Question 6.2

Created on Tue, 05/12/2015 - 23:41
Last updated on Sun, 04/10/2016 - 21:21
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Highest mark: 9.3

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The following biochemical profile is that of a 68-year-old man who has undergone endovascular repair of an abdominal aortic aneurysm that was technically difficult:

Parameter

Result

Normal Range

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 – 27

Urea

15.0 mmol/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 micromol/L

4 – 20

Conjugated Bilirubin

4 micromol/L

1 – 4

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

What is the likely cause of this biochemical profile?

 

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College Answer

Rhabdomyolysis from lower limb ischaemia

Discussion

The elevated LDH (which is non-specific) and AST (which leaks from dying muscle) are characteristic of rhabdomyolysis. This is a well-recognised complication of AAA repair, although it is typically a complication of open repair. However, this endovascular repair was apparently unusually prolonged, and thus one can assume that the surgeon had a catheter in at least one of the femoral arteries for a while, occupying much of the lumen. In this context, a period of limb ischaemia could have occurred. Other potential explanations could include trashed legs due to a shower of atheroma, or ischaemia of lumbar paraspinal muscles.

An alternative explanation is hepatic ischaemia from some sort of intraoperative injury, but this is less likely given the normal bilirubin and totally normal GGT and ALT, as well as the fact that typically endovascular repair tends to spare the hepatic circulation.

References

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.

Ferreira, José, et al. "Lumbar paraspinal rhabdomyolysis and compartment syndrome after abdominal aortic aneurysm repair." Journal of vascular surgery37.1 (2003): 198-201.

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.