Progressive Reduction in Central Blood Volume is not Detected by Sublingual Capnography
ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX
Pagination or Media Count:
Early detection and management of shock are important in optimizing clinical outcomes. One regional marker, sublingual capnography SLCO2, is particularly appealing as redistribution of blood flow away from the sublingual mucosa can happen very early in the compensatory phase of hypovolemic shock. Our objective was to test the hypothesis that SLCO2 would detect early hypovolemia in a human laboratory model of hemorrhage progressive lower body negative pressure until onset of cardiovascular collapse. Eighteen healthy nonsmoking subjects 10 males, 8 females with mean age of 28 SD, 8 years, body weight of 72 SD, 13 kg, and height of 172 SD, 9 cm were recruited to participate, of whom 17 completed the experiment. Average time to presyncope was 1,579 - 72 s mean - SE. At the time of cardiovascular collapse, lower body negative pressure altered P 0.001 systolic blood pressure mean - SE 130 - 3 vs. 98 - 2 mm Hg, pulse pressure mean - SE 58 - 2 vs. 33 - 2 mm Hg, and heart rate mean - SE 63 - 3 vs. 102 - 6 beatsmin when compared with baseline, whereas SLCO2 did not change 49.1 - 1.0 vs. 48.6 - 1.5 mm Hg, P 0.624. In a model of progressive central hypovolemia in humans, we did not detect metabolic derangements in the sublingual mucosa as measured by SLCO2.
- Anatomy and Physiology
- Medicine and Medical Research