Application of impulse oscillometry in respiratory system evaluation in elderly patients.

INTRODUCTION: Spirometry, which is a basic diagnostic tool of the respiratory system, may cause problems to patients of advanced age because of required cooperation and specific respiratory manoeuvres. Impulse oscillometry (IOS) may be an interesting alternative for spirometry as the examination is made during quiet breathing and gives information about resistive properties of the respiratory system. MATERIAL AND METHODS: This work presents the results of oscillometric measurements made in 277 patients aged 65-96 years, in whom spirometry was also performed. RESULTS: Resistances measured with IOS (R5, R5-R20) and the resonant frequency Fn correlated significantly with FEV1 (r = -0.503; -0.570 and -0.673, respectively). A comparison of the results from patients with airway obstruction confirmed in spirometry with those of the non-obstructed group showed highly significant differences in mean values of oscillometric parameters (p < 0.001). CONCLUSIONS: As R5-R20 is regarded as a measure of peripheral airways resistance, IOS may serve as an interesting complementary or alternative method for spirometry in elderly subjects for evaluation of the state of respiratory system.

Quality of spirometry in the elderly.

INTRODUCTION: Spirometry is the basic method used to diagnose and monitor obstructive diseases. Spirometric tests are performed in more and more people of advanced age (more than 65 years old). The objective of the study was to assess the quality of spirometry (measurement of the flow-volume curve) in subjects of the aforementioned age group, with reference to applicable quality criteria specified in guidelines ERS/ATS 2005 and PTChP 2006. MATERIAL AND METHODS: The study was of a retrospective nature. The authors analysed the results of spirometry performed in 1271 subjects who were 65 to 94 years old and who underwent spirometric tests in the Respiratory Physiopathology Laboratory of Kujawy-Pomorze Regional Centre of Pulmonology in Bydgoszcz over a period of 6 months. This group included 759 males (average age 73.2 ± 5.9 years) and 512 females (average age 73.2 ± 5.7 years). The quality of the spirometry was assessed according to error codes assigned to individual spirometric sessions by the software JLab 5.31 installed in the measuring system MasterScreen (CareFusion). RESULTS: Twenty-nine (2.3%) of the 1271 subjects failed to perform spirometric measurements. For the remaining 1242 subjects the following spirometry quality was determined: correctly performed spirometric test in 415 (33.4%) subjects; one error in 673 (54.2%) subjects; 2 errors in 136 (11%) subjects; 3 errors in 15 (1.2%) subjects and 4 errors in 3 (0.2%) subjects. The analysis of individual errors revealed that the lack of a plateau at the end of exhalation was found in 747 (60.1%) subjects (including only 25 (2%) subjects with FET < 6 s); increased BEV value in 7 (0.6%) subjects; abruptly finished exhalation in 36 (2.9%) subjects; and no FVC and FEV1 repeatability in 43 (3.5%) and 169 (13.6%) subjects, respectively. CONCLUSIONS: The most common error was the lack of a plateau at the end of exhalation. Therefore, paying particular attention to the final phase of exhalation during spirometry should, as a result, increase the percentage of correctly performed spirometric tests in the elderly.

Spirometry centile charts for young Caucasian children: the Asthma UK Collaborative Initiative.

RATIONALE: Advances in spirometry measurement techniques have made it possible to obtain measurements in children as young as 3 years of age; however, in practice, application remains limited by the lack of appropriate reference data for young children, which are often based on limited population-specific samples. OBJECTIVES: We aimed to build on previous models by collating existing reference data in young children (aged 3-7 yr), to produce updated prediction equations that span the preschool years and that are also linked to established reference equations for older children and adults. METHODS: The Asthma UK Collaborative Initiative was established to collate lung function data from healthy young children aged 3 to 7 years. Collaborators included researchers with access to pulmonary function test data in healthy preschool children. Spirometry centiles were created using the LMS (lambda, micro, sigma) method and extend previously published equations down to 3 years of age. MEASUREMENTS AND MAIN RESULTS: The Asthma UK centile charts for spirometry are based on the largest sample of healthy young Caucasian children aged 3-7 years (n = 3,777) from 15 centers across 11 countries and provide a continuous reference with a smooth transition into adolescence and adulthood. These equations improve existing pediatric equations by considering the between-subject variability to define a more appropriate age-dependent lower limit of normal. The collated data set reflects a variety of equipment, measurement protocols, and population characteristics and may be generalizable across different populations. CONCLUSIONS: We present prediction equations for spirometry for preschool children and provide a foundation that will facilitate continued updating.

