Elisabeth Weinhandl

Laser acupuncture in children and adolescents with exercise induced asthma

Background: Laser acupuncture, a painless technique, is a widely used alternative treatment method for childhood asthma, although its efficacy has not been proved in controlled clinical studies. Methods: A double blind, placebo controlled, crossover study was performed to investigate the possible protective effect of a single laser acupuncture treatment on cold dry air hyperventilation induced bronchoconstriction in 44 children and adolescents of mean age 11.9 years (range 7.5–16.7) with exercise induced asthma. Laser acupuncture was performed on real and placebo points in random order on two consecutive days. Lung function was measured before laser acupuncture, immediately after laser acupuncture (just before cold dry air challenge (CACh)), and 3 and 15 minutes after CACh. CACh consisted of a 4 minute isocapnic hyperventilation of –10°C absolute dry air. Results: Comparison of real acupuncture with placebo acupuncture showed no significant differences in the mean maximum CACh induced decrease in forced expiratory volume in 1 second (27.2 (18.2)% v 23.8 (16.2)%) and maximal expiratory flow at 25% remaining vital capacity (51.6 (20.8)% v 44.4 (22.3)%). Conclusions: A single laser acupuncture treatment offers no protection against exercise induced bronchoconstriction in paediatric and adolescent patients.

Atopy, lung function and bronchial responsiveness in symptom-free paediatric asthma patients

In adolescence, some paediatric asthma patients will become symptom-free and require no further treatment. There is little information on the atopic status, lung function and bronchial responsiveness of these patients. Symptom-free asthma patients (n=118) aged 7.7-19.2 yrs, were evaluated 1 year after termination of therapy. Bronchial asthma had previously been diagnosed on the basis of recurrent wheezing episodes. Atopic status was assessed by skin-prick testing. Baseline lung function was measured by spirometry, flow-volume curve and plethysmography. Bronchial responsiveness was assessed nonpharmacologically by cold dry air challenge. Eighty one patients had at least one positive skin test result, and the remaining 37 were defined as nonatopic. In atopic subjects, the prevalence of bronchial hyperresponsiveness was significantly higher than in nonatopic patients (41 out of 81 versus 7 out of 37; p=0.001). Atopic subjects showed a significantly lower maximal expiratory flow at 25% remaining vital capacity (p<0.05) and a higher residual volume (p<0.05) than nonatopic subjects. Nonatopic subjects were significantly younger than atopic patients (p<0.01). These symptom- and medication-free paediatric and adolescent asthma patients could, thus, be divided into two groups: 1) atopic subjects with a tendency towards bronchial hyperresponsiveness; and 2) nonatopic subjects with better lung function and normal bronchial responsiveness In view of the increased understanding of the epidemiology of early childhood wheezing, these findings support the concept of different pathogenic mechanisms underlying wheezing episodes in early childhood.

Reproducibility of forced expiratory flow and volume measurements in infants with bronchiolitis.

The end‐tidal rapid thoracoabdominal compression (ETRTC) technique is an established method for lung function testing in infancy. Previous work in healthy infants, however, has shown that measurements with the newly developed raised volume rapid thoracoabdominal compression (RVRTC) technique are more reproducible than those with the ETRTC technique. So far, reproducibility of the two techniques has not been compared in infants with acute airway disease. Twenty‐three infants with acute viral bronchiolitis underwent lung function assessment with both the ETRTC and the RVRTC technique. A series of 8–10 measurements with each technique was done in randomized order. Forced expired volumes at 0.5, 0.75, and 1 sec after chest compression (FEV0.5, FEV0.75, and FEV1.0) were measured with the RVRTC technique; maximum expiratory flow at functional residual capacity (V′maxFRC) was measured with the ETRTC technique. Group mean intrasubject coefficients of variation (CV) were 4.84% for FEV0.5, 5.01% for FEV0.75, 5.43% for FEV1.0, and 13.79% for V′maxFRC, respectively.

Comparing methods for assessing bronchial responsiveness in children: single step cold air challenge, multiple step cold air challenge, and histamine provocation

Cold air challenge (CACh) can be applied by either a single step (SSCACh) or a multiple step (MSCACh) protocol. The interrelationship of the responses of the different protocols has not yet been studied. Furthermore, there is contradictory information on the correlation of cold air challenge responses to the outcome of pharmacological provocations. A single and a multiple step cold air challenge and a histamine provocation were performed in random order on three consecutive days on 28 children and adolescents with bronchial asthma, who were currently symptom- and medication-free. Single step cold air challenge consisted of a 4 min isocapnic hyperventilation of dry, -10 degrees C air; the subjectss response was quantified by the induced change in forced expiratory volume in one second (FEV1). Multiple step cold air challenge consisted of a series of 3 min, cold dry air hyperventilation steps from 20 to 80% of maximal voluntary ventilation (MVV); response was expressed as the provocative dose causing a 10% fall in FEV1 (PD10). Histamine provocation consisted of a series of 2 min inhalations of stepwise increasing histamine concentrations from 0.03 to 8.0 mg.mL-1; response was expressed as the provocative concentration of histamine causing a 20% fall in FEV1 (PC20). Change in FEV1 (delta FEV1) (SSCACh) correlated closely with PD10 (MSCACh); scatter around the regression line was minimal. With one exception, both types of CACh identified the same subjects as hyper- and normoresponsive. delta FEV1 (SSCACh) correlated significantly to PC20 (histamine), but scatter around the regression line was substantial. The correlation of PD10 (MSCACh) to PC20 (histamine) failed to reach statistical significance. These results indicate that the stimulus applied and the bronchoconstrictor mechanism activated, and not the challenge protocol, determine the outcome of a cold air challenge. In clinical practice, a brief single step cold air challenge can substitute for a more time-consuming multiple step cold air challenge. As nonpharmacological challenges seem to measure a different type of bronchial responsiveness, neither a single step nor a multiple step cold air challenge can substitute for a pharmacological provocation.

