Obstructive Sleep ApneaNCT02152202
Semi-up Right Position Study
A study testing Semi-upright position and Supine position in people with Obstructive Sleep Apnea, run by University Health Network, Toronto at 4 sites in Canada.
Trial summary
Our main objective is to perform an explanatory, first stage proof of concept, randomized controlled trial to determine whether a semi-upright patient position versus a supine position while asleep in the postoperative period helps decrease the worsening of AHI in patients diagnosed with OSA and compare this to usual… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Obstructive Sleep Apnea
- What is being tested?
- Semi-upright position and Supine position
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 164 participants
- Where
- 4 sitesCanada
- Study dates
- Jul 2011to Dec 2016
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adult patients (18 years and above),
- ASA physical status I to IV,
- Undergoing elective inpatient surgery with obstructive sleep apnea (as determined by initial screening using STOP-Bang questionnaire and if at high risk (>3 points),
- Confirmed by an Apnea-hypopnea index (AHI) >5 using a diagnostic home portable polysomnography)
Who cannot join
- Patients previously diagnosed as OSA and on continuous positive airway pressure (CPAP) device;
- Known cervical, shoulder, spine abnormalities, and/or chronic pain predisposing to difficulty in maintaining a sitting position; or
- Previous intervention for OSA (e.g., uvulopalatopharyngoplasty, bariatric surgery); where sitting position is contraindicated postoperatively such as hip or spine surgery, hemodynamic instability; ambulatory surgery i.e. planned discharge on the same day of surgery.
Trial locations and contacts
4 sites in 1 country.
Canada4 sites
Mount Sinai Hospital, Department of Anesthesia
Toronto, Ontario, M5G 1X5
Toronto Western Hospital, Department of Aneshtesia
Toronto, Ontario, M5T2S8
University Health Network, Department of Anesthesia
Toronto, Ontario, M5T2S8
Toronto Western Hospital, Department of Aneshtesia
Toronto, Ontario
About this study
Official title: Does a Semi-upright Position During Sleep Prevent Worsening of Severity of Obstructive Sleep Apnea (OSA) on the Second Postoperative Night in Patients Following Elective Inpatient Surgery? A Two Arm, Parallel, Randomized, Controlled, First Stage Proof of Concept Trial
Our main objective is to perform an explanatory, first stage proof of concept, randomized controlled trial to determine whether a semi-upright patient position versus a supine position while asleep in the postoperative period helps decrease the worsening of AHI in patients diagnosed with OSA and compare this to usual care (i.e. supine patient positioning while asleep).
The investigators will evaluate whether a semi-upright position reduces: worsening of AHI (as measured with a portable PSG) on the second postoperative night (POD2); oxygen desaturation index (using a portable oxygen saturation monitor, oxygen desaturation defined as >4% change below baseline lasting for 10 seconds); REM sleep related change in AHI at baseline and POD2.; major and minor perioperative complications on postoperative day POD1, POD2, at discharge and POD 30.; length of hospital stay and readmission within 30 days; and patient satisfaction score on POD30
Read the detailed description
The proposed study is to determine whether patient positioning in supine or semi-sitting position can effectively control the worsening of OSA see in the postoperative period.
The study patient will be randomized to semi-sitting position (45 degrees incline) group or supine (0 degrees incline) group. Patients will undergo a portable sleep study on the first or second postoperative night. They will also be monitored with wristwatch oximeter pre and postoperatively according to the study protocol. Patients will be managed according to the routine care determined by the health care team. There will be no change in the clinical management of patients.
- Conditions
- Obstructive Sleep Apnea
- Being tested
- Semi-upright position, Supine position
- Medical subject headings
- Sleep Apnea, Obstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Semi-upright positionOther
Also called Semi-upright position (45 degree bed angle)
In this group patients' bed will be set into 45 degree angle during sleep in the night time.