Function of the respiratory system in patients with idiopathic scoliosis: reasons for impairment and methods of evaluation.

The paper presents the review of pathological changes which develop within the respiratory system in patients with structural progressive idiopathic scoliosis. The impairment of the function of the respiratory system is one of the principal impact of idiopathic scoliosis on the general health and function, as well as on the quality of life. Although the fatal outcomes of respiratory failure are usually prevented by a successful conservative treatment or by the spinal surgery, the reduction of the volume of the thorax, the restriction of the thorax, as well as decreased efficacy of the respiratory muscles are still a major issue (problem) for many patients with structural scoliosis that may lead to respiratory insufficiency or failure. The papers presents main functional tests to assess the respiratory impairment and the basic rules for interpretation of the results of the examination.

[Quality of spirometric measurements in children younger than 10 years of age in the light of the recommendations]. / Jakosc badania spirometrycznego u dzieci 10-letnich i mlodszych w swietle zalecen standaryzacyjnych.

INTRODUCTION: In 2005 the European Respiratory Society/American Thoracic Society (ERS/ATS) published an updated document on the standardization of spirometry (European Respiratory Journal 2005; 26: 319-338). It defines criteria for the acceptability of spirometric measurements. The aim of this retrospective study was to assess the adherence to those standards of flow-volume measurements in children younger than 10 years of age. MATERIAL AND METHODS: The analysis was carried out on the results obtained from 233 children aged 4.2-10 years, referred to a spirometric lab during a period of three months. RESULTS: 116 children (all but one preschool) did not cooperate; the results of the 117 who completed the procedure of flow-volume measurement were analysed using ERS/ATS criteria. 80.3% of the children had back extrapolated volume (Vbe) within the defined limit, but only 23.9% had forced expiratory time > 3 s. FEV(1) and FVC were repeatable in 78.6% of the children. When these three criteria were used together, the measurements were acceptable according to ATS/ERS recommendations in 17.1% of the children. Elimination of the forced expiratory time criterion has further increased their number to 63.2%. CONCLUSIONS: Specific recommendations for children should be developed, as the current requirements appear too restrictive, especially regarding the time of forced expiration.

Impulse oscillometry vs. body plethysmography in assessing respiratory resistance in children.

In 334 children aged 5-18 years, we compared the results of plethysmographic measurements of airway resistance (Raw) with oscillometric (impulse oscillometry; IOS) assessment of respiratory properties of the respiratory system (resistance (R) at 5, 20, and 35 Hz). All three resistances correlated significantly with plethysmographic Raw, and the strongest correlation was seen for R5 (r = 0.64). R5, R20, and R35 were significantly greater than Raw in the whole group. In the group of children with obstruction (FEV(1)%FVC below lower limit of normal), R5 was still greater than Raw, while R20 and R35 were not. The Bland-Altman analysis comparing plethysmographic measurements with oscillometric R5 revealed a significant difference between Raw and R5 in the whole group, which disappeared in the group of obstructed patients. Oscillometric assessment of resistive properties of the respiratory system of the lung requires less patient cooperation than does plethysmography. As the results of measurements using oscillometric R5 are similar to those obtained by plethysmography, IOS may be useful in diagnosing children with obstructive respiratory diseases.

[Usefulness of breath actuated devices in asthmatic children with bronchial obstruction]. / Przydatnosc inhalatorów uruchamianych wdechem u dzieci chorych na astme z obturacja oskrzeli.

