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F Raschke

Publications and source records attributed to F Raschke.

32 records · Page 2Linked to original sources
PubMed1995

[Chronobiological viewpoints of respiratory regulation].

Control of breathing is ruled by autonomous and behavioural necessities as well. These adaptive functions are realized by temporally structured processes, which are described, analyzed, and functionally estimated by means of the methods of chronobiology. Chronobiological labels like circadian/ultradian, internal clock, Zeitgeber, coordination, entrainment, and resetting are given as examples from sleep, wake, physical strain, and pathophysiology. They are compared to their corresponding functions in respiratory control. Disturbances in chronobiological indicators reveal functional and sleep regulating disorders.

Adaptation, Physiological↗
PubMed1993

[Incidence of obstructive sleep apnea syndrome in combination with chronic obstructive respiratory tract disease].

Polysomnographic measurements were performed in 210 indoor patients (age mean = 49.7 +/- 8.9 years, Broca mean = 126.0 +/- 20.7% FEV1%p mean = 79.9 +/- 23.9) of a pneumological rehabilitation centre who had a suspicious history or clinical symptoms of obstructive sleep apnoea. 72 had neither an airway obstruction nor a pathological apnoea index. 58 patients only suffered from airway obstruction and 42 had only a pathological apnoea index. In 38 patients, a pathological apnoea index and also airway obstructions were seen. For the last three groups we calculated the mean of the SaO2-values for an 8 hour night time period with and without n-CPAP-therapy. In both groups with only one disease a typical pattern of the SaO2-values during sleep could be demonstrated. The patients with overlap syndrome (SAS + COB) showed a superposition of both single disease SaO2-time courses even with much lower initial SaO2-values. During n-CPAP-therapy in all groups a reduction of the variations of SaO2 induced by sleep pattern and circadian rhythm are evident.

Adult↗
PubMed1993

[Use of acoustic rhinometry for determining segmental airway geometry with nasal positive or negative pressure].

The investigations show an application of nasal acoustic rhinometry for determination of segmental naso- and oropharyngeal airway cross-section during negative or positive pressure breathing. The investigations show in 16 patients with obstructive sleep apnoea (AI = 21.5), that negative pressure produces a segmentally different reduction of naso-oropharyngeal cross-section which is weakly correlated to the Broca index. But the amount of cross-sectional reduction is highly significantly correlated to the apnoea index (r = 0.64). The functional relationship between pressure load of the airways during wakefulness and the severe nature of the disease reveals the possibility of diagnostic use.

Adult↗
PubMed1993

[Prevalence of obstruction of extrathoracic and intrathoracic airways in patients with arterial hypertension].

The object of this study was to find out the difference between patients with and without arterial hypertension in respect of oxygen desaturation, obesity and obstructive sleep apnoea. 497 men were examined who had chronic diseases of the respiratory passages and whose average age was mean = 45.9 +/- 11.2 years, the Broca index being 109 +/- 17%. 106 men (age mean = 48.6 yrs, Broca index = 118.4, systolic blood pressure according to Riva-Rocci mean = 154.6 mmHg, diastolic 101.4 mmHg) had arterial hypertension. 391 men (age mean = 45.1 yrs, Broca = 107.1, BP/RRsys mean = 130.5 mmHg, BP/RRdia mean = 82.5 mmHg) had normal blood pressure. Another subdivision was effected according to frequency of oxygen desaturations measured according to frequency of oxygen desaturations measured during 8 hrs sleep (SaO2 > 90%, frequency > 80/8 hrs) and the Broca index (> 120%). 31.1% of the hypertensive and 16.6% of the normotensive patients had more than 80 SaO2 drops/8 hrs to below 90%. 44.7% of obese hypertensives and 37.1% of obese normotensives were suspected of suffering from obstructive sleep apnoea. 45 highly suspicious patients were examined by polysomnography. This was the case with 19.8% of the hypertensives and 6.1% of the normotensives. 78.9% of the hypertensives examined via polysomnography because of suspicion of pulse oximetry and/or obesity had in fact an apnoea index > 10, whereas only 41.2% of the normotensives selected according to the same criteria demonstrated this phenomenon. On the whole, patients suffering from arterial hypertension were at markedly higher risk of obstructive sleep apnoea.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Evaluation of an anamnesis questionnaire for the diagnosis of sleep apnea in patients with chronic diseases of the respiratory organs].

