Non-cardiac SurgeryNCT04453722

Prevention of Opioid-Induced Hypoxemia

An observational study of Non-cardiac Surgery, run by The Cleveland Clinic at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

To evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO. Read more about this study

Who is it for?: Ages 18 to 85 years
Conditions the study is for: Non-cardiac Surgery
What is being tested?: Oxalert Monitor Mode and Oxalert Normal mode
Type of treatment: Medical device
How many people: 49 participants
Where: 1 siteUnited States
Study dates: 26 Jun 2020to 15 Jun 2023
Phase: Observational
Are there results?: Yes, posted in the registrySummary in the doctors' view

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 to 85 years
All sexes
No healthy volunteers
Adult, Older adult

Study population: The investigators will enroll patients who are at increased risk for respiratory insufficiency. Specifically, the investigators will focus on patients scheduled for laparoscopic or open major abdominal or pelvic surgery whose analgesia is primarily opioid-based. The investigators will further restrict enrollment to obese patients (body mass index kg/m2) who are likely to have respiratory compromise. Both men and women will be recruited.

Who may be able to join

Adults having major laparoscopic and open abdominal or pelvic surgeries;
Body Mass Index ≥25 kg/m2
American Society of Anesthesiologists physical status 1-3;
Age 18-85 years old;
Able to understand and consent to the trial and fully participate;
Anticipated primary opioid analgesia after surgery;
Expected duration of hospitalization at least 24 hours after surgery;
Consenting at least 24 hours before anticipated surgery.

Who cannot join

Epidural analgesia (field and fascial plane blocks permitted);
Pre-operative SpO2 <95%;
No wrist available for the study;
Severe hearing loss;
Lack of English language fluency.
Serious hearing deficit (unable to understand normal speech in a quite environment)
Serious peripheral neuropathy (unable to feel pin prick at wrist).

Trial locations and contacts

1 site in 1 country.

United States1 site

Cleveland Clinic
Cleveland, Ohio, 44195

Other trials in United States

About this study

Official title: Wearable Device for Prevention of Opioid-Induced Hypoxemia

To evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO.

Read the detailed description

The investigators will evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO. All patients will wear the Oxalert for 24 hours preoperatively in the monitoring only mode (no alerts), throughout hospitalization up to six days, and for 24 post-discharge hours. Randomization will be to Oxalert in monitor-only mode or to its normal mode which provides progressive audible and tactile alerts for hypoxemia.

Conditions: Non-cardiac Surgery
Being tested: Oxalert Monitor Mode, Oxalert Normal mode

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Oxalert Monitor ModeDevice
The investigator will evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO. Using the Oxalert in monitor only mode.
Oxalert Normal modeDevice
The investigator will evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO using the Oxalert in monitor in normal mode

Study groups in NCT04453722
Study group	Role	What they receive
Monitor only mode		Randomization will be to Oxalert in monitor-only mode Receives: Device: Oxalert Monitor Mode
Monitor in normal mode		Randomization will be to Oxalert in monitor normal mode which provides progressive audible and tactile alerts for hypoxemia. Receives: Device: Oxalert Normal mode

What is being measured

The primary outcome is the main question the study is designed to answer.

Time-weighted Average of SpO2 Below a Threshold of 90%
Time-weighted average of SpO2 below a threshold of 90%. Oxygen Saturation measured between 0% - 100%. Oxygen Saturation <90% is considered abnormal.
Measured: during hospitalization up to 6 days and post-discharge 24 hours
Number of Participants With Desaturation Events (Saturation <90%) Lasting at Least 2 Min
Number of Participants with Desaturation Events (Saturation <90%) Lasting at Least 2 Min. All the patients were included.
Measured: during hospitalization up to 6 days and post-discharge 24 hours
Duration of Desaturation Events (Saturation <90%) Lasting at Least 2 Min
Duration of Desaturation Events (Saturation <90%) Lasting at Least 2 Mi. All desaturation events were included.
Measured: during hospitalization up to 6 days and post-discharge 24 hours
AUC of SpO2 Below a Threshold of 90%
AUC of SpO2 Below a Threshold of 90%. SpO2 from 0% -100%.
Measured: during hospitalization up to 6 days and post-discharge 24 hours
Number of Desaturation Events (Saturation <90%) Lasting at Least 2 Min
Number of desaturation events (Saturation <90%) Lasting at Least 2 Mi. All desaturation events were included.
Measured: during hospitalization up to 6 days and post-discharge 24 hours

