Obstructive Sleep Apnea and Incidence of Postoperative Delirium After Elective Knee Replacement in the Nondemented Elderly

Postoperative cognitive decline, comprising of a relatively short-lived delirium and a more persistent cognitive dysfunction, can have devastating long-term consequences including both a higher mortality rate and costs associated with the care of the cognitively impaired. To date several risk factors have been identified. This is the first prospective study employing validated measures of delirium to identify an association between preexisting obstructive sleep apnea and postoperative delirium. This study includes 106 nondemented patients 65 yr or older undergoing elective knee arthroplasty that were prospectively evaluated for postoperative delirium. The results show an incidence of 25.5% incidence of postoperative delirium.

The Effect of Diaphragm Contraction on Upper Airway Collapsibility

This study was performed to determine the mechanisms by which lung volume and upper airway collapsibility are related and whether phrenic nerve stimulation has therapeutic potential in preventing or treating upper airway obstruction.

The authors found that tonic phrenic nerve stimulation decreases upper airway collapsibility. These findings suggest that the decrease in collapsibility is primarily mediated through lung volume increase related changes in airway wall compliance and/or airway transmural pressure gradients rather than through mediastinal traction secondary to diaphragm descent. Phrenic nerve stimulation deserves further exploration as a therapy for OSA.

Sleep is Not Just for the Brain: Transcriptional Responses to Sleep in Peripheral Tissues

By using microarrays the authors compared gene expression in tissue from sleep and sleep deprived mice. The results support the notion that the molecular consequences of sleep/wake behavioral state extend beyond the brain to include peripheral tissues. Sleep state induces a highly overlapping response in both heart and lung.

Optogenetic Stimulation of Melanin Concentrating Hormone (MCH) Neurons Increases Sleep

MCH stimulation increased both non-REM and REM sleep against a very strong circadian waking drive. This has significant potential for the insomnia associated with shift-work and jet-lag, conditions where a strong waking drive blocks sleep onset

Screening of Pediatric Sleep-Disordered Breathing: A Proposed Unbiased Discriminative Set of Questions Using Clinical Severity Scales

…complaints can be ranked according to a severity hierarchy: shake child to breathe, apnea during sleep, struggle breathing when asleep, and breathing concerns while asleep, followed by loudness of snoring and snoring while asleep. As a result, the set of six hierarchically arranged questions will aid the screening of children at high risk for SDB but cannot be used as the sole diagnostic approach.

Rules for Scoring Respiratory Events in Sleep: Update of the 2007 AASM Manual for the Scoring of Sleep and Associated Events. Deliberations of the Sleep Apnea Definitions Task Force of the American Academy of Sleep Medicine

The goals of the task force were (1) to clarify and simplify the current scoring rules, (2) to review evidence for new monitoring technologies relevant to the scoring rules, and (3) to strive for greater concordance between adult and pediatric rules.

Obstructive Sleep Apnea is a Predictor of Abnormal Glucose Metabolism in Chronically Sleep Deprived Obese Adults

Sleep duration and quality, OSA, and glucose metabolism were assessed in 96 obese individuals reporting to sleep less than 6.5 hrs on a regular basis. OSA severity was associated with higher fasting glucose and insulin. Those with moderate to severe OSA had higher glucose at 120 min while undergoing a glucose tolerance test.