|Bhavani Shankar Kodali||United States||Reply to below query by Zachary:|
If a patient has cardiac arrest and CPR is being performed, there will be small appreciable waveforms seen on the capnography screen. These waveforms confirm that the endotracheal tube is correctly placed in the trachea. Since the CPR generates low cardiac output, the physiological dead space is relatively high resulting in lower overall end-tidal CO2 values. These values may range up to 25 mm Hg in a well performed CPR. The effectiveness of CPR can be judged by end-tidal PCO values. Every effort has to be made to keep end-tidal PCO2 values close to 20 mm Hg. An abrupt increase in PCO2 values (36 mm Hg as an example) may indicate return of spontaneous circulation (ROSC).
Hence the value of capnography during CPR is 1. confirm ET position, 2, effectiveness of CPR, 3. ROSC.
Ventilation during CPR is based on the standard principles of CPR in ACLS