Postoperative Cognitive Dysfunction (POCD)NCT07843186
PCO₂ Gap and Lactate as Predictors of POCD After Cardiac Surgery
An observational study of Postoperative Cognitive Dysfunction (POCD) and Cardiac Surgery, run by Ain Shams University.
Trial summary
This prospective observational study aims to evaluate whether intraoperative venous-to-arterial carbon dioxide partial pressure difference (PCO₂ gap) and arterial lactate levels can serve as early predictors of postoperative cognitive dysfunction (POCD) in elderly patients undergoing elective cardiac surgery with… Read more about this study
- Who is it for?
- Ages 65 years and older
- Conditions the study is for
- Postoperative Cognitive Dysfunction (POCD), Cardiac Surgery, Cardiopulmonary Bypass
- How many people
- 185 participants
- Where
- No sites listed yet
- Study dates
- 1 Dec 2026to 1 Aug 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 65 years and older
- All sexes
- No healthy volunteers
- Older adult
Study population: Elderly patients (65 years or older) undergoing elective cardiac surgery with cardiopulmonary bypass at El-Demerdash Hospital, Ain Shams University, Cairo, Egypt. Eligible participants will undergo routine perioperative management with serial intraoperative PCO₂ gap and arterial lactate measurements and perioperative cognitive assessment according to the study protocol.
Who may be able to join
- Age ≥65 years.
- Undergoing elective cardiac surgery with cardiopulmonary bypass (e.g., coronary artery bypass grafting or valve surgery).
- American Society of Anesthesiologists (ASA) Physical Status III.
- Able to provide written informed consent.
Who cannot join
- Refusal or inability to provide written informed consent.
- Pre-existing neurological disorders (e.g., Alzheimer's disease, Parkinson's disease, or stroke with residual neurological deficits).
- Severe psychiatric disorders requiring active treatment.
- History of drug or alcohol abuse.
- Emergency cardiac surgery.
- Significant visual or hearing impairment interfering with cognitive testing.
Show all 10Show fewer
- Inability to complete preoperative cognitive assessment.
- Preoperative dementia (MoCA score <20).
- Significant pulmonary disease (e.g., COPD or lung cancer).
- Patients meeting the protocol-defined intraoperative or postoperative exclusion criteria.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Intraoperative PCO₂ Gap and Lactate Levels as Early Predictors of Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass
This prospective observational study aims to evaluate whether intraoperative venous-to-arterial carbon dioxide partial pressure difference (PCO₂ gap) and arterial lactate levels can serve as early predictors of postoperative cognitive dysfunction (POCD) in elderly patients undergoing elective cardiac surgery with cardiopulmonary bypass. Intraoperative measurements of PCO₂ gap and lactate will be correlated with perioperative cognitive outcomes assessed using the Montreal Cognitive Assessment (MoCA) and postoperative delirium screening using the Confusion Assessment Method for the ICU (CAM-ICU).
Read the detailed description
This prospective observational cohort study will be conducted at El-Demerdash Hospital, Ain Shams University. Patients aged 65 years and older undergoing elective cardiac surgery with cardiopulmonary bypass will be enrolled. Serial measurements of the PCO₂ gap and arterial lactate will be obtained before induction, during CPB, at the end of CPB, 30 minutes after weaning from CPB, and immediately postoperatively. Cognitive function will be evaluated preoperatively and one month after surgery using the Montreal Cognitive Assessment (MoCA). Postoperative delirium will be assessed daily during ICU stay using CAM-ICU. The study will investigate the predictive value of intraoperative PCO₂ gap and lactate levels for postoperative cognitive dysfunction and determine potential cutoff values associated with cognitive decline.
