What is a normal capnography waveform?
Introduction to Capnography Waveforms EtCO2 values are recorded in mm Hg (millimeters of mercury), a unit of pressure. The normal values for patients regardless of age, sex, race, or size range between 35-45 mm Hg, or about 5% CO2.
How do you measure waveform capnography?
Two sensors can be used to measure capnography. In patients who are breathing, nasal prongs can be applied that capture exhaled air. Those prongs can also be used to administer a small amount of oxygen, or applied underneath a non-rebreather or CPAP mask.
What is shark fin waveform capnography?
Bronchoconstriction also causes the rectangular-shaped capnography waveform to have a “shark fin” appearance. A rectangular waveform indicates that difficulty breathing is from another cause that will not be helped by albuterol.
What are the 2 types of capnography?
There are two types of capnograph, “side stream” and “mainstream” (4) . In the “mainstream” technique, sampling window is in the ventilator circuit and measures CO2, while in the “side stream”, the gas analyzer is located out of the ventilator circuit.
What does a flat plateau on a capnogram mean?
In phase 3 (C to D on the capnogram), all of the gas passing by the CO2 sensor is alveolar gas which causes the capnograph to flatten out. This is often called the Alveolar Plateau. The End Tidal CO2 value displayed on the monitor is considered the value taken at end exhalation.
What two phases are most important to the interpretation of a capnography waveform?
Normal Capnography Phase I (inspiratory baseline) reflects inspired air, which is normally devoid of CO2. Phase II (expiratory upstroke) is the transition between dead space to alveolar gas.
What is the capnography waveform A graphical representation of?
Waveform capnography is a graphical representation of the concentration of CO2 exhaled, used as an indirect indicator of the actual concentration, or partial pressure, of CO2 in arterial blood.
What causes high ETCO2?
In severe cases of respiratory distress, increased effort to breathe does not effectively eliminate CO2. This causes CO2 to accumulate in the lungs and more of it to be excreted with each breath (hypercapnea), which would cause the ETCO2 level to rise.
What does a sloped upstroke on a capnogram indicate?
Prolongation or slanting of the expiratory upstroke phase II occurs when there is obstruction to expiratory gas flow (e.g., asthma, bronchospasm, obstructive pulmonary disease, and kinked endotracheal tube,1-9 or in the presence of leaks in the breathing system.
What is the alveolar plateau?
What does a sloped upstroke on a Capnogram indicate?