Secondary outcomes (2)

Patients' Attitude Toward the Device
We used 0-to-10 (Better - Worst) numerical rating scale to measure the degree of disturbing: 0 = "Not disturbed" and 10 = "Severely disturbed"; others are measured with 5-point numerical rating scales:1="Strongly disagree", 5="Strongly agree" (1=Better - 5= Worst). No subscales combining to compute a total score.
Measured: At the day of discharge and after 24 hours of discharge
Nurses' Attitude Toward the Device
We used 0-to-10 (better- worst) numerical rating scale to measure the degree of disturbing: 0 = "Not disturbed" and 10 = "Severely disturbed"; others are measured with 5-point numerical rating scales:1="Strongly disagree", 5="Strongly agree" (1= better- 5=worst).
Measured: Post-operative day 1 (POD 1)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

26 Jun 202015 Jun 2023

First posted1 Jul 2020
Study start26 Jun 2020
Primary completion30 Apr 2022
Study completion15 Jun 2023

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Non-cardiac SurgeryStudies of the same condition, open and under way.
More trials run by The Cleveland ClinicThe 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: Observational
Observational model: Cohort
Time perspective: Prospective
Enrolment: 49 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04453722
Sponsor's protocol ID: 20-505
Other IDs: 1R43DA050336-01A1
Status last verified: Aug 2025
First submitted: 10 Jun 2020
Last updated: 29 Aug 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No

Publications

Li K, Saab R, Bravo M, Mascha EJ, Han Y, Nault R, Olson L, Sessler DI. Wearable device for prevention of postoperative and post-discharge hypoxemia: A randomized pilot trial. Acta Anaesthesiol Scand. 2023 Apr;67(4):440-447. doi: 10.1111/aas.14193. Epub 2023 Jan 13.
PubMed 36583643

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Recruiting
The Effect of Virtual Reality Headsets on Pain, Anxiety, Patient Satisfaction, and Physiological Parameters in Patients Undergoing Open-Heart Surgery
Pain After Surgery, Pain and Anxiety
RecruitingPhase 4
The Impact of Perioperative Lidocaine Infusions on Enhanced Recovery After Non-Cardiac Surgery
Pain, Post Operative Analgesia
RecruitingPhase 4
Acetaminophen-Mannitol Injection and Postoperative Delirium
Postoperative Delirium
RecruitingPhase 4
Can Patients With Atrial Fibrillation Safely Discontinue Anticoagulant Therapy After Cardiac Surgery? (ATLAAC)
Atrial Fibrillation, Left Atrial Appendage Absent
Not yet recruiting
SPIP vs ESP Block in Cardiac Surgery
Cardiac Surgery, Chronic Postsurgical Pain

All Non-cardiac Surgery trials

Study at a glance

From the registry record, last updated by the sponsor on 29 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Wearable Device for Prevention of Opioid-Induced Hypoxemia
ClinicalTrials.gov ID: NCT04453722
Acronym / sponsor ID: 20-505
Conditions: Non-cardiac Surgery
Study type: Observational
Recruitment status: Completed
Enrolment: 49 participants (actual)
Lead sponsor: The Cleveland ClinicUniversity, hospital or other
Collaborators: National Institute on Drug Abuse (NIDA)
Study start: 26 Jun 2020 (actual)
Primary completion: 30 Apr 2022 (actual)
Study completion: 15 Jun 2023 (actual)
First posted: 1 Jul 2020 (actual)
Results: Posted 20 Feb 2024

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

To evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO.

