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Brain Oxygen Supply in Older Adults During Coronary Artery Bypass Grafting
Oksana Kamenskaya1, Asya Klinkova1, Irina Loginova1
1Department of Physiology, E. Meshalkin National Medical Research Center of the Ministry of Health of the Russian Federation, 15 Rechkunovskaya Street, Novosibirsk 630055, Russia.
Insights
In elderly patients undergoing coronary artery bypass grafting (CABG), a significant drop in brain oxygen saturation during cardiopulmonary bypass (CPB) increases the risk of postoperative neurological complications.
Area of Science:
- Neurosurgery
- Cardiology
- Anesthesiology
Background:
- Coronary artery bypass grafting (CABG) is a common procedure in elderly patients.
- Postoperative neurological complications can significantly impact patient outcomes after CABG.
- Cerebral oxygenation monitoring during CABG is crucial for patient safety.
Purpose of the Study:
- To evaluate cerebral oxygen supply dynamics in elderly patients during CABG.
- To test the hypothesis linking reduced intraoperative brain oxygen saturation to postoperative neurological complications.
Main Methods:
- Prospective cohort study involving 200 elderly patients undergoing CABG.
- Bilateral near-infrared spectroscopy (NIRS) used to measure regional hemoglobin oxygen saturation (rSO2) in brain hemispheres.
- Neurological complications during hospitalization were assessed.
Main Results:
- Average rSO2 levels in both hemispheres remained stable around 65% during CABG, with no significant differences across stages.
- A decrease in rSO2 by 20% or more during cardiopulmonary bypass (CPB) compared to anesthesia induction was observed in 19% of patients.
- This significant rSO2 drop during CPB was associated with an increased risk of neurological complications.
Conclusions:
- Reduced cerebral oxygen saturation during CPB is a significant risk factor for postoperative neurological complications in elderly CABG patients.
- A decrease of 20% or more in rSO2 during CPB elevates the risk of neurological complications by 5-fold (left hemisphere) and 7-fold (right hemisphere).
Objectives:
To evaluate the dynamics of the cerebral oxygen supply in patients aged ≥65 years, during coronary artery bypass grafting (CABG), and to test the hypothesis that lower intraoperative brain oxygen saturation is associated with postoperative neurological complications.
Design:
Prospective cohort study.
Setting:
The E. Meshalkin National Medical Research Center of the Ministry of Health of the Russian Federation, Novosibirsk, Russia.
Participants:
The study comprised 200 elderly patients who underwent CABG between April, 2018 and November, 2019.
Interventions:
None.
Measurements And Main Results:
The regional hemoglobin oxygen saturation (rSO2, %) of the right and left brain hemispheres were assessed during the intraoperative period using bilateral near-infrared spectroscopy. Furthermore, neurological complications during hospitalization were evaluated. At the anesthesia induction stage, the average levels of rSO2 for the right and left hemispheres were within 65% and did not differ significantly at any stage of CABG (p>0.05). The risk of neurological complications was associated with rSO2 decrease during cardiopulmonary bypass (CPB). An increased risk was associated with rSO2 decrease by 20% or more during CPB, relative to the stage of anesthesia induction, which was observed in 19% of patients.
Conclusions:
In elderly patients, the decrease in rSO2 during CPB is associated with an increased risk of neurological complications during hospitalization. This risk increases with a decrease in rSO2 by 20% or more during CPB relative to the stage of anesthesia induction, by a 5-fold and 7-fold for the left and right hemispheres, respectively.
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