Bubbles, microparticles, and neutrophil activation: changes with exercise level and breathing gas during open-water SCUBA diving

Abstract

Bubbles, microparticles, and neutrophil activation: changes with ex-ercise level and breathing gas during open-water SCUBA diving. J Appl Physiol 114: 1396–1405, 2013. First published March 14, 2013; doi:10.1152/japplphysiol.00106.2013.—The study goal was to evalu-ate responses in humans following decompression from open-water SCUBA diving with the hypothesis that exertion underwater and use of a breathing mixture containing more oxygen and less nitrogen (enriched air nitrox) would alter annexin V-positive microparticle (MP) production and size changes and neutrophil activation, as well as their relationships to intravascular bubble formation. Twenty-four divers followed a uniform dive profile to 18 m of sea water breathing air or 22.5 m breathing 32 % oxygen/68 % nitrogen for 47 min, either swimming with moderately heavy exertion underwater or remaining stationary at depth. Blood was obtained pre- and at 15 and 120 min postdive. Intravascular bubbles were quantified by transthoracic echo