Effective argon-FRC with a rebreathing technique in children with acute asthma

In children with asthma the measurement of functional residual capacity (FRC) with standard dilution techniques requires long rebreathing times of the inert gas, i.e., helium, to reach alveolar units with long time constants. A modification of the argon-freon-22 rebreathing technique enables argon to dilute in the readily accessible lung volume and potentially can give a measurement of FRC. However, the rebreathing tests cannot be prolonged for more than 1 min thus allowing argon to reach only the rapidly accessible lung units which are grossly useful in gas exchange (effective FRC, EFRC). The aim of this study was to measure the EFRC and standard lung function in children with acute severe asthma, assess their response to nebulized salbuta-mol, and evaluate the relations of the EFRC response to baseline spirometric measurements. Twenty-four asthmatic children who were admitted to the hospital with an acute asthma attack had spirometry and triplicate EFRC measurements before and after treatment with nebulized salbutamol. Eighteen patients had repeated the respiratory tests 50 days later when they had fully recovered. A significant proportion (28.9%) of the argon traces obtained at baseline before treatment did not equilibrate. However, in the great majority of these tests the oscillation of the argon traces over the last 3 breaths of the test was < 5% of the simultaneous argon concentration. The EFRC values derived from the argon traces with minimal oscillation (< 5%) were reduced during the acute asthma attack when compared with the paired values obtained after recovery (P = 0.03). The administration of salbutamol caused a fall from the baseline EFRC (P = 0.05). There was a significant correlation between the EFRC and FVC values (expressed as percentage of normal) in all 3 of the test occasions. The changes in the pretreatment and posttreatment EFRC values induced by recovery were correlated to the corresponding changes in the spirometric indices. In conclusion, rebreathing techniques can give quick measurements of EFRC in patients with acute asthma. The changes induced by recovery in baseline and postsalb-utamol EFRC follow the pattern of the corresponding spirometric indices changes and not the expected typical FRC pattern. © 1995 Wiley-Liss, Inc.     

Lung function in 3-5-year-old children with cystic fibrosis

It is well established that the lung disease of CF can occur early in life and may progress through the preschool years when accurate lung function assessment has been challenging to perform. We hypothesized that respiratory inductive plethysmography (RIP) and spirometry could be effectively performed in 3-6-year-old children and could be used to assess both longitudinal changes in lung function and the acute changes that occur during exacerbation of pulmonary disease. Both RIP and spirometry were equally feasible; however, the success rate for spirometry gradually increased with age to become higher than that for RIP in the 6-year-old subjects. Forty-four subjects were studied longitudinally and demonstrated significant increases in FVC, FEV(1), and FEV(0.5), but not in FEF(25-75) or RIP variables. There were significant differences in FVC, FEV(1), and phase angle (a measure of thoracoabdominal asynchrony) during exacerbations of lung disease. Although both RIP and spirometry were able to show differences in lung function in subjects with acute clinical worsening, spirometry was more robust in demonstrating change in lung function longitudinally and in children who had an exacerbation of lung disease.     

Spirometric pulmonary function parameters of healthy Chinese children aged 3–6 years in Taiwan

Spirometry is a well‐known technique for evaluating pulmonary function, but few studies have focused on preschool children. The aim of this study was to determine reference values of forced spirometric parameters in young Chinese children, aged 3–6 years, in Taiwan. Spirometric measurements were performed at day care centers by experienced pediatricians. Of 248 children without a history of chronic respiratory illness, at least two valid spirometric attempts were obtained from 214 children (109 boys and 105 girls; age: 36–83 [mean = 61] months; height: 90–131 [mean = 111] cm). Values of forced expiratory volume in 1 sec (FEV₁) and 0.5 sec (FEV_0.5), forced vital capacity (FVC), peak expiratory flow rate (PEF), forced expiratory between 25% and 75% FVC (FEF_25–75), and forced expiratory flow rate at 25%, 50%, and 75% of FVC (FEF₂₅, FEF₅₀, and FEF₇₅) were derived and analyzed. There were significant positive correlations between study parameters and body height, body weight, and age. Height was the most consistently correlated measurement in both boys and girls. Although boys tended to have higher spirometric values than girls, we found significant differences only in FVC and FEV₁ between boys and girls aged 6 years. The regression equations of each parameter were obtained. In conclusion, spirometric pulmonary function tests are feasible in 3‐ to 6‐year‐old children. The obtained values and regression equations provide a reference for Chinese preschool children and may be of value in evaluating pulmonary function of children with respiratory problems in this age group. Pediatr Pulmonol. 2009; 44:676–682. © 2009 Wiley‐Liss, Inc.     

