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Biomedical subjects

J H Peter

Publications and source records attributed to J H Peter.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Increase in blood pressure due to continuous obstructive snoring].

Sleep-related breathing disorders can strain the cardiovascular system. Link-ups with arterial hypertension have been confirmed in obstructive or mixed sleep apnoea which is characterised by discontinuous nocturnal snoring. On the other hand, it is known that arterial hypertension is very frequently seen in snorers. The present study deals with short-term, breathing-related blood pressure patterns and blood pressure changes during the snoring phase. 18 obstructive snoring phases were identified in 4 male patients aged 50 years (42-65), Broca index 136 (119-171). Polysomnographic measurements were carried out in the sleep laboratory and the blood pressure was continuously recorded via the a. brachialis. The short-term breathing-dependent blood pressure changes were systolic 10.8 (10-30) mmHg at the beginning and 17.5 (10-30) mmHg at the end of the snoring phase (P less than 0.01). Diastolically there was a difference of 9.4 (5-15) mmHg versus 13.9 (5-25) mmHg (P less than 0.01). During the snoring phases the systolic blood pressure increased from 140.3 (120-190) mmHg to 170.0 (145-235) mmHg and the diastolic pressure from 69.7 (50-110) mmHg to 93.1 (70-120) mmHg. The study proves that blood pressure increases occur not only in apnoeic snoring but also in continuous obstructive snoring. It is suspected that these changes are responsible for the high frequency of arterial hypertension among continuous snorers.

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↗
PubMed1991

[Sleep-related respiratory disorders: from syndromes to risk factors].

In the past, sleep related breathing disorders (SRBD) have been described rather heterogeneously in terms of complex diseases, syndromes. During the past ten years, the relevant pathogenetic mechanisms of most of the SRBD could be defined, and data concerning their epidemiology were collected. Epidemiology and dangerousness being relevant criteria, the obstructive sleep apnea syndrome must be regarded as the most considerable SRBD. According to ICSD, the prevalence of a manifest obstructive sleep apnea syndrome is estimated at 1% of the entire population at least. Our measurings have shown that more than 10% of the middle-aged (20 to 60 years) male population suffer from 10 and more mixed obstructive apneas per hour of sleep. In this group, also the other pathogenetic factors for the obstructive sleep apnea syndrome, namely hyperventilation and fragmentation of sleep due to central arousal reactions, are found. All these patients snore, and there is a broad transition from primary snoring, which has no effects on the cardiovascular system and the blood gases, via obstructive snoring up to inter-apneic snoring. With the help of today's technical equipment, it is possible to determine the role of subclinical SRBDs in terms of risk factors, e.g. for cardiovascular diseases. We expect a plain contribution to the clearing up of instances of arterial hypertonus, early invalidity, and mortality.

Adult↗
PubMed1990

[Sleep apnea].

Explore the source record for details and available documents.

Humans↗
PubMed1990

Occupational performance of a paced secondary task under conditions of sensory deprivation. I. Heart rate changes in train drivers as a result of monotony.

Twelve experienced train drivers were asked to operate the train function safety circuit (SIFA)--a paced secondary motor task which is expected to guarantee the driver's fitness for service on engines of the German Federal Railway--under laboratory conditions of extreme monotony. In spite of massive decreases in vigilance as shown by theta-activity in the EEG, all subjects were able to operate the device without major errors. A prerequisite for adequate performance is an EEG-defined arousal reaction, which is synchronized with the SIFA cycles. For 7 subjects the time-related cross-correlation coefficients between SIFA operation, alpha-activity (indicative of alertness), theta-activity (indicative of reduced vigilance), and heart rate were calculated. The central-nervous arousal found in the EEG corresponded to distinct increases in heart rate. The moments of SIFA operation after phases of light sleep correlated significantly and positively with increases in heart rate. These increases constituted a physiological overcompensation as far as the physical readiness was concerned which reached its peak after the task had been performed satisfactorily, constituting additional and superfluous occupational stress. The results of this study indicate clearly that monotony stress is not a result of occupational monotony itself, but the result of the physiological effort which is required in order to regain a level of alterness which allows adequate performance under monotonous conditions.

Electroencephalography↗
PubMed1990

Occupational performance of a paced secondary task under conditions of sensory deprivation. II. The influence of professional training.

