What Is Capnography?

Often used by paramedics in emergency situations, capnography measures carbon dioxide (CO2) levels in a patient’s exhaled breath. These measurements provide insight into how CO2 levels change over time. A CO2 patient monitor is used for individuals undergoing procedures that require anesthesia and for those with respiratory distress, to determine whether CPR was successful, or to confirm clinical death.

Capnography is important because:

• By determining blood-CO2 levels, practitioners can learn about a patient’s oxygenation and metabolism. Irregularities help health care providers learn about a patient’s condition and determine the proper course of treatment.
• Measuring EtCO2, or End Tidal CO2, levels over time provides accurate indications as to whether chest compressions are effective. If a patient is not responsive, the readings can indicate whether circulation has returned.
• It can help analyze the cause of respiratory distress. Capnography can be used to diagnose and analyze asthma, bronchitis, or chronic obstructive pulmonary disease, as well as hypoventilation prior to heart rate or blood pressure changes.

A capnograph can also identify reduced perfusion, a precursor to shock. The role of this measurement technology is expanding. It can quickly provide insights into the function of the human body and be used in pre-hospital emergency situations.

Why Is Capnography So Effective?

The machine passes a beam of infrared light over the gas sample collected from a patient’s breath. Since CO2 absorbs infrared radiation, its presence or lack thereof can be measured. The sensor receives a low amount of infrared light when CO2 levels are high, and more infrared when carbon dioxide levels are low. The capnograph then measures EtCO2 to assess cardiac output via the partial pressure of carbon dioxide the patient expires.

Waveform Capnography: Reading the Signs

One reason measuring EtCO2 is preferred over tracking ventilation rate is the quantity, shape, and trends of waveforms are the same for everyone, regardless of gender or age. Knowing a patient’s ventilation rate, target EtCO2 (35-45 mmHg), and trending of the waveforms (deteriorating, stable, or improving) is important. The shape of the waveform can also tell a lot. It should appear as a rectangle with rounded corners; the graph goes up as the patient inhales, comes to a plateau during exhalation, reaching the EtCO2 before falling back to the baseline.

The waveform can take on different shapes, depending on the patient’s condition. For example, cardiac arrest, shock, asthma, emphysema, and intubation present in specific patterns that are extremely useful to health care providers.

Patient Monitors from Medical Device Depot

We offer a wide range of patient monitors, including CO2 monitors and systems that can measure blood-gas levels, blood pressure, pulse rate, and more. The nGenuity™ patient monitor is one of them. This compact, lightweight monitor can be used for patients of any age and provides accurate measurements. Water traps remove moisture to ensure an accurate waveform at high respiration rates, while a 10.4-inch active TFT color display makes measurements easy to read.

Order now and apply for financing online. To learn more about the nGenuity and other capnography and patient monitoring equipment from Medical Device Depot, call 877-646-3300.