Study objectives: To compare sublingual tissue
Pco2, a disarmingly simple and noninvasive
measurement of the severity of perfusion failure, with gastric
tonometric Pco2 during hemorrhagic shock in
five male domestic pigs weighing between 35 and 40 kg.
Design: Prospective animal study.
Animal laboratory in a research institution.
Participants: Domestic pigs.
Interventions: Hemorrhagic shock was induced by a
modification of the Wigger’s method. BP was maintained at 50 mm Hg for
120 min followed by reinfusion of shed blood at a rate of 100 mL/min
with the aid of an infusion pump.
results: During bleeding, the mean arterial pressure decreased
from an average of 127 to 42 mm Hg, and cardiac output decreased from
7.7 to 2.4 L/min. Arterial blood lactate concentration concurrently
increased from 1.2 to 13.9 mmol/L. Sublingual
increased from 59 to 105 mm Hg, and gastric
Pco2 increased from 61 to 111 mm Hg. The
correlation between time-coincident sublingual and gastric measurements
of Pco2 was r = 0.91
(p < 0.0001). Bland-Altman analyses demonstrated a close
correspondence between the two measurements. The reinfusion of shed
blood promptly reversed the hemodynamic abnormalities and reestablished
gastric and Pslco2 to near baseline values.
This contrasted with a delayed reversal of lactic acidosis.
Conclusions: Under experimental conditions of hemorrhagic
shock, sublingual capnometry yielded measurements that were
interchangeable with those of gastric tonometry.