Twelve truck drivers operated the train function safety circuit (SIFA), a paced secondary task used as a job monitor on German railways engines, under laboratory conditions of extreme monotony, in a comparison with 12 train drivers who were well acquainted with SIFA. Alertness was determined by means of EEG evaluations. Heart rate was monitored as the parameter for physical load, and the precoded SIFA tasks as the active response parameter. In spite of significantly more frequent and more distinct decreases in alterness, the SIFA-trained subjects (TS) performed better. Nine out of 12 TS reached the stage of light sleep at least once during the experimental run, as compared to 4 out of 12 untrained subjects (US). Nevertheless, the ratio acoustic warnings/occurrence of light sleep was significantly lower in TS (P less than 0.01), and there were three operational errors (equivalent to emergency braking) in US. Whereas US received fewer acoustic warnings in the stages of slightly reduced altertness, this trend was reversed as soon as low frequency theta-activity appeared in the EEG. A time-related calculation of the cross-correlation coefficients between SIFA operation, alpha-activity, theta-EEG-activity, and heart rate showed that timing of SIFA operation interrupting phases of light sleep correlated significantly and positively with increases in heart rate. The results suggest that a mechanism of rhythmic central nervous arousal interrupting phases of decreased alertness/drowsiness can be learned, whereas the physiological consequences of the effort to prevent the deterioration of performance under conditions of monotony are not reduced by professional adaptation.

Automobile Driving↗
PubMed1990

MESAM: a heart rate and snoring recorder for detection of obstructive sleep apnea.

The high prevalence of sleep-related breathing disorders demands the development of ambulatory recording devices that can handle data with a high degree of selectivity and are easy to use and to interpret. A digital device based on the recording of heart rate and breathing sounds was developed. Patients with sleep-related breathing disorders can be preselected before they undergo sleep laboratory investigations. Treatment control can be achieved ambulatory, having an initial recording.

Ambulatory Care↗
PubMed1990

Influence of metoprolol and cilazapril on blood pressure and on sleep apnea activity.

Up to 50% of hypertensive men are subject to sleep apnea (SA). With a prevalence in men of up to 10%, SA is a common illness and hypertension (HT) one of its early symptoms. It is important to have available a drug treatment that will effectively control blood pressure (BP) without exacerbating symptoms of SA. Twelve patients with SA and HT were investigated in a double-blind, comparative trial. Patients were randomly allocated to either metoprolol (M) 100 mg daily or cilazapril (C) 2.5 mg daily. Polysomnographic measurements under standardized conditions including intraarterial BP monitoring were taken on two consecutive nights each before and after the 1-week treatment. Values in the M group were (mean +/- 95% CI) systolic BP 161 +/- 2.1 vs. 148 +/- 2.2 mm Hg (p less than 0.01); diastolic BP 98 +/- 1.8 vs. 93 +/- 1.8 mm Hg (p less than 0.01); and HR 73 +/- 1.2 vs 65 +/- 1.1 beats/min (p less than 0.01). Corresponding figures for the C group were systolic BP 140 +/- 2.1 vs. 127 +/- 2.1 mm Hg (p less than 0.01); diastolic BP 95 +/- 1.7 vs. 78 +/- 1.7 mm Hg (p less than 0.01); and HR 82 +/- 1.1 vs. 79 +/- 1.2 beats/min (p less than 0.01). Whereas C reduced both BP and HR in all sleep phases, M produced no changes during REM sleep. SA activity was 45 (range 15-91) vs. 34 (range 2-57) apneas per hour of sleep in the M group and 54 (range 21-84) vs. 40 (range 8-72) apneas per hour in the C group (p less than 0.01). There were no changes in total sleep time or in the proportions of non-REM to REM sleep. Both M and C reduce nocturnal BP in SA patients, but the effect of C is seen in all sleep phases. C has a more favorable effect on the disturbed nocturnal blood pressure of SA patients.

Adult↗
PubMed1989

Effects of cilazapril on hypertension, sleep, and apnea.

