You brought up a very good point Frostfire. As a Team Medical Sergeant I made it a point to really know the baseline vitals and medical Hx of the team members. A HR of 90 in the Team Daddy that had a baseline resting HR of 50 would be cause for concern to be sure. Couple that with the low-grade fever and neutrophilia with immature bands - voila! A Dx of sepsis is at the top of the list.
I did not initially consider this as part of the DDx
but focusing on the back pain and RO simple causes that were field treatable it was clear that TS needed Medevac ASAP.
One other point, in my day (now I sound like an ol' geezer
) we did not have field portable kits for doing a WBC. If I did and saw the neutrophilia with bands that would be reason for immediate Medevac. Now to the question of starting TS on antibiotics - probably contraindicated IMO. I don't know what the 18Ds carry these days, but I think the choice of antibiotic would be better left to the attending at a primary care facility.
Maybe some of you Docs and AD 18Ds could discuss this point (pros and cons) a bit more. I would be interested to read what you all think.