Cerebral Oxygenation Responses to Aerobatic Flight

BACKGROUND: Aerobatic pilots must withstand high and sudden acceleration forces (G_z) up to 10 G_z. The physiological consequences of such a succession of high and abrupt positive and negative G_zon the human body over time remain mostly unknown. This case report emphasizes changes in physiological factors such as cerebral oxygenation and heart rate dynamics collected in real aerobatic flights. CASE REPORT: A 37-yr-old man, experienced in aerobatic flying, voluntarily took part in this study. During two flight runs (1520 min), the pilot performed aerobatic maneuvers with multiple high (10 G_z) positive and negative accelerations. During the flights he wore a Polar heart rate sensor while cerebral oxygenation was measured continuously over his prefrontal cortex via near-infrared spectroscopy (NIRS). NIRS allows for measurement of the relative concentration changes of oxygenated hemoglobin (O₂Hb) and deoxygenated hemoglobin (HHb), making it possible to determine cerebral oxygenation and hemodynamic status. DISCUSSION: The continuous in-flight monitoring of O₂Hb and HHb revealed the large effects of successive positive and negative G_z exposures on cerebral hemodynamics alterations. The results showed a significant and positive correlation between changes in G_z exposures and O₂Hb concentration. This case report highlights that NIRS provides some valuable and sensitive indicators for the monitoring of cerebral hemodynamics during aerobatic flights exposed to multiple and high acceleration forces. To our knowledge, this first study quantifying cerebral oxygenation changes in aerobatics opens the way for the assessment of individual physiological responses and tolerance in pilots to repeated high G_z during real flights. Fresnel E, Dray G, Pla S, Jean P, Belda G, Perrey S. .