Renal

Question 1

Classic findings include skin rash, fever, and eosinophilia, with UA showing many WBCs and WBC casts.

Answer 1

Drug-induced Allergic interstitial nephritis

(NSAIDs, Zosyn, PPIs, cephalosporins, penicillins, sulfonamides, diuretics, rifampin, phenytoin, allopurinol)

Tx = d/c offending agent

Question 2

Kidneys normally compensate for intravascular volume depletion (vomiting, diarrhea) by secreting vasodilatory ____ which dilate the afferent arteriole to maintain GFR & renal perfusion.

Answer 2

prostaglandins (via ↑ COX production)

PDA: Prostaglandins Dilate Afferent

Question 3

NSAIDs inhibit COX →
Resulting in renal afferent arterial _____ →
pre-renal azotemia (>20:1)

Answer 3

vasoconstriction

(Cox = vasodilation)

Question 4

Kidney biopsy is used to diagnose ____ renal causes of acute kidney injury.

Answer 4

Intrinsic

(use if pt has: hematuria, proteinuria)

Question 5

Patients with acutely elevated creatinine & clinical signs of obstruction require imaging (preferably ____) to assess for hydronephrosis.

Answer 5

renal ultrasound

Question 6

Alcohol bingeing can lead to acute alcohol myopathy and ______, especially when combined with cocaine abuse.

Answer 6

rhabdomyolysis

(cx: AKI s/t dehydration & pigment-induced nephropathy)

Question 7

Hypovolemic shock can cause what type of AKI?

Answer 7

acute tubular necrosis (ATN)

Question 8

A BUN/Cr ratio of ___ is usually seen in Acute Tubular Necrosis (ATN)

Answer 8

10-15

Question 9

Acute Tubular Necrosis (ATN) findings that support its diagnosis are:

BUN/Cr ratio 10-15

Urine Osm ____ mOsm/L
(but never __ mEq/L

Urine Na >__
FE­­­­Na ­­> __%

Answer 9

300-350 (but never <300)

> 20

> 2%

Question 10

Broad casts are seen in patients with _____

Answer 10

chronic kidney disease (CKD)

*made in dilated tubules of enlarged nephrons that have undergone compensatory hypertrophy s/t ↓ renal function.

Question 11

Waxy casts, which are shiny and translucent, are seen in patients with _____

Answer 11

chronic kidney disease (CKD)

Question 12

Red blood cell casts are indicative of (3)

Answer 12

Glomerular disease (glomerulonephritis)
Vasculitis
HTN emergency

Question 13

White blood cell (WBC) casts are seen in cases of (3)
*white = TAP

Answer 13

Allergic Interstitial nephritis
Pyelonephritis
Transplant Rejection

*are definitive evidence that urinary WBCs originate in the kidney

Question 14

Fatty casts are seen in conditions causing ____.

Answer 14

Nephrotic syndrome

Question 15

Hyaline casts are composed almost entirely of protein and are non-specific; these may be seen in asymptomatic individuals and in patients with ___

Answer 15

pre-renal azotemia

Question 16

Muddy Brown cast are indicative of ____.

Answer 16

ATN

Question 17

Granular Cast are seen in cases of (3)

Granular = GAP

Answer 17

Glomerular disease (glomerulonephritis)
ATN
Pyelonephritis

Question 18

A [lab workup] is typically collected when a precise measure of renal function is needed (ex: renal transplant evaluation, preparation for hemodialysis).

Answer 18

24-hour creatinine clearance

*not required in most cases of AKI work-up

Question 19

present with insidious onset of flank pain and systemic symptoms (fever, weight loss), typically in patients with a recent h/o UTI (1-2m ago) or extrarenal infection (bacteremia).

Renal and perinephric ___

Answer 19

abscesses

(+/- pyuria, bacteriuria, micro-hemturia, or proteinuria)

Pyelonephritis happens shortly after UTI not weeks later.

Question 20

Prerenal AKI in an acute CHF exacerbation is most likely s/t Cardiorenal Syndrome, which involves:

↑ ___ & Renal venous pressures
resulting in
↓ ___

Answer 20

↑ CVP (R 💛 pre-load)

↓ GFR

Question 21

High-dose intravenous ___ can cause crystalluria with renal tubular obstruction.

Answer 21

acyclovir

• giving IVFs with the drug can help ↓ risk of AKI

Question 22

ACE inhibitors temporarily reduce GFR due to dilation of renal efferent arterioles and should not be initiated in the setting of ____.

