PregnancyNCT07515716
Effects of High Flow Humidified Oxygen on Umbilical Artery Acid-base Balance in Cesarean Section Under Spinal Anesthesia
A study testing high-flow nasal oxygen and conventional nasal cannula oxygen in people with Pregnancy and Cesarean Section, run by Yonsei University.
Trial summary
Spinal anesthesia is the most commonly used anesthetic technique for cesarean section in developed countries, but vasodilation and a decrease in systemic vascular resistance caused by sympathetic blockade result in hypotension in 7-74% of parturients. Read more about this study
- Who is it for?
- Ages 20 years and older, women only
- Conditions the study is for
- Pregnancy, Cesarean Section, Spinal Anesthesia
- What is being tested?
- high-flow nasal oxygen and conventional nasal cannula oxygen
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 200 participants
- Where
- No sites listed yet
- Study dates
- 7 Apr 2026to 31 Mar 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 20 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Pregnant women aged 20 years or older with American Society of Anesthesiologists (ASA) physical status class 2-3 who are scheduled to undergo cesarean section under spinal anesthesia.
Who cannot join
- Emergency surgery B. Patients in whom massive hemorrhage is anticipated, such as those with placenta previa C. Multiple pregnancy, preterm birth at less than 36 weeks of gestation, intrauterine growth restriction, or fetal anomalies D. History of hospitalization for preterm labor within the past 4 weeks requiring tocolytic therapy E. Respiratory diseases requiring oxygen therapy (e.g., moderate or severe asthma, chronic obstructive pulmonary disease) F. Individuals who are unable to read the consent form (e.g., illiterate individuals or foreigners who cannot read Korean)
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: The Effectiveness of Binaural Beats on Midazolam Requirement During Cesarean Section With Spinal Anesthesia
Spinal anesthesia is the most commonly used anesthetic technique for cesarean section in developed countries, but vasodilation and a decrease in systemic vascular resistance caused by sympathetic blockade result in hypotension in 7-74% of parturients. The fetus receives oxygen from the mother via uteroplacental blood flow, and because uteroplacental circulation during pregnancy has minimal autoregulation, uterine blood flow changes in proportion to maternal blood pressure. Therefore, a reduction in uterine blood flow due to maternal hypotension can lead to fetal hypoxia or acidosis and is associated with low Apgar scores after birth.
Oxygen administration may offer potential benefits, such as improving maternal cerebral perfusion and preventing fetal ischemic injury, and thus low-flow oxygen via a conventional nasal cannula is commonly used. However, there are few studies evaluating the effects of high-flow oxygen administration on fetal well-being during cesarean section under spinal anesthesia. Low-flow oxygen delivery through a conventional nasal cannula, which is commonly used during cesarean section under spinal anesthesia, results in a fraction of inspired oxygen (FiO₂) of less than 40% due to dilution with ambient air. In contrast, OptiFlow THRIVE (Fisher and Paykel Healthcare, Panmure, Auckland, New Zealand) is a device capable of delivering high-flow oxygen through a nasal interface, allowing administration of 100% oxygen to the mother and potentially providing greater protection against fetal ischemic injury. Delivering non-humidified oxygen at flow rates above 10 L/min causes significant discomfort in awake patients, but OptiFlow THRIVE passes the gas through a heated humidification chamber immediately before delivery, enabling the administration of warmed and humidified oxygen even at high flow rates. Therefore, this study aims to compare high-flow nasal cannula oxygen therapy initiated upon operating room admission with conventional low-flow nasal cannula oxygen therapy during cesarean section under spinal anesthesia, assessing their effects on maternal hemodynamic parameters and, ultimately, on fetal acid-base status.
