Apart from questions purely regarding equipment (eg. "Behold a tube marked (A). What's this tube do? Where are its safety features?") this topic has also ended up with all the questions about the use of that equipment, eg "How would you insert Tube A?" If the insertion of Tube A also involves some sort of numeric variables or waveforms being generated, then it stand to reason that the interpretation of such waveforms should also be viewed as a "use" of Tube A. By such convoluted logic, I have justified the inclusion of all such questions in this topic area. This includes questions about IABP troubleshooting and PA catheter readings (which might arguably belong in the Cardiothoracic ICU section), as well as questions about the respiratory variation of arterial pulse pressure (which might look less out of place in a chapter on mechanical ventilation). Disagreement regarding the author's arbitrary allocation of SAQs to potentially inappropriate topics is entirely unwelcome. Dissenters are reminded that this taxonomy was never promoted as intelligent or useful.