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Biomedical subjects

W Karrer

Publications and source records attributed to W Karrer.

At least 37 records · Page 2Linked to original sources
PubMed1997

Lung function and long term exposure to air pollutants in Switzerland. Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) Team.

The effect of long-term exposure to air pollutants was studied in a cross-sectional population-based sample of adults (aged 18 to 60 yr; n = 9,651) residing in eight different areas in Switzerland. Standardized medical examination included questionnaire data, lung function tests, skin-prick testing, and end-expiratory CO concentration. The impact of annual means of air pollutants on FVC and FEV1 was tested (controlling for age and age squared, sex, height, weight, educational level, nationality, and workplace exposure). Analyses were done separately for healthy never-smokers, ex-smokers (controlling for pack-yr), for current smokers (controlling for cigarettes per day and pack-yr smoked), and for the whole population. Significant and consistent effects on FVC and FEV1 were found for NO2, SO2, and particulate matter < 10 microm (PM10) in all subgroups and in the total population, with PM10 showing the most consistent effect of a 3.4% change in FVC per 10 microg/m3. Results for ozone were less consistent. Atopy did not influence this relationship. The limited number of study areas and high intercorrelation between the pollutants make it difficult to assess the effect of one single pollutant. Our conclusion is that air pollution from fossil fuel combustion, which is the main source of air pollution with SO2, NO2, and PM10 in Switzerland, is associated with decrements in lung function parameters in this study.

Adolescent↗
PubMed1996

Short-course therapy of pulmonary tuberculosis: doctor's compliance.

OBJECTIVE: The present study, conducted from 1986 to 1991, investigated the accuracy of treatment monitoring performed by practitioners in the out-patient treatment of pulmonary tuberculosis. DESIGN: All patients with smear or culture positive pulmonary tuberculosis, receiving 6-month short-course chemotherapy with Isoniazid (H), Rifampicin (R) and Pyrazinamide (Z), were included. Treatment had been initiated either in our unit, or shortly before, with discharge after an average time of 8 weeks. Practitioners were sent a flow sheet advising how to perform standardized ambulatory controls. RESULTS: Forty-three patients were included in the study, four of whom did not visit their practitioner after discharge. It must be assumed that they did not complete treatment. The average follow-up time of the remaining 39 patients was 159 weeks. In 13 cases the treatment was prolonged without obvious reason. For four patients who had not converted to a negative sputum culture at discharge, negativity was never been proven thereafter. Objective means of assessing patient compliance by H-urine strip testing were undertaken only in three cases. X-ray controls were performed adequately in 44.4% of the cases. By contrast monthly checks of liver enzymes had been done only in 23.1% of the patients. CONCLUSION: We conclude that even a highly standardized protocol of short-course tuberculosis treatment requires a certain level of experience and compliance on the part of the practitioner. We accordingly recommend that every case of pulmonary tuberculosis should be reviewed at least twice by a chest physician.

Adult↗
PubMed1996

Incomplete aspirin desensitization in an aspirin-sensitive asthmatic.

Aspirin desensitization is a valuable treatment for aspirin-sensitive sinusitis. We present a case where long-term desensitization failed. While undergoing desensitization, our patient had prolonged severe asthmatic reactions and therefore received high intravenous doses of prednisone. We hypothesize that high steroid doses administered at the time of desensitization may have raised the threshold of intolerance to a point where the administered aspirin doses were tolerated. Consequently, symptoms of intolerance subsided during the procedure. Subsequent tapering down of the daily prednisone dose caused a re-emergence of the symptoms of intolerance, apparently due to a decrease in the intolerance threshold.

Aspirin↗
PubMed1996

[Dangerous complication of transtracheal oxygen therapy with the SCOOP(R) system].

A portable oxygen system in combination with transtracheal O2 delivery (SCOOP(R)) permits patients with respiratory failure optimal mobility and facilitates longterm oxygen therapy. This report describes a 70 year old female with COPD that developed acute respiratory distress 18 days after inserting PRESCOOP(R) and 11 days after changing to SCOOP 1 catheter. Catheter stripping had not revealed any pathology. Flexible bronchoscopy showed a mucus ball at the catheter tip leading to a 80% stenosis of the trachea. Trials to remove the ball with forceps and a loop were not successful until a rigid bronchoscop was inserted. Up to 10% of patients develop mucus ball formation with SCOOP 1 catheter which remains in situ for 6 weeks. In patients with high risk of mucus formation (high O2 flow, viscous mucus, low FEV1) the manufacturers of SCOOP recommend catheter stripping. We consider a control bronchoscopy being safer 1 week after changing from PRESCOOP to SCOOP because one patient has been reported to have died of this complication and our patient has developed a near fatal situation.

Aged↗
PubMed1995

[Therapy-resistant asthma: causes and therapy].

