TY - JOUR
T1 - Perioperative Changes in Cerebral Blood Flow after Cardiac Surgery
T2 - Influence of Anemia and Aging
AU - Floyd, Thomas F.
AU - McGarvey, Michael
AU - Ochroch, E. Andrew
AU - Cheung, Albert T.
AU - Augoustides, John A.
AU - Bavaria, Joseph E.
AU - Acker, Michael A.
AU - Pochettino, Alberto
AU - Detre, John A.
N1 - Funding Information:
The authors thank David Alsop, PhD, and Julio Gonzalez, PhD, for technical assistance on this project. This research was supported by the Foundation for Anesthesia Education and Research, the Society of Cardiovascular Anesthesiologists, Arrow International, and the American Heart Association (EIG 9740099N).
PY - 2003/12
Y1 - 2003/12
N2 - Background. Stroke occurs in 2% to 5% and cognitive dysfunction occurs acutely in 60% to 80% of patients early after cardiac surgery. Both may have long-term consequences. Research into mechanisms behind these sequelae has been focused intraoperatively, although there is little reason to believe that injury is limited to this period. Aging prominently increases the incidence of these sequelae. Anemia with cardiac surgery is acute and severe, should cause an increase in cerebral blood flow (CBF), and may impact stroke and cognitive function in this setting. To better understand changes in perioperative CBF physiology we have measured changes in CBF and the influence of anemia and aging on these changes. Methods. Cerebral blood flow was measured using the noninvasive continuous arterial spin labeling perfusion magnetic resonance imaging method. Cerebral blood flow, mean arterial pressure, hemoglobin, hemoglobin oxygen saturation, and cardiopulmonary bypass time were recorded in 12 subjects before and 6 ± 2 days after cardiac surgery. Results. Cerebral blood flow increased from 44.6 ± 15.6 mL · 100 g -1 · min-1 to 64.4 ± 20.1 mL · 100 g-1 · min-1 after cardiac surgery, or 49.1% ± 26.7%, (p < 0.0001). The absolute change in CBF (ΔCBF) was predicted by the following regression model: ΔCBF = -55 + 0.64(Age) + 0.53(CBFPre) -3.3(ΔHgb); R2 = 0.81; p = 0.003, where CBFPre is the baseline preoperative CBF and ΔHgb is the change in hemoglobin from preoperative to postoperative periods. Conclusions. Cerebral blood flow increases after cardiac surgery, and anemia appears to be an important cause. Age appears also to be an important covariate, with advancing age further increasing the magnitude of this hyperemia. The interrelationship of aging and anemia, in determining perioperative changes in CBF, and potentially cerebral oxygenation, may have important implications for the understanding of perioperative stroke and cognitive dysfunction after cardiac surgery.
AB - Background. Stroke occurs in 2% to 5% and cognitive dysfunction occurs acutely in 60% to 80% of patients early after cardiac surgery. Both may have long-term consequences. Research into mechanisms behind these sequelae has been focused intraoperatively, although there is little reason to believe that injury is limited to this period. Aging prominently increases the incidence of these sequelae. Anemia with cardiac surgery is acute and severe, should cause an increase in cerebral blood flow (CBF), and may impact stroke and cognitive function in this setting. To better understand changes in perioperative CBF physiology we have measured changes in CBF and the influence of anemia and aging on these changes. Methods. Cerebral blood flow was measured using the noninvasive continuous arterial spin labeling perfusion magnetic resonance imaging method. Cerebral blood flow, mean arterial pressure, hemoglobin, hemoglobin oxygen saturation, and cardiopulmonary bypass time were recorded in 12 subjects before and 6 ± 2 days after cardiac surgery. Results. Cerebral blood flow increased from 44.6 ± 15.6 mL · 100 g -1 · min-1 to 64.4 ± 20.1 mL · 100 g-1 · min-1 after cardiac surgery, or 49.1% ± 26.7%, (p < 0.0001). The absolute change in CBF (ΔCBF) was predicted by the following regression model: ΔCBF = -55 + 0.64(Age) + 0.53(CBFPre) -3.3(ΔHgb); R2 = 0.81; p = 0.003, where CBFPre is the baseline preoperative CBF and ΔHgb is the change in hemoglobin from preoperative to postoperative periods. Conclusions. Cerebral blood flow increases after cardiac surgery, and anemia appears to be an important cause. Age appears also to be an important covariate, with advancing age further increasing the magnitude of this hyperemia. The interrelationship of aging and anemia, in determining perioperative changes in CBF, and potentially cerebral oxygenation, may have important implications for the understanding of perioperative stroke and cognitive dysfunction after cardiac surgery.
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U2 - 10.1016/S0003-4975(03)01074-9
DO - 10.1016/S0003-4975(03)01074-9
M3 - Article
C2 - 14667637
AN - SCOPUS:0345096360
SN - 0003-4975
VL - 76
SP - 2037
EP - 2042
JO - Annals of Thoracic Surgery
JF - Annals of Thoracic Surgery
IS - 6
ER -