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Cerebral Hemodynamic Effects of Individualized PEEP During Robotic Prostatectomy

23. august 2026 oppdatert av: Ezgi Budak Ozyalcın, Istanbul University

Comparison of the Effects of Individualized PEEP Titration Versus Standard PEEP on Transcranial Doppler-Measured Cerebral Hemodynamic Parameters and Postoperative Neurocognitive Functions in Patients Undergoing Robotic Prostatectomy in the Trendelenburg Position

This randomized clinical trial will compare two approaches to setting positive end-expiratory pressure (PEEP) during robot-assisted radical prostatectomy performed in the Trendelenburg position. The study aims to determine whether individualized PEEP, selected according to the lowest driving pressure, affects cerebral blood flow and brain oxygenation differently from standard PEEP.

Approximately 45 adult patients undergoing robot-assisted radical prostatectomy will be randomly assigned to receive either individualized PEEP or standard PEEP during general anesthesia. Cerebral blood flow will be assessed noninvasively using transcranial Doppler ultrasound, and brain oxygenation will be monitored using near-infrared spectroscopy. Participants will also undergo brief assessments of attention, cognitive function, delirium, and sedation before and after surgery, with follow-up continuing for up to 48 hours after the operation.

Both ventilation approaches are routinely used in clinical practice, and no experimental drug, device, or additional invasive procedure will be used as part of the study.

Studieoversikt

Status

Har ikke rekruttert ennå

Forhold

Intervensjon / Behandling

Detaljert beskrivelse

This single-center, prospective, randomized, parallel-group clinical trial will evaluate the effects of individualized positive end-expiratory pressure (PEEP) titration compared with standard fixed PEEP on cerebral hemodynamics during robot-assisted laparoscopic radical prostatectomy performed in steep Trendelenburg position with pneumoperitoneum.

Approximately 45 adult patients aged 18-80 years with American Society of Anesthesiologists (ASA) physical status I-III who are scheduled for robot-assisted laparoscopic radical prostatectomy will be randomized in a 1:1 ratio to either an individualized PEEP group or a standard PEEP group. All patients will receive standardized general anesthesia and volume-controlled ventilation. Ventilation will initially be set with a tidal volume of 8 mL/kg predicted body weight, an inspiratory-to-expiratory ratio of 1:2, and an inspired oxygen fraction of 0.40, with end-tidal carbon dioxide maintained at 35-40 mmHg.

In the standard PEEP group, PEEP will be maintained at 6 cmH2O following a recruitment maneuver. In the individualized PEEP group, a decremental PEEP titration will be performed after recruitment. PEEP will be decreased from 15 to 5 cmH2O in 1-cmH2O steps, and respiratory mechanics will be assessed after 12 respiratory cycles at each level. The PEEP level associated with the lowest driving pressure will be selected as the individualized PEEP and maintained during the relevant intraoperative period.

Cerebral hemodynamics will be assessed using transcranial Doppler ultrasonography of the middle cerebral artery. Pulsatility index and resistance index will be recorded, and noninvasive estimated intracranial pressure will be calculated from the pulsatility index using the formula nICPPI = 10.93 × PI - 1.28. Transcranial Doppler measurements will be performed after anesthesia induction, 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum, and 10 minutes after termination of Trendelenburg position and pneumoperitoneum before emergence from anesthesia.

The primary outcome will be the between-group difference in the change in noninvasive estimated intracranial pressure from the post-induction measurement to the measurement obtained 60 minutes after initiation of Trendelenburg position and pneumoperitoneum (ΔnICPPI, T4-T2). Secondary assessments will include cerebral oxygenation measured using near-infrared spectroscopy, additional transcranial Doppler parameters, intraoperative hemodynamic and respiratory variables, and postoperative neurocognitive outcomes.

