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HypoxemiaNCT04926649

HFLVV for Hypoxemia in Robot-assisted Cardiac Surgery

A study testing Differential ventilation to the non-dependent lung in people with Hypoxemia, run by Daping Hospital and the Research Institute of Surgery of the Third Military Medical University at 1 site in China.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial summary

These robot-assisted cardiac surgeries usually require single-lung ventilation (SLV) to facilitate surgical exposure. SLV creates ventilation/perfusion mismatch and shunt (Qs:Qt) through the collapsed lung and leads to hypoxemia. Read more about this study

Who is it for?
Ages 18 to 70 years
Conditions the study is for
Hypoxemia
What is being tested?
Differential ventilation to the non-dependent lung
Type of treatment
Surgery or procedure
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
56 participants
Where
1 siteChina
Study dates
1 Jun 2021to 15 Mar 2022
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 to 70 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • scheduled for robot-assisted cardiac surgery with cardiopulmonary bypass

Who cannot join

  • age <18 or > 70 years
  • PaO2/FiO2 ratio < 300 mmHg before anesthesia induction
  • American Society of Anesthesiologist (ASA) Grade > 3
  • Patients who were converted to conventional open-chest procedure

Trial locations and contacts

1 site in 1 country.

China1 site
  • Daping Hospital, Army Medical University

    Chongqing, Chongqing Municipality, 400042

Other trials in China

About this study

Official title: The High-frequency Low-volume Ventilation (HFLVV) for Hypoxemia During the Weaning From Cardiopulmonary Bypass in Robot-assisted Cardiac Surgery

These robot-assisted cardiac surgeries usually require single-lung ventilation (SLV) to facilitate surgical exposure. SLV creates ventilation/perfusion mismatch and shunt (Qs:Qt) through the collapsed lung and leads to hypoxemia. Pulmonary gas exchange often deteriorates after cardiopulmonary bypass (CPB) because of ischemic tissue damage. In some cases, severe hypoxemia may require the cessation of surgical procedures and the initiation of double-lung ventilation to improve oxygenation. In this study, the investigator applied the continuous positive airway pressure (CPAP) or the high-frequency low-volume ventilation (HFLVV) to the non-dependent lung (differential ventilation) during the weaning from CPB. The investigator hypothesized that the differential ventilation would produce the least interference with the surgeon's exposure and better oxygenation. The investigators evaluate the airway pressure, shunt fraction, PaO2/FiO2, cerebral oximetry, surgical field condition and the length of stay in intensive care unit of patients underwent the robot-assisted cardiac surgery.

Conditions
Hypoxemia
Being tested
Differential ventilation to the non-dependent lung
Medical subject headings
Hypoxia

What participants receive

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

  • Differential ventilation to the non-dependent lungProcedure or surgery

    When the hypoxemia occurs during sing lung ventilation in robot-assisted cardiac surgery, the non-dependent lung will be ventilated with normal tidal volume in conventional ways and the surgery procedure have to be ceased. In this trial, the non-dependent lung will be ventilated with the continuous positive airway pressure (CPAP) or the high-frequency low-volume ventilation (HFLVV) to prevent the hypoxemia.