- Conditions
- Pregnancy, Cesarean Section, Spinal Anesthesia
- Being tested
- high-flow nasal oxygen, conventional nasal cannula oxygen
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
high-flow nasal oxygenDevice
All patients will, upon admission to the operating room, be placed in the supine position and connected to standard monitoring. Once patient monitoring has been completed, patients in the high-flow nasal cannula oxygen group will receive 100% oxygen at 50 L/min via OptiFlow THRIVE. Thereafter, patients will be placed in the left lateral decubitus position, and spinal anesthesia will be performed at the lower lumbar level.
conventional nasal cannula oxygenDevice
All patients will, upon admission to the operating room, be placed in the supine position and connected to standard monitoring. Once patient monitoring has been completed, patients in the conventional nasal cannula oxygen group will receive oxygen at 2 L/min via a nasal cannula. Thereafter, patients will be placed in the left lateral decubitus position, and spinal anesthesia will be performed at the lower lumbar level.
| Study group | Role | What they receive |
|---|---|---|
| high-flow nasal oxygen group | Experimental | The group receiving oxygen via a high-flow nasal cannula Receives: Device: high-flow nasal oxygen |
| conventional nasal cannula oxygen group | Active comparator | The group receiving oxygen via a conventional nasal cannula Receives: Device: conventional nasal cannula oxygen |
What is being measured
The primary outcome is the main question the study is designed to answer.
umbilical arterial base deficit measured immediately after birth.
The attending obstetrician will obtain an umbilical arterial blood sample using a needle immediately after birth (immediately after umbilical cord clamping).
Measured: Immediately after birth (i.e., approximately 1 minute after umbilical cord clamping)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Apr 2026
- Study start7 Apr 2026 (estimated)
- Primary completion31 Mar 2027 (estimated)
- Study completion31 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PregnancyStudies of the same condition, open and under way.
- More trials run by Yonsei UniversityThe 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
- Supportive care
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Yonsei University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07515716
- Sponsor's protocol ID
- 4-2025-1105
- Status last verified
- Mar 2026
- First submitted
- 31 Mar 2026
- Last updated
- 7 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effectiveness of Binaural Beats on Midazolam Requirement During Cesarean Section With Spinal Anesthesia
- ClinicalTrials.gov ID
- NCT07515716
- Acronym / sponsor ID
- 4-2025-1105
- Conditions
- Pregnancy, Cesarean Section, Spinal Anesthesia
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Yonsei UniversityUniversity, hospital or other
- Study start
- 7 Apr 2026 (estimated)
- Primary completion
- 31 Mar 2027 (estimated)
- Study completion
- 31 Mar 2027 (estimated)
- First posted
- 7 Apr 2026 (actual)
- 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.
Spinal anesthesia is the most commonly used anesthetic technique for cesarean section in developed countries, but vasodilation and a decrease in systemic vascular resistance caused by sympathetic blockade result in hypotension in 7-74% of parturients. The fetus receives oxygen from the mother via uteroplacental blood flow, and because uteroplacental circulation during pregnancy has minimal autoregulation, uterine blood flow changes in proportion to maternal blood pressure. Therefore, a reduction in uterine blood flow due to maternal hypotension can lead to fetal hypoxia or acidosis and is associated with low Apgar scores after birth.
Oxygen administration may offer potential benefits, such as improving maternal cerebral perfusion and preventing fetal ischemic injury, and thus low-flow oxygen via a conventional nasal cannula is commonly used. However, there are few studies evaluating the effects of high-flow oxygen administration on fetal well-being during cesarean section under spinal anesthesia. Low-flow oxygen delivery through a conventional nasal cannula, which is commonly used during cesarean section under spinal anesthesia, results in a fraction of inspired oxygen (FiO₂) of less than 40% due to dilution with ambient air. In contrast, OptiFlow THRIVE (Fisher and Paykel Healthcare, Panmure, Auckland, New Zealand) is a device capable of delivering high-flow oxygen through a nasal interface, allowing administration of 100% oxygen to the mother and potentially providing greater protection against fetal ischemic injury. Delivering non-humidified oxygen at flow rates above 10 L/min causes significant discomfort in awake patients, but OptiFlow THRIVE passes the gas through a heated humidification chamber immediately before delivery, enabling the administration of warmed and humidified oxygen even at high flow rates. Therefore, this study aims to compare high-flow nasal cannula oxygen therapy initiated upon operating room admission with conventional low-flow nasal cannula oxygen therapy during cesarean section under spinal anesthesia, assessing their effects on maternal hemodynamic parameters and, ultimately, on fetal acid-base status.