Clinical efficacy of breath actuated devices depends on value of peak inspiratory flow (PIF). Therefore the aim of our study was to assess PIF Rate (PIFR) in asthmatic children with bronchial obturation (FEV1%FVC < lower limit of normal). Thirty five children aged (average) 11.5 years participated in the study. PIFR was obtained with InCheck (Clement Clark, UK) with resistance valves for Turbuhaler, Discus, Easi Breathe and Autohaler inhalers, then peak inspiratory flow was assessed spirometrically (LungTest 1000, MES SJ, Poland). Maximal value of PIFR (PIFRmax=120 l/min) was obtained by 24 (69%) children for Easi Breathe, 3 (9%) children for Autohaler, 2 (6.5%) children for Discus, for Turbuhalera none of the children reached PIFRmax, differences in assessing PIFRmax were statistically significant (p < 0.05). However, all the children were able to generate minimal and optimal PIFR for all inhalers. There were no correlation between the degree of bronchial obstruction and PIFR values, but significant correlation was found between spirometric PIF and PIFR for different devices. All four tested inhalers can be used by children with bronchial obstruction, and the highest PIFR (as well as most frequently maximal PIFR) is obtained with Easi Breathe inhaler.

Passive smoking does not increase hydrogen peroxide (H2O2) levels in exhaled breath condensate in 9-year-old healthy children.

Environmental tobacco smoke, also called passive smoking, was shown to have adverse effects on the health of children. Hydrogen peroxide (H2O2) is proposed as a sensitive marker of oxidative injury and inflammatory processes in the airways, being increased in adult active cigarette smokers. We tested whether passive smoking had an influence on H2O2 exhalation in healthy children. Thirty healthy passive smoking and 24 nonexposed healthy children aged 9 years were included in the study. Exhaled breath condensate (EBC) was obtained by spontaneous tidal volume breathing with EcoScreen (Jaeger, Germany). All subjects underwent flow-volume measurements immediately after EBC collection. Levels of H2O2 were measured fluorimetrically with the homovanillic acid method. Lung function did not differ between the passive smoking and nonexposed children groups. In the passive smoking group, EBC H2O2 concentration (median and range) was 0.32 (0.00-1.20) microM, and did not differ significantly (P >0.05) from that found in the nonexposed group, i.e., 0,22 (0.00-0.68) microM. Exhaled H2O2 did not correlate with spirometric parameters (FEV1, FEV1%FVC, and MEF50%FVC) in either group. We conclude that passive smoking does not increase H2O2 exhalation in healthy children.

[Exhaled hydrogen peroxide (H2O2) in allergic and non-allergic stable mild asthmatic children]. / Nadtlenek wodoru (H2O2) w kondensacie powietrza wydechowego u dzieci chorujacych na astme oskrzelowa alergiczna i niealergiczna o lekkim przebiegu.

The evaluation of breath condensate (BC) composition is a new, non-invasive method studying inflammation processes in several respiratory diseases. Among many inflammation markers, hydrogen peroxide (H2O2) is the most common one, and its increased level was found in BC of cystic fibrosis and asthma patients. As in children's asthma, H2O2 is present and could correlates with the severity of the disease. The aim of our study was to check whether there exist differences between levels of H2O2 in children with allergic and non-allergic asthma. 83 allergic and 33 non-allergic children with mild asthma (50 girls and 66 boys, aged 7-17 years) were included in the study. All patients were clinically stable and used inhaled corticosteroids daily, and an inhaled bronchodilator on demand. Exhaled BC was obtained by spontaneously tidal volume breathing with EcoScreen (Jaeger, Germany). The content of H2O2 in the BC was measured spectrofluorometrically (homovanillic acid method). All subjects underwent flow-volume measurements immediately after collection of the condensate. Lung function in asthmatic allergic and non-allergic children showed near normal values and did not differ between groups. In the allergic group, the median H2O2 level in the expired condensate was 0.238 (0-1.86) microM, and in non-allergic 0.192 (0-0.78) microM (p > 0.05). We conclude that hydrogen peroxide in exhaled breath condensate of children with stable mild asthma does not differ significantly in allergic and non-allergic children and activity of airway inflammation seems to independent on allergic status of patients.

Normal values for maximal static inspiratory and expiratory pressures in healthy children.