Epidemiologic studies revealed that up to 10 percent of middle-aged men show more than 10 cessations of breathing of more than 10 seconds' duration. In these patients, increased morbidity and mortality rates have been proved. More than 50 percent of apnea patients exhibit arterial hypertension, and up to 50 percent of hypertensive patients experience sleep apnea. Patients with sleep apnea and essential hypertension need special attention paid to their antihypertensive therapy because the following side effects of drugs have to be avoided: increases of cardiac insufficiency, hyperviscosity of the blood, intensification of the hypersomnia by central sedation, intensification of a pre-existing tendency towards arrhythmias, and deprivation of deep and rapid eye movement sleep. In this study, the effects of angiotensin-converting enzyme inhibitors in patients with sleep apnea and hypertension are examined. An interim evaluation of six patients (aged 50 to 57) yielded the following results: Average Broca index, 124; average blood pressure before therapy, 159/102 mm Hg; average blood pressure after therapy, 132/78; a decrease of the apnea and hypopnea index from x = 31 (range, 12 to 77) to x = 20 (range, two to 54). Therapy did not influence sleep structure: before therapy, an average of 19 percent of sleep episodes were of the rapid eye movement type (range, 11 to 32 percent); after therapy, 23 percent were of this type on average (range, 21 to 25 percent). A final evaluation will be carried out after the second study phase for 12 patients who have been treated in a double-blind scheme with metropolol versus cilazapril.

Adult↗
PubMed1989

[Snoring and sleep apnea syndrome].

Sleep apnea and obstructive snoring are sleep related breathing disorders (SRBD). Nevertheless, there is only a quantitative difference between snoring and the obstructive form of sleep apnea. Snoring occurs in at least 20% of the population; 50% of the 50 year old male snore. Although in most of the cases only harmless snoring is concerned. It becomes serious if it leads as the independent SRBD "obstructive snoring" to a continuous oxygen desaturation and a sleep disturbance or, if in cases of sleep apnea a postapnoic snoring is concerned. The snoring pattern "loud and irregular" is always a sign for a serious SRBD. Still, no exact statement can be given concerning the frequency of obstructive snoring. However, the prevalence of sleep apnea in men of the mean age group has been determined to 10%. By the so-called sleep apnea syndrome are summarized clinical pictures with symptoms and findings caused by sleep apnea, respectively with those which can be reduced by sufficiently early introduced therapy. Most frequent symptoms and findings are: hypertension, loud and irregular snoring, daytime sleepiness and nocturnal cardiac arrhythmias. Especially hypersomnia has always to be taken seriously. In relation with other symptoms and findings associated with apnea it is always an indication for the examination for sleep apnea and obstructive snoring.

Brain↗
PubMed1989

[Nasal high pressure ventilation in obstructive sleep apnea syndrome. Theoretical and practical otorhinolaryngologic aspects].

Nasal CPAP therapy has been found to be the most effective treatment of OSAS apart from tracheotomy. Its long-term application, however, can cause several ENT complications like dryness of the nasal and pharyngeal mucosa, rhinitis and an increased frequency of sinusitis and infections of the lower airways. CPAP therapy is not applicable if nasal resistance is elevated, so that septal correction may become necessary. Unsuccessful UPPP can cause pressure loss through the mouth during CPAP therapy and in this case tracheotomy remains the only alternative. In order to evaluate the clinical significance of flexible nasopharyngoscopy with Mueller's manoeuvre (FNMM), we compared the endoscopic findings of 71 patients with their individual CPAP pressure required to keep their pharynx patent during sleep, 22 patients showed poor pharyngeal wall movement, 23 patients had moderate obstruction (about 50 percent closure) and 26 patients had nearly complete or complete pharyngeal obstruction. We found that patients with poor pharyngeal mobility needed a significantly lower CPAP pressure (mean 9 mbar) than those with nearly complete pharyngeal obstruction during FNMM (mean 11 mbar). Mean CPAP pressure of patients with moderate obstruction was 10 mbar, but this group could not be separated statistically from the other groups, indicating a not exactly defined category. Rhinomanometry showed no differences in nasal resistance between all groups. There was neither a correlation between CPAP pressure and rhinomanometry, nor between CPAP pressure and BROCA Index or distance of palatal arcs.

Airway Obstruction↗
PubMed1989

Central alveolar hypoventilation and sleep. Treatment by intermittent positive-pressure ventilation through nasal mask in an adult.

Idiopathic central alveolar hypoventilation, uncommonly seen in middle-aged adults, has often been treated by tracheostomy and assisted ventilation during sleep or by implantation of a diaphragmatic pacemaker with or without tracheostomy. We report the successful treatment of a middle-aged man by the easy application of intermittent positive-pressure ventilation through a nose mask.

Humans↗
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↗