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Biomedical subjects

H Folgering

Publications and source records attributed to H Folgering.

At least 19 recordsLinked to original sources
PubMed1992

Treatment with inhaled steroids in asthma and chronic bronchitis: long-term compliance and inhaler technique.

We investigated compliance and inhaler technique in 50 patients with airway obstruction (26 asthma, 24 chronic bronchitis) being treated with inhaled steroid (beclomethasone dipropionate, BDP) via a dry powder inhaler (Rotahaler omega). Patients had already participated for one year in a 2-year trial of BDP in general practice. They were treated daily with two dry powder inhalations of 400 micrograms BDP in combination with a bronchodilator. Compliance with BDP was measured by counting capsules (single-blind) at the end of a 4-month period and through a questionnaire. Counting capsules revealed non-compliance in 46% of the patients. Compliance was not related to age, sex, diagnosis or side-effects of BDP. In chronic bronchitis, but not in asthma, compliance was related to the outcome parameters of steroid treatment (pulmonary symptoms, change in lung function and non-specific bronchial responsiveness). The inhaler technique was judged insufficient in 27% of the patients. This study stresses the importance of regular instruction in inhaler technique and proper information about prophylactic steroid treatment by the general practitioner during the treatment of asthma and chronic bronchitis.

Administration, Inhalation↗
PubMed1992

Does the continuous use of bronchodilators mask the progression of asthma or chronic bronchitis?

Recently, we published data of a 2 year randomized controlled study in which the effects of continuous versus symptomatic bronchodilator treatment in patients with moderate asthma or chronic bronchitis were investigated. The results showed that FEV1 decline in the continuously treated group was significantly larger than in the symptomatically treated group (72 versus 20 ml/year, P < 0.05). We reanalysed these data in order to investigate the hypothesis that the continuous use of bronchodilators may mask a rapid decline in lung function. Lung function decline was assessed by regression analysis of seven FEV1 measurements. Respiratory symptoms were assessed by means of the MRC questionnaire every 12 months, and they were also recorded by the patients in a weekly report. Of the participating patients 144 completed the study. Increased lung function decline in the continuously treated group was not reflected in a significant deterioration of the symptoms. Moreover, the decline in FEV1 showed no correlation at all with changes in respiratory symptoms in continuously treated patients (r = -0.03, P = 0.80), whereas in the symptomatically treated group, there was a better relation (r = -0.32, P = 0.003) to changes in respiratory symptoms. These results show that continuous bronchodilation may indeed mask the worsening of the disease. This lack of awareness of deterioration of the disease is probably caused by the continuous symptom relief of bronchodilators. It may be misleading to both patients and physicians.

Adult↗
PubMed1992

Two-year bronchodilator treatment in patients with mild airflow obstruction. Contradictory effects on lung function and quality of life.

In a two-year randomized controlled study, we studied the effects of bronchodilator treatment on the lung function and the quality of life in patients with mild airflow obstruction. The patients were randomly divided to receive either continuous or symptomatic bronchodilator treatment. Within these treatment groups, they received salbutamol in the first year and ipratropium bromide in the second or vice versa. In addition, the quality of life of the patients was compared to that of the general population. One hundred and forty-four patients completed the study. When compared to the general population, these patients showed a serious impairment in quality of life. No differences between the two drugs were found, but the results indicated that FEV1 decline in the continuously treated group was significantly larger than in the symptomatically treated group. However, this was not reflected in a significant deterioration of the quality of life in the continuous group as measured by means of the Nottingham Health Profile and the Inventory of Subjective Health. Decline in FEV1 showed no correlation with changes in quality of life scores. This may be due to a relatively rapid adjustment of the patients to a decline in FEV1, as a result of which it has no direct effect on the experienced quality of life. Another reason may be that continuous bronchodilation masks the worsening of the disease. This lack of awareness might in turn be caused by the continuous symptom relief of bronchodilators.

Albuterol↗
PubMed1992

Inhaled beclomethasone improves the course of asthma and COPD.

