Comparisons between sublingual and gastric tonometry during hemorrhagic shock

Area of Science:

• Physiology
• Critical Care Medicine
• Surgical Research

Background:

• Hemorrhagic shock severely impairs tissue perfusion.
• Gastric tonometry is an established method for assessing perfusion failure.
• Sublingual tissue PCO(2) offers a potentially simpler, noninvasive alternative.

Purpose of the Study:

• To compare sublingual tissue PCO(2) (PslCO(2)) with gastric tonometric PCO(2) in assessing hemorrhagic shock severity.
• To evaluate the interchangeability of these two noninvasive measurements.

Main Methods:

• A prospective animal study was conducted on domestic pigs.
• Hemorrhagic shock was induced using a modified Wigger's method, maintaining blood pressure at 50 mm Hg for 120 minutes.
• Sublingual and gastric PCO(2) were measured, followed by reinfusion of shed blood.

Main Results:

• Hemorrhagic shock led to significant decreases in mean arterial pressure and cardiac output, and increased lactate levels.
• Both sublingual PCO(2) and gastric PCO(2) increased significantly during shock.
• A strong correlation (r=0.91) was found between time-coincident PslCO(2) and gastric PCO(2) measurements, with close agreement shown by Bland-Altman analysis.

Conclusions:

• Sublingual capnometry provides measurements of PCO(2) that are interchangeable with gastric tonometry during experimental hemorrhagic shock.
• PslCO(2) is a viable, noninvasive method for monitoring the severity of perfusion failure.