- Keywords
- PCO₂ gap, Lactate, Postoperative cognitive dysfunction, CAM-ICU, MoCA
- Medical subject headings
- Postoperative Cognitive Complications
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Elderly Patients Undergoing Elective Cardiac Surgery with Cardiopulmonary Bypass | Patients aged 65 years or older undergoing elective cardiac surgery with cardiopulmonary bypass. Participants will undergo serial intraoperative measurements of the venous-to-arterial carbon dioxide partial pressure difference (PCO₂ gap) and arterial lactate levels. Postoperative cognitive function will be assessed using the Montreal Cognitive Assessment (MoCA), and postoperative delirium will be screened using the Confusion Assessment Method for the ICU (CAM-ICU). |
What is being measured
The primary outcome is the main question the study is designed to answer.
Predictive Value of Intraoperative PCO₂ Gap and Arterial Lactate Levels for Postoperative Cognitive Dysfunction (POCD
To evaluate whether intraoperative venous-to-arterial carbon dioxide partial pressure difference (PCO₂ gap) and arterial lactate levels predict postoperative cognitive dysfunction in elderly patients undergoing elective cardiac surgery with cardiopulmonary bypass. POCD will be assessed by changes in Montreal Cognitive Assessment (MoCA) scores from the preoperative baseline to 1 month postoperatively.
Measured: Baseline (preoperative) and 1 month postoperatively
Secondary outcomes (7)
Early Postoperative Delirium Assessed by the Confusion Assessment Method for the ICU (CAM-ICU)
To determine the occurrence of early postoperative delirium using the Confusion Assessment Method for the ICU (CAM-ICU). CAM-ICU is a dichotomous assessment (positive or negative), where a positive result indicates the presence of delirium
Measured: Daily during the first 5 postoperative days or until ICU discharge, whichever occurs first
Determination of Cutoff Values for Intraoperative PCO₂ Gap and Arterial Lactate Levels Predictive of POCD
To identify optimal cutoff values for intraoperative PCO₂ gap and arterial lactate levels associated with postoperative cognitive dysfunction in elderly patients undergoing cardiac surgery with cardiopulmonary bypass.The PCO₂ gap will be measured in mmHg, and arterial lactate concentration will be measured in mmol/L.
Measured: 1 month postoperative
Correlation of (CAM - ICU) to MoCA for prediction of cognitive impairmentat 5 days post operative
To evaluate the correlation between postoperative delirium assessed by the Confusion Assessment Method for the ICU (CAM-ICU) and postoperative cognitive function assessed by the Montreal Cognitive Assessment (MoCA).CAM-ICU will be recorded as a dichotomous result (positive or negative), with a positive result indicating the presence of delirium. MoCA will be recorded as a total score ranging from 0 to 30, with higher scores indicating better cognitive function
Measured: CAM-ICU: Daily during the first 5 postoperative days; MoCA: baseline preoperatively and 1 month postoperatively
Incidence of POCD at 1 month postoperatively, defined by a decline in MoCA scores from baseline in elderly cardiac patient.
To determine the incidence of postoperative cognitive dysfunction, defined as a decline in MoCA score from the preoperative baseline, one month after cardiac surgery
Measured: Baseline (preoperative) and 1 month postoperatively
Duration of Mechanical Ventilation in Relation to Intraoperative PCO₂ Gap and Arterial Lactate Levels
To evaluate the association between intraoperative PCO₂ gap and arterial lactate levels and the duration of mechanical ventilation following cardiac surgery with cardiopulmonary bypass. Duration of mechanical ventilation will be measured in hours from the end of surgery until successful extubation, as documented in the patient's medical and ventilator records.
Measured: Measured from the end of surgery until successful extubation (up to 30 days)
Duration of Intensive Care Unit Stay in Relation to Intraoperative PCO₂ Gap and Arterial Lactate Levels
To evaluate the association between intraoperative PCO₂ gap and arterial lactate levels and the duration of intensive care unit (ICU) stay following cardiac surgery with cardiopulmonary bypass. ICU stay will be measured in days from ICU admission after surgery until ICU discharge, as documented in the patient's medical records.
