EFFECT OF DEEP ANESTHESIA ON DEVELOPMENT OF POST-OPERATIVE COGNITIVE DYSFUNCTION

The profound deepening of medicamentous sleep down to the burst-suppression electroencephalography pattern is used to provide medication-based protection of brain during preventive temporary clipping of the major arteries when performing surgery due to cerebral aneurysms. There is no consensus about the effect of profound suppression of electrobiological activity on the development of post-operative cognitive dysfunction. The goal: to evaluate the impact of anesthesia with the burst-suppression electroencephalography pattern on the post-operative cognitive status of the patients with no cerebral disorders. Subjects and methods. 30 patients were enrolled into the prospective randomized study, they all had surgeries due to degenerative spinal diseases. All patients were divided into two groups. Anesthesia in the main group (Group 1) differed from the one in the control group (Group 2); it included administration of propofol till achieving suppression of the electrobiological activity of burst-suppression electroencephalography pattern during 15 minutes. Prior to the surgery and in 4 days after it, all patients had neuro-psychological tests using Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB) and numbers memorization techniques (NMT). Results. When testing in 4 days after surgery, results in the patients from Group 1 did not differ from pre-operative results of MoCA (Me_before = 28, Me_after= 28, Z = 0.714, p = 0.476), FAB (Me_before = 18, Me_after = 18, Z = 0.592, p = 0.554), memorization of numbers in the direct order (Me_before = 18, Me_after = 18, Z = 0.178, p = 0.859) and in the reverse order (Me_before = 18, Me_after = 18, Z = 0.548, p = 0.583). The results of the post-operative testing in Group 2 were compatible with pre-operative results of (Me_before = 18, Me_after = 18, Z = 0.459, p = 0.646), FAB (Me_before = 18, Me_after = 18, Z = 1.348, p = 0.178), memorization of numbers in the direct order (Me_before = 18, Me_after = 18, Z = 0.21, p = 0.843) and in the reverse order (Me_before = 18, Me_after = 18, Z = 0.809, p = 0.418). None of the tests detected significant differences between the Groups (U = 88, p = 0.319, Z = 0.995 for MoCA; U = 102.5, p = 0.644, Z = 0.394 for FAB; U = 92.0, p = 0.407, Z = -0.829 for memorization of numbers in the direct order, and U = 33.5, p = 0.62, Z = 0.572 for memorization of numbers in the reverse order). Conclusion. Anesthesia with burst-suppression electroencephalography pattern as a model of medication-based cerebral protection during temporary clipping of the major arteries does not cause the deterioration of cognitive status in the patients who had no cerebral pathology initially.

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