Cardiopulmonary Bypass Mean Global Oxygen Delivery May Be Associated with Neurocognitive Preservation during Hypothermic Aortic Surgery

Abstract

The purpose of this retrospective research was to investigate the relationship between mean global oxygen delivery (DO2) and neurocognitive function in adult patients who presented for aortic surgery with deep hypothermic circulatory arrest using cardiopulmonary bypass (CPB). From a pool of 132 patients, data from 100 CPB patients from 2012 to 2014 aged 50 years or older were randomly selected and analyzed, and global DO2 on CPB was used to categorize patients into those for whom the mean indexed cerebral oxygen delivery (DO2i) was either ≥272 mL O2/min/m2 (critical DO2 [DO2crit]) or less than DO2crit. Ten patients experienced either stroke or expired in the perioperative course. The proportion of patients with evidence of neurocognitive preservation was 98.3% in the group in which the DO2crit was met, compared with 80.6% in the group where DO2crit was not met (X2 [1, 100] = 3.27, p = .07). Potentially, because of causes other than DO2, the subset of patients with stroke and/or death were removed, and data from 90 cases were analyzed, and a global mean DO2i value of 239.9 mL O2/min/m2 was identified. A larger sample size with controls may yield deeper insights into the hypothesis that a mean global CPB DO2i of 239.9 mL O2/min/m2 may play a role in predicting neurocognitive preservation in this patient population.