The effects of inhaled beclomethasone dipropionate (BDP), 800 micrograms daily, on the long-term course of asthma and chronic obstructive pulmonary disease (COPD) were investigated in a prospective, controlled study, over three years. During the first two years, patients were treated with a bronchodilator only (salbutamol or ipratropium bromide). Fifty six patients (28 asthma, 28 COPD), with an unfavourable course of disease during bronchodilator therapy alone (an annual decline in forced expiratory volume in one second (FEV1) of > or = 80 ml.yr-1 in combination with at least one exacerbation.yr-1), were selected for additional treatment with inhaled beclomethasone dipropionate (BDP), 800 micrograms daily, during the third year. The FEV1 and provoking concentration of histamine producing a 20% fall in FEV1 (PC20-histamine) were assessed at six-monthly intervals. In asthma, the annual decline in prebronchodilator FEV1 of -158 ml.yr-1 during bronchodilator therapy alone was followed by a significant increase of 562 ml.yr-1 during months 1-6 of BDP treatment (p < 0.0005). During months 7-12 of BDP, the FEV1 declined slightly with -31 ml.yr-1, which was not statistically different from the annual decline before steroid therapy (p = 0.17). In COPD, the increase of 323 ml.yr-1 during months 1-6 of treatment with BDP was different from the annual decline of -156 ml.yr-1 before BDP (p < 0.05). The PC20-histamine improved by 308 doubling doses during 1-12 months of BDP in asthma (p < 0.05) but not in COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1992

A comparison of six different ways of expressing the bronchodilating response in asthma and COPD; reproducibility and dependence of prebronchodilator FEV1.

Various indices are used to express the bronchodilating response. It is unclear, however, which index is most informative. The aim of this study was to compare six expressions of the bronchodilating response and to examine: 1) the independence of the prebronchodilator forced expiratory volume in one second (FEV1); and 2) the reproducibility of the bronchodilating response. Bronchodilating responses (increases in FEV1 60 min after salbutamol 400 micrograms and ipratropium bromide 80 micrograms) on six test occasions, during two years, of 183 patients (72 asthma, 111 chronic obstructive pulmonary disease (COPD)) from a large bronchodilator intervention study were used. The dependence of the prebronchodilator FEV1 was investigated both between patients (cross-sectional analysis) and within patients (longitudinal analysis) by means of linear regression analysis. The reproducibility of the bronchodilating response was calculated by means of the coefficients of variation (CVs) of the six bronchodilating responses during two years. The CVs of the six expression indices were compared by analysis of variance (ANOVA). No index was independent of the prebronchodilator FEV1. However, some indices were significantly more dependent on the prebronchodilator lung function and, therefore, less reproducible than others. The "% initial" index (change as a percentage of the prebronchodilator value) was the most dependent on the prebronchodilator lung function and had the worst reproducibility (CV ranged from 50-61%). The "% possible" (change as a percentage of the predicted minus prebronchodilator value) and "% achievable" (change as a percentage of the maximal postbronchodilator minus prebronchodilator value) indices were the least dependent on the prebronchodilator value and had the highest reproducibility (CV ranging from 34-53%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Bronchodilator treatment in moderate asthma or chronic bronchitis: continuous or on demand? A randomised controlled study.

OBJECTIVE: To examine the effect of bronchodilator treatment given continuously versus on demand on the progression of asthma and chronic bronchitis and to compare the long term effects of a beta 2 adrenergic drug (salbutamol) and an anticholinergic drug (ipratropium bromide). DESIGN: Two year randomised controlled prospective 'crossover' study in which patients were assigned to one of two parallel treatment groups receiving continuous treatment or treatment on demand. SETTING: 29 general practices in the catchment area of the University of Nijmegen. PATIENTS: 223 patients aged greater than or equal to 30 with moderate airway obstruction due to asthma or chronic bronchitis, selected by their general practitioners. INTERVENTIONS: 1600 micrograms salbutamol or 160 micrograms ipratropium bromide daily (113 patients) or salbutamol or ipratropium bromide only during exacerbations or periods of dyspnoea (110). No other pulmonary treatment was permitted. MAIN OUTCOME MEASURES: Decline in ventilatory function and change in bronchial responsiveness, respiratory symptoms, number of exacerbations, and quality of life. RESULTS: Among 144 patients completing the study, after correction for possible confounding factors the decline in forced expiratory volume in one second was -0.072 l/year in continuously treated patients and -0.020 l/year in those treated on demand (p less than 0.05), irrespective of the drug. The difference in the decline in patients with asthma was comparable with that in patients with chronic bronchitis (asthma: 0.092 v -0.025 l/year; chronic bronchitis: -0.082 v -0.031 l/year). Bronchial responsiveness increased slightly (0.4 doubling dose) with continuous treatment in chronic bronchitis, but exacerbations, symptoms, and quality of life were unchanged. Salbutamol and ipratropium bromide had comparable effects on all variables investigated. CONCLUSIONS: Continuous bronchodilator treatment without anti-inflammatory treatment accelerates decline in ventilatory function. Bronchodilators should be used only on demand, with additional corticosteroid treatment, if necessary.

