Tourniquet measures should be taken if the person has been entrapped for more than 2 hours. Initial hospital management
The clinician must protect the patient against hypotension, kidney failure, acidosis, hyperkalemia and hypocalcemia. Admission to an intensive care unit, preferably one experienced in trauma medicine, may be appropriate; even well-seeming patients need observation. Treat open wounds as surgically appropriate, with debridement, antibiotics and tetanus toxoid; apply ice to injured areas. Breathing and circulation must be checked out and the patient should be given oxygen if eligible. Oral or intravenous fluids must be given depending on the measured amounts of electrolytes, arterial blood gases, and muscle enzymes.Intravenous hydration of up to 1.5 L/h should continue to prevent hypotension. A urinary output of at least 300 mL/h should be maintained with IV fluids and mannitol, and hemodialysis considered if an increase in urine is not achieved. Use intravenous sodium bicarbonate to keep the urine pH at 6.5 or greater, to prevent myoglobin and uric acid deposition in kidneys. To prevent hyperkalemia/hypocalcemia, consider the following adult doses:
calcium gluconate 10% 10 mL or calcium chloride 10% 5 mL IV over 2 minutes
sodium bicarbonate 1 meq/kg IV slow push
regular insulin 5–10 U
50% glucose 1–2 ampules IV bolus
kayexalate 25–50 g  with sorbitol 20% 100 mL by mouth or rectum.Even so, abnormal heart rhythms may develop; electrocardiographic monitoring is advised, and specific treatment begun promptly. References
Sever MS, Vanholder R, Lameire N (2006). "Management of crush-related injuries after disasters". The New England Journal of Medicine. 354 (10): 1052–63. doi:10.1056/NEJMra054329. PMID 16525142.
External links

Life or Limb: What happens when your leg gets trapped under a building?