Hemoglobin Oxygen Saturation with Mild Hypoxia and Microgravity
INTRODUCTION: Microgravity (μG) exposure and even early recovery from μG in combination with mild hypoxia may increase the alveolar-arterial oxygen (O2) partial pressure gradient.
METHODS: Four male astronauts on STS-69 (1995) and four on STS-72 (1996) were exposed on Earth to an acute sequential hypoxic challenge by breathing for 4 min 18.0%, 14.9%, 13.5%, 12.9%, and 12.2% oxygen–balance nitrogen. The 18.0% O2 mixture at sea level resulted in an inspired O2 partial pressure (PIo2) of 127 mmHg. The equivalent PIO2 was also achieved by breathing 26.5% O2 at 527 mmHg that occurred for several days in μG on the Space Shuttle. A Novametrix CO2SMO Model 7100 recorded hemoglobin (Hb) oxygen saturation through finger pulse oximetry (Spo2, %). There were 12 in-flight measurements collected. Measurements were also taken the day of (R+0) and 2 d after (R+2) return to Earth. Linear mixed effects models assessed changes in Spo2 during and after exposure to μG.
RESULTS: Astronaut Spo2 levels at baseline, R+0, and R+2 were not significantly different from in flight, about 97% given a PIo2 of 127 mmHg. There was also no difference in astronaut Spo2 levels between baseline and R+0 or R+2 over the hypoxic challenge.
CONCLUSIONS: The multitude of physiological changes associated with μG and during recovery from μG did not affect astronaut Spo2 under hypoxic challenge.
Conkin J, Wessel JH III, Norcross JR, Bekdash OS, Abercromby AFJ, Koslovsky MD, Gernhardt ML. Hemoglobin oxygen saturation with mild hypoxia and microgravity. Aerosp Med Hum Perform. 2017; 88(6):527–534.
METHODS: Four male astronauts on STS-69 (1995) and four on STS-72 (1996) were exposed on Earth to an acute sequential hypoxic challenge by breathing for 4 min 18.0%, 14.9%, 13.5%, 12.9%, and 12.2% oxygen–balance nitrogen. The 18.0% O2 mixture at sea level resulted in an inspired O2 partial pressure (PIo2) of 127 mmHg. The equivalent PIO2 was also achieved by breathing 26.5% O2 at 527 mmHg that occurred for several days in μG on the Space Shuttle. A Novametrix CO2SMO Model 7100 recorded hemoglobin (Hb) oxygen saturation through finger pulse oximetry (Spo2, %). There were 12 in-flight measurements collected. Measurements were also taken the day of (R+0) and 2 d after (R+2) return to Earth. Linear mixed effects models assessed changes in Spo2 during and after exposure to μG.
RESULTS: Astronaut Spo2 levels at baseline, R+0, and R+2 were not significantly different from in flight, about 97% given a PIo2 of 127 mmHg. There was also no difference in astronaut Spo2 levels between baseline and R+0 or R+2 over the hypoxic challenge.
CONCLUSIONS: The multitude of physiological changes associated with μG and during recovery from μG did not affect astronaut Spo2 under hypoxic challenge.
Conkin J, Wessel JH III, Norcross JR, Bekdash OS, Abercromby AFJ, Koslovsky MD, Gernhardt ML. Hemoglobin oxygen saturation with mild hypoxia and microgravity. Aerosp Med Hum Perform. 2017; 88(6):527–534.
Keywords: gas exchange; oxygen dissociation curve; pulmonary edema; spaceflight
Document Type: Research Article
Publication date: 01 June 2017
- This journal (formerly Aviation, Space, and Environmental Medicine), representing the members of the Aerospace Medical Association, is published monthly for those interested in aerospace medicine and human performance. It is devoted to serving and supporting all who explore, travel, work, or live in hazardous environments ranging from beneath the sea to the outermost reaches of space. The original scientific articles in this journal provide the latest available information on investigations into such areas as changes in ambient pressure, motion sickness, increased or decreased gravitational forces, thermal stresses, vision, fatigue, circadian rhythms, psychological stress, artificial environments, predictors of success, health maintenance, human factors engineering, clinical care, and others. This journal also publishes notes on scientific news and technical items of interest to the general reader, and provides teaching material and reviews for health care professionals.
To access volumes 74 through 85, please click here. - Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- Submit Articles
- Ingenta Connect is not responsible for the content or availability of external websites
Receive new issue alert- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content