Muscle oxygen saturation during hyperthermic central hypovolemia (1104.21)
Abstract
During normothermia, a reduction in near infrared spectroscopy (NIRS) derived muscle oxygen saturation (SmO2) is an indicator of central hypovolemia. Hyperthermia reduces tolerance to central hypovolemia. This study tested the hypothesis that reductions in NIRS derived SmO2 would be similar throughout normothermic and hyperthermic central hypovolemia to pre‐syncope. Ten healthy males (32 ± 5 y) underwent central hypovolemia via progressive lower‐body negative pressure (LBNP) to pre‐syncope during normothermia and hyperthermia (+1.2 ± 0.1°C increase in internal temperature). NIRS derived SmO2 (Reflectance Medical Inc.) was measured throughout and analyzed as the absolute change from pre‐LBNP. Hyperthermia reduced (P2 was similar (P=0.654) between normothermia (74.1 ± 5.0%) and hyperthermia (72.6 ± 6.9%). SmO2 decreased (P2 during central hypovolemia to pre‐syncope. However, a potentially confounding influence of hyperthermia‐induced increases in skin blood flow affecting the NIRS derived SmO2 signal cannot be discounted.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 01, 2014
- Source ID
- 10.1096/fasebj.28.1_supplement.1104.21
Entities
People
- Babs Soller
- Craig G Crandall
- Eric Rivas
- Jena Kern
- Naomi Kennedy
- Víctor A. Convertino
- Zachary J Schlader
Organizations
- Institute for Exercise and Environmental Medicine
- Texas Woman's University
- United States Department of Defense