ACE and Hypertension: The risk factors were age > 46.5 years, smoking, BMI > 28.5 kg/m2, hypertension, diabetes, utilization of angiotensin-converting enzyme inhibitors (ACEI), haemoglobin < 10.8 gm/dl, baseline creatinine > 1.41 mg/dl, eGFR < 65.2 ml/min./1.73 m2, serum uric acid > 5.2 mg/dl, stone volume > 1748 mm3, large tract size, long operative time, and intra-operative bleeding.