Internal Medicine: Acute Kidney Injury and Urinary Tract Infection Flashcards
What is AKI?
Acute kidney injury
Spectrum of disease associated with a sudden onset of renal parenchymal injury
What happens with an abrupt drop in kidney function?
- Abnormal GFR, tubular function and urine production
- Sudden inability to maintain fluid, acid-base and electrolyte balance
- May result in azotaemia
What are the causes of AKI?
- Decreased renal blood flow
- Toxins- ABs, NSAIDs, ethylene glycol, lillies (cats), grapes (dogs)
- Intrinsic renal diseases- leptospirosis, pyelonephritis
- Systemic diseases
Describe the pathophysiology of AKI
4 stages
* Initiation phase- damage starts
* Extension phase- ishaemia, hypoxia, inflammatory response, ongoing cellular injury, cell death
* Maintenance phase- stabilisation of GFR, azotamiea, uraemia
* Recovery phase- azotamia improves and the tubules undergo repair can be marked polyuria during this stage
When does AKI, AKD and CKD occur?
AKI- 0-7 days
AKD- 7-90 days
CKD- >90 days
What history may highlight AKI?
- Recent onset of anorexia, polydipsia, vomiting
- May get CNS signs in ethlylene glycol
- Toxin exposure/nephrotoxis drugs
- Vaccination- lepto
What may be found on a physical exam of an animal with AKI?
- Uraemic breath
- Hypothermia- unless infection
- ± kidney pain or enlargment
- Tachycardia- dehydration, pain
- Bradycardai- hyperkalaemia
What may be found on blood samples and urine for an animal with AKI?
§
Blood
* Azotaemia
* Increased phosphate
* Hyperkalaemia
* Calcium variable
Urine
* Probably isothenuric
* Can see glucosuria, haematuria
* Sediment- casts, WBCs, bacteria, crystals
Potassium often down with chronic
What are the differences in symptoms with AKI and CKD?
How is AKI treated?
- Treatment to eliminate the cause- induce vomiting if toxin ingestion
- Supportive treatment- initial IVFT based on degree of hydration (improve renal blood flow, oxygen supply and GFR
What lillies are certified safe?
Calla lily
Peace lily
What can aggressive fluid therapy cause?
- Increased renal venous pressure and renal interstitial oedema
- Cerebral oedema
- Pulmonary oedema
- Myocardial oedema
- Hepatic congestion
- Tissue oedema
Not reccomended
How should anuria or oliguria be managed?
- Specific and supportive Tx
- Animal rehydrates
- If urine flod > 2ml/kg/h- carry on
- If under (oliguria) reassess hydration/BP:
Reduce IVFT
Place catheter
Start treatment to increase urine output
What canbe used to increase urine output?
Furosemide
* Increases urine output but does not improve GFR
* Allows you to carry on with IVFT
Not recomended in human medicine as may slow referral for dialysis
What needs to be avoided post rehydration of an animal?
Polyuria
Acid base/electrolgy abnormalities
* Metabolic acidosis frequently occurs
* Bicarb treatment can be risky
Hyperkalaemia
Other then rehydration and managment of it what other treatments may be required for AKI?
Vomiting
* Maropitant
Hypertension
* exacerbated by overhydration
* Reduce IVFT, give diuretics
Nutrtition
* AKI is highly catabolic
When should dialysis be considered?
When diuresis- increased urine production
Cannot be achieved
Very expensive- not common
Liverpool don’t do it
When should euthanasia be considered for AKI?
Despite treatment renal function worsens, fails to improve or does not improve sufficiently to be managed at home
- Dialysis
or - Euthanasia
If a dog has undergone a large surgery (GA) and has become hypotensive for several minutes is it safe to give an NSAID?
No
Should avoid renal insults after a potential primary one
2 year old FN cross breed
* Sudden onset vomiting
* Lethargic
* BCS 5/9
* Spayed 3 days ago
* Temp 37.5
* Cratinine high
Is AKI or CKD more likely
AKI
2 year olf FN Lhasa
* Gradual onset vomiting
* PUPD 2 months
* Bright
* BCS 3/9
* Temp 37.5
* Creatinine high
AKI or CKD?
CKD
What are the following definitions?
1. UTI
2. Bacteriuria
3. Pyuria?
- Adherence, multiplication and persistence of an infectious agent within the urinary system
- Bacteria in the urine- not a UTI
- White blood cells in the urine- not a UTI
What are the different classifications of UTIs in small animals?
- Sporadic bacterial cystitis
- Recurrent bacterial cystitis
- Pyelonephritis
- Bacterial prostatitis- male
- Subclinical bacteriuria
What clinical findings may be obvious with UTI?
What blood results may be present?
Clinical findings
* Cystitis may cause dysuria, pollakiuria, haematuria or urinary incontinence
* Pyelonephritis may cause abdominal pain, AKI, or septicaemia- may also be PU/PD
Blood results
* Lower UTIs- likely none
* Upper UTIs- bloods may show septicaemia
What is the main way to diagnosed UTI?
Urine culture
Cystocentesis best way to sample
How is sporadic bacterial cystitis treated?
- ABs for 3-5 days
- NSAIDs can be used as well
- Amoxicillin, cephalexin or trimethoprim
No need to culture if simple-sporadic baterial cystitis
Not fluoroquinolones or extened release cephalosporins
How should recurrent bacterial cystitis be treated?
What can predispose?
- Treat for 3-5 days- consider 7-14 days
- Find predisposing factor and treat
Predisposing- e.g
* Endocrinopathy
* Kidney disease
* Abnormal vulva
* Congenital
* Prostatis disease
* Bladder tumour
* Polypoid cystitis
* Urolithiasis
* Immunosuppressive therapy
* Urinary incontinence
- How long should pyelonephritis be treated for?
- How long should prostatitis be treated for?
- How long should sub-clinical bacteriuria be treated for?
- 10-14 days
- ABs that penetrate blood-prostate barrier- sulphonamides, fluoroquinolones- 4 weeks
- Treatment not recommneded
Does cystitis cause PUPD?
False
What type of UTI does the following dog have?
4yo FN Lab
Stranguria, haematuria
Bright
BCS 5/9
Bacteria on culture
3rd episode this year
Recurrent bacterial cystitis
If entire male has UTI what is presumed?
Presume bacterial prostatitis and treat for