Short-term effects of physiotherapy on ventilation inhomogeneity in cystic fibrosis patients with a wide range of lung disease severity

BACKGROUND Lung clearance index (LCI) is increasingly used as a study endpoint for therapeutic interventions in cystic fibrosis (CF) patients. We set out to assess the effect of chest physiotherapy on ventilation inhomogeneity in clinically stable patients with CF lung disease of varying severity. METHODS In 29 CF patients (7.3-43.7 years) N2MBW (nitrogen multiple breath washout), plethysmography, and spirometry measurements were conducted, followed by 30 min of supervised PEP mask chest physiotherapy and repeated measurements 30 min after therapy. RESULTS We observed a mean change in LCI after physiotherapy from 15.00 to 14.80 (range, -4.84 to 3.37; p=0.578). In seven patients, LCI decreased, and in ten patients, LCI increased by ≥1. For the whole group, statistically significant improvements were seen in Reff, FEV1, FVC, and MEF50. CONCLUSIONS By opening up previously poorly ventilated lung regions, physiotherapy may either increase or decrease ventilation inhomogeneity; the short-term effect of physiotherapy on LCI appears to be unpredictable.

Effects of nedocromil and salbutamol on airway reactivity in children with asthma

Nedocromil and salbutamol are effective drugs in preventing exercise-induced asthma (EIA). The aim of this study was to compare the protective effects of both drugs and a combination of both drugs against cold dry air-induced bronchoconstriction, using cold dry air challenges (CACh) as a surrogate for exercise. Twenty-five atopic children (mean age 13.7, range 8–18 yrs) with EIA participated in the study. Lung function tests were performed before medication, 30 min after medication and just before CACh, and 3 and 15 min after the challenge on four consecutive days. CACh consisted of a 4-min isocapnic hyperpnoea of −10°C, absolutely dry air. Treatment consisted of nedocromil (two puffs of 2 mg) plus placebo, salbutamol (two puffs of 100 µg) plus placebo, the combination of both drugs, and placebo alone, in a random order. Both active drugs were significantly more protective than placebo and the combination showed an additive effect. Mean maximum postchallenge decrease in forced expiratory volume in one second after placebo was 27±8.1%, 12±9.5% after nedocromil, 8±10.4% after salbutamol, and 4.5±6.7% after the combination of both drugs, respectively. These results suggest that both drugs protect against exercise-induced asthma. Although not as effective as salbutamol and combined medication, nedocromil can give sufficient protection for many patients.

Effect of sleep stages on measurements of passive respiratory mechanics in infants with bronchiolitis

The measurement of passive respiratory mechanics by the single‐breath occlusion technique is one of the more frequently used tests of infant lung function. Measurements are routinely done under chloral hydrate sedation, and a possible influence of sleep stages on these measurements has not been evaluated so far. We combined the assessment of passive respiratory mechanics with sleep stage monitoring in 44 infants and toddlers with mild to moderately severe bronchiolitis. In 31 infants, only nonrapid eye movement (NREM) sleep was recorded. In 13 patients who showed both NREM and rapid eye movement (REM) sleep, compliance of the respiratory system was significantly lower during REM than NREM sleep (73.2 ± 19.7 vs. 81.2 ± 21.3 mL/kPa, P = 0.0007), while resistance remained essentially unchanged. This finding was explained by an unchanged airway opening pressure in combination with a significantly decreased extrapolated volume. As tidal volume did not change from NREM to REM, this indicates reduced dynamic elevation of lung volume during REM sleep and thus supports previous observations of decreased lung volume in this sleep stage. From a practical perspective, these findings argue for the monitoring of sleep stage during measurements of passive respiratory mechanics, thereby increasing the complexity of these measurements significantly. Pediatr Pulmonol. 1999; 27:273–277.

Small airway function before and after cold dry air challenge in pediatric asthma patients during remission

We wanted to compare cold dry air challenge (CACh) induced changes in spirometric parameters with changes in nitrogen multiple breath washout (N2MBW) parameters in pediatric asthma patients during clinical remission over the past year (ie, with “inactive asthma”). As N2MBW assesses ventilation heterogeneity we expected to gain detailed information about peripheral airways contribution.