Measurement of inert gas narcosis and its degree is difficult during operational circumstances, hence the need for a reliable, reproducible and adaptable tool. Although being an indirect measure of brain function, if reliable, critical flicker fusion frequency (CFFF) could address this need and be used for longitudinal studies on cortical arousal in humans...

INTRODUCTION: Breath-hold diving-induced hemoptysis (BH-DIH) has been reported in about 25% breath-hold divers (BHD) and is characterized by dyspnea, coughing, hemoptysis and chest pain. We investigated whether eNOS G894T, eNOS T786C and ACE insertion/deletion I/D genetic variants, are possible BH-DIH risk factors...

The clinical application of Hyperbaric Oxygen Therapy (HBOT), although based on sound physiological principles as well as on a logical rationale, has often been characterized by empirical procedures, and the choice of the treatment schedules has been more fortuitous than rational. The indication for HBOT and the treatment protocol are originated by the general and often acritical assumption that a given lesion or malfunction is caused, facilitated or worsened by hypoxia. Furthermore, the increasingly common use of multiplace hyperbaric chambers, where many patients can be treated at the same time, although maximizing the cost benefit ration of HBOT and the performance of the chamber technical and nursing personnel justified the commonly adopted routine of using average treatment pressures and schedules without considering the differences between indications, patients, disease conditions and the evolving physiopathological stages of the healing process in the individual patients. As a consequence, it is quite frequent to witness the very strange paradox that a treatment based on extremely solid physiological grounds is often applied empirically and nonrationally.

PURPOSE: The purpose of this study was (1) to further explore the heart rate dynamics and assess a potential cardiovascular risk in response to 4000 m jumps in experienced skydivers; (2) to assess whether there is an impact of such jumps on skydivers' cortical arousal or not, which may impact their decision making processes...

Introduction: Heart rate variability (HRV) during underwater diving has been infrequently investigated because of environment limitations and technical challenges. This study aims to analyze HRV changes while diving at variable hyperoxia when using open circuit (OC) air diving apparatus or at constant hyperoxia using a closed-circuit rebreather (CCR).