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Completed

NCT Number: NCT01045122

Sedation in Patients at Risk for Upper Airway Collapse

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).

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Key information

Conditions

Obstructive Sleep Apnea Apnea Dyssomnias Nervous System Diseases Respiration Disorders Respiratory Tract Diseases Sleep Apnea Syndromes Sleep Apnea, Obstructive Sleep Disorders, Intrinsic Sleep Wake Disorders

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Rochester

Rochester, New York, 14642, United States

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with mild or no Sleep disorder breathing
  • Patients with moderate to severe Sleep disorder breathing

Exclusion criteria

  • No unstable medical conditions
  • Anatomic pathology of airway
  • Pregnancy or nursing
  • Inability to fit an anesthesia facemask
  • Excessive alcohol or drug abuse
  • Bleeding abnormalities
  • Claustrophobia

Treatment and study plan

Propofol

Drug

For propofol, the current study will employ the Marsh parameters, with an initial effect site target concentration of 1.0 mcg/ml, a level likely to produce only mild sedation. Though our patient population is expected to be predominantly obese, a previous pharmacokinetic study has validated that constant infusions utilizing the dosing scheme of mcg-1•kg-1•min will yield similar effect site concentrations.25 The effect site target will be increased in increments approximately every five minutes until the pharmacodynamic targets defined in the study are attained.

Other names: Diprivan

Dexmedetomidine

Drug

For dexmedetomidine, an intravenous loading dose of 0.5 mcg/kg will be infused over 10 minutes and followed by an infusion starting at 0.5 mcg/kg/hr. This infusion will be titrated up to a maximum of 1.2 mcg/kg/hr.

Other names: Precedex

Primary outcomes

  1. Respiratory Disturbance Index

    Time frame: during infusion of study drugs

    respiratory events (apneas, hypopneas) per hour

Sponsors and collaborators

Lead sponsor

University of Rochester

Other

Registry information

Official study title

Sedation in Patients at Risk for Sleep-induced Upper Airway Collapse

Important dates

Study start
2006
Primary completion
2008
Study completion
2008
First posted
Jan 8, 2010
Registry last updated
Apr 27, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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