Despite the introduction of new and potent antiasthmatic drugs, a minority of asthma patients, remains without response to therapy. Some of the patients with asthma refractory to therapy actually do not have asthma at all, but suffer from another syndrome mimicking asthma. Asthma may also exist in combination with a syndrome mimicking asthma (e.g. vocal cord dysfunction). Patients may then get treated with high doses of corticosteroids unnecessarily, because the symptoms due to vocal cord dysfunction are misinterpreted as being asthmatic. Sometimes asthma is complicated by an independent factor (e.g. gastroesophageal reflux), which does not respond to antiasthmatic drugs. In all cases of asthma being unresponsive to therapy, the diagnosis of asthma must be questioned, and other complicating factors need to be excluded. The patient's compliance should be encouraged, and correct handling of modern inhalation devices has to be monitored. Patients with refractory asthma should also undergo flexible bronchoscopy to exclude morphologic changes of the bronchial system and to obtain mucosal biopsies.

Aspergillosis, Allergic Bronchopulmonary↗
PubMed1995

[Sleep and respiration].

Nocturnal sleep-associated breathing disorders have only been investigated thoroughly since about 15 years. From these studies it became clear that many respiratory disorders, in particular chronic obstructive ones, may severely impair nocturnal breathing and thus oxygen supply. by physiologically reduced ventilation at night, particularly in patients with already reduced pulmonary function, oxygen supply may become insufficient. In order to prevent late sequelae, early invalidity or precocious death, a comprehensive diagnostic approach is mandatory. Therapy consists of thorough anti-obstructive and anti-inflammatory inhalations, aided by additional oxygen supply during the night sleep in selected cases. Sleep-apnea syndrome is a frequent disease. About 3%, of males between 25 and 75 and at least 1% of females particularly after menopause, are affected. In most cases diagnosis can be suspected by clinical symptoms and nocturnal pulse oximetry. Sensitivity of pulse oximetry, however, is insufficient, thus polysomnography is necessary to establish the diagnosis and to control therapy. The most important therapeutic measure is to establish a nocturnal nasal continuous positive airway pressure (nCPAP) that may lead to immediate amelioration of symptoms and may normalize survival of patients. In particular, patients with obstructive sleep apnea should not drive motorized vehicles because of their excessive daytime sleepiness until a therapeutic success is evident. In this paper chronic obstructive pulmonary diseases, the central and the obstructive sleep-apnea syndrome are covered in particular.

Adult↗
PubMed1994

[The treatment of obstructive sleep apnea].

Diagnosis of obstructive sleep apnea syndrome may be suspected clinically, screened for by oximetry and proven by polysomnography. A sufficient number of centers performing polysomnography and providing appropriate treatment is available today in Switzerland. The patient does not need to be admitted to a university center since nearly all high altitude clinics with pneumonologic orientation are equipped to diagnose and treat patients with obstructive sleep apnea syndrome. The treatment of choice is nocturnal CPAP-therapy which is simple, poor in complications and well tolerated. Regular follow-up by cantonal leagues for pulmonary diseases, practising pneumologists and pneumonologic centers are, however, necessary.

Adult↗
PubMed1994

[Mechanical home ventilation: indications for and application of nocturnal ventilation using nasal masks in chronic hypoventilation].

Mechanical ventilation at home has formerly been used mainly to treat respiratory failure after poliomyelitis. Nowadays this method has been refined such that insufflation is no longer necessary through a tracheostoma but via either a specially molded or a customized nose-mask. Ventilation occurs mainly at night for periodic relief of the respiratory musculature. Indications are restrictive ventilatory deficits such as kyphoscoliosis or the postthoracoplasty syndrome, slowly progressing neuromuscular diseases and sometimes traumatic tetraparesis. Evaluation and instruction of the patient take place in a pneumologic center in close cooperation with the cantonal leagues for pulmonary diseases and the family physician. Accordingly a collaboration of all social and medical institutions as well as the participation of close relatives are a prerequisite for a successful mechanical ventilation at home.

Chronic Disease↗
PubMed1994

[Nocturnal oxygen therapy in chronic obstructive bronchitis?].

Patients with chronic obstructive pulmonary disease suffer often from sleeping disorders. A cause for these complaints is the disturbed respiration during sleep. By such ventilatory alterations arterial oxygenation is decreased and periodic severe desaturation may occur. For investigation of oxygenation during the night, pulse oximetry is suited best. For difficult problems polysomnography may be used. Treatment is based primarily on optimal anti-obstructive therapy with bronchodilators and antiinflammatory agents and an adapted physical therapy. In selected patients administration of oxygen by a nasal tube is advantageous. Patients with severe desaturation and with an overlap syndrome profit most from additional oxygen treatment. Survival can thus be prolonged and the quality of life is improved.

Blood Gas Monitoring, Transcutaneous↗
PubMed1993

Comparison of bronchodilator effects of fenoterol/ipratropium bromide and salbutamol in patients with chronic obstructive lung disease.

