[Scuba diving in children: Physiology, risks and recommendations]. / Buceo en la edad pediátrica: fisiología, riesgos y recomendaciones.

INTRODUCTION: The increase in recreational scuba diving in recent years, including children, involves risks and the possibility of accidents. While legislation, conditions and risks of scuba diving are well documented in adults, scientific evidence in scuba diving by children and adolescents is sparse and isolated. Furthermore, existing guidelines and recommendations for adults cannot be transferred directly to children. METHODS: These circumstances have led to the Group on Techniques of the Spanish Society of Pediatric Pulmonology (SENP) to perform a literature search to review and update the knowledge about scuba diving in children. RESULTS: Physiological adaptations of the body are examined during the dive, as well as the anatomical and physiological characteristics of children that should be taken into account in scuba diving. The most common types of accidents and its causes, as well as the risks of scuba diving practice in children with previous diseases are discussed, along with details of the medical and psychological requirements for scuba diving to be considered in the assessment of child and adolescent. CONCLUSIONS: A list of recommendations for scuba diving with compressed air in children is presented by a group of experts.

Consensus on drug treatment, definition and diagnosis for insomnia.

Thirty-four experts and a literature supervisor got together in order to reach a 'consensus' regarding the definition, diagnosis and pharmacological treatment of insomnia. Insomnia is a subjective perception of dissatisfaction with the amount and/or quality of sleep. It includes difficulty in initiating or maintaining sleep or early awakening with inability to fall asleep again. It is associated with complaints of non-restorative sleep and dysfunction of diurnal alertness, energy, cognitive function, behaviour or emotional state, with a decrease in quality of life. The diagnosis is based on clinical and sleep history, physical examination and additional tests, although polysomnography is not routinely indicated. Therapy should include treatment of the underlying causes, cognitive and behavioural measures and drug treatment. Hypnotic therapy can be prescribed from the onset of insomnia and non-benzodiazepine selective agonists of the GABA-A receptor complex are the drugs of first choice. It is recommended that hypnotic treatment be maintained in cases where withdrawal impairs the patient's quality of life and when all other therapeutic measures have failed. Experience suggests that intermittent treatment is better than continuous therapy. The available data do not confirm safety of hypnotics in pregnancy, lactation and childhood insomnia. Benzodiazepines are not indicated in decompensated chronic pulmonary disease but no significant adverse effects on respiratory function have been reported with zolpidem and zopiclone in stable mild to moderate chronic obstructive pulmonary disease and in treated obstructive sleep apnoea syndrome. Data for zaleplon are inconclusive. If the patient recovers subjective control over the sleep process, gradual discontinuation of hypnotic treatment can be considered.

Cognitive function in patients with sleep apnea after acute nocturnal nasal continuous positive airway pressure (CPAP) treatment: sleepiness and hypoxemia effects.

Patients with sleep apnea are typically hypersomnolent during the daytime and may demonstrate higher order cognitive dysfunction. A persistent problem in interpreting impaired neuropsychological test performance in such patients is whether the observed deficits can be explained wholly by impaired vigilance. We examined 37 sleep apnea patients prior to and immediately subsequent to successful sleep apnea treatment with nasal continuous positive airway pressure (CPAP). Patients were evaluated immediately after morning awakening in the sleep lab. A brief neuropsychological evaluation, was administered at that time. Following this, alertness was measured with a 30-min polysomnographically determined sleep latency test. Both test (approximately 50 min in duration) were performed once following a baseline (diagnostic) night in the sleep lab and once in the morning following a CPAP (therapeutic) night in the lab. Subgroup analyses indicted that while vigilance impairment can account for some of the decreased test performance seen in sleep apnea (auditory verbal learning) the effects of severe nocturnal hypoxemia appear to affect other function (sustained attention in repetitive arithmetic calculations) that were not easily modified by treatment. Thus, performance on the recall trial of the Rey Auditory Verbal Learning Test increased from pre-CPAP to post-CPAP for the increased alertness group but decreased significantly for the decreased alertness group. On the Wilkinson Addition Test, non-hypoxemic patients showed statistically significant improvement in problems correctly solved from pre-CPAP to post-CPAP, but the hypoxemic patients showed only a marginal increase. These results are compatible with other studies suggesting that patients having sleep apnea may incur deficits as a result of both decreased vigilance and hypoxemia, and that at least some of these deficits are immediately reversible.

Ultradian rhythms in gross motor activity of adult humans.

During waking h, the existence of ultradian rhythms in gross motor activity has been described in nonprimates, nonhuman primates and newborn humans, but not in adult humans. Some of the previous studies suggested that the appearance of these rhythms could be favored by conditions of isolation and low environmental demands. To confirm the existence of ultradian rhythmicity in the gross motor activity of adult humans and to describe their characteristics, an actimeter was used to record the mobility of 13 adults who remained alone and isolated for 5 h (15:00-20:00) in a monotonous environment with nothing to do. Least squares rhythmometry analysis showed that the gross motor activity of 12 out of 13 subjects had significant rhythms (p < 0.05) within the ultradian band, with periods of between 0.5 and 2.5 h. There were important individual differences between the dominant periods and the same subject might show more than one significant period. These rhythms were stable and they tended to appear immediately the experiment began. The results suggest that a philogenetically old mechanism that organizes gross motor activity in ultradian rhythms exists in adult humans.