Risks for Impaired Cerebral Autoregulation During Cardiopulmonary Bypass and Postoperative Stroke

Fixing Hearts and Protecting Minds

“…Impairment of autoregulation occurs in ≈20% of patients undergoing cardiopulmonary bypass for CABG surgery and is associated with increased perioperative stroke risk (a rate of 12.8% compared with 2.7% in those with preserved autoregulation). 8 Those patients with preexisting or vascular disease are particularly vulnerable, because their lower limit for autoregulation may be set higher.…”

Alpha-stat, beach chair, cerebral autoregulation… But who is at risk?

“…Cette méthode a été utilisée avec succès chez des patients présentant des lésions à la tête et, plus récemment, chez des patients de chirurgie cardiaque en période périopératoire. [13][14][15][16] Les données recueillies auprès des patients de chirurgie cardiaque sont particulièrement pertinentes et montrent un éventail étonnamment étendu de LIAC pendant la circulation extracorporelle (CEC) -d'absente chez certains patients à considérablement plus élevée que 50 mmHg chez d'autres. 14,15 Les recherches menées auprès de ces patients avec CEC ont également révélé une incidence accrue d'accident vasculaire cérébral (AVC) postopératoire ainsi que d'autres atteintes des organes cibles chez les patients dont la TAM était inférieure à la LIAC.…”

“…14,15 Investigations in these CPB patients have also reported an increased incidence of postoperative stroke as well as other end-organ damage in patients in whom MAP was below LLA. 14,16,17 These studies and others in preoperative patients 18 have underscored the validity of the concept of the ''brain as the index organ'', as initially described in a widely disseminated clinical study on the impact of cerebral oximetry monitoring 19 and subsequently confirmed in a more recent series of separate outcomes studies. 17,20,21 Our own data 15 have shown the surprising variability of the LLA and have further underscored the impact that CPB-related changes (e.g., laminar flow, viscosity, etc.)…”

“…This has been successfully employed in head-injured patients and more recently in perioperative cardiac surgical patients. [13][14][15][16] The data from cardiac surgical patients is particularly germane and shows a surprisingly wide range of LLA during cardiopulmonary bypass (CPB) -absent in some patients and significantly greater than 50 mmHg in others. 14,15 Investigations in these CPB patients have also reported an increased incidence of postoperative stroke as well as other end-organ damage in patients in whom MAP was below LLA.…”

“…[13][14][15][16] The data from cardiac surgical patients is particularly germane and shows a surprisingly wide range of LLA during cardiopulmonary bypass (CPB) -absent in some patients and significantly greater than 50 mmHg in others. 14,15 Investigations in these CPB patients have also reported an increased incidence of postoperative stroke as well as other end-organ damage in patients in whom MAP was below LLA. 14,16,17 These studies and others in preoperative patients 18 have underscored the validity of the concept of the ''brain as the index organ'', as initially described in a widely disseminated clinical study on the impact of cerebral oximetry monitoring 19 and subsequently confirmed in a more recent series of separate outcomes studies.…”