Sedation in Patients at Risk for Upper Airway Collapse

2014-07-24 14:10:23 | BioPortfolio


Overview of Protocol:

Between Subject - Repeated Measures design will be used to assess the airway response of two groups of subjects under two different sedated conditions. Each group will be comprised of six subjects and will be categorized according to their baseline profile for risk for SDB (< 10 RDI or > 25 RDI). Some subjects will have been prescribed continuous positive airway pressure (CPAP) therapy by their treating physician as a result of their overnight sleep study. CPAP treatment is effective in splinting the airway open and thus decreasing the incident of airway collapse during sleep. Thus, CPAP utilization will also be tracked as an independent and continuous variable as regular CPAP use has been found to be associated with increased resistance to UAC (upper airway collapse).

The experimental conditions will evaluate upper airway patency and instability in response to two forms of intravenous sedation: propofol and dexmedetomidine.

Subjects will be continuously monitored during each experimental condition for respiratory effort and flow, and for EEG, EMG, and ECG.

Respiratory instability will first be assessed while subjects are under sedation without any airway provocation. The degree of respiratory instability will be quantified in terms of the following measurements: a modified Respiratory Disturbance Index (RDIsedated), respiratory arousals, and minute ventilation. The apneic periods will be classified by their mixture of central and obstructive components.All outcome measurements are assessed over the period of sedation which last for approximately one hour.

Upper airway patency will be quantified in terms of the critical pharyngeal pressure (Pcrit) (the pressure beyond which complete upper airway collapse occurs, see background).


The propensity to experience sleep disordered-breathing (SDB) is controlled by the interplay of anatomic factors (i.e. BMI, neck circumference, retrognathia) and neurological drive (sleep stage, arousal). The interaction of baseline anatomic factors and drug-induced altered neurologic drive may also convey a risk for upper airway collapse (UAC) in patients receiving analgesics, or sedation/anesthesia.1;2 While there is mainly only anecdotal evidence to support the proposition that SDB is a strong predictor of sedation-related adverse events,3;4 there is such a remarkable consensus of opinion regarding this association that, for example, the American Society of Anesthesiologists is developing guidelines to specifically address the issue of managing this group of "at risk" patients who are to undergo sedation or anesthesia. SDB is a term that is used to describe a spectrum of sleep-related breathing disturbances. Obstructive Sleep Apnea (OSA) is a condition that incorporates SDB with daytime symptoms (i.e. hypersomnolence). These terms are commonly used interchangeably.

At this juncture, what is needed are clear demonstrations: 1) that SDB confers risk for sedation-related adverse events (epidemiologically and/or experimentally), 2) of the patient and drug factors that moderate/mediate the risk, and 3) of the mechanisms responsible for the patient by drug interactions.

This proposed project will, in a preliminary way, address the first and second of these issues. Specifically, the upper airway characteristics of patients with different severity classifications of SDB will be assessed while under the influence of two, neuropharmacologically distinct, intravenous sedatives.

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator)


Obstructive Sleep Apnea


Propofol, Dexmedetomidine


University of Rochester
New York
United States




University of Rochester

Results (where available)

View Results


Published on BioPortfolio: 2014-07-24T14:10:23-0400

Clinical Trials [1554 Associated Clinical Trials listed on BioPortfolio]

Dexmedetomidine Versus Propofol for Continuous Sedation in the Intensive Care Unit (ICU)

Patients in the ICU who need help with their breathing are put onto a machine called a ventilator and are also given a medicine, called a sedative, which helps them to sleep and makes them...

Vasoactive Hormones and Oxygen Saturation During Apneic Events in Patients With Obstructive Sleep Apnea

The mechanisms involved in development and maintenance of hypertension in obstructive sleep apnea are not clarified. We hypothesize that patients with obstructive sleep apnea have an abno...

The Effect of Obstructive Sleep Apnea Treatment on Dizziness, Vertigo

Obstructive Sleep Apnea may cause dizziness or vertigo through hypoxia of the vestibular nuclei in the brain. Treating sleep apnea may improve dizziness or vertigo.

Effects of Positive Airway Pressure (PAP) in Children With Obstructive Sleep Apnea (OSA)

Obstructive sleep apnea is a problem for a large number of children and can result in problems with thinking patterns, behaviors and sleep if left untreated. Little is known about how posi...

REV 002 Observational Study of the ReVENT Sleep Apnea System: Minimally Invasive Treatment for Obstructive Sleep Apnea

The purpose of this post-market observational study is to assess the effectiveness and patient perception of benefit of the ReVENT Sleep Apnea System in patients diagnosed with Obstructive...

PubMed Articles [2157 Associated PubMed Articles listed on BioPortfolio]

Association of Obstructive Sleep Apnea Syndrome and Buerger's Disease: a Pilot Study.