Lung volumes and distribution of ventilation in survivors to congenital diaphragmatic hernia (CDH) during infancy

The assessment of lung volumes, particularly functional residual capacity (FRC), is crucial for understanding lung development during infancy in CDH patients.AIM: To evaluate changes in lung function during infancy in subjects with CDH treated with a "gentle ventilation" technique and delayed surgery strategy in the neonatal period. METHODS: 13 CDH infants were studied twice and compared with a population of 28 healthy infants (HI). Tidal-Volume (Vt), respiratory rate (RR) and time to peak expiratory flow/expiratory time ratio (tPTEF/Te) were measured with an ultrasonic flow meter; Compliance (Crs) and Resistance (Rrs) of the respiratory system were studied with the single occlusion technique; FRC and Lung Clearance Index (LCI), were assessed with the sulfur hexafluoride (SF6) wash-in/wash-out technique. The differences between the first (T1) and second (T2) measurement in the CDH group were assessed by the Student's t-test for paired values. For each set of measurement (T1 and T2) the values were compared with HI by Student's t-test. RESULTS: Mean age at test was 7.5 +/- 5.2 months for HI, 4.5 +/- 2.5 at T1 and 11.9 +/- 4.5 months at T2 for CDH infants. At T1 there were no significant differences between CDH infants and HI in Vt, Crs, and FRC, while tPTEF/te ratio was lower and RR, Rrs, and LCI were higher in CDH patients than in HI. At T2 Vt, Crs, and FRC remained normal in CDH patients as well as RR that, at this time was not different between CDH and healthy infants; tPTEF/te remained below and Rrs and LCI remained above normal ranges, indicating a persistent impairment in lower airways patency. CONCLUSIONS: Lung function in infants with severe CDH is characterized by a persistent impairment in airways patency and significant inhomogeneity of ventilation, suggesting a peripheral bronchial obstruction even if the other lung function tests are within normal ranges.     

The treatment of functional constipation significantly increased quality of life in children aged 4–17 years

Background/AimsIn this study, it was aimed to investigate the effect of 6-week treatment on quality of life in 4–17-year-old children with functional constipation.Materials and MethodsThe children 4–17 years old diagnosed as functional constipation according to Rome IV criteria, between June and December 2018 were included in the study. KINDL scales were applied to patients and their parents before starting treatment for 6 weeks and after the end of the treatment.ResultsThe study was completed with 42 patients. The majority of the patients (54,8%) were female cases and the general part of them (45,2%) were between 4–6 years old. The age at onset of constipation was found to be 5,19±3,658 years. Total KINDL scores of both children and parents were lower before the treatment. Significant improvement was observed in the symptoms of constipation after 6 weeks of treatment. There was a statistically significant (p<0,05) increase in children’s subgroup and total KINDL scores after treatment. Parental subgroup and total KINDL scores also showed a statistically significant (p<0,05) increase after treatment. The treatment of functional constipation was found to be highly effective with the eyes of both children and parents in improving the quality of life. (Eta value, η2.>0,25)ConclusionA significant increase was observed in all areas of life quality and total score in children with functional constipation after a regular treatment. We think that the treatment of children with functional constipation will significantly improve their quality of life     