A double-blind, randomized cross-over trial was carried out in 24 patients with chronic airflow obstruction. The patients were required to demonstrate a minimum 15% absolute increase in forced expiratory volume (FEV1) after a standard dose (0.4 mg) of fenoterol (F). On a separate occasion the effect of ipratropium bromide (IB; 0.04 mg) on FEV1 was tested also; according to the increase in FEV1 the patients were grouped into IB responders (delta FEV1 > 15%) and IB nonresponders (delta FEV1 < 15%). Two puffs of F/IB (0.1 mg/0.04 mg), salbutamol (S; 0.2 mg) and placebo (P) were given by metered-dose inhaler at the same time of the day on three different occasions. FEV1 and specific airway resistance (sRaw) were assessed before and at specific intervals following inhalation. The results showed that F/IB and S produced similar maximal increases in FEV1 (delta FEV1 32% for F/IB and 31% for S) and decreases in sRaw (delta sRaw 24% for F/IB and 21% for S). These effects were significantly different both from baseline values and from P. FEV1 was still significantly different 8 h after inhalation from P in the F/IB group, but not in the group that received S. The effect of IB on FEV1 in the pretest was compared with the subsequent response to F/IB. In IB responders F/IB seemed to produce slightly more effective bronchodilation. Side effects were minimal and clinically insignificant. In conclusion, F/IB, with its ability to effect sustained bronchodilation without adverse side effects, is a viable alternative to a monotherapy in chronic obstructive pulmonary disease.

Aerosols↗
PubMed1991

[Diagnosis and treatment of pulmonary infection due to Mycobacterium malmoense].

To date more than 150 patients with Mycobacterium malmoense disease have been reported. These infections are rare and only in one case, so far not published, is this species associated with Aids. Most reported cases were seen in northern Europe. We present three pulmonary cases from Switzerland. M. malmoense causes lung disease resembling tuberculosis clinically and in chest X-ray. Disease is considered to be present when two and more sputums or bronchial washings are acid-fast bacilli smear-positive and culture-positive. M. malmoense grows slowly on egg-based bacteriological media; the incubation time is at least 6 weeks and the use of special solid or liquid media is recommended. Person-to-person transmission is rare and, in contrast to tuberculosis, isolation of the patient is not necessary and subsequent close contact persons do not need to be evaluated. It seems that a combination of isoniazid, rifampicin and ethambutol given for more than 12 months is the best regimen.

Adult↗
PubMed1991

[Pickwick syndrome. A case example of an obesity-hypoventilation syndrome, combined with obstructive sleep apnea].

Nocturnal intrinsic disorders of sleep are much more common than hitherto assumed. In middle-aged men, a prevalence of 0.3 to 3% of severe obstructive sleep apnea syndromes necessitating treatment is expected. The international classification of sleep disorders (ICSD 1990) contains the definitions and descriptions of the different entities. A patient with combined obstructive sleep apnea and a hypoventilation syndrome due to obesity serves to illustrate problems with diagnosis and particularly treatment of this respiratory disorder during sleep. The most frequent sleep disorders are briefly presented and placed in the context of other concomitant somatic diseases. Because of the possible serious course of nocturnal hypoxemias, the conclusion is justified that a timely and accurate diagnosis is essential for the patient. Transcutaneous oximetry during the night is sufficient as screening procedure. It can be applied to outpatients. In depth, evaluation should be carried out at a specialized center with polysomnography.

Adult↗
PubMed1991

[Long-term trans-tracheal oxygen therapy. Simple management for the patient--improved compliance].

Long-term oxygen therapy is an established treatment of severe hypoxemia in patients with chronic obstructive or other pulmonary diseases. Quality of life and survival time can be improved significantly. Objective patient evaluation and compliance are most important. The transtracheal oxygen therapy is an alternative method to nasal cannulas for oxygen supply. Cosmetic problems and nasal discomfort are avoided. The oxygen flow-rate can be reduced by up to 50%. If an on demand-system is used, the oxygen flow-rate can be adapted to exercise. The change and cleaning of the catheter is easy and is performed twice daily by the patient himself.

Humans↗
PubMed1990

[Respiration of patients with chronic lung disease at 500 and 1500 meter above sea level].

There is plentiful literature on respiration at high altitude (3000-8000 m above sea level) and its cardiopulmonary sequelae. But little is known about changes in ventilation and in pulmonary gas exchange at altitudes of 1,000-2,000 m above sea level. We studied 68 patients 500 and 1,500 m above sea level. On the arrival of the patients at 534 m above sea level we measured the arterial blood gases, pulse rate, respiratory rate and a breathing score. The same measurements were repeated on arrival at 1,500 m above sea level. A lung function test (FEV1, FVC, PEF, MEF 25-75) was also performed. The patients were divided into three groups: asthmatics, chronic bronchitics and restrictive patients. A control group was formed of patients without lung disease. Within all groups, the pO2 and the pCO2 diminishes significantly, no significant difference between the groups was found. In patients with lung disease oxygen saturation changes from 94.1% to 91.8% (COPD) and from 95.3% to 93.4% (restrictive patients). Age, smoking habits, lung function test and blood gases at 534 m are not predictors of the blood gases at altitude in COPD patients. But patients with restrictive lung disease show a positive correlation between age and change in pO2, as well as between severity of the restrictive disease and the change in oxygen saturation. The change of pO2 in COPD patients is not relevant clinically, as there is only minimal change in oxygen saturation. We conclude that patients of all degrees of COPD and patients with light to moderate restrictive lung disease can safely tolerate a difference in altitude from 534 to 1,500 m.

Aged↗