Esophageal pco2 as a monitor of perfusion failure during
hemorrhagic shock.
Sato, Yoji, Max Harry Weil, Wanchun Tang, Shijie Sun, Jianlin Xie, Joe
Bisera, Hidehiro Hosaka.
The Institute of Critical Care Medicine, Palm Springs, CA, Nihon
Kohden Corporation, Tokyo, Japan
APStracts 3:0476A, 1996.
Measurement of gastric wall PCO2 (PgCO2) by tonometric method has
emerged as an attractive option for estimating visceral perfusion
during circulatory shock. However, gastric acid secretion obfuscates
the tonometric measurement. We therefore investigated the option of
measuring PCO2 in the esophagus to minimize these restraints.
Hemorrhagic shock was induced in five Sprague-Dawley rats and five
rats served as sham controls. PgCO2 was measured with an ion
-sensitive field effect transistor (ISFET) which was surgically
implanted into the gastric wall. Esophageal luminal PCO2 (PeCO2) was
measured by a second ISFET sensor. During hemorrhagic shock, mean
arterial pressure declined from 150 mm Hg to 50 mmHg. Gastric blood
flow decreased from 58 to 12 ml/min/100g (21% of pre-shock) and
esophageal blood flow from 44 to 7 ml/min/100g (16% of pre-shock).
PgCO2 simultaneous increased from 47 to 116 mmHg and PeCO2 from 47 to
127 mmHg. The increases in PgCO2 were highly correlated with
increases in PeCO2 (r=0.90).
Esophageal tonometry may therefore serve as a practical alternative to
gastric tonometry.
Received 25 March 1996; accepted in final form 5 September 1996.
APS Manuscript Number A303-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996