The aim is to activate clinical reasoning through anticipating test results.
Before the results are available, simply ask:
What is the result of the test?
This can be done with blood gases, x-rays, other blood tests, ECGs etc
Have the learner predict actual values where possible and explain their rationales.
When able, it can be useful to later review the actual results and have the learner discuss why they are different and what this means for the initial impression.
Thanks to Professor Hugh Grantham for this teaching pearl.