Answer 22

AKI

Question 23

Contrast-associated acute kidney injury is characterized by a rise in serum creatinine ____ after intraarterial contrast administration followed by a gradual return to baseline.

Answer 23

24-48 hours

(prevent by giving IVFs before)

Question 24

Most cases of renal failure result in
[electrolyte abnormality]
due to reduced renal phosphorus excretion.

Answer 24

hypocalcemia

Question 25

Patients who have acute **renal failure** and _____ often have an underlying **malignancy**.

Answer 25

hypercalcemia (ex: Multiple Myeloma) bc acute renal failure is supposed to cause hypocalcemia

Question 26

**multiple myeloma** (MM) induced **hypercalcemia** can cause **AKI** due to **clogging** of the renal tubules with calcium deposits or _____.

Answer 26

**immunoglobulin light chains** (classically presents with anemia, bone pain, hypercalcemia, and acute renal failure)

Question 27

Elevated ____ is likely the major driver of **AKI** in cardiorenal syndrome.

Answer 27

**central venous pressure** (leads to elevated **renal venous pressure and congestion**. This reduces the glomerular capillary filtration gradient)

Question 28

**Acute renal allograft rejection** is predominantly T-cell mediated and usually occurs within the first ___ following transplant.

Answer 28

6 months

Question 29

**Acute** renal allograft rejection results in an asymptomatic rise in **serum creatinine**. The diagnosis is confirmed by **renal biopsy** showing ___ of the intima. Treatment is with _____.

Answer 29

lymphocytic infiltration high-dose IV **glucocorticoids**

Question 30

____ results from excessive immunosuppression in renal allograft recipients and leads to **tubulointerstitial nephritis**. Renal biopsy reveals **intranuclear** ____ and a **mixed** lymphocytic and **neutrophilic** infiltrate.

Answer 30

BK virus reactivation intranuclear inclusions (cx: ureteral stenosis/obstruction)

Question 31

Acute toxicity to ____ involves **vasoconstriction** of the **afferent and efferent** renal arterioles, leading to prerenal AKI and hypertension.

Answer 31

calcineurin inhibitors (tacrolimus) immunosuppresor in Kidney Transplant pt

Question 32

metformin is renally cleared, the drug should be discontinued in ___

Answer 32

renal insufficiency/ AKI

Question 33

Hepatorenal syndrome has acute renal failure (Cr >1.5) with a very low urine sodium level (<10 mEq/L), and an absence of blood, casts, or protein in urine. Creatinine does not improve with ___.

Answer 33

intravenous fluid resuscitation

Question 34

**Angiotensin II** causes arteriolar vasoconstriction of ___ and systemic vessels, which **improves GFR** and blood pressure

Answer 34

efferent ACE: AngII Constricts Efferent

Question 35

Benign prostatic hyperplasia can cause an **obstructive uropathy** that presents as a slowly rising creatinine level. A ___ examination, which should be performed in all patients being evaluated for **creatinine elevation** or **CKD**

Answer 35

renal ultrasound

Question 36

70% of cases with **interstitial nephritis** are caused by drugs such as (8) Discontinuing the offending agent is the treatment.

Answer 36

NSAIDs Cephalosporins Penicillins (Pip-Tazo) / Sulfonamides (TMP-SMX) allopurinol PPI rifampin phenytoin

Question 37

High-dose intravenous ____ can cause crystalluria with renal **tubular obstruction**. Administering **fluids** with the drug can help reduce the risk of AKI.

Answer 37

acyclovir

Question 38

What antibiotic can cause **acute tubular necrosis**, usually after >5-7 days of use.

Answer 38

Aminoglycosides (amikacin, gentamicin)

Question 39

Nonsteroidal anti-inflammatory drugs inhibit prostaglandin synthesis, which can cause ___.

Answer 39

prerenal azotemia/AKI afferent vasoconstriction (worse if pt is already volume down)

Question 40

Evaluation of **neonatal acute kidney injury** includes a ____.

Answer 40

renal and bladder ultrasound (RBUS)

Question 41

Acute ____ can cause **hematuria**, AKI, fever, and **flank pain**. Most common in patients with **analgesic overuse** or **sickle cell anemia**.

Answer 41

papillary necrosis

Question 42

**HRS** occurs due to _____, decreased vascular resistance (SVR), and local **renal vasoconstriction** with decreased perfusion.

Answer 42

splanchnic arterial dilation

Question 43

The most common **inciting** factors of HRS include (2)

Answer 43

SBP gastrointestinal bleeding