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H Pasterkamp

Publications and source records attributed to H Pasterkamp.

46 records · Page 3Linked to original sources
PubMed1985

Interference of cardiovascular sounds with phonopneumography in children.

We have used fast Fourier transform and power spectra analysis to determine possible interference of cardiovascular sounds with the analysis of breath sounds in children. Ten normal children, 8 to 13 yr of age, were studied with sound transducer over midprecordium, right upper lobe, and right lower lobe along with simultaneously recorded ECG and air flow. Detection of R-waves facilitated sampling of sound segments at defined flow rates, with inclusion or exclusion of heart sounds. Measurements during breath-holding and without heart sounds served as baseline values. Heart sounds were only slightly attenuated over the right upper lobe. There was a considerable overlap in the power spectra of heart and breath sounds, mainly in frequencies below 100 Hz. Analysis of low-frequency components of normal breath sounds requires sampling during parts of the cardiac cycle that are free of cardiovascular sounds.

Adolescent↗
PubMed1985

The effect of anticholinergic treatment on postexertional wheezing in asthma studied by phonopneumography and spirometry.

Postexertional wheezing is an important clinical sign of nonspecific airway hyperreactivity. We have studied wheezing after exercise in 6 asthmatic subjects, 13 to 20 yr of age, using spectral analysis of recorded tracheal sounds. Automated spectral characterization was used to measure wheezing as a proportion of respiratory time. Anticholinergic treatment with ipratropium bromide (Atrovent) was compared with placebo to investigate effects on postexertional wheezing, and pulmonary function was compared with the result of respiratory sound analysis. Atrovent did not abolish exercise-induced bronchospasm but improved preexercise lung function and thereby caused a parallel upward shift in the response curves. Wheezing after Atrovent was significantly less, later in onset, and mainly expiratory at 20 min after exercise. Wheezing as a percentage of total respiratory time correlated well with FEV1, Vmax50, and SGaw. Analysis of respiratory sounds and automated quantification of wheezing may be a useful complementary test of bronchial obstruction in asthma.

Adolescent↗
PubMed1984

Response to cold air hyperventilation in normal and in asthmatic children.

To assess the sensitivity of isocapnic hyperventilation with cold air in detecting airway hyperreactivity in asthmatic children, we studied 13 asthmatic patients (mean age 11.1 years) and 10 normal children. Cold air challenge consisted of 4 minutes of moderate hyperventilation plus another 4 minutes of maximal hyperventilation, both with subfreezing air (-16 degrees to -18 degrees C). Exercise and IHCA tests were done within 5 days and in random sequence. Mean (+/- SE) maximal % delta FEV1 after IHCA was 27 +/- 5.1% in the asthmatic children vs 4.5 +/- 1.2% in the normal subjects (P less than 0.01), even though there were no significant differences in the maximal minute ventilation equivalent between the two groups. Mean maximal % delta FEV1 after exercise was 31.7 +/- 5.6 in the asthmatic group. There was no difference in the sensitivity of the exercise and IHCA tests to detect bronchospasm in asthmatic children. Airway obstruction after IHCA was sharp and brief: maximal at 3 minutes after challenge, and back to 10% of baseline after 11 minutes. In seven asthmatic children the refractoriness to cold air and exercise was studied by repeating each test within 30 minutes; all seven showed significant refractoriness to exercise, and six showed no refractoriness to IHCA. We conclude that exercise and cold air-induced bronchospasm have different physiologic mechanisms, and that cold air testing can be used as a routine challenge to identify airway hyperreactivity in children.

Adolescent↗
PubMed1984

Arterial oxygen desaturation following salbutamol inhalation in acute asthma.

The practicality and accuracy of a new ear oximeter was evaluated. The SaO2 measured with this instrument correlated significantly with simultaneous SaO2 measurements with another ear oximeter in 12 children (age three months to 20 years) with chronic pulmonary or cardiac diseases (r = 0.93, p less than 0.001), and also correlated significantly (r = 0.96, p less than 0.001) with calculated SaO2 based on blood gas measurements of blood from the left side of the heart obtained during cardiac catheterization. The SaO2 was then measured continuously and readings were taken before and five, 15, and 30 minutes after salbutamol inhalation by face mask in 18 children. Following treatment, mean PEFR increased significantly, and mean SaO2 was significantly lower than preinhalation values at five and 15 minutes postinhalation. At 30 minutes, SaO2 had returned to control values. In nine of 18 subjects, SaO2 fell greater than or equal to 5 percent. This response was not predictable on the basis of different parameters (treatment, heart rate, PEFR). The findings suggest that supplemental O2 may be required during the first 30 minutes posttreatment.

Acute Disease↗
PubMed1983

The effects of chronic hyperinflation, nutritional status, and posture on respiratory muscle strength in cystic fibrosis.

We measured maximal static inspiratory and expiratory pressures (PImax and PEmax) in 25 patients with cystic fibrosis (CF) and 80 normal control subjects to determine whether chronic hyperinflation and malnutrition reduce PImax and PImax/PEmax, respectively. In addition, we examined the effect of posture on pressures generated. We used a diminution in PEmax as an index of a malnutrition effect on pressures generated. The patients with CF, although significantly hyperinflated (ratio of residual volume to total lung capacity, 0.49), generated PImax values similar to those of the control subjects (p greater than 0.05). Despite evidence of malnutrition (mean body mass percentile, 78%) the PEmax values of patients with CF and those of control subjects were comparable (p greater than 0.05). There was no postural effect on pressures generated in the normal subjects or the CF group as a whole. We conclude that respiratory muscle strength is normal or supranormal in CF, despite chronic hyperinflation and malnutrition.

Adolescent↗
PubMedDate not supplied

Endogenous opiates and response to exercise in asthmatic children and adolescents.

Whether endorphins secreted during stressful exercise may play a role in the physiologic response of asthmatics was investigated. Thirteen asthmatic subjects were studied: seven (mean age 16 years +/- 2.8 SEM) had perennial asthma and exercise-induced bronchospasm (EIB), and six (mean age 18 years +/- 2) had mild seasonal asthma without EIB. Each subject performed two matched progressive exercise challenges on consecutive days. Baseline lung function was measured before each challenge and was measured again after exercise at regular intervals for 30 minutes. One minute before exercise each subject received intravenously either i.v. naloxone (0.04 mg/kg), an opiate receptor blocker, or saline, in a double-blind crossover fashion. Heart rate, oxygen consumption, minute ventilation, tidal volume, and arterial oxygen saturation were recorded throughout the tests. During the two challenges these parameters were not significantly different for all 13 patients. The mean percentage reduction in FEV1 after exercise for the seven subjects with EIB was slightly but not significantly less with naloxone (25% +/- 7 SEM) than with placebo (32% +/- 7) during the first 10 minutes after exercise. Naloxone had no obvious effect on EIB or the other parameters measured in association with strenuous exercise in asthmatic patients.

Adolescent↗
PubMedDate not supplied

Spectral analysis of breath sounds in normal newborn infants.

To determine whether breath sounds in newborns are different from those described in older subjects, fast Fourier transform and power spectra analysis were performed on recorded breath sounds from 14 normal newborns. A respiration-triggered sampling technique was applied to compare early, middle, and late phases of inspiration and expiration, using a thoracic impedance signal. Peak frequencies were found in the range described for normal breath sounds in older subjects, and the frequency range of breath sounds was similar to that reported for older children and adults. The difference in breath sound quality of normal newborns appears to depend on the sound intensity during expiration. In contrast to older subjects, newborns showed only slightly less sound intensity during expiration; in the late phases of inspiration and expiration this intensity was almost equal.

Female↗