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Completed

NCT Number: NCT07361068

Assessment of Brain Oxygen Drops During Surgery and Related Risk Factors for Cognitive Problems After Heart Surgery

This study examines whether decreases in brain oxygen levels during cardiac surgery are linked to postoperative cognitive dysfunction and identifies other factors that may increase the risk of cognitive impairment.

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Key information

Conditions

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

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Bursa Yuksek Ihtisas Traning and Research Hospital

Bursa, 16000, Turkey (Türkiye)

About this study

In this prospective study, the relationship between intraoperative cerebral oxygen saturation and postoperative cognitive dysfunction (POCD) was investigated in adult patients undergoing elective cardiac surgery with cardiopulmonary bypass (CPB). Patients with a preoperative Mini-Mental State Examination (MMSE) score ≥ 24, no history of cerebrovascular disease, and no conditions that could interfere with near-infrared spectroscopy (NIRS) monitoring were included.

Measurements were recorded at the following time points: T0 (before induction), T1 (15 minutes after induction), T2 (5 minutes after initiation of CPB), T3 (during the hypothermic phase of CPB), T4 (rewarming phase of CPB, at 34 °C), T5 (termination of CPB), and T6 (upon admission to the intensive care unit). Patients were divided into two groups according to postoperative cognitive outcomes: those who developed POCD and those who did not.

Cognitive function was assessed using the MMSE preoperatively and on postoperative days 4, 7, and 30. During surgery, cerebral oxygen saturation was measured at predefined time points using NIRS probes placed on the frontal region, and detailed intraoperative and perioperative data were recorded. Standardized interventions were implemented when a decrease of more than 20% in regional cerebral oxygen saturation (rSO₂) from baseline was detected in order to maintain adequate cerebral oxygenation.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Planned elective CPB surgery
  • Provision of written informed consent
  • Absence of communication barriers that could interfere with preoperative and postoperative MMSE assessment
  • No history of cerebrovascular disease
  • Preoperative MMSE score ≥24
  • Education level of at least high school
  • Absence of any frontal deformity that could hinder NIRS monitoring

Exclusion criteria

  • Preoperative use of antipsychotic or antidepressant medications
  • Emergency cardiac surgery indication
  • Presence of ≥50% carotid artery stenosis

Treatment and study plan

Primary outcomes

  1. Incidence of Postoperative Cognitive Dysfunction (POCD)

    Time frame: Baseline (preoperative, before surgery) and postoperative day 4, postoperative day 7, and postoperative day 30.

    Postoperative cognitive dysfunction (POCD) is defined as a decline in cognitive performance assessed using the Mini-Mental State Examination (MMSE), with a score of ≤23 at any postoperative assessment compared with a preoperative baseline MMSE score of ≥24. This primary outcome evaluates the association between intraoperative cerebral oxygen desaturation, measured by near-infrared spectroscopy (NIRS) as a reduction of >20% from baseline regional cerebral oxygen saturation (rSO₂), and postoperative cognitive dysfunction following cardiac surgery with cardiopulmonary bypass.

Secondary outcomes

  1. Intraoperative Cerebral Oxygen Desaturation Measured by NIRS

    Time frame: Perioperatively (during surgery) through immediate postoperative period (upon ICU admission).

    Magnitude of intraoperative decreases in regional cerebral oxygen saturation (rSO₂) relative to baseline, measured using near-infrared spectroscopy (NIRS) at predefined intraoperative time points.

    Measurements are recorded at:

    T0: before induction of anesthesia T1: 15 minutes after induction of anesthesia T2: 5 minutes after initiation of cardiopulmonary bypass (CPB) T3: hypothermic phase of CPB T4: rewarming phase of CPB (34 °C) T5: weaning from CPB T6: upon admission to the intensive care unit (ICU)

  2. Postoperative Cognitive Performance Over Time Assessed by MMSE

    Time frame: Baseline (preoperative, before surgery) and postoperative day 4, postoperative day 7, and postoperative day 30.

    Changes in cognitive performance over time assessed using the Mini-Mental State Examination (MMSE) to evaluate early and late postoperative cognitive recovery.

  3. Operation Time

    Time frame: From skin incision to skin closure during surgery

    Operation time will be compared between patients with and without postoperative cognitive dysfunction (POCD).

    Measure : Minute

  4. Cardiopulmonary Bypass (CPB) Duration

    Time frame: From initiation to termination of cardiopulmonary bypass during surgery (single intraoperative assessment).

    Cardiopulmonary bypass duration will be compared between patients with and without postoperative cognitive dysfunction (POCD).

    Measure : Minute

  5. Aortic Cross-Clamp (ACC) Duration

    Time frame: From application to removal of the aortic cross-clamp during surgery (single intraoperative assessment)

    Aortic cross-clamp duration will be compared between patients with and without postoperative cognitive dysfunction (POCD).

    Meusure: Minute

  6. Time to Extubation

    Time frame: From completion of surgery until successful extubation, assessed up to 30 postoperative days

    Time to extubation will be compared between patients with and without postoperative cognitive dysfunction (POCD).

    Measure: Hour

  7. Intensive Care Unit Length of Stay

    Time frame: From ICU admission after surgery until ICU discharge, assessed up to 30 postoperative days.

    Length of intensive care unit stay will be compared between patients with and without postoperative cognitive dysfunction (POCD).

    Measure: Hour

  8. Hospital Length of Stay

    Time frame: From hospital admission for cardiac surgery until hospital discharge, assessed up to 30 postoperative days.

    Hospital length of stay will be compared between patients with and without postoperative cognitive dysfunction (POCD).

    Measure: Day

  9. Correlation Between Perioperative Clinical Variables and Postoperative MMSE Scores

    Time frame: Postoperative day 4, postoperative day 7, and postoperative day 30.

    Correlation between perioperative clinical variables and postoperative cognitive performance assessed using the Mini-Mental State Examination (MMSE). Variables correlated with MMSE scores include: Operation time (minutes) Cardiopulmonary bypass (CPB) duration (minutes) Aortic cross-clamp (ACC) duration (minutes) Intensive care unit (ICU) length of stay (hours) Hospital length of stay (days)

Sponsors and collaborators

Lead sponsor

Bursa Yuksek Ihtisas Training and Research Hospital

Other Gov

Registry information

Official study title

Evaluation of Intraoperative Cerebral Desaturation and Risk Factors Associated With Cognitive Dysfunction After Cardiac Surgery

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Jan 22, 2026
Registry last updated
Jan 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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