If the pt is critical/unresponsive and there is not enough time for critical care I would use the caveat. But does it apply to the exam? I never thought it did, but I have something here from the American College of Emergency Physicians saying it does right at the end of the description of the caveat...
"The level 5 caveat- the definition of 99285 includes the concept that the History, Exam, and MDM requirements must be met "within the constraints impose the urgency of the pt's clinical condition and/or mental status". Most Medicare carriers require a description of the pt's urgent condition and the physician's thought process. So make sure to document why the severity of your pts illness precludes performing a full History or EXAM."
"The level 5 caveat- the definition of 99285 includes the concept that the History, Exam, and MDM requirements must be met "within the constraints impose the urgency of the pt's clinical condition and/or mental status". Most Medicare carriers require a description of the pt's urgent condition and the physician's thought process. So make sure to document why the severity of your pts illness precludes performing a full History or EXAM."