A 35-year-old woman is admitted 4 hours after a severe crush injury to her right forearm sustained in a motor vehicle collision. She has severe swelling and pain in the forearm. Compartment pressure measurement shows anterior compartment pressure of 32 mmHg (diastolic BP 70 mmHg). She undergoes emergent fasciotomy. Postoperatively, her urine becomes dark brown (cola-colored), and serum creatinine rises from 0.9 to 2.8 mg/dL within 24 hours. What is the most likely complication, and what is the most appropriate immediate intervention?