In regards to the contraindication for NTG regarding SBP dropping by 1/3 or more, should we basing this off the very first BP obtained on that call, or a BP obtained right before NTG usage? Ie. ischemic chest pain 00:00 BP of 180/100 00:03 SBP of 150/90 00:04 NTG usage 00:09 BP 115/75. In this case a 65 (180-115) point drop would rule us out if 1st BP counted, but a 35 (150-115) point drop would not rule us if BP prior to NTG used. As pts can often be particularly stressed/anxious right when we walk in the door, it would make sense to me that the BP closest to actual administration would be most indicative of their true clinical state. 

Please see the answer from Ask MAC Sept 29, 2016. In short: The initial value is the BP reading that is taken prior to the administration of the first dose of NTG. 

Cardiac Ischemia,Cardiac/Circulation

Contraindication, Nitro, Nitroglycerine, SBP, Systolic Blood Pressure

Link to Sept 29, 2016 Q&A