In this study we evaluated the incidence and severity of obstructive sleep apnea and Obstructive sleep apnea syndrome in patients with thromboangiitis obliterans for reduction of crisis. In 40 patient...

Systemic prostacyclin and thromboxane production in obstructive sleep apnea.

Obstructive sleep apnea increases the risk of cardiovascular diseases. Alternations in prostacyclin and thromboxane concentrations and balance could constitute one of mechanisms linking sleep apnea an...

Associations Between Obstructive Sleep Apnea, Sleep Duration, and Abnormal Fasting Glucose: The Multi-Ethnic Study of Atherosclerosis.

No data exist as to the role of ethnicity in the associations between obstructive sleep apnea (OSA), sleep duration, and metabolic dysfunction.

Physical Inactivity Is Associated with Moderate-Severe Obstructive Sleep Apnea.

To investigate whether low levels of physical activity were associated with an increased occurrence of obstructive sleep apnea (OSA), OSA-related symptoms, and cardiometabolic risk.

Drug-induced sleep endoscopy in the identification of obstruction sites in patients with obstructive sleep apnea: a systematic review.

Obstructive sleep apnea syndrome has multifactorial causes. Although indications for surgery are evaluated by well-known diagnostic tests in the awake state, these do not always correlate with satisfa...

Medical and Biotech [MESH] Definitions

A condition associated with multiple episodes of sleep apnea which are distinguished from obstructive sleep apnea (SLEEP APNEA, OBSTRUCTIVE) by the complete cessation of efforts to breathe. This disorder is associated with dysfunction of central nervous system centers that regulate respiration. This condition may be idiopathic (primary) or associated with lower brain stem lesions; chronic obstructive pulmonary disease (LUNG DISEASES, OBSTRUCTIVE); HEART FAILURE, CONGESTIVE; medication effect; and other conditions. Sleep maintenance is impaired, resulting in daytime hypersomnolence. Primary central sleep apnea is frequently associated with obstructive sleep apnea. When both forms are present the condition is referred to as mixed sleep apnea (see SLEEP APNEA SYNDROMES). (Adams et al., Principles of Neurology, 6th ed, p395; Neurol Clin 1996;14(3):611-28)

Disorders characterized by multiple cessations of respirations during sleep that induce partial arousals and interfere with the maintenance of sleep. Sleep apnea syndromes are divided into central (see SLEEP APNEA, CENTRAL), obstructive (see SLEEP APNEA, OBSTRUCTIVE), and mixed central-obstructive types.

A disorder characterized by recurrent apneas during sleep despite persistent respiratory efforts. It is due to upper airway obstruction. The respiratory pauses may induce HYPERCAPNIA or HYPOXIA. Cardiac arrhythmias and elevation of systemic and pulmonary arterial pressures may occur. Frequent partial arousals occur throughout sleep, resulting in relative SLEEP DEPRIVATION and daytime tiredness. Associated conditions include OBESITY; ACROMEGALY; MYXEDEMA; micrognathia; MYOTONIC DYSTROPHY; adenotonsilar dystrophy; and NEUROMUSCULAR DISEASES. (From Adams et al., Principles of Neurology, 6th ed, p395)

Dyssomnias (i.e., insomnias or hypersomnias) associated with dysfunction of internal sleep mechanisms or secondary to a sleep-related medical disorder (e.g., sleep apnea, post-traumatic sleep disorders, etc.). (From Thorpy, Sleep Disorders Medicine, 1994, p187)

HYPOVENTILATION syndrome in very obese persons with excessive ADIPOSE TISSUE around the ABDOMEN and DIAPHRAGM. It is characterized by diminished to absent ventilatory chemoresponsiveness; chronic HYPOXIA; HYPERCAPNIA; POLYCYTHEMIA; and long periods of sleep during day and night (HYPERSOMNOLENCE). It is a condition often related to OBSTRUCTIVE SLEEP APNEA but can occur separately.

More From BioPortfolio on "Sedation in Patients at Risk for Upper Airway Collapse"

Quick Search

Relevant Topics

Sleep Disorders
Sleep disorders disrupt sleep during the night, or cause sleepiness during the day, caused by physiological or psychological factors. The common ones include snoring and sleep apnea, insomnia, parasomnias, sleep paralysis, restless legs syndrome, circa...

Asthma COPD Cystic Fibrosis Pneumonia Pulmonary Medicine Respiratory Respiratory tract infections (RTIs) are any infection of the sinuses, throat, airways or lungs.  They're usually caused by viruses, but they can also ...

Pharmacy is the science and technique of preparing as well as dispensing drugs and medicines. It is a health profession that links health sciences with chemical sciences and aims to ensure the safe and effective use of pharmaceutical drugs. The scope of...

Searches Linking to this Trial