms was altered in COPD patients. We conclude that reduced oxygen availability, probably in combination with muscle disuse, may determine muscle alterations in chronic obstructive pulmonary disease patients. The altered correlations between myosin heavy chain and light chain isoforms suggest that co-ordinated protein expression is lost in chronic obstructive pulmonary disease muscles.
In vivo ultrasound assessment of respiratory function of abdominal muscles in normal subjects
Authors: Misuri G , Colagrande S , Gorini M , Iandelli I , Mancini M , Duranti R , Scano G
Published: January 2003

Ultrasonography has recently been proposed for assessing changes in thickness and motion of the diaphragm during contraction in humans. Data on ultrasound assessment of abdominal muscles in humans are scarce. We therefore investigated the changes in thickness and the relevant mechanical effects of abdominal muscles using this technique during respiratory manoeuvres in normal subjects. We evaluated the thickness of the abdominal muscle layers in six normal male subjects (aged 26-36 yrs) using a 7.5 MHz B-mode ultrasound transducer. Gastric (Pg) and mouth pressures, muscle thickness of external oblique (EO), internal oblique (IO), transversus abdominis (TA) and rectus abdominis (RA) were assessed at functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), during progressive (PEEs) and maximal expiratory efforts (MEEs) against a closed airway and during homolateral (HTR) and contralateral (CTR) trunk rotation. Abdominal muscle thickness was found to be reproducible (coefficient of variation and two-way analysis of variance). Compared to FRC, the thickness of IO, TA and RA significantly increased at RV and during MEEs, whereas EO remained unchanged; at TLC, the thickness of IO and TA significantly decreased. During PEEs, a significant relationship between increase in Pg and TA thickness was observed in all subjects, the thickness of the other abdominal muscles being inconsistently related to Pg. Finally, a significant increase in the thickness of IO and EO was found during HTR and CTR, respectively. We conclude that during maximal expiratory manoeuvres, transversus abdominis, internal oblique and rectus abdominis thickened similarly. Transversus abdominis seems to be the major contributor in generating abdominal expiratory pressure during progressive expiratory efforts. External oblique seems to be preferentially involved during trunk rotation. These results suggest the possible value of studying the abdominal muscles by ultrasonography in various respiratory disorders.
Incremental threshold loading: a standard protocol and establishment of a reference range in naive normal subjects
Authors: Johnson PH , Cowley AJ , Kinnear WJ
Published: January 2003

Incremental threshold loading (ITL) has been proposed as a test of inspiratory muscle strength and endurance. To date, however, there has been no standardized protocol for an ITL test, and no reference range, with different investigators using a variety of different pressure increments in small numbers of subjects. We developed an ITL test using the weighted plunger (WP) principle, which uses standard increments of pressure. In our protocol subjects inspire through the WP generating an initial threshold opening pressure of 10 cmH2O. This pressure is raised at 2 min intervals in increments of 5 cmH2O until they fail to lift the plunger on two consecutive attempted breaths. Sixty healthy volunteers (30 males and 30 females) aged 20-80 yrs performed the ITL test. Twelve subjects (six females and six males) performed the test twice to assess reproducibility and repeatability. Using stepwise multiple linear regression, we regressed the maximum threshold pressure sustained for a full 2 min (Pmax) against age, height, weight and static maximum inspiratory mouth pressure (MIP). Pmax was significantly related to age but not to either height or weight, the regression equation for males was Pmax (cmH2O)=103.8 - (1.0 x age in years), and for females was Pmax (cmH2O)=93.7 - (1.0 x age in years). The within-subject standard deviation for those repeating the ITL test was 5.4 cmH2O. Incremental threshold loading is a simple technique with good reproducibility, which most naive subjects can use without difficulty. By using standard pressure increments and performing the test in a large number of naive subjects, we have established a reference range that should be applicable wherever similar pressure increments are used.
Bronchial anastomotic complications following lung transplantation: still a major cause of morbidity?
Authors: Schmid RA , Boehler A , Speich R , Frey HR , Russi EW , Weder W
Published: January 2003