Detailed description

Study design

Observational model: Cohort
Time perspective: Prospective
Number of arms: 2

Arm	Type	Receives
Monitor only mode	–	Device: Oxalert Monitor ModeRandomization will be to Oxalert in monitor-only mode
Monitor in normal mode	–	Device: Oxalert Normal modeRandomization will be to Oxalert in monitor normal mode which provides progressive audible and tactile alerts for hypoxemia.

Who may qualify

Ages: 18 to 85 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult
Study population: The investigators will enroll patients who are at increased risk for respiratory insufficiency. Specifically, the investigators will focus on patients scheduled for laparoscopic or open major abdominal or pelvic surgery whose analgesia is primarily opioid-based. The investigators will further restrict enrollment to obese patients (body mass index kg/m2) who are likely to have respiratory compromise. Both men and women will be recruited.

Key inclusion criteria (8 listed)

Adults having major laparoscopic and open abdominal or pelvic surgeries;
Body Mass Index ≥25 kg/m2
American Society of Anesthesiologists physical status 1-3;
Age 18-85 years old;
Able to understand and consent to the trial and fully participate;

Key exclusion criteria (7 listed)

Epidural analgesia (field and fascial plane blocks permitted);
Pre-operative SpO2 <95%;
No wrist available for the study;
Severe hearing loss;
Lack of English language fluency.

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
Oxalert Monitor ModeThe investigator will evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO. Using the Oxalert in monitor only mode.	Device	Monitor only mode
Oxalert Normal modeThe investigator will evaluate the feasibility of a fully randomized validation trial for the Oxalert EPO using the Oxalert in monitor in normal mode	Device	Monitor in normal mode

Primary outcome

Time-weighted Average of SpO2 Below a Threshold of 90%
Time frame: during hospitalization up to 6 days and post-discharge 24 hours
Time-weighted average of SpO2 below a threshold of 90%. Oxygen Saturation measured between 0% - 100%. Oxygen Saturation <90% is considered abnormal.
Number of Participants With Desaturation Events (Saturation <90%) Lasting at Least 2 Min
Time frame: during hospitalization up to 6 days and post-discharge 24 hours
Number of Participants with Desaturation Events (Saturation <90%) Lasting at Least 2 Min. All the patients were included.
Duration of Desaturation Events (Saturation <90%) Lasting at Least 2 Min
Time frame: during hospitalization up to 6 days and post-discharge 24 hours
Duration of Desaturation Events (Saturation <90%) Lasting at Least 2 Mi. All desaturation events were included.
AUC of SpO2 Below a Threshold of 90%
Time frame: during hospitalization up to 6 days and post-discharge 24 hours
AUC of SpO2 Below a Threshold of 90%. SpO2 from 0% -100%.
Number of Desaturation Events (Saturation <90%) Lasting at Least 2 Min
Time frame: during hospitalization up to 6 days and post-discharge 24 hours
Number of desaturation events (Saturation <90%) Lasting at Least 2 Mi. All desaturation events were included.

2 secondary outcomes

Patients' Attitude Toward the Device
Time frame: At the day of discharge and after 24 hours of discharge
Nurses' Attitude Toward the Device
Time frame: Post-operative day 1 (POD 1)

Results and safety

Results posted to the registry on 20 Feb 2024, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Oxalert in Monitor Only Mode	24	23
Oxalert in Monitor in Normal Mode	25	24

Primary outcome: Time-weighted Average of SpO2 Below a Threshold of 90%

Time frame: during hospitalization up to 6 days and post-discharge 24 hours. Median (Inter-Quartile Range). Unit: % of SpO2

Measure	Oxalert in Monitor Only Mode n = 23	Oxalert in Monitor in Normal Mode n = 24
In hospital TWA SpO2 <90% (%)	0.29 (0.04 to 0.71)	0.11 (0.03 to 0.25)
Post-discharge TWA SpO2 <90% (%)	0.16 (0.04 to 0.81)	0.10 (0.04 to 0.32)

Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Median Difference (Final Values): -0.1 (95% CI -0.4 to 0), p = 0.120, Wilcoxon (Mann-Whitney)
Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Median Difference (Final Values): -407 (95% CI -1816 to 208), p = 0.349, Wilcoxon (Mann-Whitney)
Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Median Difference (Final Values): -0.1 (95% CI -0.2 to 0), p = 0.307, Wilcoxon (Mann-Whitney)