Adult↗
PubMed1991

Effects of allergy and age on responses to salbutamol and ipratropium bromide in moderate asthma and chronic bronchitis.

The bronchodilating responses to 400 micrograms salbutamol and 80 micrograms ipratropium bromide were studied in 188 patients with chronic bronchitis (n = 113) or asthma (n = 75) and mild to moderate airflow obstruction (forced expiratory volume in one second (FEV1) above 50% but below 2 SD of predicted value) in a crossover study on two days a week apart. Both the patients with asthma and the patients with chronic bronchitis varied considerably in their responses to the salbutamol and the ipratropium bromide. The mean increase in FEV1 in the subjects with asthma was higher after salbutamol (0.371 or 18% of the prebronchodilator value) than after ipratropium bromide (0.26 1 or 13%). In chronic bronchitis there was no difference between the increase in FEV1 after salbutamol (0.161 or 7%) and after ipratropium bromide (0.191 or 8%). When patients were categorised into those with a better response to salbutamol 400 micrograms and those with a better response to ipratropium bromide 80 micrograms, patients with chronic bronchitis responded better in general to ipratropium bromide whereas asthmatic patients responded better to salbutamol. The response pattern was also related to allergy and age, allergic patients and patients under 60 being more likely to respond better to salbutamol 400 micrograms than non-allergic patients and older patients, who benefited more from ipratropium bromide 80 micrograms. The response pattern was not related to sex, smoking habits, lung function, bronchial reactivity, respiratory symptoms, or number of exacerbations during the preceding year.

Age Factors↗
PubMed1991

Accuracy, precision and linearity of the portable flow-volume meter Microspiro HI-298.

The accuracy, precision and linearity of a new portable flow-volume meter, the Microspiro HI-298 (Chest Corporation, Tokyo, Japan), was investigated using a Fleisch no. 4 pneumotachograph as a standard. After connection and calibration of the pneumotachograph and the Microspiro, a healthy subject performed 44 forced vital capacity (FVC) manoeuvres at different levels of lung inflation. The FVC of these expirations ranged from 2.5-5.1 l. Linear regression of Microspiro values (dependent variable) on Fleisch pneumotachograph values (independent variable) showed that a good linear relationship existed: Pearson correlation coefficients ranged from 0.938-0.985. Linearity of the Microspiro was good except for the peak expiratory flow rate (PEFR) and the maximal expiratory flow at 25% of the expired volume (MEF75). The random error (measure of precision) of all flow-volume (F-V) indices was lower than 5%. The systematic error (measure of accuracy) was low for the forced expiratory volume in one second (FEV1) and the FVC (1% and 4.6%, respectively) but much higher for the instantaneous expiratory flows (PEFR 11.0%; MEF75 7.0%; MEF50 8.5%; MEF25 11.4%). Only the total error in FEV1 complied with the tolerance of 4% of the European Community for Coal and Steel (ECCS). When the measured values were adjusted according to the regression equations of this study, all F-V indices were accurate and precise within 5%. It was concluded that the portable Microspiro HI-298 is a useful instrument for bedside, work-site spirometry and for use in general practice.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1990

Accuracy and reproducibility of the Assess peak flow meter.

The variability of peak flow measurements was studied in 24 patients with airway obstruction, using 12 Assess peak flow meters and a Fleisch pneumotachograph type 4 as a standard. The Assess peak flow meter gave systematic under-readings of 19-34% (low accuracy). The value scale of the Assess peak flow meter should be adjusted. As systematic under-readings do not influence the variability in peak flow measurements, variability was only caused by the random error of the instrument. The random error of the Assess peak flow meter was relatively low: about 4% of the measured peak flow value (high precision). The contribution of the Assess peak flow meter to the total variability of peak flow measurements showed a linear relationship (r = 0.53) with the value of the peak flow rate itself and varied from 9% (at 3 l.s-1) to 86% (at 10.8 l.s-1). Reading errors of the peak flow meter were responsible for about 1% of the total variability. The remaining variability is probably caused by the correctness of the peak flow performance and the motivation of the patient.

Adult↗
PubMed1989

The effect of respiration on diastolic blood flow velocities in the human heart.

