Intermittent hypoxia and the practice of anesthesia.
ABSTRACT Intermittent hypoxia, a powerful and unique stimulus, leads to physiologic changes that are distinct from those associated with either single or continuous hypoxic exposure. There is an accumulating body of evidence that the neurocognitive, inflammatory and cardiovascular symptoms that characterize the syndrome of obstructive sleep apnea are linked to the stimulus of intermittent hypoxia. In addition, altered sensitivities to opiates in children with obstructive sleep apnea have been linked to recurrent hypoxia during sleep. Therefore anesthesiologists should have an understanding of this important stimulus.
SourceAvailable from: Anthony G Doufas[Show abstract] [Hide abstract]
ABSTRACT: Obstructive sleep apnea (OSA) is a common health problem among surgical patients. Human evidence supports that important components of OSA like sleep fragmentation and intermittent hypoxia may enhance pain behavior and also increase sensitivity to opioid analgesia. To the extent that these effects might affect postoperative opioid pharmacology, OSA may impact the risk for opioid-induced ventilatory impairment (OIVI), a potentially seri-ous complication in the postoperative patient. On the other hand, certain pathophysiological features of OSA might promote the development of OIVI due to enhancing respiratory compromise and/or through suppressing arousal from sleep in response to an airway obstruction event. Nonetheless, possible determinants of OIVI are not limited to factors associated with sleep-disordered breathing and current evidence does not support a direct relationship between an isolated preoperative diagnosis of OSA and increased risk for OIVI during postoperative analgesic therapy. Older age, comorbidity burden, and increased postoperative sedation, seem to be important promoters of potentially severe OIVI in the postoperative patient. Accepted strategies to prevent OIVI without interfering with postoperative analgesia include adopting opioid-sparing analgesic techniques, as well as establishing intense patient monitoring with emphasis on the respiratory and mental capacities. Keywords Anesthesia Á Obstructive sleep apnea (OSA) Á Opioids Á Opioid-induced ventilatory impairment (OIVI) Á Postoperative pain Á Respiratory depression Introduction01/2014; DOI:10.1007/s40140-013-0047-0
Article: Pediatric Obstructive Sleep Apnea.[Show abstract] [Hide abstract]
ABSTRACT: Obstructive sleep apnea syndrome (OSAS) is a disorder of airway obstruction with multisystem implications and associated complications. OSAS affects children from infancy to adulthood and is responsible for behavioral, cognitive, and growth impairment as well as cardiovascular and perioperative respiratory morbidity and mortality. OSAS is associated commonly with comorbid conditions, including obesity and asthma. Adenotonsillectomy is the most commonly used treatment option for OSAS in childhood, but efforts are underway to identify medical treatment options.Anesthesiology Clinics 03/2014; 32(1):237-261. DOI:10.1016/j.anclin.2013.10.012
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ABSTRACT: Obstructive sleep apnoea (OSA) has become a major public health concern as its incidence and severity have increased in tandem with the obesity epidemic. In children, OSA is now recognized as a common disorder and can be associated with significant morbidity. OSA belongs to a spectrum of diagnoses known as sleep-related breathing disorders in which the airway is completely (apnoea) or partially (hypopnoea) occluded during sleep despite continued respiratory efforts. This airway obstruction can cause abnormal gas exchange leading to hypoxaemia, hypercapnia, sleep fragmentation, and their attendant physiological and behavioural consequences. The degrees of hypercapnia, hypoxaemia, and upper airway airflow reduction are the primary factors determining the severity of OSA. In young children, adenotonsillar hypertrophy is the most common anatomical abnormality associated with OSA, and adenotonsillectomy is, therefore, the most common surgical intervention. Perioperative complications associated with adenotonsillectomy are more common in children with severe OSA. A thorough understanding of the pathophysiology of OSA, careful and complete preoperative assessment, meticulous intraoperative and postoperative management, and early recognition of potential perioperative complications are essential to optimization of outcomes. The safe anaesthetic management of a child with OSA requires an anaesthetic technique tailored to the underlying aetiology and severity of OSA and the surgical procedure. This review focuses on the epidemiology, pathogenesis, and diagnosis of OSA, and the state-of-the-art and future directions in the perioperative management of children with OSA.BJA British Journal of Anaesthesia 12/2013; 111 Suppl 1(suppl 1):i83-i95. DOI:10.1093/bja/aet371 · 4.35 Impact Factor