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Cerebral Hemodynamic Effects of Individualized PEEP During Robotic Prostatectomy

23 de agosto de 2026 atualizado por: 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.

Visão geral do estudo

Descrição detalhada

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.

Tipo de estudo

Intervencional

Inscrição (Estimado)

45

Estágio

  • Não aplicável

Contactos e Locais

Esta seção fornece os detalhes de contato para aqueles que conduzem o estudo e informações sobre onde este estudo está sendo realizado.

Contato de estudo

Locais de estudo

      • Istanbul, Turquia (Türkiye), 34077
        • Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine
        • Contato:
        • Subinvestigador:
          • Onur Kökçü
        • Investigador principal:
          • Ezgi Budak Özyalçın

Critérios de participação

Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.

Critérios de elegibilidade

Idades elegíveis para estudo

  • Adulto
  • Adulto mais velho

Aceita Voluntários Saudáveis

Não

Descrição

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

Plano de estudo

Esta seção fornece detalhes do plano de estudo, incluindo como o estudo é projetado e o que o estudo está medindo.

Como o estudo é projetado?

Detalhes do projeto

  • Finalidade Principal: Ciência básica
  • Alocação: Randomizado
  • Modelo Intervencional: Atribuição Paralela
  • Mascaramento: Triplo

Armas e Intervenções

Grupo de Participantes / Braço
Intervenção / Tratamento
Experimental: 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.
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.
Outros nomes:
  • Driving Pressure-Guided PEEP
Comparador Ativo: Standard PEEP Group
Patients assigned to this group will undergo a recruitment maneuver followed by standard fixed PEEP of 6 cmH2O during mechanical ventilation.
Following a recruitment maneuver, PEEP will be maintained at a fixed level of 6 cmH2O during mechanical ventilation.

O que o estudo está medindo?

Medidas de resultados primários

Medida de resultado
Descrição da medida
Prazo
Change in Noninvasive Estimated Intracranial Pressure
Prazo: 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

Medidas de resultados secundários

Medida de resultado
Descrição da medida
Prazo
Middle Cerebral Artery Pulsatility Index
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: 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
Prazo: 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

Colaboradores e Investigadores

É aqui que você encontrará pessoas e organizações envolvidas com este estudo.

Patrocinador

Datas de registro do estudo

Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados ​​pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.

Datas Principais do Estudo

Início do estudo (Estimado)

19 de agosto de 2026

Conclusão Primária (Estimado)

19 de novembro de 2026

Conclusão do estudo (Estimado)

30 de novembro de 2026

Datas de inscrição no estudo

Enviado pela primeira vez

18 de agosto de 2026

Enviado pela primeira vez que atendeu aos critérios de CQ

23 de agosto de 2026

Primeira postagem (Real)

25 de agosto de 2026

Atualizações de registro de estudo

Última Atualização Postada (Real)

25 de agosto de 2026

Última atualização enviada que atendeu aos critérios de controle de qualidade

23 de agosto de 2026

Última verificação

1 de agosto de 2026

Mais Informações

Termos relacionados a este estudo

Plano para dados de participantes individuais (IPD)

Planeja compartilhar dados de participantes individuais (IPD)?

NÃO

Informações sobre medicamentos e dispositivos, documentos de estudo

Estuda um medicamento regulamentado pela FDA dos EUA

Não

Estuda um produto de dispositivo regulamentado pela FDA dos EUA

Não

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