Lung function in diastrophic dysplasia

Diastrophic dysplasia (DD) is a rare skeletal dysplasia characterized by short-limbed short stature, contractures and early degeneration of joints, and spinal deformities such as scoliosis. Mortality is increased in the neonatal period, in part due to tracheo- and bronchomalacia. Additionally, spinal deformities are very rigid, decreasing mobility of the chest cage. The aim of our study was to evaluate lung volumes and airway flow dynamics in patients with DD. A total of 31 patients (12 males, 19 females) underwent a detailed clinical examination measurements of standing height PA-radiography of the spine, flow-volume spirometry, and body plethysmography. The patients were assigned to two groups: children and adolescents (0-18 years, n = 18) and adults (over 18 years, n = 13). The mean spirometric parameters were mostly within the predicted value range, although the variation was wide. At least one abnormally low spirometry parameter was found in 6 (33%) of the children and adolescents and in 7 (54%) of the adults. Mean forced vital capacity (FVC) was 104% (range 48-163%) of predicted values in the children and adolescents and 95% (58-140%) of the adults. Peak expiratory flow (PEF) values were abnormal in 4 (22%) of the children and adolescents and in 5 (39%) adults. The mean plethysmographic parameters were all within the predicted value range. At least one abnormal plethysmographic value was found in 6 (33%) of the children and adolescents and in 4 (31%) of the adults. Airway resistance (Raw) was significantly higher in the adults than in the children and adolescents (P = 0.016), and was abnormally high in 3 (23%) of the adults. The angle of thoracic or thoracolumbar scoliosis correlated with the percentages of the predicted values of FVC (r(s) = - 0.66), forced expired volume in 1 sec (FEV(1)) (r(s) = - 0.56), and total lung capacity (TLC) (r(s) = - 0.67). Age correlated with the FEV(1)/FVC ratio (r(s) = - 0.41), with the maximal expired flow at 50% FEV (MEF(50)) values (r(s) = - 0.55), with the residual volume (RV) values (r(s) = - 0.47), and with the RV/TLC ratio (r(s) = - 0.43). Variable bronchial obstruction was found in 1 (6%) child and in 2 (17%) adults. Although the patients with DD had, on average, normal lung volumes, large individual variation occurred. Airway resistance was increased in adults. The angle of scoliosis correlated inversely with lung volume parameters.     

Lung function in children with diabetes mellitus

A cross-sectional study design was undertaken to assess pulmonary function in children with insulin-dependent diabetes mellitus (IDDM), and to establish if there is any relationship with diabetic factors and complications. Thirty-eight children (10 +/- 1.8 years) with IDDM and without clinical or radiological evidence of lung involvement, and 41 healthy age-matched reference subjects, underwent a pulmonary function study. Thirteen (34%) of 38 subjects with IDDM were studied at the onset of their disease. Adjusted values expressed as SD score of forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV(1)), and the transfer factor for carbon monoxide (TLCO) were found to be significantly lower than in controls (-0.54 +/- 0.87 vs. 0.40 +/- 1.10, P = 0.0008; -0.11 +/- 0.96 vs. 0.52 +/- 1.07, P = 0.01; -1.60 +/- 1.07 vs. -0.57 +/- 1.28, P = 0.001, respectively). These differences also existed in the group investigated at onset of diabetes. Residual volume (RV) and RV/total lung capacity ratio (RV/TLC) were significantly higher in the whole group of patients with IDDM than in controls (-0.20 +/- 0.83 vs. -0.80 +/- 0.88, P = 0.003; and 26 +/- 6.2 vs. 21 +/- 5.0, P = 0.0002, respectively). Seventeen patients (45%) had abnormal pulmonary function (SD score, less than -1.64): 16 subjects had reduced TLCO, 4 had reduced FVC, and in 3 of the 17, both functional indices were abnormal. There was no significant relationship between pulmonary function indices and diabetic factors or complications. The only significant association was between abnormal TLCO and females (P = 0.03), suggesting that sex may be a predisposing factor for the development of pulmonary complications. This study supports the view that the lung is functionally involved in children with IDDM early on in the course of the disease.     

Lung function values from a longitudinal study of healthy children and adolescents

From a cohort of 543 healthy children and adolescents, subjects were studied annually to obtain longitudinal data so that precise predictive values for lung volumes and flows from ages 8 to 19 years could be obtained. Strict guidelines for subject selection and pulmonary function testing were used. These data are presented in a readily usable form as equations, graphs, and tables.     

Polarcardiographic and vectorcardiographic study of 70 normal children aged 3-4 years

This polarcardiographic and vectorcardiographic study of 70 normal children, aged three to four years using the Frank lead system, provides data on an important age group that were not previously available. High-resolution xyz signals, recorded on magnetic tape, were edited, digitized, compressed, and fed into a digital computer together with typed information. Computer outputs included measurements, analysis, VCG loops, Aitoff plots of P?, ?, and ? directions, derived 12-lead ECGs, and polar tracings. Conventional ECGs were also recorded; differences from the derived ECG were not clinically significant. Various normal bounds for polar coordinate variables were established, such as criteria for diagnosing left ventricular hypertrophy. There was a significant sex difference in the ? directions, which were more posterior than those previously reported for adults. Among the VCGs, it was interesting to note several patterns suggesting persistence of right ventricular forces.     

