A 58-year-old woman with chronic kidney disease (CKD Stage 4, eGFR 22 mL/min/1.73m²) and hepatic cirrhosis presents for elective hip arthroplasty. During induction, she receives propofol and fentanyl. For neuromuscular blockade, the anesthesiologist administers rocuronium 0.6 mg/kg IV. After 45 minutes of surgery, neuromuscular monitoring (train-of-four) shows 1 out of 4 responses. What is the PRIMARY reason for prolonged neuromuscular blockade in this patient?