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Biomedical subjects

M Gabriel

Publications and source records attributed to M Gabriel.

At least 145 records · Page 8Linked to original sources
PubMed1977

[Factors causing apneas in otherwise healthy newborns: a neurophysiological Concept (author's transl)].

The possible origins of apneic spells in otherwise healthy neonates are reviewed. An analysis is made of how breathing is organized by the central and peripheral neuronal system, and how the overall control of breathing is sometimes inhibited by various active sleep mechanisms. From the neurophysiological point of view, a review is also made of various therapeutical approaches for the prevention or reduction of apneas. The hypothetical correlation between the sudden infant dealth syndrome and neonatal apneas is disussed briefly.

Apnea↗
PubMed1976

Cardiac slowing and respiratory arrest in preterm infants.

Changes in respiration and heart rate during sleep states have been recorded by a polygraphic device in healthy preterm infants. Cardiac slowing/bradycardia often coincide with respiratory arrest/apnea. Bradycardia starts early during apneic spells. The incidence of respiratory arrest and cardiac slowing and their simultaneous occurrence is significantly increased by the active or REM sleep state. The physiologic, inhibitory mechanisms of active sleep suggest a neurogenic etiology of episodes of cardiac slowing/bradycardia and/or respiratory arrest/apnea in prematures.

Apnea↗
PubMed1976

Apneic spells and sleep states in preterm infants.

The incidence of apneic spells during different sleep states active sleep, quiet sleep, and undifferentiated sleep was determined in eight preterm infants of 30 to 35 weeks' conceptional age, by means of a polygraphic recording technique. They were free of perinatal and postnatal complications other than apnea. During their active or rapid eye movement (REM) sleep they showed significantly more apneic episodes which were also longer lasting and they were accompanied by bradycardia of a greater severity. The organization of the immature nervous system with a preponderance of inhibitory synaptic connections and the additional inhibition of spinal motoneurons during REM sleep are likely to be the cause of apneic spells in otherwise "normal" preterm infants.

Apnea↗
PubMed1976

Transcutaneous PO2 monitoring in routine management of infants and children with cardiorespiratory problems.

Results are reported concerning the clinical application of the transcutaneous PO2 method (tc PO2 method) according to Huch et al. for monitoring arterial PO2. Thirty long-term continuous tc PO2 recordings were made in 22 ventilated children and infants with cardiorespiratory problems in four different pediatric intensive care units (Zürich, Göttingen, Kassel, and Mainz). These recordings were compared with 132 arterial PO2 determinations made during the same period of time. There was a linear relationship and a close correspondence between arterial PO2 and tc PO2 (r = .94). The continuous recordings have shown that the variability of PO2 is much greater than assumed so far by single blood gas analysis. This fact restricts greatly the value of single samples. Continuous tc PO2 monitoring has proved to be a great help in optimal respirator setting.

Child↗
PubMed1975

Intracellular recordings from different types of medullary respiratory neurons of the cat.

Respiratory neurons were recorded intracellularly within the lateral region of the lower brain stem of vagotomized and artificially ventilated cats. Bulbospinal, vagal, and antidromically nonresponsive types of neurons were distinguished by means of vagal and intraspinal stimulation. Almost all types of neurons discharged a burst of action potentials during one of the two phases of the central respiratory cycle, as indicated by phrenic nerve activity. The discharge pattern of the different types of neurons were described. The origin of the spntaneous changes of the membrane potential was investigated by measurements of the reversal potentials and membrane conductance changes. The results reveal that both inspiratory and expiratory types of neurons receive an excitatory input during their discharge period, and a reciprocal inhibitory input during their silent period. In addition, one type of neuron was described which receives inhibitory inputs during both inspiration and expiration. Recurrent inhibition, as indicated by hyperpolarizing postsynaptic potentials and membrane conductance changes following the antidromic action potential seems to exist only within the network of the vagal neurons. Suggestions are made about the functional organization of the neuronal network of the medullary respiratory system and the mechanism generating its rhythmic activity.

Animals↗