IngentaConnect Cerebral Blood Flow Velocity and Psychomotor Performance During A...

Abstract:

Blogg SL, Gennser M. Cerebral blood flow velocity and psychomotor performance during acute hypoxia. Aviat Space Environ Med 2006; 77:107–13.

Introduction: The physiological effects of hypoxic environments can help determine safe limits for workers where cognitive and motor performance is important. We investigated the effects of a PIO₂ of 15 kPa and 10 kPa on medial cerebral artery blood flow velocity (CBFV) and psychomotor performance. Methods: Over 3 sessions, each involving 3 separate test batteries, 13 subjects breathed either 21 kPa PIO₂ (control), 15 kPa PIO₂, or 10 kPa PIO₂. The tests measured reaction time, spatial orientation, voluntary repetitive movement, and fine manipulation. CBFV, PETCO₂, PETO₂, SaO₂, and BP were recorded throughout. Results: ANOVA analysis showed that 15 kPa PIO₂ did not significantly change psychomotor test performance. The mean number of incorrect responses in the reaction time test significantly increased to 5.6 (SD ± 4.0) while breathing 10 kPa PIO₂, as did the mean number of errors (7.7 ± 5.0) in the fine manipulation test. Only 10 kPa PIO₂ affected CBFV, causing a significant increase in flow from 50 ± 6.5 cm · s⁻¹ to 55 ± 10.3 cm · s⁻¹. CBFV significantly increased during three psychomotor tests while breathing air; however, it did not increase further during psychomotor testing in hypoxia. Discussion: A PIO₂ of 15 kPa did not affect subject performance, and should not cause operational risk. At 10 kPa PIO₂, accuracy and vigilance were slightly affected; however, the reduction in oxygenation was not great enough to cause major decrements. CBFV was not a good indicator of mental stress during hypoxia.

Cerebral Blood Flow Velocity and Psychomotor Performance During Acute Hypoxia