The Blood Gas Machine – Measuring Oxygen, pH, Carbon Dioxide, Tips and Tricks and Derived Variables

To round out the year, here are three tutorials on the blood gas machine, blood gas analysis and the blood gas printout.

The first tutorial looks at how oxygen is measured using the Clark Electrode on the blood gas analyser and demonstrates the importance of co-oximetry in modern blood analysis. From that the fractional saturation of hemoglobin with oxygen is derived.

The second tutorial explains the Glass Electrode that measures pH and PCO2. Subsequently I cover problems you might encounter with blood gas sampling. If you don’t want to watch the technical stuff, I strongly recommend you scroll to the middle of the tutorial (12 minutes in) as it covers information that all healthcare practitioners must know.

The final tutorial looks at all of that other data that appears on blood gas printouts that you may never have understood – and it can be really confusing – DERIVED or calculated variables (bicarbonate, temperature correction, TCO2, O2 content, Base Excess, Standard Bicarbonate, Anion Gap etc.). I cover both the Radiometer ABL machines and the GEM 5000. I guarantee you’ll learn something.

TUTORIALS ON CAPNOMETRY AND CAPNOGRAPHY

Here are three tutorials on inspiratory and expiratory CO2 gas analysis. Tutorial 1 looks at Capnometry and the process behind measuring CO2 in exhaled gas. I cover mainstream CO2 analysis and explain why the end tidal CO2 (EtCO2) may be high or low. Tutorial 2 addresses the Capnograph, the trace and anomalies of the Capnograph at the time of intubation. I also explain Sidestream and Microstream CO2 and gas analysis. The final tutorial will be very helpful to anesthesiologists, particularly those taking exams: I go through a series of abnormal Capnographs, explaining why they are abnormal. I guarantee that you will learn something.