Respiratory resistance and impedance magnitude in healthy children aged 2-18 years

Two hundred eighteen healthy children aged 2 to 18 years were studied using a modification of the forced oscillation technique. Reference values with height as predictor were determined for total respiratory resistance and impedance during inspiration, expiration, and throughout the whole respiratory cycle at an oscillation frequency of 4 Hz and, in a subpopulation of 61 children, at frequencies of 2 and 12 Hz. Mean total inspiratory resistance, determined at 4 Hz, decreased with growth from 1.3 kPa X 1(-1) X s at 2 years of age to 0.3 kPa X 1(-1) X s at 18 years. Variability in the results between individuals, expressed in terms of coefficient of variation, was found to be +27% and -21%, respectively, and within individuals, 9%. Resistance during expiration was on average 16% higher than during inspiration and the variability within individuals was 11%. A marked decrease in resistance was found in small children when the frequency was increased from 2 to 12 Hz. The frequency dependence of respiratory resistance observed in small children changes gradually with growth, in parallel with the reduction of total respiratory resistance, to an adult pattern in which no significant change in resistance can be noted between frequencies of 2 and 12 Hz.     

Gas trapping in normal infants and in infants with cystic fibrosis

Two different methods for estimating trapped gas volume have been described in the literature. The purpose of this study was to use both of these methods to estimate and compare trapped gas volumes in normal infants and infants with cystic fibrosis (CF). Thirty normal infants and 29 infants with CF, ages 1 month to 3 years, were studied. Pulmonary function tests, including raised volume forced expiratory flows, plethysmographic functional residual capacity (FRC(pleth)), and fractional lung volumes, were measured. Then functional residual capacity was measured by nitrogen washout (FRC(nitrogen)). Following nitrogen washout, lungs were then inflated three times to 30 cm H(2)O, using 100% oxygen. This process was repeated until no further nitrogen could be washed from the lungs. The volume of trapped gas (tg) was calculated from the total additional amounts of nitrogen expired following lung inflations. The difference between FRC(pleth) and FRC(nitrogen) provided a second estimate of trapped gas volume (delta V). Mean tg and delta V values for normal infants were 2.5 +/- 3.5 ml and 15.6 +/- 30.4 ml, respectively. Mean tg and delta V values for infants with CF were 5.8 +/- 7.7 ml and 33.2 +/- 43.8 ml, respectively. Both tg and delta V did not differ significantly between normal infants and infants with CF. Measured following raised volume forced expiratory maneuvers, delta V and tg do not distinguish infants with CF from normal infants as well as do other currently available tests of infant lung function.     

Respiratory resistance by impulse oscillometry in healthy Iranian children aged 5-19 years

The impulse oscillation system (IOS) measures respiratory impedance (Zrs) in terms of resistance (Rrs) and reactance (Xrs) at multiples of 5 Hz. These measurements can be used clinically to help diagnose and monitor respiratory disorders, independent of effort. There is, as yet, no information on reference values for IOS in Iranian adolescents.The predictive equation for resistance and impedance at 5 and 15 and 25 Hz, for the first time, in 509 Iranian adolescent subjects (265 boys (aged 6-19 years) and 253 girls (aged 5-19 years) were determined. Gender-specific linear prediction equations were developed by multiple regression analysis; with measuring (R5, R15, R25, X5, X15, X 25) as dependent variables regressed against age (A) and height (H).For both genders, age and height had negative effects on resistance, while age and height had a positive effect on reactance. The prediction equations for R5 and X5 are as follows: R5: -1.35x10(-5) x agex2.823 - 0.001 x height x1.022 + 0.547 for girlsX5: 1.78x10(-7)x age x1.08 + 0.002 height x4.150 - 0.539, for girls R5: -6.19x10(-7)x age x 3.820 - 6.78E-005 x height x1.651 + 0.691 for boysX5: 6.95x10(-23) x age x16.226 + 0.004 height x 0.846- 0.430, for boys, respectively. Our results therefore provide an original frame of reference for R5, R15, R25, X5, X15, X25 in Iranian adolescents population, obtained from a standardized forced oscillation technique.