Acute Renal Failure and Kidney injury Flashcards
What is ARF?
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
Are changes in Createnine within the reference range significant?
Can be
Relative changes for patient most important thing to consider
What clinical history might an AKI patient have?
Non-specific
- malaise, lethargy, weakness
- anorexia, vomiting, diarrhoea
Known toxin ingestion
Altered urine output
Signs of concurrent disease
What physical exam findings can be associated with acute kidney injury?
Dehydration Oral ulceration/uraemic odour Hypothermia Brady or tachy cardia Swollen painful kidneys (CAN BE NORMAL)
What questions should you alway ask when discovering a new azotaemia on bloods?
Acute or Chronic?
Pre-renal, renal or post renal
What might you suspect CKD over AKI?
History
- PU/PD for a while
- insidious weight loss
CS
- renal size shrunken/abnormal
Non regenerative anaemia
CKD mineral bone disorder 2ry renal hyperPT
Can hyperphosphataemia help differentiate between acute and chronic kidney disease?
NO
Occurs in both
Changes in phosphate happen almost straight away with renal dysfunction
What causes azotaemia ?
- High production of nitrogenous wastes e.g. raw diets (pre-renal)
- Low GFR
- pre - reduced renal perfusion e.g. hypovol
- renal - intrinsic or functional disease
- post - obstruction bilateral ureteral or urethral - Reabsorption of urine escaped from tract (post-renal)
What does a low USG indicate in a dog that is azotaemic?
PRE-RENAL
What are the three main causes of acute kidney injury?
How common is each?
Tubular necrosis (very) Interstitial nephritis (quite) Acute glomerulonephritis (uncommon)
What broad categories of insults cause tubular necrosis?
Ischaemia
Toxins
How would you treat pyelonephritis?
Culture urine
Empirical antibiotic therapy initially
Re culture on treatment
Reculture post treatment
What can predispose a patient to pyelonephritis?
Anatomical
- ectopic ureters
- perineal urethrostomy
Medical
- diabetes,
- renal disease
- nephroliths
Iatrogenic
- catheters,
- steroids
How does Leptospirosis affect the kidney?
Interstitial nephritis
What Leptospira serovars are associated with interstitial nephritis?
Non vaccinal
What other pathologies may be present with Leptospira infection?
Hepatic necrosis
Thrombocytopaenia
Vasculitis
How can you diagnose leptospirosis ?
Rising titre to non-vaccinal seovar
PCR
How would you treat leptospirosis ?
How would you clear carrier status?
AMOXY-CLAVULANTE
Doxycycline to clear carrier status
What can cause ischaemic tubular necrosis?
Hypotension
Decreased effective intravascular volume
Sepsis
Drugs
What therapeutic agents may cause tubular necrosis and AKI?
Antimicrobials
- aminogluycosides
- tetracyclines
Chemo
- doxorubicin (cats)
- cis and carboplatin
- methotrexate
NSAIDs
ACE is
IV contrast agents
What might predispose a patient to getting hospital acquired acute kidney injury ?
Advanced age Fever Dehydration Cardiac disease Pre-existing renal disease Anaesthesia/surgery Nephrotoxic drug administration
How should you manage AKI?
Treat inciting cause
Improve renal haemodynamics
(Via IVFT)
Maintain homeostasis
Supportive care
- nutrition
- control vomiting
What does a high anion gap mean?
Acidosis
What might suggest leptospira for a case with AKI?
Increased bilirubin on bloods -> hepatic necrosis
Why can it be difficult to diagnose leptospirosis?
Titres initially can be negative but become positive during recovery
