Brain Oxygen Supply in Older Adults During Coronary Artery Bypass Grafting
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.