This study was performed to evaluate the effects of respiration on diastolic blood flow velocity and its relevance for the determination of pulsed Doppler reference values from diastolic blood flow. Doppler signals were recorded from both the atrial and ventricular sides of the mitral valve and the tricuspid valve in 215 healthy volunteers (120 males and 95 females, with ages ranging from 1-65 years). Respiratory signals were recorded simultaneously by a mercury strain gauge around the thorax. From the medians of Doppler spectra the maximum velocity during early diastole (VmaxE), during atrial contraction (VmaxA) and the ratio between VmaxE and VmaxA (EA ratio) were obtained. On the atrial side of the tricuspid valve, VmaxE and VmaxA were significantly higher during inspiration than during expiration. On the ventricular side of the tricuspid valve, this was only found for VmaxE. On the atrial side of the mitral valve, VmaxE and VmaxA were significantly lower during inspiration than during expiration. At the ventricular side of the mitral valve, this was found only for VmaxE. No significant effect of respiration was found on the EA ratio. We conclude that there is a respiration-related effect on VmaxE and VmaxA. However, no significant effect is found on the EA ratio. Thus, for the determination of the EA ratio in intersubject studies, information about the respiratory cycle is not relevant.

Adolescent↗
PubMed1989

Treatment of patients with airflow obstruction by general practitioners and chest physicians.

The study comprised 223 patients with airflow obstruction and/or bronchial hyperreactivity from 29 general practices in the catchment area of Nijmegen University. Fifty-six patients were treated by 19 chest physicians, the remaining 167 by their general practitioners (GPs), without specialist care. The specialists treated more allergic patients than the GP (p less than 0.05). No other relevant differences in sex, age, smoking behaviour, and severity of the disease (symptoms, lung function, and bronchial hyperreactivity) could be observed between these two groups of patients. Chest physicians prescribed almost three times as many drugs as GPs. No immediate response to the prescribed bronchodilators was found in 16% of the patients treated by the GPs, nor in 20% of the patients treated by the specialists. We could identify only a weak relationship between the severity of the disease (symptoms and pulmonary function combined) and the prescribed pharmacotherapy: with growing degrees of severity the GP seems to prescribe more bronchodilators, the specialist more inhaled corticosteroids. Prescribed pharmacotherapy should be based on the combination of symptoms, pulmonary function, bronchial hyperreactivity, and reversibility on the prescribed bronchodilators.

Adult↗
PubMed1988

Hyperventilation syndrome and muscle fatigue.

Fatigue is a frequent complaint from patients suffering from the hyperventilation syndrome. Fatigue was quantified in terms of the endurance time that a certain force can be generated in a sustained handgrip contraction, and in terms of the time course of changes in certain parameters of the EMG-power spectrum of the contracting muscles. This was done in a group of 25 normal subjects and a group of 30 patients suffering from the hyperventilation syndrome. No difference in endurance times was found. The EMG-fatiguability in the hyperventilation group developed even slower than in the normal group. In three normals the fatigue parameters were also measured in three conditions of normo-, hypo-, and hyper-capnia. No intraindividual correlations were found between fatigue parameters and CO2-levels. Neither were such correlations found between individuals in the hyperventilation group and the normal group. It is concluded that the subjective feelings of fatigue in the hyperventilation patients cannot be corroborated by the objective measurements used in this study. Thus their fatigue is not of a peripheral type. The levels of CO2 do not have an effect on objectively measured fatigue parameters. The hypothesis that lactate accumulation in contracting muscles mediates EMG-fatiguability, cannot explain the present results, and therefore is not supported by results from this study.

Adult↗
PubMed1988

Exercise and training in patients with chronic obstructive lung disease.

Exercise protocols and training are used more and more in diagnostic procedures and as a tool in improving physical, social and psychological functioning in chronic obstructive lung disease patients. Before starting a training programme in chronic obstructive lung disease patients, one should exclude ventilatory-limited patients from the group. A maximal ergometer test with arterial blood samples or pulse oximetry must be performed. In mild forms of chronic obstructive lung disease with no ventilatory insufficiency demonstrable with exercise testing, the patient can be trained with no restrictions. Endurance training is permitted. It should be noted that it is possible to train the muscular and cardiovascular system up to a new, possible ventilatory maximum. In severe chronic obstructive lung disease endurance training is accompanied by hypoxia, with an associated risk of rhythm disturbances and right heart failure. Training with supplemental oxygen can reduce this risk, but should be done only under close medical supervision. In very severe chronic obstructive lung disease, when endurance training is only marginally possible even with supplemental oxygen, suppleness, coordination and relaxation exercises should be emphasised in rehabilitation programmes. Postural exercises and breathing control exercises can also give great subjective improvements in this often very disabled group of patients. Furthermore they can reduce fear and panic when dyspnoea occurs. Training of the respiratory muscles in patients with chronic obstructive lung disease must be regarded as an experimental therapy. The clinical importance remains uncertain. Exercise-induced bronchoconstriction should not limit exercises or training, provided it is treated correctly.