The frequency of bronchial anastomotic complications following lung transplantation has decreased in recent years, but continues to be a potential cause of morbidity and mortality. We have, therefore, reviewed the results of 67 consecutive bronchial anastomoses at risk in 43 patients surviving more than 7 days following lung transplantation. The bronchial anastomoses were performed using a standardized technique, without direct or indirect revascularization. Regular triple immunosuppressive therapy was given, including prednisone (0.5 mg x kg(-1) daily) starting on the day of surgery. Bronchial healing was graded using the Couraud classification. The median follow-up time was 14 months (range 1-45 months). No major airway complications occurred. On 236 serial bronchoscopic examinations, no anastomotic stenoses were observed. One anastomosis showed limited focal necrosis (2 mm) (Couraud 3a), and two anastomoses had partial primary mucosal healing without necrosis (Couraud 2a). In all other anastomoses, primary mucosal healing (Couraud 1) was observed. Carefully performed bronchial anastomosis according to the technique described enables reliable bronchial healing and yields a low complication rate. Additional measures, such as direct revascularization, forced telescoping, omentum wrap and interruption of steroid therapy, are not necessary.
Airway versus transbronchial biopsy and BAL in lung transplant recipients: different but complementary
Authors: Ward C , Snell GI , Orsida B , Zheng L , Williams TJ , Walters EH
Published: January 2003

Lung transplantation is now an established therapeutic intervention for end-stage cardiopulmonary disease in humans. Chronic rejection, in the form of bronchiolitis obliterans syndrome (BOS), remains the commonest cause of morbidity and mortality in those surviving more than 3 months. The pathology of BOS involves airway changes. We have evaluated the potential for endobronchial biopsies (EBB) to complement existing sampling methods used in allograft monitoring and have compared the results of EBB findings with those of bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) in 18 clinically stable patients. We found that all the EBB had inflammatory cells present but that only five TBB specimens had evidence of inflammation, with airway material being present in 78% of the TBB. Paired BAL and EBB yielded different results, with no correlations between total macrophages, lymphocytes, CD4+ cells or CD8+ cells. We conclude that endobronchial biopsies are potentially useful as an additional sample for the monitoring of inflammation in lung allografts, since they yield different, and potentially complimentary, information to bronchoalveolar lavage and transbronchial biopsy.
Alpha1-antitrypsin phenotypes in patients with cryptogenic fibrosing alveolitis: a case-control study
Authors: Hubbard R , Baoku Y , Kalsheker N , Britton J , Johnston I
Published: January 2003

Cryptogenic fibrosing alveolitis (CFA) is an interstitial lung disease, which by definition is of unknown aetiology. Recent evidence has suggested that smoking and occupational exposure to dusts may be environmental risk factors for the disease, but there has been little research into potential host risk factors. One previous study has suggested that the prevalence of abnormal alpha1-antitrypsin phenotypes may be increased in patients with CFA. Since alpha1-antitrypsin is important in regulating inflammation within the lung in response to environmental exposures, such abnormalities may be of aetiological importance in this disease. We have compared the alpha1-antitrypsin phenotypes of 189 patients with CFA with 189 age-, sex-, and community-matched controls. This sample size was sufficient to provide more than 95% power to detect an odds ratio (OR) of 2.5. Alpha1-antitrypsin phenotype was established by isoelectric focusing, and the prevalence of abnormal phenotypes in cases and controls was compared by conditional logistic regression. Personal smoking histories were obtained by postal questionnaire. The prevalence of abnormal alpha1-antitrypsin phenotypes was similar in cases and controls (12.7 versus 15.3%; OR 0.88; 95% confidence interval 0.49-1.57; p=0.66). No interaction was found between the presence of abnormal alpha1-antitrypsin phenotypes and a history of smoking. We conclude that cryptogenic fibrosing alveolitis is not associated with abnormal alpha1-antitrypsin phenotypes.