Apnea

Les apnées du prématuré constituent encore actuellement un problème clinique majeur, imposant des choix thérapeutiques parfois difficiles. Des apnées plus ou moins longues surviennent chez presque tous les grands prématurés, témoignant d’une instabilité de la régulation respiratoire en rapport avec l’immaturité. Au rôle causal de celle-ci peut toutefois s’ajouter celui de nombreuses pathologies néonatales, qui peuvent aussi contribuer à la survenue d’apnées et doivent être recherchées et traitées. Les apnées du prématuré de courte durée (moins de dix secondes, sans hypoxémie ou bradycardie associée) peuvent être considérées comme sans risque pour l’enfant. Les apnées plus longues entraînent une hypoxémie et un ralentissement de la fréquence cardiaque et des perturbations de l’hémodynamique et de l’oxygénation cérébrales, susceptibles d’entraîner des effets délétères pour le développement à long terme. L’évaluation de leur degré de gravité immédiate et de leurs risques à long terme demeure imprécise. Les décisions thérapeutiques ne peuvent s’appuyer que sur assez peu de données scientifiques. Le citrate de caféine est un traitement efficace des apnées du prématuré, largement utilisé depuis des décennies. Mais c’est seulement très récemment qu’une évaluation rigoureuse de ses bénéfices et de ses inconvénients a été menée. Elle a mis en évidence la faible toxicité du citrate de caféine, et des bénéfices inattendus chez les enfants traités : diminution de fréquence des dysplasies bronchopulmonaires, de la persistance du canal artériel, et, à 18 mois, diminution du taux d’infirmité motrice cérébrale. La pression expiratoire positive par voie nasale, traitement également efficace des apnées, peut être utilisée en cas d’échec ou d’insuffisance du traitement par caféine et en association avec lui.Prematurity apnea remains a major clinical problem that requires treatment choices which are sometimes difficult. Prematurity apnea occurs in most infants of gestational age at birth less than 33 weeks. It is a developmental disorder which usually reflects a “physiological” immaturity of respiratory control. However, neonatal diseases may be associated and play an additive role, resulting in an increased incidence of apnea. Careful screening should therefore be performed in order to make sure that no other factor than immaturity is involved in the occurrence of apnea. Short apnea (less than 10 s, without hypoxemia and bradycardia), due to immaturity, are not clinically relevant. More prolonged apnea, that last for more than 15 or 20 s, and / or apnea associated with bradycardia or oxygen desaturation, results in short-term disturbances of cerebral haemodynamics and oxygenation, which may negatively impact on neurodevelopmental outcome. Evaluating the immediate severity of apnea and the risks that apnea may affect long-term outcome remains a challenge. The choice of treatments is based on a few evidences. Caffeine citrate, which reduces the incidence of apnea, has been used for decades. However, a thorough evaluation of risks and benefits of this medication has been performed only recently. Caffeine citrate was found to be safe and resulted in unexpected benefits. In treated infants, compared with controls, indeed, a decreased incidence of the following complications was recorded: bronchopulmonary dysplasia at 36 weeks of conceptional age, patent ductus arteriosus, cerebral palsy at 18 months of age. Nasal CPAP can be used in association with caffeine citrate, when the latter is not effective enough.

During diving, marine mammals must rely on the efficient utilization of a limited oxygen reserve sequestered in the lungs, blood and muscles. To determine the effects of exercise and apnea on the use of these reserves, we examined the physiological responses of adult bottlenose dolphins (Tursiops truncatus) trained to breath-hold on the water surface or to dive to submerged targets at depths between 60 and 210 m. Changes in blood lactate levels, in partial pressures of oxygen and carbon dioxide and in heart rate were assessed while the dolphins performed sedentary breath-holds. The effects of exercise on breath-hold capacity were examined by measuring heart rate and post-dive respiration rate and blood lactate concentration for dolphins diving in Kaneohe Bay, Oahu, Hawaii. Ascent and descent rates, stroke frequency and swimming patterns were monitored during the dives. The results showed that lactate concentration was 1.1+/-0.1 mmol l(-1) at rest and increased non-linearly with the ...

OBJECTIVE. Chronic snoring that does not adhere to the criteria for a diagnosis of obstructive sleep apnea syndrome may be associated with learning and behavioral problems. We investigated the sleep structure of chronic snorers who had an apnea-hypopnea index of <1 event per hour and analyzed the cyclic alternating pattern. METHODS. Fifteen successively seen chronic snorers (9.8 ± 4 years) with an apnea-hypopnea index of <1 and 15 aged-matched control subjects (10.3 ± 5 years) underwent an investigation of their sleep with the determination of non–apneic-hypopneic breathing abnormalities polysomnographic scoring using current criteria and analysis of the cyclic alternating pattern. RESULTS. Chronic snorers have evidence of flow limitations and tachypnea during sleep even if they do not present with apneas, hypopneas, and decrease in oxygen saturations. They also present with abnormal cyclic alternating pattern rates and changes in phase A of cyclic alternating pattern compared...

