Decreases in organ blood flows associated with increases in sublingual P CO 2 during hemorrhagic shock

Abstract

Earlier studies demonstrated that not only the stomach but also the esophageal wall served as an appropriate site for estimating the severity of circulatory shock by using tonometric methods. We then conceived of the option of sublingual tonometry. In the present study, we tested the hypothesis that the changes in sublingual [Formula: see text] serve as indicators of decreases in blood flow to sublingual and visceral tissue. In Sprague-Dawley rats, sublingual[Formula: see text] increased from 50 to 127 Torr and arterial blood lactate increased from 0.9 to 11.2 mmol/l during bleeding. Sublingual blood flow simultaneously decreased to ∼32% of preshock values. After reinfusion of shed blood, organ blood flows and sublingual [Formula: see text] were promptly restored to near-baseline values. There were corresponding decreases in blood flows in the tongue, stomach, jejunum, colon, and kidneys during hemorrhagic shock. Increases in sublingual[Formula: see text] were highly correlated with decreases in sublingual blood flow ( r= 0.80), tongue blood flow ( r = 0.81), gastric blood flow ( r = 0.74), jejunal blood flow ( r = 0.65), colon blood flow ( r = 0.80), and renal blood flow ( r = 0.75). Unbled control animals demonstrated no significant changes. Therefore, we anticipate that sublingual tonometry will provide a useful, noninvasive alternative for monitoring visceral [Formula: see text].