You are transporting a 48-year-old male patient between medical facilities...
During the history, you learn that the patient was involved in a fall at work and suffered a hip fracture and a head injury. The patient is now presenting with labored breathing at 30/min that has progressively worsened over the last 24 hours, a heart rate of 104, and a blood pressure of 98/70. On auscultation, you hear diffuse rales. The patient denies any complaints of pain other than those related to his recent fall. What is the most likely cause of the patient's respiratory distress?