Prospective multicentre study of acute renal failure in arterial surgical patients

Abstract

Abstract Background Acute renal failure following vascular surgery is associated with a high risk of death. The aims of this study were to identify the incidence and risk factors for acute renal failure in arterial surgical patients. Methods A prospective longitudinal clinical study of consecutive arterial surgical patients, including those undergoing interventional radiological procedures, in 13 UK vascular units was devised. Data were collected locally in each unit using a standard pro forma. Impaired renal function was defined as an admission creatinine level greater than 125 μmol l−1, while a 50 per cent rise in creatinine was defined as acute renal failure. Results Some 1566 patients were enrolled by the 13 units in a 6-month interval (January to June 1999); 124 (7·9 per cent) developed postoperative renal failure. The incidence of renal failure varied according to operation type: abdominal aortic aneurysm 17·6 per cent, thoracoabdominal aneurysm 45·4 per cent, carotid endarterectomy 0·8 per cent, aortobifemoral bypass 10·9 per cent, infrainguinal bypass 5·2 per cent, extra-anatomic bypass 5·2 per cent, embolectomy 14·0 per cent, endovascular procedure 5·0 per cent, radiological procedure 4·2 per cent and amputation 4·5 per cent. The in-hospital mortality rate for all patients was 7·2 per cent, which increased to 37·1 per cent in patients who developed acute renal failure. Significant risk factors for the development of renal failure were thoracoabdominal aneurysm repair (45·4 per cent), emergency surgery (19·4 per cent), surgery on the abdominal aorta (17·6 per cent), pre-existing renal impairment (19·4 per cent) and hypertension (8·3 per cent). Diabetes mellitus, hyperlipidaemia, recent angiography, non-steroidal analgesics, metformin or angiotensin converting enzyme inhibitors were not predictive of the development of renal failure. In 21·8 per cent of patients renal failure developed in association with multiple organ failure. No patient who survived developed end-stage renal failure. Conclusion The incidence of acute renal failure following arterial surgery was 7·9 per cent associated, as expected, with a significant mortality rate (37·1 per cent). Emergency aortic surgery carried the highest risk. Patients developing acute renal failure required intensive management, including renal support, but no patient survived to develop end-stage renal failure.