Maximal static respiratory pressures are a simple measure of respiratory muscle strength. In order to construct a set of equations describing normal values, we measured maximal inspiratory (P(Imax)) and expiratory (P(Emax)) pressures in 296 children (144 boys and 152 girls), aged 7-14 years, in sitting and standing positions. The boys reached higher values in sitting and standing positions for P(Imax) (-8.29 +/- 2.69 and -8.19 +/- 2.73 kPa, respectively) and P(Emax) (8.02 +/- 2.32 and 7.94 +/- 2.32 kPa, respectively) than girls (-6.53 +/- 1.99 and -6.60 +/- 2.03 kPa for P(Imax) and 6.91 +/- 1.79 and 7.13 +/- 1.81 kPa for P(Emax) for sitting and standing positions, respectively); the differences between boys and girls were highly significant (P < 0.001 in all instances). There were no differences regarding body position during measurements in both genders. Multiple correlation analysis showed significant correlations of pressures to age in boys in all cases, but in girls only for P(Imax) in standing position. Therefore, equations describing reference values were constructed with respect to age as the independent variable. Maximal pressures also correlated with maximal inspiratory and expiratory flows. The measurements of P(Imax) and P(Emax) are useful in assessing respiratory muscle strength despite their relatively large variability. P(Imax) and P(Emax) also correlate with maximum peak expiratory and inspiratory flows. Children generate lower pressures and lower maximal flows than adolescents and adults.

Reference values for forced inspiratory flows in children aged 7-15 years.

In order to construct reference equations, we attempted to measure forced inspiratory flows, i.e., peak inspiratory flow (PIF) and maximal inspiratory flow at 50% of FVC (MIF50%FVC) in 332 healthy schoolchildren aged 7-15 years during flow-volume loop measurements, using an electronic spirometer. In 255 children (122 boys and 133 girls), the results were satisfactory. Statistical analysis revealed that the only predictive variables were sex and height. The best fit of the data was obtained with the power model (Y = A * H(B)); the coefficients of correlation between flows and height ranged from 0.66-0.77, and were slightly greater for boys. Forced inspiratory flows in children increase with height, and the variability is higher than for forced expiratory flows. Reference values for forced inspiratory flows can be useful in assessing the ability of children to generate affective inspiratory flows for choosing an inhalation device, or in resolving diagnostic problems, e.g., extrathoracic obstruction.

[Serum level of leptin and neuropeptide Y in children with mild asthma]. / Leptyna i neuropeptyd Y w surowicy dzieci chorych na astme oskrzelowa o lekkim przebiegu.

Leptin (LEP) and neuropeptide Y (NPY) are involved in the maintenance of energy balance and create regulatory loops on central and peripheral stage between neuropeptides and hormones, additionally regulated by other physiological stimuli. According to data confirming tendency to overweight and obesity in asthmatic children we have examined the influence of mild asthma on neurohormonal balance. 43 children, aged 7-17 years, including 27 steroid naive mild asthmatic children aged (mean+/-SD) 12.3+/-2.6 years and 16 age matched healthy children participated in the study. Serum LEP and NPY levels were measured radioimmunologically (RIA). Serum leptin level in asthmatic children was 2.84+/-2.1 ng/ml and did not differ to that of healthy children -3.49+/-1.65 ng/ml, both in boys (p=0.85) and girls (0.49). Similarly, we did not observe any differences between NPY levels in asthmatic (113.5+/-31.1 micromol/ml) and healthy (98.5+/-21.9 micromol/ml (p=0.17)), irrespective to sex. Significant correlations between leptin levels and body mass index (BMI) in asthmatics (r=0.62, p=0.01) and healthy children (r=0.56, p=0.02) were observed. We conclude, that mild asthma in children seems not to affect neurohormonal regulation of energy balance.

Transient reference values for impulse oscillometry for children aged 3-18 years.

Impulse oscillometry (IOS) is a technique of assessing mechanical properties of respiratory system by means of measuring resistances and reactances in a number of frequencies during tidal breathing. It is especially useful in preschool children, however has also been validated in older children and adults. The aim of the present study was to construct equations describing normal values of oscillatory parameters in pediatric population of healthy polish children. Six hundred twenty-six healthy children aged 3.1-18.9 years (278 boys and 348 girls) completed the study. Analysis revealed that body height was the best predictor and resistances are best described with exponential model while reactances with linear one, with correlation coefficient r reaching the value of 0.9. Oscillometric resistances decrease with height, while reactances increase. Reference values for children and adolescents will allow not only the interpretation of the measurement, but also will make possible to study changes of oscillometric indices during growth.