Measured: From ICU admission after surgery until ICU discharge, up to 30 days
Duration of Hospital Stay in Relation to Intraoperative PCO₂ Gap and Arterial Lactate Levels
To evaluate the association between intraoperative PCO₂ gap and arterial lactate levels and the duration of hospital stay following cardiac surgery with cardiopulmonary bypass. Hospital stay will be measured in days from the end of surgery until hospital discharge, as documented in the patient's medical records.
Measured: From the end of surgery until hospital discharge, up to 30 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Sep 2026
- Study start1 Dec 2026 (estimated)
- Primary completion1 May 2028 (estimated)
- Study completion1 Aug 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postoperative Cognitive Dysfunction (POCD)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 185 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ain Shams University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07843186
- Sponsor's protocol ID
- FMASU MD309/2025
- Status last verified
- Jun 2026
- First submitted
- 29 Jun 2026
- Last updated
- 25 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intraoperative PCO₂ Gap and Lactate Levels as Early Predictors of Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass
- ClinicalTrials.gov ID
- NCT07843186
- Acronym / sponsor ID
- FMASU MD309/2025
- Keywords
- PCO₂ gap, Lactate, Postoperative cognitive dysfunction, CAM-ICU, MoCA
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 185 participants (estimated)
- Lead sponsor
- Ain Shams UniversityUniversity, hospital or other
- Study start
- 1 Dec 2026 (estimated)
- Primary completion
- 1 May 2028 (estimated)
- Study completion
- 1 Aug 2028 (estimated)
- First posted
- 25 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective observational study aims to evaluate whether intraoperative venous-to-arterial carbon dioxide partial pressure difference (PCO₂ gap) and arterial lactate levels can serve as early predictors of postoperative cognitive dysfunction (POCD) in elderly patients undergoing elective cardiac surgery with cardiopulmonary bypass. Intraoperative measurements of PCO₂ gap and lactate will be correlated with perioperative cognitive outcomes assessed using the Montreal Cognitive Assessment (MoCA) and postoperative delirium screening using the Confusion Assessment Method for the ICU (CAM-ICU).
Detailed description
This prospective observational cohort study will be conducted at El-Demerdash Hospital, Ain Shams University. Patients aged 65 years and older undergoing elective cardiac surgery with cardiopulmonary bypass will be enrolled. Serial measurements of the PCO₂ gap and arterial lactate will be obtained before induction, during CPB, at the end of CPB, 30 minutes after weaning from CPB, and immediately postoperatively. Cognitive function will be evaluated preoperatively and one month after surgery using the Montreal Cognitive Assessment (MoCA). Postoperative delirium will be assessed daily during ICU stay using CAM-ICU. The study will investigate the predictive value of intraoperative PCO₂ gap and lactate levels for postoperative cognitive dysfunction and determine potential cutoff values associated with cognitive decline.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Elderly Patients Undergoing Elective Cardiac Surgery with Cardiopulmonary Bypass | – | –Patients aged 65 years or older undergoing elective cardiac surgery with cardiopulmonary bypass. Participants will undergo serial intraoperative measurements of the venous-to-arterial carbon dioxide partial pressure difference (PCO₂ gap) and arterial lactate levels. Postoperative cognitive function will be assessed using the Montreal Cognitive Assessment (MoCA), and postoperative delirium will be screened using the Confusion Assessment Method for the ICU (CAM-ICU). |
Who may qualify
- Ages
- 65 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Older adult
- Study population
- Elderly patients (65 years or older) undergoing elective cardiac surgery with cardiopulmonary bypass at El-Demerdash Hospital, Ain Shams University, Cairo, Egypt. Eligible participants will undergo routine perioperative management with serial intraoperative PCO₂ gap and arterial lactate measurements and perioperative cognitive assessment according to the study protocol.
Key inclusion criteria (4 listed)
- Age ≥65 years.
- Undergoing elective cardiac surgery with cardiopulmonary bypass (e.g., coronary artery bypass grafting or valve surgery).
- American Society of Anesthesiologists (ASA) Physical Status III.
- Able to provide written informed consent.
Key exclusion criteria (10 listed)
- Refusal or inability to provide written informed consent.
