Acute extremity compartment syndrome.

(M2.OR.16.4690) A 40-year-old patient is brought into the emergency department after suffering a motor vehicle crash where he was pinned underneath his motorcycle for about 30 minutes before a passerby called 911. While evaluating him per your institution's trauma guidelines, you discover pain upon palpation of his right lower extremity which is much larger than his left counterpart. The patient admits to decreased sensation over his right lower extremity and cannot move his leg. There are no palpable dorsalis pedis or posterior tibial pulses on this extremity, and it is colder and paler in comparison to his left side. Measured compartment pressure of his distal right leg is 35 mm Hg. What is the next best step in this patient's care?

(M2.OR.16.161) A 25-year-old patient is brought into the emergency department after he was found down by the police in 5 degree celsius weather. The police state the patient is a heroin-user and is homeless. The patient's vitals are T 95.3 HR 80 and regular BP 150/90 RR 10. After warming the patient, you notice his left lower leg is now much larger than his right leg. On exam, the patient has a loss of sensation on his left lower extremity. There is a faint palpable dorsalis pedal pulse, but no posterior tibial pulse. The patient is unresponsive to normal commands, but shrieks in pain upon passive stretch of his left lower leg. What is the most probable cause of this patient's condition?