Capnography: What EMS chiefs and leaders need to know
Use this information to engage your field providers about how capnography improves patient care and outcomes
By Chris Cebollero
As EMS leaders, we put a team around us to handle areas of specialization from operations to communications and clinical care to education. Trusting that team to accomplish the mission is an important component of organizational success. Nevertheless, as leaders, we still need to have a working knowledge of all areas within our organization. This is what EMS chiefs and leaders need to know about the use of capnography by our workforce.
An additional vital sign
While assessing patients, the knowledge we gather from vital signs allows our clinicians to make precise diagnoses and employ the appropriate management and treatment. Capnography is often referred to as the seventh vital sign, and can be used in intubated and nonintubated patients. Combining all vital sign information, especially as they change over time, allows our personnel to drill down on both ventilation and perfusion status.
Reading the capnogram
As cells produce CO2, it is the responsibility of the lungs to remove this waste from the body. The balance between the rise and fall of end tidal CO2 (ETCO2) is captured in a waveform. It is this waveform that allows a quick and reliable reference to determine the effectiveness of pulmonary function.
This is a normal waveform. The y-axis displays ETCO2 over time, the x-axis.
During inspiration, CO2 is essentially zero on the x-axis baseline. Each waveform has four phases:
Phase 1: This occurs as exhalation begins, corresponding to the A to B segment on the capnogram.
Phase 2: Is distinguished by a swift rise in CO2 concentration as the dead space is replaced with alveolar gas, which is B to C on the above capnogram.
Phase 3: In this phase gas passing by the capnography sensor is alveolar gas, which causes the waveform to flatten out. You may also hear C to D referred to as the alveolar plateau. The ETCO2 value is at the end of exhalation.
Phase 4: This is marked by the swift decline of the waveform, corresponding to D to E on the above capnogram.
There are many indications for the use of capnography. This technology can be utilized in both intubated and nonintubated patients. Capnography allows your providers to better understand of the patient's condition for the following indications:
- Cardiopulmonary Resuscitation (CPR)
- Return of Spontaneous Circulation (ROSC)
- Monitoring sedated patients
- Monitoring intubated patients
- Monitoring respiratory distress from asthma, COPD and CHF
- Hyperventilation or anxiety
- Monitoring the adequacy of pulmonary perfusion
- Confirming tracheal rather than esophageal intubation
This last indication, confirming tracheal intubation, assists with minimizing liability to any organization worried about failure to intubate patients and monitor intubated patients. Continuous capnogram date can counter accusations of a failed or misplaced intubation. You have the documentation to show otherwise.
Capnography is a transcendent technology for EMS
The use of capnography is the best tool for EMS field since the 12-lead EKG. This technology will assist your field providers in determining life-threatening conditions not only in the lungs, but also in the cardiovascular system.
The use of waveform capnography has transcended the way providers diagnose, manage, treat and also determine whether treatment is working. From a clinical quality improvement standpoint, you now have a clear way to prove and monitor ETT placement, determine the quality of CPR and detect ROSC.
As a leader, engage your workforce with patient care discussions, and with the above information at your disposal, discuss the particulars of what the capnogram shows and how this tool improves patient care and outcomes.