Study groups in NCT04926649
Study groupRoleWhat they receive
Conventional ventilation groupSham comparatorConventional SLV and complementary with DLV when necessary. When SLV was initiated, the patient was ventilated with left lung. FiO2 of 1.0, tidal volume of 6ml/kg, respiratory rate of 16-24 bpm, PEEP of 5-10 cmH2O. The right lung was totally collapsed. If the SpO2 decreased lower than 90%, DLV was started and the operation was paused until the SpO2 increased to 100%. Then the operation was restarted.
Receives: Procedure: Differential ventilation to the non-dependent lung
CPAP groupActive comparatorSLV of left lung and CPAP of right lung, and complementary with DLV when necessary. When SLV was initiated, the patient was ventilated with left lung. FiO2 of 1.0, tidal volume of 6ml/kg, respiratory rate of 16-24 bpm, PEEP of 5-10 cmH2O. After the right lung was totally collapsed, CPAP was started with the pressure less than 8 cmH2O. If SpO2 decreased lower than 90%, DLV was started and the operation was paused until the SpO2 increased to 100%. Then the operation was restarted.
Receives: Procedure: Differential ventilation to the non-dependent lung
HFLVV groupExperimentalSLV of left lung and HFLVV of right lung, and complementary with DLV when necessary. When SLV was initiated, the patient was ventilated with left lung. FiO2 of 1.0, tidal volume of 6ml/kg, respiratory rate of 16-24 bpm, PEEP of 5-10 cmH2O. After the right lung was totally collapsed, HFLVV was started with tidal volume of 2ml/kg, respiratory rate of 60 bpm. If SpO2 decreased lower than 90%, DLV was started and the operation was paused until the SpO2 increased to 100%. Then the operation was restarted.
Receives: Procedure: Differential ventilation to the non-dependent lung

What is being measured

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

  1. Changes of arterial PaO2

    Arterial PaO2 (in mmHg) defined as a measurement of partial pressure of oxygen in arterial blood

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  2. Changes of PaO2/FiO2 ratio

    PaO2/FiO2 ratio defined as the ratio of PaO2 to fractional inspired oxygen (FiO2 expressed as a fraction)

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

Secondary outcomes (12)
  1. Changes of Heart rate

    Heart rate in beat per minute

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV

  2. Changes of mean blood pressure

    mean blood pressure in mmHg

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  3. Changes of cardiac stroke volume variation

    Cardiac stroke volume variation in percentages

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  4. Changes of venous pressure of jugular vein

    Venous pressure of jugular vein in cmH2O

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  5. Changes of tidal volume

    Tidal volume of both lungs in milliliter

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  6. Changes of respiratory rates

    Respiratory rates of both lungs in breath per minute

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  7. Changes of airway pressure

    Airway pressure of both lungs in mmHg

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  8. Changes of end-tidal carbon dioxide tension

    End-tidal carbon dioxide tension in mmHg

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  9. Changes of blood oxygen saturation

    Blood oxygen saturation of both upper and lower extremities in percentages

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  10. Changes of the pulmonary shunt fraction

    Qs/Qt = ((CcO2 - CaO2) / (CcO2 - CvO2)) * 100

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  11. Changes of regional cerebral oxygen saturation

    regional cerebral oxygen saturation in percentages

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

  12. Changes of the surgical field

    The surgeon's evaluation of the surgical field, graded from 0 (no interference) to 3 (maximal interference)

    Measured: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]

Timeline

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

  1. First posted15 Jun 2021
  2. Study start1 Jun 2021
  3. Primary completion15 Dec 2021 (estimated)
  4. Study completion15 Mar 2022 (estimated)

Resources

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
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
56 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04926649
Sponsor's protocol ID
2021-59
Status last verified
Jun 2021
First submitted
31 May 2021
Last updated
15 Jun 2021
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Kremer R, Aboud W, Haberfeld O, Armali M, Barak M. Differential lung ventilation for increased oxygenation during one lung ventilation for video assisted lung surgery. J Cardiothorac Surg. 2019 May 6;14(1):89. doi: 10.1186/s13019-019-0910-2.

    PubMed 31060627

Questions about this trial

What is this clinical trial studying?

A study testing Differential ventilation to the non-dependent lung in people with Hypoxemia, run by Daping Hospital and the Research Institute of Surgery of the Third Military Medical University at 1 site in China.

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 1 inclusion and 4 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: status not confirmed, as of the sponsor's last update on 15 Jun 2021. 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 China. 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. Some participants in this study may receive a placebo. 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?

Results are not available in the source record.

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?

Changes of arterial PaO2 (time frame: 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV]). The study lists 2 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 NCT04926649, 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 15 Jun 2021; AzTrials last refreshed its copy on 6 Nov 2026.

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