Reassessment of a meta-analysis of intraoperative cerebral oximetry-based management studies

  • Jason A. DavisEmail author
  • Rhodri Saunders

To the Editor,

We read with interest the meta-analysis regarding intraoperative cerebral oximetry-based monitoring for maximizing perioperative outcomes by Zorrilla-Vaca et al.1 We note, however, some important discrepancies between the original source literature and the data that are used in the current analysis, which raise concerns. While conclusions regarding the primary outcome of cognitive impairment are not impacted, the means to reach that conclusion are at times not as accurate as they could be, and some of the secondary outcome conclusions differ in significance.

A primary example of discrepancy is in the studies used for the postoperative delirium outcome (Fig. 6). Of the six studies analyzed, three of them actually make no mention of “postoperative delirium”, “POD”, or “delirium” in the text or supplementary materials.2, 3, 4Nor is there any mention of instruments typically used to assess POD in patients, such as the Confusion Assessment Method for the Intensive Care Unit...



Coreva Scientific is a private consultancy that has received fees from Medtronic Inc. for analyses of medical devices. Medtronic played no role in initiating or influencing the current submitted work.

Conflicts of interest

None declared.

Editorial responsibility

This submission was handled by Dr. Hilary P. Grocott, Editor-in-Chief, Canadian Journal of Anesthesia.

Supplementary material

12630_2019_1469_MOESM1_ESM.pdf (6 mb)
Supplementary material 1 (PDF 6127 kb)


  1. 1.
    Zorrilla-Vaca A, Healy R, Grant MC, et al. Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials. Can J Anesth 2018; 65: 529-42.CrossRefPubMedGoogle Scholar
  2. 2.
    Murkin JM, Adams SJ, Novick RJ, et al. Monitoring brain oxygen saturation during coronary bypass surgery: a randomized, prospective study. Anesth Analg 2007; 104: 51-8.CrossRefPubMedGoogle Scholar
  3. 3.
    Rogers CA, Stoica S, Ellis L, et al. Randomized trial of near-infrared spectroscopy for personalized optimization of cerebral tissue oxygenation during cardiac surgery. Br J Anaesth 2017; 119: 384-93.CrossRefPubMedGoogle Scholar
  4. 4.
    Vretzakis G, Georgopoulou S, Stamoulis K, et al. Monitoring of brain oxygen saturation (INVOS) in a protocol to direct blood transfusions during cardiac surgery: a prospective randomized clinical trial. J Cardiothorac Surg 2013; 8: 145.CrossRefPubMedPubMedCentralGoogle Scholar
  5. 5.
    Deschamps A, Hall R, Grocott H, et al. Cerebral oximetry monitoring to maintain normal cerebral oxygen saturation during high-risk cardiac surgery: a randomized controlled feasibility trial. Anesthesiology 2016; 124: 826-36.CrossRefPubMedGoogle Scholar
  6. 6.
    Colak Z, Borojevic M, Bogovic A, Ivancan V, Biocina B, Majeric-Kogler V. Influence of intraoperative cerebral oximetry monitoring on neurocognitive function after coronary artery bypass surgery: a randomized, prospective study. Eur J Cardiothorac Surg 2015; 47: 447-54.CrossRefPubMedGoogle Scholar
  7. 7.
    Cohn SM, Pearl RG, Acosta SM, et al. A prospective randomized pilot study of near-infrared spectroscopy-directed restricted fluid therapy versus standard fluid therapy in patients undergoing elective colorectal surgery. Am Surg 2010; 76: 1384-92.PubMedGoogle Scholar
  8. 8.
    Denault A, Deschamps A, Murkin JM. A proposed algorithm for the intraoperative use of cerebral near-infrared spectroscopy. Semin Cardiothorac Vasc Anesth 2007; 11: 274-81.CrossRefPubMedGoogle Scholar

Copyright information

© Canadian Anesthesiologists' Society 2019

Authors and Affiliations

  1. 1.Coreva ScientificBaden WürttembergGermany

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