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

NCT06865027 | Enrolling By Invitation

• 2 other identifiers: REK:7449212022088
• Study Type: interventional
• Target: 46
• Locations: 1 country
• Sites: 1

Brief Summary

Patients scheduled for robot-assisted prostatectomy will be randomized to either high or low concentrations of carbon dioxide in the blood. This will be managed by applying different ventilation strategies during anesthesia.The levels will be distinctly different. 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.

Conditions

Circulation System; Intracranial Pressure; Cerebral Perfusion Pressure; Cognitive Function

Keywords

RALP surgery; Postoperative cognitive disorder; Cerebral perfusion pressure; Cerebral circulation; Cerebral autoregulation; Trendelenburg position; Robot-assisted laparoscopic prostatectomy; Transcranial Doppler ultrasound

Outcome Measures

Primary Outcomes (1)

• ICA flow

  Changes in cerebral blood flow (ml/s) during surgery

  day of surgery

Secondary Outcomes (3)

• Cognitive performance

  5 days pre-surgery and 1 day post-surgery

• Cerebral perfusion pressure

  Day of surgery

• Cardiac index (L/min)

  Day of surgery

Study Arms (2)

Hypercapnia

OTHER

PaCO2: 6.4-7.0 kPa

Other: Ventilation strategy

Normocapnia

OTHER

PaCO2: 5.0-5.5 kPa

Other: Ventilation strategy

Interventions

Ventilation strategy OTHER

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.

Also known as: normocapnia, hypercapnia

Hypercapnia; Normocapnia

Eligibility Criteria

• Age: 55 Years - 80 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may not qualify if:

• Poorly controlled hypertension (resting BP \>165/90 on pre-study consult).
• 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.

Sponsors & Collaborators

• University Hospital, Akershus: lead
• University of Oslo: collaborator

Study Sites (1)

Akershus University Hospital

Lørenskog, 1478, Norway

Location

MeSH Terms

Conditions

Postoperative Cognitive Complications

Condition Hierarchy (Ancestors)

Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Cognitive Dysfunction; Cognition Disorders; Neurocognitive Disorders; Mental Disorders

Study Officials

• Signe Søvik, Professor, MD, PhD

  University Hospital, Akershus

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The participant and investigator are blinded. The anesthesia providers are not blinded.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor, Senior Consultant, PhD

Model Details: Clinical double blinded randomized interventional study

Study Record Dates

• First Submitted: February 26, 2025
• First Posted: March 7, 2025
• Study Start: January 24, 2025
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): September 30, 2026
• Last Updated: December 29, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

NO (1)