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Unrecognised Obstructive Sleep Apnea Study (OSA)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01494181
Recruitment Status : Completed
First Posted : December 16, 2011
Last Update Posted : January 29, 2018
Information provided by (Responsible Party):
Dr. Frances Chung, University Health Network, Toronto

Brief Summary:

Plan of investigation:

This is an observational cohort study to determine the effect of OSA, independent of other risk factors, on postoperative vascular events. The study is conceived, designed and will be conducted, and analyzed independent to any company. There is no commercial sponsorship.

Condition or disease
Obstructive Sleep Apnea

Detailed Description:
The potential study subjects will be approached by study coordinator at preoperative clinic. If the patient is interested in participating the study, he/she will be screened and consented. Undetected or untreated OSA will be established by STOP-Bang questionnaire and subsequent overnight PSG by using Apnea Link Plus which is level ( 2 ) at patient's home.The following data will be recorded: including age, gender, history of coronary artery disease, prior revascularization, cerebrovascular disease, peripheral vascular disease, critical aortic valvular stenosis, congestive heart failure, atrial fibrillation, diabetes treated with insulin or an oral diabetic drug, hypertension, hypercholesterolemia treated with drug therapy, tobacco use, renal insufficiency and the type of surgery. For all study patients, the nocturnal blood oxygen saturation will be monitored by a pulse oximeter (PULSOX 300i) for first 3 nights postoperatively.During their stay in hospital, patients will be followed daily, and outcomes will be recorded, until discharge.. ECG will be measured preoperatively and repeated on day 1 to 3 after surgery. Venous blood will be collected 6-12 hours and on the first 3 days after surgery for measuring cTnT concentration.If patient's ECG is abnormal and/or patient is positive for troponin test, treating physician will be contacted for further treatment. Patient will be contacted 30 days after surgery by phone to ascertain if they have experienced any adverse out come.

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Study Type : Observational
Actual Enrollment : 1200 participants
Observational Model: Other
Time Perspective: Prospective
Official Title: Postoperative Vascular Events in Unrecognised Obstructive Sleep Apnea
Study Start Date : July 2011
Actual Primary Completion Date : January 2018
Actual Study Completion Date : January 2018

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Sleep Apnea

Primary Outcome Measures :
  1. primary outcome of this study is postoperative vascular event within 30 days after surgery [ Time Frame: 30 days ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   45 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Surgical patient

Patients Inclusion & Exclusion Criteria:

Inclusion criteria:

Ethics Committee approval and informed consent will be obtained. We plan to study patients at moderate-to-high risk for postoperative vascular complications because our data from other trials suggested that the incidence of OSA in these patients is higher than the general population. We will include patients who are:

  1. adult males and females, age ≥ 45 years, undergoing elective non-cardiac surgery that is expected to require a postoperative hospital stay of more than 3 nights, and
  2. at increased risk for postoperative vascular events, defined as having at least one of the following risk factors (a) high-risk surgery (intra-peritoneal, intra-thoracic or supra-inguinal vascular surgery); (b) history of ischemic heart disease; (c) history of congestive heart failure; (d) history of cerebrovascular disease (d) diabetes requiring insulin therapy (e) serum creatinine > 175 µmol/L.

Exclusion criteria:

Patients will be excluded if:

  1. they have a previous diagnosis of OSA or any sleep-related breathing disorder and on treatment
  2. they are unwilling or physically unavailable for PSG on any night before surgery;
  3. their surgery included tonsillectomy, septoplasty, uvuloplasty, pharyngoplasty, tracheostomy, or prolonged (> 48 hrs) postoperative mechanical ventilation of the lungs is anticipated. It is because these procedures/interventions are likely to cure or at least modify the severity of OSA.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01494181

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Canada, Ontario
The Scarborough hospital
Scarborough, Ontario, Canada
Hong Kong
Prince of Wales Hospital
Shatin, Hong Kong
Unversity Malaya Medical Centre
Kuala Lumpur, Malaysia
Khoo Teck Puat Hospital
Singapore, Singapore, 768828
Sponsors and Collaborators
University Health Network, Toronto
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Principal Investigator: Frances Chung, MBBS, FRCPC University Health Network, Toronto
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Dr. Frances Chung, Staff Anesthesiologist, University Health Network, Toronto Identifier: NCT01494181    
Other Study ID Numbers: Version Nov 14, 2011
First Posted: December 16, 2011    Key Record Dates
Last Update Posted: January 29, 2018
Last Verified: January 2018
Keywords provided by Dr. Frances Chung, University Health Network, Toronto:
obstructive sleep apnea
vascular events
Additional relevant MeSH terms:
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Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases