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Randomized Controlled Trial
. 2025 Jun;39(3):571-580.
doi: 10.1007/s10877-025-01290-2. Epub 2025 Apr 12.

Impact of cardiopulmonary bypass flow on the lower limit of cerebral autoregulation during cardiac surgery: a randomized cross-over pilot study

Olivier Desebbe  1   2 , Antoine Berna  3 , Alexandre Joosten  4 , Darren Raphael  5 , Ghislain Malapert  6 , Dimitri Rolo  3 , Fabio Silvio Taccone  7 , Laurent Gergele  8
Affiliations
Randomized Controlled Trial

Impact of cardiopulmonary bypass flow on the lower limit of cerebral autoregulation during cardiac surgery: a randomized cross-over pilot study

Olivier Desebbe et al. J Clin Monit Comput. 2025 Jun.

Abstract

Assessment of cerebral autoregulation is challenging under different hemodynamic conditions during cardiac surgery and must be rapidly calculated in order to optimize mean arterial pressure (MAP). Whether systemic flow during cardiopulmonary bypass impacts the lower limit of cerebral autoregulation (LLA) remains unclear. Forty patients requiring cardiac surgery were included in this randomized crossover study. Patients assigned to the conventional/high blood flow arm received 20 min of conventional cardiopulmonary bypass (CPB) blood flow (2.2 L/min.m-²) followed by 20 min of high blood flow (2.8 L/min.m-²), both during aortic cross clamping. Patients assigned to the high/conventional arm received the same flows but in reverse order. During each 20-minute period, MAP was gradually increased from 40 to 90 mmHg, while PaCO2, hematocrit, depth of anesthesia, central temperature and arterial oxygen tension were kept constant. Continuous cerebral blood flow velocities of the middle cerebral artery (Fv) were monitored using transcranial doppler. Cerebral autoregulation was calculated using a Pearson's correlation coefficient (Mean flow index, Mxa) between the MAP and Fv. Mxa values were then plotted across MAP ranges. The LLA was defined as the corresponding MAP value when Mxa initially decreased and crossed the threshold value of 0.4. A mixed model, including the LLA as the dependent variable, the CPB flow and period as fixed effects and patients as a random effect was used to compare conventional and high CPB flows. Thirty-seven patients were analyzed. The LLA mean difference between groups, adjusted on the period, was - 2.8 (SE 2.4) mmHg with 95% CI [-7.8, + 2.1 mmHg], p = 0.2538). 24% of patients presented an LLA < 65 mmHg during the conventional CPB flow phase versus 35% during the high CPB flow phase. Increasing the cardiopulmonary pump flow did not decrease the LLA during cardiac surgery.

Keywords: Cardiopulmonary bypass; Cerebral autoregulation; Mean arterial pressure; Pump flow.

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Conflict of interest statement

Declarations. Ethical approval: This study was approved by the Ethics Committee Sud-Méditerranée I, Marseille, France (IDRCB: 2021-A00783-38) on September 24th, 2022, and was preregistered in www.clinicaltrials.gov under NCT05681741 on January 11th, 2023. The authors followed Consort guidelines. Patient written informed consent was obtained before surgery. This was a prospective single-center, cross-over randomized, interventional, open trial conducted between January, 2023 and July, 2023 at the Sauvegarde Clinic, in Lyon, France, a non-university hospital with a significant volume of cardiac surgery (n = 700 /year). Competing interests: The authors declare no competing interests.

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References

    1. Ono M, Arnaoutakis GJ, Fine DM, Brady K, Easley RB, Zheng Y, et al. Blood pressure excursions below the cerebral autoregulation threshold during cardiac surgery are associated with acute kidney injury**. Crit Care Med. 2013;41:464. https://doi.org/10.1097/CCM.0b013e31826ab3a1 . - DOI - PubMed - PMC
    1. Hori D, Ono M, Rappold TE, Conte JV, Shah AS, Cameron DE, et al. Hypotension after cardiac operations based on autoregulation monitoring leads to brain cellular injury. Ann Thorac Surg. 2015;100:487–93. https://doi.org/10.1016/j.athoracsur.2015.03.036 . - DOI - PubMed - PMC
    1. Ono M, Joshi B, Brady K, Easley RB, Zheng Y, Brown C, et al. Risks for impaired cerebral autoregulation during cardiopulmonary bypass and postoperative stroke. Br J Anaesth. 2012;109:391–8. https://doi.org/10.1093/bja/aes148 . - DOI - PubMed - PMC
    1. Pieri M, De Simone A, Rose S, De Domenico P, Lembo R, Denaro G, et al. Trials focusing on prevention and treatment of delirium after cardiac surgery: A systematic review of randomized evidence. J Cardiothorac Vasc Anesth. 2020;34:1641–54. https://doi.org/10.1053/j.jvca.2019.09.028 . - DOI - PubMed
    1. Joshi B, Ono M, Brown C, Brady K, Easley RB, Yenokyan G, et al. Predicting the limits of cerebral autoregulation during cardiopulmonary bypass. Anesth Analg. 2012;114:503–10. https://doi.org/10.1213/ANE.0b013e31823d292a . - DOI - PubMed

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