Postoperative attention and cognitive status will be assessed using the Months of the Year Backwards Test, delirium using the Nursing Delirium Screening Scale, and sedation/agitation using the Richmond Agitation-Sedation Scale. These assessments will be performed at predefined postoperative time points for up to 48 hours. Additional postoperative cognitive and delirium assessments will include the Mini-Mental State Examination and 3D-Confusion Assessment Method. The transcranial Doppler operator and postoperative outcome assessors will be blinded to group allocation, while the anesthesiologist performing the PEEP intervention cannot be blinded.

Studietype

Intervensjonell

Registrering (Antatt)

45

Fase

  • Ikke aktuelt

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiekontakt

Studiesteder

  • Tyrkia (Türkiye)
      • Istanbul, Tyrkia (Türkiye), 34077
        • Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine
        • Ta kontakt med:
        • Underetterforsker:
          • Onur Kökçü
        • Hovedetterforsker:
          • Ezgi Budak Özyalçın

Deltakelseskriterier

Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.

Kvalifikasjonskriterier

Alder som er kvalifisert for studier

  • Voksen
  • Eldre voksen

Tar imot friske frivillige

Nei

Beskrivelse

Inclusion Criteria:

  • Age 18 to 80 years American Society of Anesthesiologists (ASA) physical status I-III Scheduled for robot-assisted laparoscopic radical prostatectomy Provision of written informed consent

Exclusion Criteria:

  • Body mass index (BMI) >35 kg/m² History of surgery requiring at least 1 hour of mechanical ventilation within the previous 2 weeks Severe pulmonary disease New York Heart Association (NYHA) class III-IV heart failure Progressive neuromuscular disease Known cerebrovascular malformation Head or neck anatomical conditions preventing adequate transcranial Doppler ultrasonography Refusal to participate in the study Intraoperative conversion to open surgery

Studieplan

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Designdetaljer

  • Primært formål: Grunnvitenskap
  • Tildeling: Randomisert
  • Intervensjonsmodell: Parallell tildeling
  • Masking: Trippel

Våpen og intervensjoner

Deltakergruppe / Arm
Intervensjon / Behandling
Eksperimentell: Individualized PEEP Group
Patients assigned to this group will undergo a recruitment maneuver followed by decremental PEEP titration from 15 to 5 cmH2O in 1-cmH2O steps. After 12 respiratory cycles at each PEEP level, the PEEP associated with the lowest driving pressure will be selected and maintained.
Annen: Individualized PEEP Titration
Following a recruitment maneuver, PEEP will be decreased from 15 to 5 cmH2O in 1-cmH2O steps. Respiratory mechanics will be assessed after 12 respiratory cycles at each step, and the PEEP level producing the lowest driving pressure will be selected as the individualized PEEP and maintained.
Andre navn:
  • Driving Pressure-Guided PEEP
Aktiv komparator: Standard PEEP Group
Patients assigned to this group will undergo a recruitment maneuver followed by standard fixed PEEP of 6 cmH2O during mechanical ventilation.
Annen: Standard PEEP Group
Following a recruitment maneuver, PEEP will be maintained at a fixed level of 6 cmH2O during mechanical ventilation.

Hva måler studien?

Primære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
Change in Noninvasive Estimated Intracranial Pressure
Tidsramme: After anesthesia induction and 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum
Noninvasive estimated intracranial pressure (nICPPI), expressed in mmHg, will be calculated from the middle cerebral artery pulsatility index (PI) measured by transcranial Doppler ultrasonography using the formula nICPPI = 10.93 × PI - 1.28. The outcome is the change in nICPPI from after anesthesia induction to 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum, calculated as the later value minus the post-induction value.
After anesthesia induction and 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum

