SHAD-Nisat: A Composite Study of Shallow Saturation Diving Incorporating Long Duration Air Saturation with Excursions, Deep Nitrox Saturation, and Switch from Nitrogen to Helium.

摘要

The four SHAD dives looked at air for breathing in saturation at 50 and 60 fsw. Excursions from these depths demonstrated possible work procedures, covering depths ranging between 5 and 250 fsw and for times as long as 8 hours. The exposures were well tolerated but disclosed problems with oxygen toxicity in daily 8-hour excursions to 100 fsw and an increased sensitivity to extra oxygen breathing in several of the divers. The long air exposures caused red blood cell losses; recovery began a few days after return to normal pressure. The divers were also deconditioned, presumably because of the confinement and several weeks of inactivity. Decompressions from descending excursions were free of bends but some ascending excursions caused itching and ultrasonically-detectable bubbles. Two of three divers became nauseated 3 hours after beginning a saturation exposure in an atmosphere containing 0.22 atm oxygen, balance nitrogen, at 7 atm abs; the sick divers felt better after P02 was raised to 0.3 atm.