Acute Kidney Injury

Question 1

AKI recognition

Answer 1

Serum creatinine and urine output…higher creatinine means lower GFR

Urine output will be low with creatinine elevated

Question 2

Risk factors for AKI

Answer 2

Older, diabetes, CHF, CKD, prior AKI

Insult can lead to injury, but we cannot really measure until there is dysfunction

HF immediately lead ot dysfunction but may have no injury…sepsis will have change due to injury

SCr and UOP are markers of kidney function but not necessarily kidney injury

Question 3

CHF vs. Sepsis

Answer 3

Pos damage and neg functioonal - subclinical AKI

No damage but functional change - think CHF - functional AKI

Both positive - established AKI (sepsis)

Question 4

Why is SCr not enough>

Answer 4

Delays AKI detection as it IDs changes in clearance but not renal injury

SCr mandates time-dependent cumulative increment of Cr

Renal injury could occur with minimal over functional looss - subclinical AKI

Question 5

ATN

Answer 5

FeNa>1-2
FeUrea 50-65
RTEC/granular casts
Isoshethnuria 
Tbular proeinura

Question 6

Pre-renal

Answer 6

Volume depletion, ADHF, cirrhosis/HRS< meds

NeNa<1
Feurea<35
Bland urine
BUN/Scr>20
High Uosm

Question 7

AIN/pyeloneprhotis

Answer 7

WBC casts

Question 8

Prerenal azotemia

Answer 8

IV volume depletion
Dec CO
Dec SVR
Renal vasoconstriction
Abnormal renal autoreg 
Decreased abdominal perfusion pressure (MAP-IAP)

Question 9

ATN

Heavy metals 
Ethylene glycol
Hemolysis
Myoglobin
Tumor lysis syndrome

Answer 9

proximal RTA

CaOx cyrstals

MAHA, DIC

CPK/Phos/Ca

uric acid

Question 10

TMAs

Answer 10

Thrombocytopenia and schistocytes

Check the CBC

Question 11

RBC casts, dysmorphic RBCs, proteinuria, lipiduria

Grnaular casts and RTE cells

Answer 11

GN or vasculitis

ATN

Question 12

WBCs with casts, no or mild proteinuira

RBCS and WBCs with no or variable casts

Answer 12

AIN, pyeloneprhitis, obstruction

AIN, obstruction, renal infarcvtion,

Question 13

RBCs

WBCs

Bland or few cells with little or no casts or proteinuria

Answer 13

urlogic causes

Infection, urinary tract TB or TIN, atheroembolic dz

Pre-renal, obstruction, hypercalcemia, myeloma kidney, earlyy ATN, vascular dz, TMA, TLS

Question 14

Outcomes of acute kidney injury

Answer 14

Only about half go home…10% die

5-10% of hospitalized have htis and more in ICU

Higher risk of CVD and HTN

Greater risk of CKD