In a Rehabilitation Clinic for Diseases of the Respiratory Organs we examined 497 male patients aged 45.9 +/- 11.1 years with a relative weight of 109 +/- 16.7% who were suffering from chronic diseases of the respiratory tract (66.2% chronic bronchitis, 33.8% asthma bronchiale, 49.6% obstruction of the respiratory tract). They were subjected to a detailed physical examination and were given an anamnestic questionnaire for the purpose of diagnosing sleep-related respiratory disturbances (Siegrist et al., 1987). In addition, whole body plethysmography was performed in all patients as well as a pulse-oximetric examination during night sleep. Using factor analysis, it was possible to extract 5 factors from the 23 items of the anamnesis questionnaire. With these 5 factors, 60.5% of the total variance could be explained. These factors describe: 1. Dyspnoea (35.3%); 2. Vigilance (8.5%); 3. Sleep disturbances (6.3%); 4. Headache (5.8%) and 5. Snoring (4.7%). Different factor patterns are seen for different groups of patients. In patients suspected of an obstructive sleep apnoea syndrome, however, it will always be necessary to perform further stage-wise diagnosis to safeguard the diagnosis.

Adult↗
PubMed1991

Peripheral chemoreceptor reflex in obstructive sleep apnea patients; a relationship between ventilatory response to hypoxia and nocturnal bradycardia during apnea events.

15 patients with obstructive sleep apnea syndrome and arterial hypertension (H-OSAS), 25 normotensive patients with sleep apnea syndrome (N-OSAS) and 20 healthy age-matched controls (C) were included in this study. Ventilatory responses to activation (hypoxia) and inactivation (hyperoxia) of carotid chemoreceptors were studied in all subjects. Relationship between hypoxic ventilatory reactivity and nocturnal bradycardia during apnea-phases was analysed in both groups of patients. Results and conclusions. 1. We found an impairment of ventilatory response to hypoxia in H-OSAS and N-OSAS patients. However, the increase in ventilation in response to hypoxia was significantly greater in H-OSAS as compared to N-OSAS patients. 2. An augmented ventilatory response to inactivation of carotid chemoreceptors (the decrease in ventilation), observed in H-OSAS patients, indicates an increase in resting peripheral chemoreceptors drive in this group of patients. 3. The relationship between ventilatory response to hypoxia and nocturnal bradycaria in obstructive sleep apnea patients suggests, that hypoxic reactivity of arterial chemoreceptors might be involved in the origin of bradycardia during apnea events.

Bradycardia↗
PubMed1990

Functional asymmetry in carotid sinus cardiac reflexes in humans.

The reflex cardiac response to activation (CBA) and inactivation (CBI) of the left and right carotid baroreceptors was studied in 30 healthy subjects, aged between 24 and 38 years. The CBA was evoked by applying negative pressure (from -20 to -60 mmHg) for 10 s to the left and right carotid sinus regions separately or both together, using two small neck capsules. The CBI was produced by applying left and right positive neck pressure (from 20 to 60 mmHg) for 10 s. The blood flow velocity was measured non-invasively with a Doppler scanner placed in the suprasternal notch. Blood flow acceleration was calculated and used as an indication of left cardiac contractility. Heart rate was measured continuously. Differences were found between right and left carotid sinus responses to CBA and CBI. The maximal response of the R-R interval was significantly greater during right CBA than during left CBA (the average gain: R-R.mmHg-1 2.69 ms.mmHg-1 and 1.75 ms.mmHg-1, respectively). Also, the reflex CBI response was significantly greater for the right (3.16 ms.mmHg-1) than for the left (2.22 ms.mmHg-1). The reflex decrease/increase in blood-flow acceleration in response to CBA/CBI was significantly greater during left than during right-sided activation/inactivation. It is suggested that the functional asymmetry was related to differences in right/left-sided cardiac innervation as well as to central ipsilateral projection of the carotid baroreceptor afferents to the nuclei tractus solitarii.

Adult↗
PubMed1989

Attenuation of augmented ventilatory response to hypoxia in essential hypertension in the course of aging.

