Real-time heart rate variability analysis as a means of hypercapnia detection.

We hypothesized that heart rate variability (HRV) can be used as a physiological monitor of exposures to hypercapnia. HRV was analyzed in 15 male subjects breathing air and then air plus 4%, 5% or 6% carbon dioxide (CO2). A progressive elevation in randomness of HRV best depicted as a divergence of data on Poincar é plots of self-similarity occurred as CO2 increased, and resolved when returning sd to ambient conditions.

Echocardiographic evaluation of intracardiac venous gas emboli following in-water recompression.

Decompression sickness is a potentially fatal illness. Optimal treatment is dry recompression with hyperbaric oxygen. In-water recompression (IWR) offers expedited treatment but has insufficient evidence to recommend it as a treatment option.

Ketogenic diet for high partial pressure oxygen diving.

Introduction: A ketogenic diet (KD) may decrease central nervous system oxygen toxicity symptoms in divers, and in view of this implication a feasibility/ toxicity pilot study was performed to demonstrate tolerance of KD while performing normal diving profiles. The exact mechanism of neuroprotection from the KD remains unknown; however, evidence to support the efficacy of the KD in reducing seizures is present in epilepsy and oxygen toxicity studies, and may provide valuable insight in diving activities.

Methods: Three divers (two males and one female ages 32-45 with a history of deep diving and high pO2 exposure) on the KD made dives to varying depths in Hawaii using fully closed-circuit MK-15 and Inspiration rebreathers.