Sekundære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
Middle Cerebral Artery Pulsatility Index
Tidsramme: After anesthesia induction; 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum; and 10 minutes after termination of Trendelenburg position and pneumoperitoneum, before emergence from anesthesia
Middle cerebral artery pulsatility index (PI) will be measured using transcranial Doppler ultrasonography. PI is a dimensionless index derived from the cerebral arterial blood flow velocity waveform. PI values will be recorded at each predefined assessment time point.
After anesthesia induction; 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum; and 10 minutes after termination of Trendelenburg position and pneumoperitoneum, before emergence from anesthesia
Middle Cerebral Artery Resistance Index
Tidsramme: After anesthesia induction; 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum; and 10 minutes after termination of Trendelenburg position and pneumoperitoneum, before emergence from anesthesia
Middle cerebral artery resistance index (RI) will be measured using transcranial Doppler ultrasonography. RI is a dimensionless index derived from the cerebral arterial blood flow velocity waveform. RI values will be recorded at each predefined assessment time point.
After anesthesia induction; 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum; and 10 minutes after termination of Trendelenburg position and pneumoperitoneum, before emergence from anesthesia
Regional Cerebral Oxygen Saturation Measured by Near-Infrared Spectroscopy
Tidsramme: Before anesthesia induction; after anesthesia induction; 30 and 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum; immediately before termination of Trendelenburg position; and 10 minutes after termination, before emergence
Regional cerebral oxygen saturation (rSO2) will be measured using bilateral frontal near-infrared spectroscopy (NIRS) and expressed as a percentage (%). Left and right frontal rSO2 values will be recorded separately at each predefined intraoperative assessment time point.
Before anesthesia induction; after anesthesia induction; 30 and 60 minutes after initiation of steep Trendelenburg position and pneumoperitoneum; immediately before termination of Trendelenburg position; and 10 minutes after termination, before emergence
Months Backward Test Performance Score
Tidsramme: Preoperatively and at 12, 24, 36, and 48 hours after surgery
Attention and cognitive performance will be assessed using the Months Backward Test (MBT), in which participants are asked to recite the months of the year in reverse order. Performance will be rated using the detailed 0-to-10-point grading system described by Meagher et al. Higher scores indicate better test performance, based on the participant's ability to understand and engage with the task, sustain and shift attention, complete the reverse sequence, recognize or correct errors, complete the test without errors, and complete the task within the specified time.
Preoperatively and at 12, 24, 36, and 48 hours after surgery
Nursing Delirium Screening Scale Total Score
Tidsramme: In the post-anesthesia care unit or intensive care unit, and at 12, 24, 36, and 48 hours after surgery
Postoperative delirium symptoms will be assessed using the Nursing Delirium Screening Scale (NuDESC). The NuDESC total score ranges from 0 to 10 points, with higher scores indicating greater delirium symptom severity. The outcome will be reported as the NuDESC total score in points at each assessment.
In the post-anesthesia care unit or intensive care unit, and at 12, 24, 36, and 48 hours after surgery
Richmond Agitation-Sedation Scale Score
Tidsramme: In the post-anesthesia care unit or intensive care unit, and at 12, 24, 36, and 48 hours after surgery
Sedation and agitation will be assessed using the Richmond Agitation-Sedation Scale (RASS). The RASS score ranges from -5 (unarousable) to +4 (combative), with 0 indicating an alert and calm state. The outcome will be reported as the RASS score in points at each assessment.
In the post-anesthesia care unit or intensive care unit, and at 12, 24, 36, and 48 hours after surgery

Samarbeidspartnere og etterforskere

Det er her du vil finne personer og organisasjoner som er involvert i denne studien.

Sponsor

Istanbul University

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart (Antatt)

19. august 2026

Primær fullføring (Antatt)

19. november 2026

Studiet fullført (Antatt)

30. november 2026

Datoer for studieregistrering

Først innsendt

18. august 2026

Først innsendt som oppfylte QC-kriteriene

23. august 2026

Først lagt ut (Faktiske)

25. august 2026

Oppdateringer av studieposter

Sist oppdatering lagt ut (Faktiske)

25. august 2026

Siste oppdatering sendt inn som oppfylte QC-kriteriene

23. august 2026

Sist bekreftet

1. august 2026

Mer informasjon

Begreper knyttet til denne studien

Nøkkelord

Andre studie-ID-numre

  • E-24687260-604.01-1662792

Plan for individuelle deltakerdata (IPD)

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NEI

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Studerer et amerikansk FDA-regulert medikamentprodukt

Nei

Studerer et amerikansk FDA-regulert enhetsprodukt

Nei

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