Accession Number:

ADA551762

Title:

Oxygen Breathing Accelerates Decompression from Saturation at 40 msw in 70-kg Swine

Descriptive Note:

Journal article

Corporate Author:

NAVAL MEDICAL RESEARCH CENTER SILVER SPRING MD

Report Date:

2010-07-01

Pagination or Media Count:

8.0

Abstract:

Submarine disaster survivors can be transferred from a disabled submarine at a pressure of 40 meters of seawater msw to a new rescue vehicle however, they face an inherently risky surface interval before recompression and an enormous decompression obligation due to a high likelihood of saturation. The goal was to design a safe decompression protocol using oxygen breathing and a trial-and-error methodology. We hypothesized that depth, timing, and duration of oxygen breathing during decompression from saturation play a role to mitigate decompression outcomes. Methods Yorkshire swine 67-75 kg, compressed to 40 msw for 22 h, underwent one of three accelerated decompression profiles 1 13.3 h staged air decompression to 18 msw, followed by 1 h oxygen breathing, then dropout 2 direct decompression to 18 msw followed by 1 h oxygen breathing then dropout and 3 1 h oxygen prebreathe at 40 msw followed by 1 h mixed gas breathing at 26 msw, 1 h oxygen breathing at 18 msw, and 1 h ascent breathing oxygen. Animals underwent 2-h observation for signs of DCS. Results Profile 1 14.3 h total resulted in no deaths, no Type II DCS, and 20 Type I DCS. Profile 2 2.1 h total resulted in 13 death, 50 Type II DCS, and 75 Type I DCS. Profile 3 4.5 h total resulted in 14 death, 21 Type II DCS, and 57 Type I DCS. No oxygen associated seizures occurred. Discussion Profile 1 performed best, shortening decompression with no death or severe DCS, yet it may still exceed emergency operational utility in an actual submarine rescue.

Subject Categories:

  • Anatomy and Physiology
  • Submarine Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE