Dynamic Cerebral Autoregulation after Cardiopulmonary Bypass.
BackgroundCerebral hemodynamic disturbances in the peri- or postoperative period may contribute to postoperative cognitive dysfunction (POCD) in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). We therefore examined dynamic cerebral autoregulation (dCA) post-CPB and changes in neurocognitive function in patients that had undergone CABG.Materials and MethodsWe assessed dCA by transfer function analysis of spontaneous oscillations between arterial blood pressure and middle cerebral artery blood flow velocity measured by transcranial Doppler ultrasound in eight patients 6 hours after the cessation of CPB; 10 healthy volunteers served as controls. Neurocognitive function was assessed by four specific tests 1 day prior to and 3 days after CPB.ResultsEven though patients exhibited systemic inflammation and anemic hypoxemia, dCA was similar to healthy volunteers (gain: 1.24 [0.94-1.49] vs. 1.22 [1.06-1.34] cm mm Hg-1s-1,p= 0.97; phase: 0.33 [0.15-0.56] vs. 0.69 [0.50-0.77] rad,p= 0.09). Neurocognitive testing showed a perioperative decline in the Letter Digit Coding Score (p= 0.04), while weaker dCA was associated with a lower Stroop Color Word Test (rho =  - 0.90;p= 0.01).Discussion and ConclusionWe found no changes in dCA 6 hours after CPB. However, based on the data at hand, it cannot be ruled out that changes in dCA predispose to POCD, which calls for larger studies that assess the potential impact of dCA in the early postoperative period on POCD.
Centre of Inflammation and Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark.
Claus Behrend
CB
Christiansen
Centre of Inflammation and Metabolism, University Hospital Rigshospitalet, Copenhagen, Denmark.
Ronan M G
RM
Berg
Department of Intensive Care 4131, University Hospital Rigshospitalet, Copenhagen, Denmark.
Ronni
R
Plovsing
Department of Infectious Diseases, University Hospital Rigshospitalet, Copenhagen, Denmark.
Andreas
A
Ronit
Renal and Vascular Research Section, Department of Biomedical Sciences, University of Copenhagen, Faculty of Health Sciences, Copenhagen, Denmark.
Niels-Henrik
NH
Holstein-Rathlou
The Heart Centre, University Hospital Aarhus, Aarhus, Denmark.
Stig
S
Yndgaard
Neurointensive Care Unit 2093, Department of Neuroanaesthesia, University Hospital Rigshospitalet, Copenhagen, Denmark.
Kirsten
K
Møller
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D057190:Stroop Test; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial; D055815:Young Adult