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Medical providers have long used pulse oximetry as a quick and easy way to assess blood oxygen levels. But the amount of carbon dioxide a person exhales is equally useful information, providing key details about ventilation. Capnography machines are widely used in the field and provide clear data on the amount of carbon dioxide exhaled during each breathing phase. Using a capnograph during aspiration reduces the risk of hypoxia and provides more detailed information about patients at risk for severe aspiration-related complications.
Waveform capnography measures the amount of carbon dioxide a patient exhales during each phase of breathing. The readout provides two pieces of data: numbers and graphs. This number is a measure of CO2 pressure at the end of each exhalation and normally ranges from 35-45 mmHg. This number is called end-tidal carbon dioxide, or ETCO2. The graph is a waveform showing carbon dioxide levels throughout the breathing cycle. The health graph is a rectangle that periodically moves up and down. Other shapes—especially sharp up-and-down shark fins—indicate poor ventilation. The capnograph can measure CO2 using the nose tip or an adapter attached to the BVM.
Capnography measures pulse oximetry and patient observations usually cannot. Patients may have good oxygenation readings because they are able to inhale enough oxygen even though they are heading towards respiratory failure. Capnographs provide early warning of poor ventilation and help guide treatment decisions. For example, patients with high ETCO2 who are at risk for respiratory arrest may require BVM ventilation.
The resuscitation process from cardiac arrest can be stressful, confusing, and condition-specific. Capnography machine is an important tool in the rescue of cardiac arrest patients.
Key points for using a capnograph in cardiac arrest:
P - the position of the tracheal tube (Position of the tube)
Capnography was more sensitive and specific than auscultation and capnography in judging the position of the endotracheal tube.
Q—Quality of CPR
Early detection of low-quality compressions.
R - Return of spontaneous circulation (ROSC)
The sudden increase in end-tidal carbon dioxide heralds the return of spontaneous circulation and does not require interruption of CPR to check the pulse.
S - Strategy (Strategy)
Can help clinicians determine the underlying cause of cardiac arrest.
T - Termination
End-tidal carbon dioxide values less than 10 mm Hg 20 minutes after resuscitation are already accurate predictors of death.
Capnographs work best with other quality equipment, including reliable suction. Seconds are counted when the patient presents with respiratory distress, airway obstruction, or airway trauma. Portable emergency suction machines allow you to take care of patients quickly without the risk and effort of transferring them to an ambulance.
