Rogers CA, et al. - This study tested a near-infrared spectroscopy (NIRS)-based algorithm for the personalized optimization of cerebral oxygenation during cardiopulmonary bypass, emphasizing mainly on its impact on perioperative injury to the brain, heart, and kidneys when compared with a ‘generic’ non-NIRS-based algorithm (standard care). Findings did not lend support to the use of NIRS-based algorithms for the personalized optimization of cerebral oxygenation in adult cardiac surgery.

Methods

• This randomized controlled trial was performed on participants in three UK centres.
• Participants were randomized with concealed allocation to a NIRS (INVOS 5100; Medtronic Inc., Minneapolis, MN, USA)-based ‘patient-specific’ algorithm that included a restrictive red cell transfusion threshold (haematocrit 18%) or to a ‘generic’ non-NIRS-based algorithm (standard care).
• The NIRS algorithm aimed to maintain cerebral oxygenation at an absolute value of > 50% or at > 70% of baseline values.
• Cognitive function measured up to 3 months postsurgery was the primary outcome for the trial.

Results

•  This study included eligible randomized patients who underwent valve or combined valve surgery and coronary artery bypass grafts using cardiopulmonary bypass between December 2009 and January 2014 (n=98 patient-specific algorithm; n=106 generic algorithm).
• Findings demonstrated no difference between the groups for the three core cognitive domains (attention, verbal memory, and motor coordination) or for the non-core domains psychomotor speed and visuo-spatial skills.
• Researchers observed that the NIRS group had higher scores for verbal fluency; mean difference 3.73 (95% confidence interval 1.50, 5.96).
• In addition, they noted that red cell transfusions, biomarkers of brain, kidney, and myocardial injury, adverse events, and health-care costs were similar between the groups.