Intragastric PCO2 has been recognized to rise in states of gastric hyp
operfusion. A device including a gas-permeable balloon on a convention
al sump nasogastric tube (TRIP catheter, Tonometrics) has permitted si
mple measurement of the intragastric PCO2 following equilibration of i
ntragastric PCO2 with saline in the balloon, This method is slow to eq
uilibrate and time-consuming, We describe an automated method using ai
r instead of saline in the balloon with measurement using capnography,
Equilibration is much faster using air and the automated system permi
ts measurements to be taken at regular intervals (10 minutes) without
additional workload.