MedEd Bytes series

MedEd Bytes is a video series that offers a quick and digestible learning format that can help solidify your understanding of different therapies leveraged in patient monitoring and respiratory interventions. In this series, we’ll cover topics such as capnography waveforms, the technology behind pulse oximetry, modes of ventilation, and more. To stay up to date with the series, please subscribe to our YouTube channel or start watching the series below.

MedEd Bytes: Microstream™ capnography sampling lines bench study

Capnography is the continuous, noninvasive monitoring and display of exhaled carbon dioxide (CO2) levels over time, offering vital information on a patient’s ventilatory status and during cardiopulmonary resuscitation. Accurate end-tidal CO2 (EtCO2) measurements and high-quality waveforms depend largely on the sampling line. Commercial sampling lines vary significantly in aspects such as cannula design, oxygen delivery, and tubing volume, all of which can impact their performance. 

In the following bytes, we will review the bench test study to assess the accuracy and overall performance of the nine commercially available sampling lines when used with the Microstream™ capnography monitor.

Byte 1: Introduction

Here we will be reviewing recent bench tests evaluating nine sidestream capnography sampling lines compatible with the Microstream™ capnography monitoring system, by assessing accuracy, filter performance, and mechanical durability.

 

3:11

Byte 2: Rise times with variable respiratory rates

To assess the rise times associated with different sampling lines, the study employed a calibrated solenoid-based breathing simulator capable of delivering controlled CO2 concentrations at various respiratory rates.

4:31

Byte 3: EtCO2 accuracy under various conditions

To test sampling line accuracy under these adverse conditions, the study mimicked a natural breathing cycle with variable exhaled CO2 concentration an anatomical airway model and artificial lung simulator.  Using this model, the investigator tested EtCO2 accuracy under five conditions with both normal and shallow breathing.

3:52

Byte 4: Filter performance

During sidestream gas sampling with capnography, the temperature of exhaled breath may decrease as it travels through the sampling line away from the patient, resulting in water condensation and subsequent filter clogging.

1:48