8.7 Conclusion
We have now discussed the basics of ABG interpretations. It is best to try to practice as much as you can. It will become second nature the more you do it. The best way to approach ABG interpretation is to understand the “why” and not just memorize the patterns. In the next chapter, we will take these skills and start to make changes on ventilation settings, so make sure you understand the relationships between CO2, HCO3 and pH.
A final word of caution with ABG interpretations
Sometimes when looking at ABGs is easy to miss a “normal” gas. Clinicians can get so caught up with diagnosing a problem, that they may miss a normal reading. If all values are within normal limits, that ABG is normal and no other interpretation is needed. Normal means the body is perfectly balanced with no extra acid or base anywhere. All values are normal—there is a perfectly matched game of Tug O’ War with the pH/rope in the normal position and with normal team numbers on both sides.
Review
ABG interpretation is an essential part of effective ventilation, as the information you learn will inform initial settings (when possible) and adjustments. In this chapter, you learned about the theory behind arterial blood gases: the acid-base “Tug O’ War” in the body. Then, you learned what an ABG is, and the values that it produces: pH, pCO2, pO2, HCO3. Finally, you learned how to answer the four main questions that underly the ABG interpretation:
- Uncompensated, partially compensated or fully compensated?
- Respiratory or metabolic?
- Acidosis or alkalosis?
- Hypoxemic, hyperoxic, or normal?
Effective patient-ventilator interaction significantly impacts the duration of ventilation and the length of stay in the intensive care unit, directly influencing the occurrence of complications. To reduce these risks, patient assessment plays an important role in promptly identifying any signs of asynchrony and implementing appropriate corrective measures. By prioritizing patient monitoring and intervention, clinicians can foster improved outcomes, reduce ventilation time, and enhance the overall quality of ICU care.
What’s next?
In the next chapter, we will learn what to do with ABG results, and patient – ventilator interactions, in the context of choosing and adjusting ventilator settings.
“Chapter 8 Conclusion” from Basic Principles of Mechanical Ventilation by Melody Bishop, © Sault College is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.
