Acute Renal Failure and Kidney injury

Question 1

What is ARF?

Answer 1

A clinical syndrome characterised by sudden (within 48h) onset of haemodynamic, filtration, and excretory failure of the kidneys.

Subsequent accumulation of metabolic toxins and dysregulation of fluid, electrolyte and acid-base balance

Question 2

Are changes in Createnine within the reference range significant?

Answer 2

Can be

Relative changes for patient most important thing to consider

Question 3

What clinical history might an AKI patient have?

Answer 3

Non-specific

• malaise, lethargy, weakness
• anorexia, vomiting, diarrhoea

Known toxin ingestion
Altered urine output

Signs of concurrent disease

Question 4

What physical exam findings can be associated with acute kidney injury?

Answer 4

Dehydration
Oral ulceration/uraemic odour
Hypothermia 
Brady or tachy cardia
Swollen painful kidneys (CAN BE NORMAL)

Question 5

What questions should you alway ask when discovering a new azotaemia on bloods?

Answer 5

Acute or Chronic?

Pre-renal, renal or post renal

Question 6

What might you suspect CKD over AKI?

Answer 6

History

• PU/PD for a while
• insidious weight loss

CS
- renal size shrunken/abnormal

Non regenerative anaemia
CKD mineral bone disorder 2ry renal hyperPT

Question 7

Can hyperphosphataemia help differentiate between acute and chronic kidney disease?

Answer 7

NO
Occurs in both

Changes in phosphate happen almost straight away with renal dysfunction

Question 8

What causes azotaemia ?

Answer 8

1. High production of nitrogenous wastes e.g. raw diets (pre-renal)
2. Low GFR
   - pre - reduced renal perfusion e.g. hypovol
   - renal - intrinsic or functional disease
   - post - obstruction bilateral ureteral or urethral
3. Reabsorption of urine escaped from tract (post-renal)

Question 9

What does a low USG indicate in a dog that is azotaemic?

Answer 9

PRE-RENAL

Question 10

What are the three main causes of acute kidney injury?

How common is each?

Answer 10

Tubular necrosis (very)
Interstitial nephritis (quite)
Acute glomerulonephritis (uncommon)

Question 11

What broad categories of insults cause tubular necrosis?

Answer 11

Ischaemia

Toxins

Question 12

How would you treat pyelonephritis?

Answer 12

Culture urine
Empirical antibiotic therapy initially
Re culture on treatment
Reculture post treatment

Question 13

What can predispose a patient to pyelonephritis?

Answer 13

Anatomical

• ectopic ureters
• perineal urethrostomy

Medical

• diabetes,
• renal disease
• nephroliths

Iatrogenic

• catheters,
• steroids

Question 14

How does Leptospirosis affect the kidney?

Answer 14

Interstitial nephritis

Question 15

What Leptospira serovars are associated with interstitial nephritis?

Answer 15

Non vaccinal

Question 16

What other pathologies may be present with Leptospira infection?

Answer 16

Hepatic necrosis
Thrombocytopaenia
Vasculitis

Question 17

How can you diagnose leptospirosis ?

Answer 17

Rising titre to non-vaccinal seovar

PCR

Question 18

How would you treat leptospirosis ?

How would you clear carrier status?

Answer 18

AMOXY-CLAVULANTE

Doxycycline to clear carrier status

Question 19

What can cause ischaemic tubular necrosis?

Answer 19

Hypotension
Decreased effective intravascular volume
Sepsis
Drugs

Question 20

What therapeutic agents may cause tubular necrosis and AKI?

Answer 20

Antimicrobials

• aminogluycosides
• tetracyclines

Chemo

• doxorubicin (cats)
• cis and carboplatin
• methotrexate

NSAIDs
ACE is
IV contrast agents

Question 21

What might predispose a patient to getting hospital acquired acute kidney injury ?

Answer 21

Advanced age 
Fever
Dehydration
Cardiac disease 
Pre-existing renal disease 
Anaesthesia/surgery 
Nephrotoxic drug administration

Question 22

How should you manage AKI?

Answer 22

Treat inciting cause
Improve renal haemodynamics
(Via IVFT)
Maintain homeostasis

Supportive care

• nutrition
• control vomiting

Question 23

What does a high anion gap mean?

Answer 23

Acidosis

Question 24

What might suggest leptospira for a case with AKI?

Answer 24

Increased bilirubin on bloods -> hepatic necrosis

Question 25

Why can it be difficult to diagnose leptospirosis?

Answer 25

Titres initially can be negative but become positive during recovery