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Portable hyperbaric chamber In 1997, a hiking expedition was stranded for 38 days on...

Portable hyperbaric chamber In 1997, a hiking expedition was stranded for 38 days on the Tibetan side of Mount Everest at altitudes over 5200 m. For 30 days the party was stranded above 6500 m in severe weather conditions. While at altitudes over 8000 m, 10 climbers suffered acute mountain sickness. A 37-year-old climber with acute pulmonary edema (buildup of fluid in the lungs) was treated with a portable Gamow bag (see Figure 9.19), named after its inventor, Igor Gamow. The Gamow bag is a windowed cylindrical portable hyperbaric chamber constructed of nonpermeable nylon that requires constant pressurization with a foot pump attached to the bag. The climber enters the bag, and a person outside pumps air into the bag so that the air pressure inside is somewhat higher than the outside pressure. The bag and pump have a 6.76-kg mass. The volume of the inflated bag is 0.476 m³. The maximal bag pressure is 0.14 X 10⁵ N/m² above the air pressure at the site where it is used. In the 1997 climb, with the temperature at -20 °C, the bag was filled in about 2 min with 10–20 pumps per minute. This raised the pressure in the bag to 0.58 X 10⁵ N/m² (equivalent to an elevation of 4400 m) instead of the actual outside pressure of 0.43 X 10⁵ N/m² at the 6450-m elevation. The treatment lasted for 2 h, with the person inhaling about 15 times/min at about 0.5 L/inhalation, and was successful—the pulmonary edema disappeared.