Supine positionOther
Also called Control group
Control: Supine position during nocturnal sleep for at least two postoperative nights.
| Study group | Role | What they receive |
|---|---|---|
| Semi-upright position | Experimental | Semi-upright position defined as 45 degrees incline from horizontal of the patients bed during nocturnal sleep, for two postoperative nights. Daytime naps will be excluded. A regular pillow may be used by the patients based upon the level of comfort and also to support the head in a neutral position. Receives: Other: Semi-upright position |
| Control group (Supine position) | Other | In this group patients' bed will be set into Supine/0 degree angle during sleep in the night time. Patient will be managed according to routine care Receives: Other: Supine position |
What is being measured
The primary outcome is the main question the study is designed to answer.
Comparison of worsening of severity of OSA using the Apnea-hypopnea index (AHI) as determined by a portable polysomnography study from baseline (preoperatively) to the second postoperative night.
The AHI is used as a surrogate outcome to establish the diagnosis of OSA (AHI>5) and severity of OSA as per the guidelines from American Academy of Sleep Physicians (AASP).5 It is a continuous outcome and is measured by counting the number of apneas (complete cessation of airflow for more than 10 s) and hypopneas (airflow reduction more than 50%) despite continuing breathing efforts and thus differentiating from central events (absence of breathing efforts). The relationship of AHI to clinical outcomes of relevance has been well established in the literature.
Measured: 3days
Secondary outcomes (2)
Major and minor perioperative complications and length of hospital stay on postoperative day (POD) 1, POD2, at discharge and POD 30 will be recorded based on chart review.
The oxygen desaturation index; REM sleep related change in AHI at baseline and POD2 and time spent in lateral position while asleep will be deciphered from the PSG data.
Measured: 30 days
Hospital stay
Length of hospital stay, readmission within 30 days, and patient satisfaction score will be recorded and telephonic interview with the patient on POD30.
Measured: 30 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jun 2014 (estimated)
- Study startJul 2011
- Primary completionDec 2016
- Study completionDec 2016
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Obstructive Sleep ApneaStudies of the same condition, open and under way.
- More trials run by University Health Network, TorontoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 164 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Health Network, Toronto
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Frances Chung, University Health Network, Toronto
- Investigators
- Frances Chung, MD, Principal investigator, University Health Network, Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02152202
- Sponsor's protocol ID
- Protocol version july 17, 2011
- Status last verified
- May 2016
- First submitted
- 22 May 2014
- Last updated
- 4 May 2026
- Results posted
- No
- Data monitoring committee
- No
Publications
Lukachan GA, Yadollahi A, Auckley D, Gavrilovic B, Matelski J, Chung F, Singh M. The impact of semi-upright position on severity of sleep disordered breathing in patients with obstructive sleep apnea: a two-arm, prospective, randomized controlled trial. BMC Anesthesiol. 2023 Jul 13;23(1):236. doi: 10.1186/s12871-023-02193-y.
PubMed 37443016
Study at a glance
From the registry record, last updated by the sponsor on 4 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Does a Semi-upright Position During Sleep Prevent Worsening of Severity of Obstructive Sleep Apnea (OSA) on the Second Postoperative Night in Patients Following Elective Inpatient Surgery? A Two Arm, Parallel, Randomized, Controlled, First Stage Proof of Concept Trial
- ClinicalTrials.gov ID
- NCT02152202
- Acronym / sponsor ID
- Protocol version july 17, 2011
- Conditions
- Obstructive Sleep Apnea
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 164 participants (actual)
- Lead sponsor
- University Health Network, TorontoUniversity, hospital or other
- Study start
- Jul 2011 (actual)
- Primary completion
- Dec 2016 (actual)
- Study completion
- Dec 2016 (actual)
- First posted
- 2 Jun 2014 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Our main objective is to perform an explanatory, first stage proof of concept, randomized controlled trial to determine whether a semi-upright patient position versus a supine position while asleep in the postoperative period helps decrease the worsening of AHI in patients diagnosed with OSA and compare this to usual care (i.e. supine patient positioning while asleep).