Exercise Test↗
PubMed1988

Studying the control of breathing in man.

The control system of breathing can be considered as a closed-loop system, consisting of two subsystems: the controlling system and the controlled system. Both subsystems are defined by their input-output relationships. In the controlling system the input is the blood gas value; the output is some parameter of ventilation. The controlled system is characterized by an input of ventilation, and an output of blood gas values. In the closed-loop situation the control of breathing can be influenced by outside "disturbances", threatening to disrupt the regulation of the constancy of the internal environment. When studying the control of breathing, and therefore studying the strengths or defects of this homeostatic system, one has to decide whether one intends to investigate the closed-loop or the open-loop situation, and which defect in a subsystem may be the cause of a disrupted homeostasis. What non-feedback stimuli may be active at the moment of the investigation? How can they be kept constant or eliminated? What possible effects from drugs, beverages, nutrients (possibly consumed hours earlier) may still be present? In particular, the output parameters of the controlling system should be carefully chosen to represent that part of the system that one intends to investigate. Disruptions of the control of breathing may have serious consequences for several categories of patients, e.g. those with chronic obstructive pulmonary disease (COPD), asthma, sleep apnoea, sudden infant death syndrome, several neurological syndromes, and the hyperventilation syndrome. Adequate investigation of the control of breathing in these patients is of great importance for their treatment.

Carbon Dioxide↗
PubMed1987

Hyperventilation and panic attacks.

The symptoms of hyperventilation syndrome and panic disorder are very similar. A questionnaire was used to assess the incidence of panic disorder in 274 patients; 35% of the patients with hyperventilation and only 5% of the non-hyperventilating patients showed panic disorder. The authors conclude that hyperventilation plays an important role in panic disorder and in generalized anxiety disorder.

Adult↗
PubMed1986

Ventilatory response to CO2 in infants with alleged sleep apnoea.

Twenty-eight children whose parents reported sleep apnoea were investigated. In 15 infants apnoeic periods during sleep could be confirmed during clinical observation. Ventilatory responses to CO2 were measured in all infants, in 23 during sleep in 5 only when awake. A very wide range of CO2 sensitivities was found. In four children there was no ventilatory response or even a paradox one: a decrease in ventilation as PACO2 was increased. Two of these non-responding children died later, one still sleeps in a respirator aged three, and one developed a normal CO2 sensitivity a few months later. It is concluded that the parent's account of an apnoeic incident during sleep is not always reliable. A ventilatory response to CO2 is a useful tool with which to identify infants at risk of death, possibly related to a defective control of ventilation. The actual value of the CO2 sensitivity hardly gives any useful information, due to the wide range of "normal" reactions. No or negative ventilatory responses to CO2 seem to be indicators of high risk children, and may possibly play a role in SIDS incidents.

Carbon Dioxide↗
PubMed1986

Postoperative analgesia by nicomorphine intramuscularly versus high thoracic epidural administration. Effects on ventilatory and airway occlusion pressure responses to CO2.

In this study the effects of nicomorphine, administered either intramuscularly or by high thoracic epidural route, on the ventilatory and airway occlusion pressure response to CO2 were investigated and compared. Twenty-four patients scheduled for thoracic surgery were allocated randomly to postoperative pain relief by i.m. nicomorphine or by high thoracic epidural nicomorphine. The ventilatory response to 5% carbon dioxide was measured in all patients: first 1 day before operation, secondly on the first day after surgery immediately before nicomorphine administration and finally after the administration, at the moment when no further rise in end-tidal PCO2 (PETCO2) was measured. Respiratory response was assessed in two ways, by measuring minute ventilation (VE) and mouth occlusion pressure (P0.1). There was a significant depression in ventilatory response to CO2 in the intramuscular group (P = 0.03) due to nicomorphine as assessed by the slope of VE vs PETCO2. No significant depression was found in the epidural group, irrespective of measurement of VE or P0.1. No significant shift of apnoeic threshold-PETCO2 was observed in either group.

Analgesia↗