Effects of low-grade hypoxia on performance in a vigilance situation.

OAM report.PDFTech ReportFAA-AM-71-11DOT/FAA/AM-71/11MalesHypoxiaVigilanceAltitudeOxygenPhysiological aspectsHeart rateRespiratory systemBreathTemperatureBloodBlood analysisPerformance testsCarbohydratesPsychological aspectsLightInstrument displaysMusclesMuscular systemOxidationExperimentsTemperature measurementHuman subject testingUnited StatesCivil Aerospace Medical InstituteFiorica, VincentBurr, Mary JoMoses, RussellCivil Aeromedical InstituteUnited States. Office of Aviation MedicineNTL-AVIATION-Aviation Human FactorsNTL-AVIATION-Aviation Safety/AirworthinessNTL-SAFETY AND SECURITY-Aviation Safety/AirworthinessNTL-SAFETY AND SECURITY-Human FactorsNTL-LAWS AND REGULATIONS-Federal Standards and RulesNTL-LAWS AND REGULATIONS-Aviation Laws and RegulationsUS Transportation CollectionForty male subjects participated in a study to examine the relationship between low-grade hypoxia and vigilance performance. At an altitude equivalent of 11,500 feet in a low-pressure chamber, subjects without supplemental oxygen did not respond differently from well-oxygenated subjects at the same altitude with respect to such physiologic measures as heart rate, respiratory frequency, internal body temperature, or plasma concentrations of glucose or lactate. Nor were these measures significantly different between groups studied at altitude and ground level controls.The only evidence of hypoxia observed in the altitude/room air group was in terms of a decrease in blood oxygen saturation measured with an earpiece oximeter. Vigilance performance deteriorated with time in all groups. No significant differences, however, could be detected between the hypoxic group and the well-oxygenated groups.It is concluded that a four-hour exposure to 11,500 feet of altitude has no demonstrable effect on the performance of a simple vigilance task under the conditions examined here. Because of the limitations concerning test subjects and the test used in this study, its results do not affect compliance with FAR 91.32, supplemental oxygen rule