Physiological Monitoring: Expired Air

In the first of our new Physiological Monitoring Series, we'd like to examine why measuring expired air during laboratory experiments is so important.  Sure, there are the initial reasons like improving surgical survivability of small animals and validating respiratory status during surgery, but the positive impact of respiratory gas monitoring reaches even further. 

CWE's line of Respiratory Gas Analyzers offer unique, streamlined (sidestream to be exact), and easy-to-use equipment for measuring end-tidal CO2 and O2 in a variety of applications from mice to humans to dolphins to elephants; including hypoxia and control of breathing studies, general surgeries with mice, rats, and larger animals, studies with marine mammals, etc.  But that's not all...

A few of the benefits of routine CO2 measurement are:

  • Verification of proper endotracheal intubation (avoiding esophageal intubation, as often happens with very small animals)
  • Recording data documents proper use and care of laboratory animals.
  • Aids in setting appropriate ventilator parameters to avoid hypo- or hyper-ventilation (assisted animals)
  • Assessing ventilator and/or anesthesia circuit configuration or problems (e.g., rebreathing may be occurring if CO2 waveform does not return to baseline)
  • Gauging anesthesia levels (spontaneously breathing animals)
  • Reduces the requirements for blood gas analysis
  • Indirect effects: e.g., hypo- or hyperthermia will result in lower or higher ETCO2

To learn more about the importance of CO2 monitoring specifically, we invite you to take a look at our CO2 white paper that's attached below.