A 54-year-old man is brought in by ambulance and police. He was

found not rousable on the street. The ambulance team thinks he might have

injected heroin. At the scene, his GCS was 15 then deteriorated to 10 enroute.

On examination in the ED, his RR is 10/min, SaO2 92% on room

air, HR 100/min, BP 90/70 mm Hg. He has pin-point pupils. You note a fresh IV

access mark (track mark) on the left side of his neck.

You have secured IV access and placed him on

cardiorespiratory monitoring with supplemental oxygen. His GCS is 8. HR 100

bpm, BP 85/50 mm Hg, RR drops to 4/min. SAO2 86% on oxygen.

Question: