If you don't pass out during hypovolemic shock, does that mean the brain does not sustain damage?

Shock. This is a complex question, shock has a specific definition, and injury to organs is based on degree of hypo-perfusion, duration, and response to the shock. Age of the patient, medical history, other disease all affect the sequelae of shock. If the patients is awake and doing well, suggest that the brain is being perfused and should have sustained long term damage. Best of luck.