Waveform capnography guides ventilation rates and confirms airway placementĮxcessive positive pressure ventilation frequently occurs during resuscitation and is extremely harmful. Compression feedback helps determine whether compression adjustments can make perfusion better, and ETCO2 shows when good compressions do not generate effective perfusion. Low ETCO2 (below 10 mm HG) may be caused by either poor compression technique, or from low perfusion and metabolism after a long downtime or shock despite good compressions.

Compressions may also generate small capnography waveforms from passive air exchange between ventilations, which also provides feedback on compression rate. The higher the ETCO2, the better the perfusion generated by CPR, and the better the chances of survival are. An ETCO2 reading above 15 mm HG indicates compressions are generating perfusion. Both are important to guide treatment, and both should be applied as early as possible.Ī higher ETCO2 reading during resuscitation correlates with improved cardiac output and patient outcomes. ETCO2 provides feedback on how effective compressions are at perfusing vital organs. These prompt the compressor to adjust their technique, and detect the need to change compressors due to fatigue. Several devices are available that provide real-time feedback on compression quality. The depth of each compression should be at least 2 inches, but not greater than 2.4 inches, the hands must come completely off the chest on the upstroke, compressions should be delivered at a rate of 100-120 time a minute, with pauses only for compressor changes. Compression feedback devices measure CPR quality, ETCO2 measures how the body responds to itĬonsistent, high quality chest compressions are essential for successful cardiac arrest resuscitation. If the patient has a pulse and is breathing, look for a problem with the capnography circuit, such as secretions in the filter or kinks in the tubing. If the patient has a pulse and is not breathing, initiate positive pressure ventilation. If a pulse is felt, then check for breathing, because respiratory arrest will also cause a loss of ETCO2. If a capnography waveform is lost, check for a pulse immediately, and initiate CPR if one cannot be felt. This is especially true in bradycardic patients receiving transcutaneous pacing. The tracing on an ECG monitor may not even change after the patient loses pulses the patient’s heart may still have electrical activity but no pumping action. Pulse-oximetry depends on circulation at the location where the probe is placed, which is inconsistent in patients in shock or with cold extremities. Other monitoring devices are less reliable for detecting cardiac arrest. If a waveform is produced with exhalation, some circulation is present.

Waveform capnography is also useful for hypotensive patients with decreased mentation, where detection of a carotid pulse can be difficult. This is even true for patients with good air movement while receiving positive pressure ventilation. As soon as the heart stops, the capnography waveform will disappear and the ETCO2 reading will change to zero. A change in any of those will be immediately detected with waveform capnography, which is valuable information while caring for critically ill and injured patients.īesides constant palpation of a carotid pulse, waveform capnography is the most reliable prehospital monitoring device to detect the immediate loss of circulation. Loss of ETCO2 may be the first sign that CPR is neededĮnd-tidal CO2 (ETCO2) detection requires air movement in and out of the lungs (ventilation), CO2 production from cellular metabolism, and blood flow to the lungs to excrete the CO2.

Normal range of capnography