36 patients with essential hypertension and 15 of their adult descendants were investigated and compared with age-matched control groups of 33 and 15 healthy subjects, respectively. The ventilatory response to oxygen breathing and to progressive normo- und isocapnic hypoxia were studied. The reduction of ventilation during hyperoxia was significantly greater in all hypertensive patients. An augmented ventilatory response to hypoxia was found in 20- to 40-year-old patients whereas the older patients (41-60 years) were not different from the age-matched control subjects. Our results indicate that the augmented hypoxic sensitivity in early hypertension, as found also in the young adult descendants with family background of hypertension, is attenuated with age, similar to the normotensive subjects.

Adult↗
PubMed1989

[The diurnal rhythm of chemosensitivity and its contribution to nocturnal disorders of respiratory control].

UNLABELLED: Circadian variation of chemosensitivity was examined under constant standardized metabolic and climatic conditions. Progressive hyperoxic hypercapnia tests and progressive isocapnic hypoxia tests were applied every 2 h in 10 healthy male subjects employing rebreathing (6 l spirometer). During the 24 h run they were confined to bed. They were allowed sleep at their convenience, but were woken for examination, and were given a low-protein isocaloric diet after each of the 13 tests. For assessment of psychophysiological performance, auditory reaction time, flicker fusion frequency, and self ratings of mood and activation were applied. ECG, body core temperature, nasal respiration, tcpaO2 and galvanic skin resistance were recorded continuously for 24 hrs. RESULTS: Chemosensitivity revealed a highly significant circadian variation with respect to a shift in the CO2-response (amplitude +/- 3 mmHg), and an amplitude of +/- 12 mmHg for the O2-response. Maximal sensitivity was found at 5 p.m., the absolute minimum at 5 a.m. Body core temperature, auditory reaction time, and flicker fusion frequency paralleled these changes in chemosensitivity. The results show that there is a pronounced 24 h cycle of chemosensitivity that is independent of sleep. Since chemosensitivity, and respiratory drive keeping upper and lower airways patent, are closely related, it is concluded that the circadian variation in chemosensitivity may substantially contribute to nocturnal increase in airway resistance, and central and obstructive apneas as well.

Adult↗
PubMed1989

[Diagnosis of the function of respiratory control in patients with obstructive sleep apnea syndrome].

UNLABELLED: Twenty-five patients with OSAS were investigated and compared with an age-matched control group of 20 healthy volunteers. The ventilatory responses to pure oxygen administration, active hyperventilation, progressive hyperoxic hypercapnia and progressive isocapnic hypoxia were studied in all subjects. RESULTS: Hypoxic ventilatory response in OSAS patients was significantly diminished as compared with the control group. Hypercapnic ventilatory response, decrease in ventilation due to chemoreceptor inactivation during oxygen respiration and after hyperventilation did not differ in the two groups. The diminished response to hypoxia in OSAS patients was correlated with the increased respiration-synchronous changes in nasal resistance. Our data seem to suggest that in OSAS patients the diminished responsiveness to hypoxia may increase the likelihood of nocturnal apnea. A decrease in hypoxic inspiratory drive appears to be one mechanism initiating upper airway occlusion.

Carbon Dioxide↗
PubMedDate not supplied

Arousals and aircraft noise - environmental disorders of sleep and health in terms of sleep medicine.

World wide rules for sleep staging originate to 1967. Since then many investigations aimed to give numbers for the degree of sleep disturbances due to air traffic noise. But the variables used, such as the amount of relative sleep stages, total sleep time, or sleep efficiency, could not explain impairment in health and performance sufficiently. The beginning of the eighties has given new insight into the restorative functions of sleep, according to sleep fragmentation by micro-arousals. These are originating in autonomous dysfunctions during sleep, leading to non-restorative sleep. Environmentally related sleep disturbances are described, EEG and vegetative (micro)-arousals, and the actual knowledge in sleep medicine is given in terms of the international classification of sleep disorders (ICSD). The effects on health, and disturbed performance capacity during the day are shown by self ratings of 160 patients. Elevated metabolic rate caused by micro-arousal and/or insomnia, may play an additional role in health impairment.

Aircraft↗