Study design
- Primary purpose
- Supportive care
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| high-flow nasal oxygen group | Experimental | Device: high-flow nasal oxygenThe group receiving oxygen via a high-flow nasal cannula |
| conventional nasal cannula oxygen group | Active comparator | Device: conventional nasal cannula oxygenThe group receiving oxygen via a conventional nasal cannula |
Who may qualify
- Ages
- 20 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Pregnant women aged 20 years or older with American Society of Anesthesiologists (ASA) physical status class 2-3 who are scheduled to undergo cesarean section under spinal anesthesia.
Key exclusion criteria (1 listed)
- Emergency surgery B. Patients in whom massive hemorrhage is anticipated, such as those with placenta previa C. Multiple pregnancy, preterm birth at less than 36 weeks of gestation, intrauterine growth restriction, or fetal anomalies D. History of hospitalization for preterm labor within the past 4 weeks requiring tocolytic therapy E. Respiratory diseases requiring oxygen therapy (e.g., moderate or severe asthma, chronic obstructive pulmonary disease) F. Individuals who are unable to read the consent form (e.g., illiterate individuals or foreigners who cannot read Korean)
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 |
|---|---|---|
| high-flow nasal oxygenAll patients will, upon admission to the operating room, be placed in the supine position and connected to standard monitoring. Once patient monitoring has been completed, patients in the high-flow nasal cannula oxygen group will receive 100% oxygen at 50 L/min via OptiFlow THRIVE. Thereafter, patients will be placed in the left lateral decubitus position, and spinal anesthesia will be performed at the lower lumbar level. | Device | high-flow nasal oxygen group |
| conventional nasal cannula oxygenAll patients will, upon admission to the operating room, be placed in the supine position and connected to standard monitoring. Once patient monitoring has been completed, patients in the conventional nasal cannula oxygen group will receive oxygen at 2 L/min via a nasal cannula. Thereafter, patients will be placed in the left lateral decubitus position, and spinal anesthesia will be performed at the lower lumbar level. | Device | conventional nasal cannula oxygen group |
Primary outcome
umbilical arterial base deficit measured immediately after birth.
Time frame: Immediately after birth (i.e., approximately 1 minute after umbilical cord clamping)
The attending obstetrician will obtain an umbilical arterial blood sample using a needle immediately after birth (immediately after umbilical cord clamping).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Apr 2026.
- Individual participant dataSharing planned: No
Related trials for Pregnancy
Recruiting
Methylation Profiling in Self-Samples for Identification of (Epi)Genetic Biomarkers for Gynecological Cancers
Gynaecological Cancers, Ovarian Cancer
RecruitingPhase 1/2
Study of INBRX-106 and INBRX-106 in Combination With Pembrolizumab (Keytruda®) in Subjects With Locally Advanced or Metastatic Solid Tumors (Hexavalent OX40 Agonist)
Solid Tumor, Non-Small Cell Lung Cancer
RecruitingObservational study
Population Pharmacokinetics of Temocillin in Acute Enterobacterial Pyelonephritis in Children
Pyelonephritis
Active, not recruitingPhase 3
A Study of Belzutifan (MK-6482) in Combination With Lenvatinib Versus Cabozantinib for Treatment of Renal Cell Carcinoma (MK-6482-011)
Carcinoma, Renal Cell
Recruiting
Safety and Performance of UCon Patch Electrode
Urinary Incontinence, Urinary Incontinence, Urge
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.
Questions about this trial
What is this clinical trial studying?
A study testing high-flow nasal oxygen and conventional nasal cannula oxygen in people with Pregnancy and Cesarean Section, run by Yonsei University.
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 1 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: opening soon, as of the sponsor's last update on 7 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Seung Hyun Kim, Professor (82-10-3292-2351, anesshkim@yuhs.ac), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
umbilical arterial base deficit measured immediately after birth. (time frame: Immediately after birth (i.e., approximately 1 minute after umbilical cord clamping)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 7 Apr 2026; AzTrials last refreshed its copy on 8 Nov 2026.