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MECHANISM OF INJURY, ASSOCIATED OUTCOME AND INTERVENTION

Learn more about impaired autoregulation causing cerebral desaturation:

Mechanism of Injury

  • Cerebral autoregulation maintains cerebral blood flow during fluctuations in mean arterial pressure. However, once mean arterial pressure passes above or below the limits of autoregulation, cerebral blood flow becomes pressure dependent.
  • In patients undergoing cardiopulmonary bypass, the lower limit of autoregulation can vary widely, from 40 to 90 mmHg.1
  • Up to 50% of patients demonstrate impaired cerebral autoregulation during cardiac surgery during rewarming.2

Associated Outcome

  • CABG patients with impaired autoregulation are more likely to suffer perioperative stroke than those with intact autoregulation.3
  • The incidence of delirium is four times higher in patients whose MAP exceeds the upper limit of autoregulation.4
  • Ono et al. determined that the time and magnitude of blood pressure below the threshold of cerebral autoregulation was independently associated with major morbidity and mortality.5
Intervention % of all interventions6
Adjust mean arterial pressure 34.2

MECHANISM OF INJURY, ASSOCIATED OUTCOME AND INTERVENTION

Learn more about impaired autoregulation causing cerebral desaturation:

Mechanism of Injury

  • Cerebral autoregulation maintains cerebral blood flow during fluctuations in mean arterial pressure. However, once mean arterial pressure passes above or below the limits of autoregulation, cerebral blood flow becomes pressure dependent.
  • In patients undergoing cardiopulmonary bypass, the lower limit of autoregulation can vary widely, from 40 to 90 mmHg.1
  • Up to 50% of patients demonstrate impaired cerebral autoregulation during cardiac surgery during rewarming.2

Associated Outcome

  • CABG patients with impaired autoregulation are more likely to suffer perioperative stroke than those with intact autoregulation.3
  • The incidence of delirium is four times higher in patients whose MAP exceeds the upper limit of autoregulation.4
  • Ono et al. determined that the time and magnitude of blood pressure below the threshold of cerebral autoregulation was independently associated with major morbidity and mortality.5
Intervention % of all interventions6
Adjust mean arterial pressure 34.2

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  • 1. Joshi B, Ono M, Brown C, et al. Predicting the limits of cerebral autoregulation during cardiopulmonary bypass. Anesthesia and analgesia. 2012;114(3):503-510.
  • 2. Joshi B, Brady K, Lee J, et al. Impaired autoregulation of cerebral blood flow during rewarming from hypothermic cardiopulmonary bypass and its potential association with stroke. Anesthesia and analgesia. 2010;110(2):321-328.
  • 3. Ono M, Joshi B, Brady K, et al. Risks for impaired cerebral autoregulation during cardiopulmonary bypass and postoperative stroke. British journal of anaesthesia. 2012;109(3):391-398.
  • 4. Hori D, Brown C, Ono M, et al. Arterial pressure above the upper cerebral autoregulation limit during cardiopulmonary bypass is associated with postoperative delirium. British journal of anaesthesia. 2014;113(6):1009-1017. View Abstract
  • 5. Ono M, Brady K, Easley RB, et al. Duration and magnitude of blood pressure below cerebral autoregulation threshold during cardiopulmonary bypass is associated with major morbidity and operative mortality. The Journal of thoracic and cardiovascular surgery. 2014;147(1):483-489.
  • 6. Deschamps A, Lambert J, Couture P, et al. Reversal of decreases in cerebral saturation in high-risk cardiac surgery. Journal of cardiothoracic and vascular anesthesia. 2013;27(6):1260-1266. View Abstract
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