Fatigue in the military: towards a fatigue detection test based on the saccadic velocity.

Fatigue is a major contributing factor to operational errors. Therefore, the validation of objective and sensitive indices to detect fatigue is critical to prevent accidents and catastrophes. Whereas tests based on saccadic velocity (SV) have become popular, their sensitivity in the military is not yet clear, since most research has been conducted in laboratory settings using not fully validated instruments. Field studies remain scarce, especially in extreme conditions such as real flights. Here, we investigated the effects of real, long flights on SV. We assessed five newly commissioned military helicopter pilots during their aviation training. Pilots flew Sikorsky S-76C helicopters, under instrumental flight rules, for more than 2 h (ca. 150 min). Eye movements were recorded before and after the flight with an eye tracker using a standard guided-saccade task. We also collected subjective ratings of fatigue. SV significantly decreased from the Pre-Flight to the Post-Flight session in all pilots by around 3% (range: 1-4%). Subjective ratings showed the same tendency. We provide conclusive evidence about the high sensitivity of fatigue tests based on SV in real flight conditions, even in small samples. This result might offer military medical departments a valid and useful biomarker of warfighter physiological state.

Surgical correction of disc pathology in fighter pilots: a review of 14 cases.

BACKGROUND: Disorders of the spine are common in fighter crewmembers. The high cost of training and experience for pilots makes it important to use all reasonable clinical means to restore grounded pilots to their flying duties, provided that all safety standards are maintained. To date, there has been limited research into specific surgical treatment of spine injury in pilots. This study was designed to examine the efficacy of surgical procedures in Spanish Air Force fighter pilots with injuries to the spine, as well as the aeromedical disposition of such pilots. METHODS: A retrospective study was conducted using the medical records of 14 fighter pilots with symptomatic spinal disorders treated by surgery. RESULTS: The 14 pilots underwent surgery: 12 cases involved fusion of vertebral structures (arthrodesis), while 2 pilots underwent discectomy. All pilots were subsequently given waivers to resume flying duties. DISCUSSION: The successful return to flight status of these pilots indicates the practical application of surgical techniques that safely stabilize the spine. However, due the sample limited size of the sample, further studies are needed.

Expression of nitrergic system and protein nitration in adult rat brains submitted to acute hypobaric hypoxia.

Changes in the nitric oxide (NO) system of the rat cerebral cortex were investigated by immunohistochemistry, immunoblotting, and NO synthase (NOS) activity assays in adult rats submitted for 30 min to hypoxia, in a hypobaric chamber at a simulated altitude of 38,000 ft (11000 m) (154.9 mm Hg). The cerebral cortex was studied after different survival times, 0 and 24 h, 5, 8, 15, and 30 days of reoxygenation. This situation led to morphological alterations in the large type I interneurons, as well as immunoreactive changes in the appearance and number of the small neurons (type II), both containing neuronal NOS (nNOS). Some of these small neurons showed immunoreactive cytoplasm and short processes; others, the more numerous during all reoxygenation periods, contained the immunoreactive product mainly related to a perinuclear ring. Ultrastructurally, these small neurons exhibited changes in nuclear structures as in the shape of the nuclear membrane, in the distribution of heterochromatin, and in the nucleolar morphology. The reaction product for nitrotyrosine, as a marker of protein nitration, showed modifications in distribution of the immunoreactive product. No expression was found for inducible NOS (iNOS). All these modifications were accompanied by increased nNOS and nitrotyrosine production as demonstrated by Western blotting and calcium-dependent activity, returning to control conditions after 30 days of reoxygenation, suggesting a reversible NO mechanism of action.

Medicina Aeronáutica y Seguridad Aérea / No disponible

No disponible

La Medicina Aeroespacial, una especialidad necesaria / No disponible

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Tolerancia a la hipoxia en relación con la edad / Hypoxia tolerance in relationship with age

Introducción: La hipoxia es uno de los grandes problemas dentro del mundo aeronáutico. La falta de oxígeno afecta a la capacidad intelectual, psicomotora y estado de alerta del individuo. Las alteraciones pueden ser muy variadas. Esta variabilidad individual dependerá de muchos factores, uno de los factores que podría influir en la respuesta del SNC a los efectos de la deprivación de oxígeno es la edad. Objetivos. El objetivo de este trabajo es estudiar si existen diferencias, respecto a la edad, en la capacidad de actuación y reacción del personal de vuelo, bajo condiciones de hipoxia. Sujetos y métodos: Se estudiaron 161 tripulantes aéreos que realizaron un vuelo de entrenamiento en una cámara de baja presión. Se cuantificó el grado de alteraciones de las funciones cognitivas, mediante un test desarrollado durante un vuelo. Resultados: El grupo de sujetos cuyas edades estaban comprendidas entre 30 y 39 años obtuvieron estadísticamente (p<0,05) mejores resultados en el test que el grupo entre 20-29 años y aunque no es estadísticamente significativo, el primer grupo tiende a una mejor respuesta en el test sobre el grupo de mayores de 40 años. Conclusiones: Los tripulantes aéreos entre 30 y 39 años reúnen las condiciones idóneas de experiencia, por un lado y por otro se encuentran en una edad donde todavía no se ha manifestado el deterioro de las capacidades cognitivas y psicomotoras por el envejecimiento, para tolerar las condiciones de hipoxia (AU)