Literature Updates from July 2012

Mechanisms Mediating Effects of Nitric Oxide on Perifornical Lateral Hypothalamic Neurons

Nitric oxide is a gaseous neurotransmitter that has been implicated in the regulation of sleep. In this study the authors investigated contributions of adenosinergic, GABAergic, and sGC-cGMP signaling mechanisms in mediating nitrergic influences on a major wake-promoting structure, the perifornical-lateral hypothalamic area neurons.

Disrupted Sleep Without Sleep Curtailment Induces Sleepiness and Cognitive Dysfunction Via the Tumor Necrosis Factor-Alpha Pathway

This study demonstrates the activation of inflammatory mechanisms, more specifically TNF-alpha-dependent pathways after frequent sleep arousals.

National In-Hospital Morbidity and Mortality Trends After Lumbar Fusion Surgery Between 1998 and 2008

Studying trends in perioperative outcomes in spine surgical patients the authors found that mean patient age and comorbidity burden increased along with significant increases in peri-operative complications including pulmonary and cardiac. These trends highlight the need for appropriate peri-operative services to optimize outcomes in an increasingly morbid and older population of patients undergoing lumbar fusion.

Utilization of Critical Care Services Among Patients Undergoing Total Hip and Knee Arthroplasty: Epidemiology and Risk Factors

The authors sought to identify the incidence and risk factors for the use of critical care services among orthopedic patients and compare the characteristics and outcomes of patients who require critical care services to those who do not. The presence of pulmonary compromise was associated with the highest odds for the use of critical care services (OR 18.44 (16.55, 20.55)).

Pulmonary Hypertension: An Important Predictor of Outcomes in Patients Undergoing Non-Cardiac Surgery

The authors of this article report on perioperative outcomes in a large cohort of patients undergoing non-cardiac surgery, comparing those with and without pulmonary hypertension. They conclude, that in addition to the traditionally known risk factors for outcomes such as coronary artery disease, diabetes mellitus, chronic renal insufficiency, and American Society of Anesthesiology class, the presence of underlying pulmonary hypertension can have a significant negative impact on perioperative outcomes.

A Multisite Randomized Trial of Portable Sleep Studies and Positive Airway Pressure Autotitration Versus Laboratory-Based Polysomnography for the Diagnosis and Treatment of Obstructive Sleep Apnea: The HomePAP Study

This study tests the utility of an integrated clinical pathway for obstructive sleep apnea (OSA) diagnosis and continuous positive airway pressure (CPAP) treatment using portable monitoring devices. A home-based strategy for diagnosis and treatment compared with in-laboratory PSG was not inferior in terms of acceptance, adherence, time to treatment, and functional improvements.

Association Between Treated and Untreated Obstructive Sleep Apnea and Risk of Hypertension

Compared with participants without OSA, the presence of OSA was associated with increased adjusted risk of incident hypertension; however, treatment with CPAP therapy was associated with a lower risk of hypertension.

Effect of Continuous Positive Airway Pressure on the Incidence of Hypertension and Cardiovascular Events in Nonsleepy Patients with Obstructive Sleep Apnea: A Randomized Controlled Trial

In patients with OSA without daytime sleepiness, the prescription of CPAP compared with usual care did not result in a statistically significant reduction in the incidence of hypertension or cardiovascular events. However, the study may have had limited power to detect a significant difference.

Outpatient Anesthesia for Patients with Obstructive Sleep Apnea: Results of a National Survey

This survey shows that outpatient surgery for patients with sleep apnea is common practice in Germany. It is also performed when patients have moderate or severe OSAS and for respiratory tract surgery. This means that the management of OSA patients in Germany does not conform to the ASA OSA guidelines.

Clinical Manifestations of Obstructive Sleep Apnoea in Pregnancy: More Than Snoring and Witnessed Apnoeas

Sleep disordered breathing and its symptoms have been associated with a multitude of fetal and maternal complications including gestational hypertensive disorders, gestational diabetes and possibly pre-term labour and other markers of alterations in fetal wellbeing. The disease remains underdiagnosed in the general population but likely also in pregnancy, mostly because providers do not appropriately screen for the disorder. This case series describes patients with diagnoses such as chronic hypertension, pre-eclampsia, pulmonary hypertension, nocturnal asthma and panic attacks, who were diagnosed with sleep disordered breathing and offered treatment with CPAP during pregnancy.