The investigators will evaluate whether a semi-upright position reduces: worsening of AHI (as measured with a portable PSG) on the second postoperative night (POD2); oxygen desaturation index (using a portable oxygen saturation monitor, oxygen desaturation defined as >4% change below baseline lasting for 10 seconds); REM sleep related change in AHI at baseline and POD2.; major and minor perioperative complications on postoperative day POD1, POD2, at discharge and POD 30.; length of hospital stay and readmission within 30 days; and patient satisfaction score on POD30
Detailed description
The proposed study is to determine whether patient positioning in supine or semi-sitting position can effectively control the worsening of OSA see in the postoperative period.
The study patient will be randomized to semi-sitting position (45 degrees incline) group or supine (0 degrees incline) group. Patients will undergo a portable sleep study on the first or second postoperative night. They will also be monitored with wristwatch oximeter pre and postoperatively according to the study protocol. Patients will be managed according to the routine care determined by the health care team. There will be no change in the clinical management of patients.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Semi-upright position | Experimental | Other: Semi-upright positionSemi-upright position defined as 45 degrees incline from horizontal of the patients bed during nocturnal sleep, for two postoperative nights. Daytime naps will be excluded. A regular pillow may be used by the patients based upon the level of comfort and also to support the head in a neutral position. |
| Control group (Supine position) | Other | Other: Supine positionIn this group patients' bed will be set into Supine/0 degree angle during sleep in the night time. Patient will be managed according to routine care |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adult patients (18 years and above),
- ASA physical status I to IV,
- Undergoing elective inpatient surgery with obstructive sleep apnea (as determined by initial screening using STOP-Bang questionnaire and if at high risk (>3 points),
- Confirmed by an Apnea-hypopnea index (AHI) >5 using a diagnostic home portable polysomnography)
Key exclusion criteria (3 listed)
- Patients previously diagnosed as OSA and on continuous positive airway pressure (CPAP) device;
- Known cervical, shoulder, spine abnormalities, and/or chronic pain predisposing to difficulty in maintaining a sitting position; or
- Previous intervention for OSA (e.g., uvulopalatopharyngoplasty, bariatric surgery); where sitting position is contraindicated postoperatively such as hip or spine surgery, hemodynamic instability; ambulatory surgery i.e. planned discharge on the same day of surgery.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Semi-upright positionAlso: Semi-upright position (45 degree bed angle)In this group patients' bed will be set into 45 degree angle during sleep in the night time. | Other | Semi-upright position |
| Supine positionAlso: Control groupControl: Supine position during nocturnal sleep for at least two postoperative nights. | Other | Control group (Supine position) |
Primary outcome
Comparison of worsening of severity of OSA using the Apnea-hypopnea index (AHI) as determined by a portable polysomnography study from baseline (preoperatively) to the second postoperative night.
Time frame: 3days
The AHI is used as a surrogate outcome to establish the diagnosis of OSA (AHI>5) and severity of OSA as per the guidelines from American Academy of Sleep Physicians (AASP).5 It is a continuous outcome and is measured by counting the number of apneas (complete cessation of airflow for more than 10 s) and hypopneas (airflow reduction more than 50%) despite continuing breathing efforts and thus differentiating from central events (absence of breathing efforts). The relationship of AHI to clinical outcomes of relevance has been well established in the literature.
2 secondary outcomes
Major and minor perioperative complications and length of hospital stay on postoperative day (POD) 1, POD2, at discharge and POD 30 will be recorded based on chart review.
Time frame: 30 days
Hospital stay
Time frame: 30 days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 May 2026.
- Derived from this study: PubMed 37443016Lukachan GA, Yadollahi A, Auckley D, Gavrilovic B, Matelski J, Chung F, Singh M. The impact of semi-upright position on severity of sleep disordered breathing in patients with obstructive sleep apnea: a two-arm, prospective, randomized controlled trial. BMC Anesthesiol. 2023 Jul 13;23(1):236. doi: 10.1186/s12871-023-02193-y.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Frances Chung, MD principal investigator
University Health Network, Toronto
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Semi-upright position and Supine position in people with Obstructive Sleep Apnea, run by University Health Network, Toronto at 4 sites in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Comparison of worsening of severity of OSA using the Apnea-hypopnea index (AHI) as determined by a portable polysomnography study from baseline (preoperatively) to the second postoperative night. (time frame: 3days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02152202, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 May 2026.