A 64 year old diabetic with vasculopathy undergoes an attempted endovascular repair of an abdominal aortic aneurysm. However the procedure is abandoned because of technical difficulties and he undergoes a surgical repair. In the first 6 hours after the procedure, he is noted to be oliguric and a blood test reveals a creatinine of 0.24 mmol/L (pre op value 0.15 mmol/L).
a) List 5 likely causes of deterioration in renal function.
The patient is administered IV fluids overnight. Despite stable blood pressure overnight, the next morning he is noted to be still oliguric. The plasma biochemistry is as follows:
| Sodium | 137 mmol/L | (135-145) |
| Potassium* | 6.3 mmol/L | (3.2-4.5) |
| Chloride* | 106 mmol/L | (100-110) |
| Bicarbonate* | 18 mmol/L | (22-33) |
| Urea* | 15.0mmol/L | (3.0-8.0) |
| Creatinine* | 0.34 mmol/L | (0.07-0.12) |
| Total calcium* | 1.75 mmol/L | (2.15-2.6) |
| Phosphate* | 2.75 mmol/L | (0.7-1.4) |
| Albumin | 26 g/L | (33-47) |
| Globulins | 35 g/L | (25-45) |
| Total bilirubin | 20 μmol/L | (4-20 μmol/L) |
| Conjugated bilirubin | 4 μmol/L | (1-4 μmol/L) |
| GGT | 6 U/L | (0-50) |
| ALP | 100 U/L | (40-110) |
| LDH* | 3800 U/L | (110-250) |
| AST* | 2100 U/L | (<40) |
| ALT | 100 U/L | (<40) |
a) List 5 likely causes of deterioration in renal function.
b) What is the likely cause of this plasma biochemistry?
a) List 5 likely causes of deterioration in renal function.
1. Hypovolemia
2. Abdominal compartment syndrome
3. Renal artery trauma
4. Low output state from myocardial dysfunction from cross clamping and
5. peri-op ischemia
6. Use of contrast
7. Post op bleeding
8. Ischemic rhabdomyolysis
9. Nephrotoxic drugs
b) What is the likely cause of this plasma biochemistry?
Rhabdomyolysis from lower limb ischemia
a) List 5 likely causes of deterioration in renal function.
Why has this patient's creatinine doubled?
There could be various reasons.
One may divide the answer by pathophysiological criteria (pre-renal, renal and post-renal) or one may organise them by aetiology. The following structures are suggested:
Answer organised by pathophysiology:
Answer organised by aetiology:
b) What is the likely cause of this plasma biochemistry?
Well, its clearly rhabdomyolysis (LDH and AST are enzymes which leak out of ischaemic muscle).
The question about rhabdomyolysis following AAA repair was truncated and reused as Question 6.2 in the second paper of 2012, where one might find a more detailed discussion of this complication.
Dattilo, Jeffery B., et al. "Clinical failures of endovascular abdominal aortic aneurysm repair: incidence, causes, and management." Journal of vascular surgery 35.6 (2002): 1137-1144.
Vanholder, Raymond, et al. "Rhabdomyolysis." Journal of the American Society of Nephrology 11.8 (2000): 1553-1561.
Bosch, Xavier, Esteban Poch, and Josep M. Grau. "Rhabdomyolysis and acute kidney injury." New England Journal of Medicine 361.1 (2009): 62-72.
Woodrow, G., A. M. Brownjohn, and J. H. Turney. "The clinical and biochemical features of acute renal failure due to rhabdomyolysis." Renal failure 17.4 (1995): 467-474.
Miller III, C. C., et al. "Serum myoglobin and renal morbidity and mortality following thoracic and thoraco-abdominal aortic repair: does rhabdomyolysis play a role?." European Journal of Vascular and Endovascular Surgery 37.4 (2009): 388-394
Safi, Hazim J., et al. "Predictive factors for acute renal failure in thoracic and thoracoabdominal aortic aneurysm surgery." Journal of vascular surgery 24.3 (1996): 338-345.