Hypotensive to hypertensive trauma

[LACoGurneyjockey]

Had an MVA the other day, car got rear ended at about 60-70 from a stop. Front seat restrained passenger, no airbags, orher vehicle's driver said the patient was unconscious for an unknown amount of time. 4-5ft of deformity to the rear passenger side of the car. Patient was a GCS of 7-10 enroute improving then declining and back and fourth throughout the hour long transport. My question on the call is more about his vitals however.
Initial BP on scene was 140/80. That progressively dropped over about 20-30 minutes to a low of 60/30. After 500ml of fluid he was back up to 100/70. Stopped the bolus, and rechecked the pressure in 5-10 minutes and it had come up to 190/110. Heart rate remained in the 100-120 range during the entire time.
I'm just looking for some feedback as to what you all think might be going on here. His belly got progressively more distended and by the time we cleared the hospital it was starting to bruise. Left pupil was dilated and sluggish, and cataract of the right pupil made it impossible to assess. Otherwise no outward signs of trauma. Any ideas?

 

[Gurby]

Worried about brain injury And obviously he's got significant internal bleeding going on.

What was his breathing like?

 

[LACoGurneyjockey]

Rapid and shallow, but maintaining his sats

 

[Gurby]

Was the breathing regular, irregular, Biot's?
Moving air on both sides equally?

 

[LACoGurneyjockey]

Regular, equal chest movement, clear lung sounds. I considered head trauma and ICP obviously, but I would have expected a lower heart rate for more of a typical cushings. I guess the combination of his bleeding with the head trauma could cause the tachy and hypertension. I just hadn't experienced it like that before

 

[AllGoode]

Was the breathing regular, irregular, Biot's?
Moving air on both sides equally?

I'll bite. What would Biot's respirations be suggestive of?

 

[Gurby]

I'll bite. What would Biot's respirations be suggestive of?

"Biot's respiration is caused by damage to the pons due to strokes or trauma or by pressure on the pons due to uncal or tentorial herniation."
https://en.wikipedia.org/wiki/Biot's_respiration

The medulla is one of the most important autonomic control centers, and the pons is right above the medulla. If that area of the CNS was affected, maybe it could help explain the fluctuation of blood pressure.