The following blood tests are from an otherwise well 53-year-old female, admitted to a general medical ward five days previously for intravenous antibiotic therapy for lower limb cellulitis. Her admission blood tests were all normal. Over the last 24 hours she has become progressively oliguric, but remains otherwise stable with normal vital signs.

The results of her full blood count and urea and electrolytes are as follows:

Parameter

Patient Value

Normal Adult Range

Haemoglobin

132 g/L

130 - 175

White Cell Count

9.8 x 109/L

4.0 - 11.0

Platelets

321 x 109/L

150 - 450

Neutrophils

10.4 x 109/L*

1.8 - 7.5

Lymphocytes

2.06 x 109/L

1.50 - 4.00

Monocytes

0.3 x 109/L

0.2 - 0.8

Eosinophils

4.3 x 109/L*

0.0 - 0.4

Haematocrit

0.35*

0.40 - 0.52

Mean Cell Volume

92 fl

82 - 98

Mean Cell Haemoglobin

29.9 oa/cell

27.0 - 34.0

Mean Cell Haemoglobin Concentration

326 g/L

310 - 360

Sodium

140 mmol/L

135 - 145

Potassium

3.8 mmol/L

3.2 - 4.5

Chloride

106 mmol/L

100 - 110

Bicarbonate

22 mmol/L

22 - 27

Urea

28.0 mmol/L*

3.0 - 8.0

Creatinine

310 µmol/L*

45 - 90

Total Calcium

2.17 mmol/L

2.15 - 2.60

Phosphate

1.6 mmol/L*

0.7 - 1.4

Albumin

31 g/L*

33 - 47

Total Bilirubin

20 umol/L

4 - 20

Conjugated Bilirubin

4 µmol/L

1 - 4

y-Glutamvl transferase

22 U/L

0 - 50

Alkaline  phosphatase

60 U/L

40 - 110

Lactate  dehydrogenase

213 U/L

110 - 250

Aspartate transaminase

34 U/L

< 40

Alanine  aminotransferase

25 U/L

< 40

Give the likeliest cause of her oliguria. (20% marks)

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College answer

Allergic / Acute Interstitial nephritis secondary to antibiotic use.      

Discussion

The eosinophils. They are high.

Everything else is normal.

It could be nothing else. The cellulitis, presumably it got flucloxacillin - and then the cillin caused an interstitial nephritis, as they tend to do. 

References

References

Perazella, Mark A., and Glen S. Markowitz. "Drug-induced acute interstitial nephritis." Nature Reviews Nephrology 6.8 (2010): 461-470.