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Biomedical subjects

D Kurtz

Publications and source records attributed to D Kurtz.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Apnea following hyperventilation in man.

To assess the incidence of posthyperventilation apnea (PHA), breathing patterns after active voluntary hyperventilation were determined during EEG recording by means of: (1) a thermocouple in 1060 patients; (2) a pneumotachograph coupled with a capnograph in 100 further patients. All the patients were randomly chosen. PHA of 12.6 +/- 0.48 occurred in only 18% of awake subjects and was not related to the magnitude of the lowering of end-tidal FECO2 during the test. PHA frequency increased when sleep followed hyperventilation and in patients with clinical or EEG evidence of cerebral pathology and seemed to be age-related. This study supports the hypothesis that in man a central neural mechanism closely linked to vigilance and connected with active breathing supplies sufficient neural facilitation to prevent the apnea consequent on the decrease in chemical humoral stimulation. Posthyperventilation sleep reduces this neural facilitation, allowing the lack of chemical stimulation to induce apnea. The high incidence of PHA reported in some studies might be due to a decrease in vigilance which was not detected by the usual behavioral or electroencephalographic tests.

Adolescent↗
PubMedDate not supplied

Auditory event-related potentials in obstructive sleep apnea: effects of treatment with nasal continuous positive airway pressure.

Event-related potentials (ERPs) were recorded in 47 patients with obstructive sleep apnea (OSA) syndrome prior to and after 6 weeks of treatment with continuous positive airway pressure (CPAP). Compared with a control group, the OSA patients showed ERP abnormalities: lengthened P3 latencies and decreased N2-P3 amplitudes. After 6 weeks of CPAP treatment, there was a highly significant improvement in the abnormal ERPs: the P3 and N2 latencies were shortened, but remained longer than in controls, and the N2-P3 and N1-P2 amplitudes were increased. No correlations could be established with various sleep variables. ERPs may be used as an electrophysiological marker of brain dysfunction; treatment of OSA with CPAP is probably responsible for functional brain modifications. On the other hand, possible relationships between the ERP abnormalities and the neuropsychological disorders observed in OSA remain to be established.

Adult↗
PubMedDate not supplied

[Value of electroencephalographic serveillance in the framework of resuscitation in coma caused by acute drug intoxication].

The authors carried out long-term clinical and E.E.G. studies on 100 cases of acute drug poisoning. They made the following conclusions: - in unexplained coma, the E.E.G. can indicate toxic aetiology and may sometimes even suggest which drug is responsible, especially for certain chemical groups (barbiturates, phenothiasines, benzodiazepines); - the E.E.G. picture contributes a valuable indication of the depth of coma; the way in which it evolves affects the prognosis; - the effectiveness of therapy may be judged by monitoring cerebral electrical activity.

Acute Disease↗
PubMedDate not supplied

[Study of recovery and the post-anaesthetic period (author's transl)].

The authors compare recovery and the post-anaesthetic period in 45 patients anaesthetised with a combination of either pentothal, nitrous oxide, fluothane and dolosal (group 1, 24 subjects), or of pentothal, nitrous oxide and phenoperidine (group 2, 21 subjects). The quality of recovery was judged at the end of anaesthesia by determining of occurrence of the first response to 3 types of stimulation (calling the name, noise and pain) and the density of these responses during each minute. During the post-anaesthetic period the respective percentages of wakefulness and sleep were calculated. In this way the authors demonstrate a significant (P less than 0.01) shortening in recovery time for group 2, reactivity to own name occurring first in both groups, and a very significant (P less than 0.001) increase in the percentage of physiological sleep in subjects of group 2 during the post-anaesthetic stage.

Adolescent↗