The Effect of Arterial Carbon Dioxide Levels on Cerebral Blood Flow and Cerebral Autoregulation in the Steep Trendelenburg Position During Robot-assisted Prostatectomy, and Its Effect on Postoperative Cognition
NCT ID: NCT06865027
Last Updated: 2025-12-29
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
ENROLLING_BY_INVITATION
NA
46 participants
INTERVENTIONAL
2025-01-24
2026-09-30
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
The investigators will assess whether different concentrations of carbon dioxide in blood results in different brain blood flow levels and different intracranial pressure during laparascopic surgery in the head-down tilted position. The investigators also will assess if different carbon dioxide level will manifest in different cognitive abilities in the two study groups, measured on day 1 post-surgery.
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
Anesthesia and surgery will proceed as usual, with the exception that the respiratory support the participants receive during the surgery will be adjusted as described below. The participants will receive standard monitoring of heart rate, blood pressure, and blood oxygen levels. Before surgery, the anesthesia team will per routine insert two plastic cannulas into the left arm for administering medication, and a plastic cannula into the participant's left wrist for close monitoring of the participant's blood pressure.
Study participants will undergo four additional steps:
1. Before surgery, an anesthesiologist will insert a thin plastic cannula into a superficial vein on the side of the neck. The cannula is the same type as the ones used on the arm and has a diameter of 1.1 mm. The purpose of this cannula is to measure the pressure of the blood returning from the brain to the heart. The procedure involves brief, moderate pain associated with the needle insertion. The plastic cannula will be removed before the participant wakes up from anesthesia.
2. Just before and during surgery, a trained anesthesiologist will perform ultrasound measurements on the right side of the participant's neck, temple, and the outside of the eyelid. Each measurement lasts 4-5 minutes. This will not prolong the time spent in the operating room. The measurements will cause no discomfort.
3. All patients undergoing prostate removal with robotic surgery receive respiratory support with a ventilator during anesthesia. In this study, the investigators will adjust the ventilator to control the carbon dioxide (CO2) levels towards either the lower or upper normal range for CO2. A blinded randomization will determine the group assignment. Regardless of which group a participant is assigned to, their CO2 level will be maintained within a range routinely used during anesthesia and considered completely safe.
In the project, the investigators will collect and record participant information. The investigators will store recordings of the participants' pulse, blood pressure, breathing depth and rhythm, levels of oxygen and CO2 in the participants' blood, medication doses used during surgery, and results of blood tests taken during surgery. From the participants' medical records, the investigators will retrieve and record the participants' age, gender, height, weight, whether the participants have chronic diseases, and which regular medications the participants use.
Cognitive tests of reaction time and problem-solving abilities will be administered a few days before and one day after surgery.
Receiving information about an illness, undergoing a surgical procedure, receiving general anesthesia, peroperative CO2 levels, body position during robotic surgery, and postoperative pain medication all affect the body physically and may trigger stress and anxiety. The investigators want to assess this impact using a well-established method that tests reaction time through five exercises on an iPad. The method has been developed for use in patients. Those participating in the study will be asked to perform this test at the outpatient clinic a few days before surgery and one day after surgery.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Keywords
Explore important study keywords that can help with search, categorization, and topic discovery.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
RANDOMIZED
PARALLEL
PREVENTION
TRIPLE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Hypercapnia
PaCO2: 6.4-7.0 kPa
Ventilation strategy
The selected PaCO2 targets are:
Normocapnia: PaCO2: 5.0-5.5 kPa Hypercapnia: PaCO2: 6.4-7.0 kPa
The adjustments on the ventilator needed to achieve these targets will be administered by the anesthetic nurse and attending anesthesiologist and held within the following limitations:
Tidal volume: 4 - 8ml ml/kg IBW Inspiratory pressure 5-30 cm H2O Respiration rate 10-18 per minute PEEP 5-10 mmHg
\*IBW: 50 + 0.91 (height in centimeters - 152.4) Peep, I:E ratio, and FiO2 will be administered at the anesthetic nurse's and the anesthesiologist's discretion.
Normocapnia
PaCO2: 5.0-5.5 kPa
Ventilation strategy
The selected PaCO2 targets are:
Normocapnia: PaCO2: 5.0-5.5 kPa Hypercapnia: PaCO2: 6.4-7.0 kPa
The adjustments on the ventilator needed to achieve these targets will be administered by the anesthetic nurse and attending anesthesiologist and held within the following limitations:
Tidal volume: 4 - 8ml ml/kg IBW Inspiratory pressure 5-30 cm H2O Respiration rate 10-18 per minute PEEP 5-10 mmHg
\*IBW: 50 + 0.91 (height in centimeters - 152.4) Peep, I:E ratio, and FiO2 will be administered at the anesthetic nurse's and the anesthesiologist's discretion.
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
Ventilation strategy
The selected PaCO2 targets are:
Normocapnia: PaCO2: 5.0-5.5 kPa Hypercapnia: PaCO2: 6.4-7.0 kPa
The adjustments on the ventilator needed to achieve these targets will be administered by the anesthetic nurse and attending anesthesiologist and held within the following limitations:
Tidal volume: 4 - 8ml ml/kg IBW Inspiratory pressure 5-30 cm H2O Respiration rate 10-18 per minute PEEP 5-10 mmHg
\*IBW: 50 + 0.91 (height in centimeters - 152.4) Peep, I:E ratio, and FiO2 will be administered at the anesthetic nurse's and the anesthesiologist's discretion.
Other Intervention Names
Discover alternative or legacy names that may be used to describe the listed interventions across different sources.
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Exclusion Criteria
* Emphysema of the lung.
* Previous spontaneous pneumothorax.
* Cerebrovascular disease. Including but not limited to previous SAH, EDH, SDH, hemorrhage from AVM, known AVM and stenosis in carotid or cerebral arteries.
* Intracranial malignancy or metastases from primary cancer.
* Significant cardiovascular disease (NYHA class III or IV).
* Renal failure grade 4 or 5 (estimated GFR \<30).
* Anatomical hinders for performing ultrasound of the right carotid artery or middle cerebral artery.
* Primary language other than Scandinavian.
* Diagnosed dementia of any subtype.
55 Years
80 Years
MALE
No
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
University of Oslo
OTHER
University Hospital, Akershus
OTHER
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Signe Søvik
Professor, Senior Consultant, PhD
Principal Investigators
Learn about the lead researchers overseeing the trial and their institutional affiliations.
Signe Søvik, Professor, MD, PhD
Role: STUDY_DIRECTOR
University Hospital, Akershus
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Akershus University Hospital
Lørenskog, , Norway
Countries
Review the countries where the study has at least one active or historical site.
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
2022088
Identifier Type: OTHER_GRANT
Identifier Source: secondary_id
REK:744921
Identifier Type: -
Identifier Source: org_study_id