- Pre-existing neurological disorders (e.g., Alzheimer's disease, Parkinson's disease, or stroke with residual neurological deficits).
- Severe psychiatric disorders requiring active treatment.
- History of drug or alcohol abuse.
- Emergency cardiac surgery.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Predictive Value of Intraoperative PCO₂ Gap and Arterial Lactate Levels for Postoperative Cognitive Dysfunction (POCD
Time frame: Baseline (preoperative) and 1 month postoperatively
To evaluate whether intraoperative venous-to-arterial carbon dioxide partial pressure difference (PCO₂ gap) and arterial lactate levels predict postoperative cognitive dysfunction in elderly patients undergoing elective cardiac surgery with cardiopulmonary bypass. POCD will be assessed by changes in Montreal Cognitive Assessment (MoCA) scores from the preoperative baseline to 1 month postoperatively.
7 secondary outcomes
Early Postoperative Delirium Assessed by the Confusion Assessment Method for the ICU (CAM-ICU)
Time frame: Daily during the first 5 postoperative days or until ICU discharge, whichever occurs first
Determination of Cutoff Values for Intraoperative PCO₂ Gap and Arterial Lactate Levels Predictive of POCD
Time frame: 1 month postoperative
Correlation of (CAM - ICU) to MoCA for prediction of cognitive impairmentat 5 days post operative
Time frame: CAM-ICU: Daily during the first 5 postoperative days; MoCA: baseline preoperatively and 1 month postoperatively
Incidence of POCD at 1 month postoperatively, defined by a decline in MoCA scores from baseline in elderly cardiac patient.
Time frame: Baseline (preoperative) and 1 month postoperatively
Duration of Mechanical Ventilation in Relation to Intraoperative PCO₂ Gap and Arterial Lactate Levels
Time frame: Measured from the end of surgery until successful extubation (up to 30 days)
Duration of Intensive Care Unit Stay in Relation to Intraoperative PCO₂ Gap and Arterial Lactate Levels
Time frame: From ICU admission after surgery until ICU discharge, up to 30 days
Duration of Hospital Stay in Relation to Intraoperative PCO₂ Gap and Arterial Lactate Levels
Time frame: From the end of surgery until hospital discharge, up to 30 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Sep 2026.
- Individual participant dataSharing planned: No
Related trials for Postoperative Cognitive Dysfunction (POCD)
Enrolling by invitationPhase 4
Effects of Ciprofol on Perioperative Neurocognitive Function in Elderly Patients Undergoing Daytime Surgery
PND, POCD - Postoperative Cognitive Dysfunction
Not yet recruiting
BrainProtect-guided, Real-time Cerebral Autoregulation Monitoring and Protection of Brain During Cardiac Surgery With Cardiopulmonary Bypass Requiring Heart-lung Machine
Cerebral Autoregulation Impairment, Postoperative Cognitive Dysfunction
Not yet recruitingPhase 4
Effects of Remimazolam on Postoperative Cognitive Dysfunction and Neuroinflammatory Biomarkers in Patients Undergoing Aortic Arch Surgery
Aortic Aneurysm of the Proximal Arch, Aortic Aneurysms Arch
Active, not recruitingObservational study
"Effects of Fluid Status and Regional Cerebral Oxygenation on Postoperative Cognitive Dysfunction in Patients Undergoing Lower Extremity Surgery Under General and Spinal Anesthesia."
Postoperative Cognitive Deficit (POCD)
Not yet recruitingObservational study
Cerebral Oximetry During Awake Carotid Endarterectomy
Carotid Stenosis, Carotid Artery Diseases
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
An observational study of Postoperative Cognitive Dysfunction (POCD) and Cardiac Surgery, run by Ain Shams University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 25 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Mariam Mohamed Hesham, Master (01013933073, Mariamhesham@med.asu.edu.eg), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Predictive Value of Intraoperative PCO₂ Gap and Arterial Lactate Levels for Postoperative Cognitive Dysfunction (POCD (time frame: Baseline (preoperative) and 1 month postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Sep 2026.