Population analysed: number of participants analyzed for in hospital outcome and post-discharge outcome are different

Primary outcome: Number of Participants With Desaturation Events (Saturation <90%) Lasting at Least 2 Min

Time frame: during hospitalization up to 6 days and post-discharge 24 hours. Count of participants. Unit: Participants

Measure	Oxalert in Monitor Only Mode n = 23	Oxalert in Monitor in Normal Mode n = 24
In hospital any event	20	21
Post-discharge any event	14	14

Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Risk Ratio (RR): 0.96 (95% CI 0.22 to 4.27), p >0.99, Fisher Exact
Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Risk Ratio (RR): 1.0 (95% CI 0.35 to 2.90), p >0.99, Chi-squared

Population analysed: number of participants analyzed for in hospital outcome and post-discharge outcome are different

Primary outcome: Duration of Desaturation Events (Saturation <90%) Lasting at Least 2 Min

Time frame: during hospitalization up to 6 days and post-discharge 24 hours. Median (Inter-Quartile Range). Unit: counts / minutes

Measure	Oxalert in Monitor Only Mode n = 23	Oxalert in Monitor in Normal Mode n = 24
In hospital Total duration	76 (3 to 531)	30 (7 to 145)
In hospital Duration> 2 min	34 (0.8 to 465)	8 (2 to 63)
In hospital Mean duration-all patients	4.7 (2.8 to 8.6)	2.7 (2.3 to 3.6)
In hospital Mean duration for events in those with any events	5.1 (3.5 to 8.7)	2.7 (2.6 to 3.7)
Post-discharge Duration	5 (0 to 70)	6 (0 to 12)

Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Median Difference (Final Values): -6.0 (95% CI -26.0 to 4.0), p = 0.354, Wilcoxon (Mann-Whitney)
Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Median Difference (Final Values): -46.1 (95% CI -274 to 5.1), p = 0.133, Wilcoxon (Mann-Whitney)
Oxalert in Monitor Only Mode vs Oxalert in Monitor in Normal Mode: Median Difference (Final Values): -24.1 (95% CI -213 to 0.1), p = 0.075, Wilcoxon (Mann-Whitney)

Population analysed: number of participants analyzed for in hospital outcome and post-discharge outcome are different

Primary outcome: AUC of SpO2 Below a Threshold of 90%

Time frame: during hospitalization up to 6 days and post-discharge 24 hours. Mean (Inter-Quartile Range). Unit: % * min

Measure	Monitor Only Mode n = 23	Monitor in Normal Mode n = 24
In hospital AUC	1260 (117 to 5278)	635 (204 to 1513)
Post-discharge AUC	130 (47 to 1038)	121 (27 to 428)

2 secondary outcomes are reported in the full results.

Adverse events

Time frame: During hospitalization up to13 days. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Oxalert in Monitor Only Mode	0 of 24 (0%)	3 of 24 (12.5%)	0 of 24
Oxalert in Monitor in Normal Mode	0 of 25 (0%)	2 of 25 (8%)	0 of 25

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 29 Aug 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 36583643Li K, Saab R, Bravo M, Mascha EJ, Han Y, Nault R, Olson L, Sessler DI. Wearable device for prevention of postoperative and post-discharge hypoxemia: A randomized pilot trial. Acta Anaesthesiol Scand. 2023 Apr;67(4):440-447. doi: 10.1111/aas.14193. Epub 2023 Jan 13.

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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.

Daniel Sessler, MD principal investigator

The Cleveland Clinic

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

An observational study of Non-cardiac Surgery, run by The Cleveland Clinic at 1 site in United States.

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 8 inclusion and 7 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 29 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. 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?

Yes. Results are posted in the registry (first posted 20 Feb 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Time-weighted Average of SpO2 Below a Threshold of 90% (time frame: during hospitalization up to 6 days and post-discharge 24 hours). The study lists 5 primary outcomes in all. 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 NCT04453722, 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 29 Aug 2025; AzTrials last refreshed its copy on 6 Nov 2026.