BACKGROUND: Few (conflicting) studies have quantitatively assessed neurocognitive effects of deep hypothermic circulatory arrest (DHCA). We assess neurocognitive function quantitatively before and after DHCA in comparison with non-DHCA patients. METHODS: Sixty-two aortic surgical patients underwent a battery of neuropsychometric tests, both preoperative and postoperative, evaluating multiple aspects of memory, processing speed, executive function, and global cognition. Thirty-three patients did not require DHCA, and 29 underwent DHCA as the sole means of cerebral protection. Neurocognitive deficit was defined as greater than 20% decline in 2 or more cognitive areas. Preoperative and postoperative test scores, as well as incidence of neurocognitive deficit, were compared within each group, and between the non-DHCA and DHCA groups. RESULTS: There were no significant differences in the postoperative versus preoperative scores in any cognitive area tested between DHCA and non-DHCA groups. There was also no difference between the 2 groups in incidence of neurocognitive deficit; 13 non-DHCA, 11 DHCA (p = 1.00). In addition, there was no correlation between time under DHCA and incidence of neurocognitive deficit. Within both groups, there was a decline in memory in the areas of acquisition, retention, and delayed recall. Within the DHCA group, recognition was also affected. CONCLUSIONS: While cardiac surgery had some effects on memory, overall neurocognitive function was well preserved and not different between DHCA and non-DHCA patients. Time under DHCA up to 40 minutes was also found to be safe neurocognitively. This study provides strong evidence that straight DHCA effectively preserves neurocognitive function.
BACKGROUND: Few (conflicting) studies have quantitatively assessed neurocognitive effects of deep hypothermic circulatory arrest (DHCA). We assess neurocognitive function quantitatively before and after DHCA in comparison with non-DHCA patients. METHODS: Sixty-two aortic surgical patients underwent a battery of neuropsychometric tests, both preoperative and postoperative, evaluating multiple aspects of memory, processing speed, executive function, and global cognition. Thirty-three patients did not require DHCA, and 29 underwent DHCA as the sole means of cerebral protection. Neurocognitive deficit was defined as greater than 20% decline in 2 or more cognitive areas. Preoperative and postoperative test scores, as well as incidence of neurocognitive deficit, were compared within each group, and between the non-DHCA and DHCA groups. RESULTS: There were no significant differences in the postoperative versus preoperative scores in any cognitive area tested between DHCA and non-DHCA groups. There was also no difference between the 2 groups in incidence of neurocognitive deficit; 13 non-DHCA, 11 DHCA (p = 1.00). In addition, there was no correlation between time under DHCA and incidence of neurocognitive deficit. Within both groups, there was a decline in memory in the areas of acquisition, retention, and delayed recall. Within the DHCA group, recognition was also affected. CONCLUSIONS: While cardiac surgery had some effects on memory, overall neurocognitive function was well preserved and not different between DHCA and non-DHCA patients. Time under DHCA up to 40 minutes was also found to be safe neurocognitively. This study provides strong evidence that straight DHCA effectively preserves neurocognitive function.