The Role of Barometric Pressure in High Altitude Illness
Abstract
We wished to determine if descent or oxygen is more effective for treatment of high altitude pulmonary edema (HAPE). We compared a lightweight (4 kg) hyperbaric chamber (a simulated descent of 1700m) at 4300 meters on Mt. McKinley (440 torr). Ten control subjects and nine HAPE subject were given one hour of oxygen breathing (approx 28% oxygen) and one hour of pressurization at 110 torr (2.1 psi) in the bag in a randomized order. Alveolar oxygen pressures were matched for the two treatments to determine if pressurization had benefits in addition to raising the inspired oxygen pressure. SaO2% increased with both treatments (32% increase with pressurization vs 31% with oxygen). Symptomatic improvement was similar. A drop in hemoglobin was observed with pressurization (11% decrease in HAPE vs 3% in controls), suggesting a rapid flux of fluid into the intravascular compartment as previously reported. The portable hyperbaric chamber appears to be an effective, safe and practical method of treating mountain sickness and pulmonary edema, avoids the weight and expense of oxygen cylinders, and can be used for long periods of time. Increasing the Partial Pressure of Oxygen (PO2) by pressurization or by raising inspired PO2 may be equally effective in improving oxygenation. Pressurization may be more effective in mobilizing extravascular fluid. Further research is needed to determine the optimal length of treatment with the hyperbaric chamber, the reoccurrence of illness after hyperbaric treatment, and whether oxygen or pressurization is more effective for treatment of high altitude illness.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 12, 1988
- Accession Number
- ADA208839
Entities
People
- Peter H. Hackett