You are transporting a 32-year-old male involved in a high-speed motor vehicle collision who presents with a Glasgow Coma Scale (GCS) score of 6, unequal pupils, and hypotension. The patient shows signs of decerebrate posturing. What is the most critical initial intervention you should perform?
Provide fluid resuscitation
Reduce intracerebral pressure
Ensure adequate oxygenation and airway protection
Administer hypertonic saline