Shaking-impact syndrome (SIS) is a leading cause of traumatic brain injury in infants and young children. Evaluation of these children requires a detailed history and physical examination as well as documentation of intracranial injury with neuroimaging, a dilated fundoscopic examination, a skeletal survey and other laboratory studies. Debate still exists as to the exact mechanisms of brain injury in these patients. The various contributions of shaking alone, shaking with impact, and apnea are discussed. Differences of injury type and severity between accidental traumatic brain injury and SIS are delineated. The long-term neurodevelopmental outcome for survivors of SIS is generally poor. Because few treatment options are successful in reducing the morbidity and mortality of this syndrome, prevention may be the only reasonable solution.

Objective: To provide an update of the 1995 American Academy of Neurology guideline with regard to the following questions: Are there patients who fulfill the clinical criteria of brain death who recover neurologic function? What is an adequate observation period to ensure that cessation of neurologic function is permanent? Are complex motor movements that falsely suggest retained brain function sometimes

Sudden unexpected death in epilepsy (SUDEP) is the most common cause of death directly related to epilepsy, and most frequently occurs in people with chronic epilepsy. The main risk factors for SUDEP are associated with poorly controlled seizures, suggesting that most cases of SUDEP are seizure-related events. Dysregulation in cardiac and respiratory physiology, dysfunction in systemic and cerebral circulation physiology, and seizure-induced hormonal and metabolic changes might all contribute to SUDEP. Cardiac factors include bradyarrhythmias and asystole, as well as tachyarrhythmias and alterations to cardiac repolarization. Altered electrolytes and blood pH, as well as the release of catecholamines, modulate cardiac excitability and might facilitate arrhythmias. Respiratory symptoms are not uncommon during seizures and comprise central apnea or bradypnea, and, less frequently, obstruction of the airways and neurogenic pulmonary edema. Alterations to autonomic function, such as a r...

Great strides have been made in our understanding of developmental respiratory neurobiology. A clear picture is, therefore, emerging of the physiological mechanisms that underlie apnea of prematurity. The ventral surface of the medulla and adjacent areas play a key integrative function for central CO2 chemosensitivity and modulation of afferent inputs from peripheral chemoreceptors and laryngeal afferents. Maturational change in medullary neurotransmitter function appears to contribute to the physiological events that characterize apnea of prematurity. Despite this greater scientific insight, therapeutic strategies for neonatal apnea have changed little in 30 years. Xanthine therapy and continuous positive airway pressure remain the mainstay of therapy while other therapeutic approaches have been inadequately studied. Our understanding of a possible relationship between the triad of apnea, bradycardia and desaturation, and impaired neurodevelopmental outcome is also limited. These are all issues that need our attention if optimal therapy and outcome are to be provided for preterm infants with immature respiratory control.

[AMAZON LINK BELOW TO BOOK ITSELF -- TOC and book intro in downloadable .pdf]  Encyclopedia of Sleep and Dreams: The Evolution, Function, Nature, and Mysteries of Slumber explores the evolution, nature, and functions of sleep and dreams. The encyclopedia is divided into two volumes and is arranged alphabetically by entry. Topics include nightmares and their treatment, how sleep and dreams change across the lifetime, and the new field of evolution of sleep and dream. While this book includes ample material on the science of sleep and dreams, content is drawn from a broad range of disciplinary contexts, including history and anthropology.

Sympathetically mediated renal vasoconstriction may contribute to the pathogenesis of hypertension in older adults, but empirical data in support of this concept are lacking. In 10 young (26 ± 1 yr) and 11 older (67 ± 2 yr) subjects, we quantified acute hemodynamic responses to three sympathoexcitatory stimuli: local cooling of the forehead, cold pressor test (CPT), and voluntary apnea. We hypothesized that all stimuli would increase mean arterial blood pressure (MAP) and renal vascular resistance index (RVRI) and that aging would augment these effects. Beat-by-beat MAP, heart rate (HR), and renal blood flow velocity (from Doppler) were measured in the supine posture, and changes from baseline were compared between groups. In response to 1°C forehead cooling, aging was associated with an augmented MAP (20 ± 3 vs. 6 ± 2 mmHg) and RVRI (35 ± 6 vs. 16 ± 9%) but not HR. In older adults, there was a positive correlation between the cold-induced pressor response and forehead pain (R = 0.7...

Purpose: Sedation is becoming more commonplace for pediatric patients undergoing minor procedures. Fortunately, electronic monitors have contributed to a reduction in the associated respiratory adverse events (RAEs). To test the hypothesis that adding the pretracheal stethoscope (PTS) to standard monitoring methods (SMMs) may improve RAE detection in sedated pediatric dental patients, the frequency of RAEs detected by SMMs (i.e. visual observation, capnography, and pulse oximetry) was compared to that detected by SMMs alongside continuous PTS auscultation. Study design: A prospective, randomised, controlled trial was performed with 100 pediatric patient participants of ASA≤2, who were scheduled to receive dental treatment under 0.75 mg/kg and oxygen. Patients were randomised into Groups A (n=50; SMMs) and B (n=50; SMMs+PTS). Inclusion criteria were behavioral management problems and intolerance to dental treatment despite behavioral management techniques or nitrous oxide administrat...