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Unrecognised Obstructive Sleep Apnea Study (OSA)

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2016 by University Health Network, Toronto
Information provided by (Responsible Party):
Dr. Frances Chung, University Health Network, Toronto Identifier:
First received: December 12, 2011
Last updated: May 25, 2016
Last verified: May 2016

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.

Obstructive Sleep Apnea

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Postoperative Vascular Events in Unrecognised Obstructive Sleep Apnea

Resource links provided by NLM:

Further study details as provided by University Health Network, Toronto:

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

Estimated Enrollment: 400
Study Start Date: July 2011
Estimated Study Completion Date: December 2017
Estimated Primary Completion Date: December 2017 (Final data collection date for primary outcome measure)
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.

Ages Eligible for Study:   45 Years and older   (Adult, Senior)
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.
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01494181

Contact: Dr. Frances Chung, MBBS, FRCPC 4166035800 ext 5433
Contact: Sohail Iqbal, MD 4167908307

Canada, Ontario
The Scarborough hospital Recruiting
Scarborough, Ontario, Canada
Contact: Stanley Tam, MD   
Contact: Sohail Iqbal    4167908307   
Sub-Investigator: Stanley Tam, MD         
Hong Kong
Prince of Wales Hospital Recruiting
Shatin, Hong Kong
Contact: Matthew Chan, MBBS    +85226322736   
Principal Investigator: Matthew Chan, MBBS         
Unversity Malaya Medical Centre Recruiting
Kuala Lumpur, Malaysia
Contact: Wang Chew Yin, MBChB, FRCA    60379492050   
Sub-Investigator: Wang Chew Yin, MBChB         
Khoo Teck Puat Hospital Not yet recruiting
Yishun, Singapore, 768828
Contact: Edwin Seet Cheu Ping, MBBS    65-66022317   
Sub-Investigator: Edwin Seet, MD         
Sponsors and Collaborators
University Health Network, Toronto
Principal Investigator: Frances Chung, MBBS, FRCPC University Health Network, Toronto
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Dr. Frances Chung, Staff Anesthesiologist, University Health Network, Toronto Identifier: NCT01494181     History of Changes
Other Study ID Numbers: Version Nov 14, 2011
Study First Received: December 12, 2011
Last Updated: May 25, 2016

Keywords provided by University Health Network, Toronto:
obstructive sleep apnea
vascular events

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Respiration Disorders
Respiratory Tract Diseases
Signs and Symptoms, Respiratory
Signs and Symptoms
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases processed this record on April 28, 2017