ACUTE KIDNEY INJURY (AKI)-INVESTIGATIONS

SUMMARY

BLOODS
1. Serum U/E/Cr
2. ANA/ENA/dsDNA/C3 & C4/ANCA (MPO/PR3)/anti-GBM antibodies (auto-immune diseases)
3. ASOT/anti-DNase B (post streptococcal glomerulonephritis)
4. SPEP/serum free light chains (paraprotein/myeloma disease)

URINE
5. MSU M/C/S: for infections & to inspect for casts
6. Bland urine sediment: no glomerular red cells, favous pre-renal/ATN/myeloma/interstitial renal disease
7. Active urine sediment: glomerular red cells, seen in acute glomerulonephritis
8. Hyaline/granular/tubular/epithelial casts: suggestive of ATN
9. Pr/Cr: Proteinuria > 1g/d (Pr/Cr > 0.1), suggestive of glomerular/intrinsic renal disease
10. Urine BJP: suggests immunoglobinopathy

IMAGING
11. US/CT KUB: to exclude renal tract obstruction (hydronephrosis)

BIOPSY
12. Renal biopsy: if suspicion of intrinsic renal disease or if disease not explicable by pre-renal/ATN

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].