Print Email Facebook Twitter Inspired Carbon Dioxide During Hypoxia: Effects on Task Performance and Cerebral Oxygen Saturation Title Inspired Carbon Dioxide During Hypoxia: Effects on Task Performance and Cerebral Oxygen Saturation Author van Dorp, E. Los, M. Dirven, P. Sarton, E. Valk, P. Teppema, L. Stienstra, R. Dahan, A. TNO Defensie en Veiligheid Publication year 2007 Abstract Introduction: Exposure to a hypoxic environment has a deleterious effect on physiological and mental functions. We studied the effect of added inspired CO2 during artificially induced hypoxic normobaric hypoxia (oxygen saturation ∼80%) on complex task performance. Methods: In random order, 22 healthy volunteers were exposed to 3 gas mixtures for 50 min each: sham hypoxia (SH, PetO2 103 mmHg without inspired CO2); isocapnic hypoxia (IH, PetO2 ∼40 mmHg, PetCO2 clamped to 0.4 mmHg above resting values); and poikilocapnic hypoxia (PH, PetO2 ∼40 mmHg; no inspired CO2). Brain oxygenation was measured using near infrared spectroscopy. During minutes 25-45 of hypoxia, subjects performed vigilance and task performance tests used in aviation research: the Vigilance and Tracking test and the Multi-Attribute Task battery (MAT-bat). The tests varied in difficulty with the tracking tests considered most difficult. Results: PetCO2 levels differed significantly among groups: IH 42.8 ± 0.7, SH 39.0 ± 0.7, and PH 36.8 ± 0.7 mmHg. Brain oxygenation levels were significantly higher during IH than PH (62.2 ± 1.0 vs. 59.1 ± 1.3%). The results of the performance tests indicated a negative effect of PH vs. SH on most function tests. For the Tracking test of the MAT-bat, performance was worst during PH, but returned to baseline during IH. Discussion: We demonstrate the ability of added inspired CO2 to improve performance during hypoxia by preventing PH-associated hypocapnia-induced vasoconstriction of brain blood vessels. Our results are relevant to aerospace medicine and other circumstances in which complex tasks are performed in a hypoxic environment such as mountain climbing and working in confined spaces. Copyright © by Aerospace Medical Association. Subject AviationComplex task performanceIsocapniaPoikilocapniaSimulation of pilotingVigilanceCarbon dioxideAlertnessInfrared spectroscopyMulti attribute task batteryOxygen saturationTask performanceVasoconstrictionVigilance and tracking testCarbon DioxideCerebrovascular CirculationCognitionBrainOximetryOxygenPulmonary VentilationSpectroscopy, Near-InfraredTask Performance and AnalysisTidal Volume To reference this document use: http://resolver.tudelft.nl/uuid:0653c477-4108-4924-ba31-fadde02761c0 TNO identifier 20074 Source Aviation, Space, and Environmental Medicine, 78 (7), 666-672 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.