Anoxic Brain Injury post-Cardiac Arrest

My mom’s heart stopped for 19 minutes. She’s been hospitalised for 12 days now. She has anoxic brain injury, post-cardiac arrest seizures, Cushing’s Triad and cerebral Edema. She has swelling on the ventricle thalamus, generalised effacement of cortical sulci and ventricular system, partial effacement of the basal cisterns; biateral symmetrical basal ganglia hypodensity and hyperdense falx.

Every time her sedatives are reduced, she would cough, hold her breathes, and her heart rate would significantly drop below 40 bpm. We requested that she undergoes tracheostomy (they said they have to do surgery because her veins are small). The doctors said the procedure is preferable and more comfortable for her instead of the ventilation (tubes).

My question is… in your opinion, what is her survival rate? And when she survives, would she suffer? If so, what symptoms may she experience?

Doctors don’t know the full extent of her brain injury because she’s been heavily sedated.