Renal Flashcards Preview

Core Conditions > Renal > Flashcards

Flashcards in Renal Deck (18)
Loading flashcards...
1
Q

What are the usual presenting compliants for urinary problems?

A

Obstructive:

  • poor flow
  • hesitancy
  • intermittency
  • terminal dribbling

Irritative:

  • frequency
  • urgency
  • nocturia
  • incontinence
2
Q

What are some causes of urinary dysfunction?

A

Obstructive:

  • BPH
  • Ca prostate
  • stricture

Irritative:

  • seconday to obstruction
  • UTI
  • Ca bladder
  • stone
  • diabetes
  • TB
3
Q

What is the definition of acute urinary retention?

A

Sudden and painful inability to pass urine.

4
Q

What are the causes and precipitants of acute urinary retention in males?

A

Causes:

  • BPH
  • prostate cancer
  • stricture
  • neurological (stroke, PD, acute spinal cord injury)

Acute precipitants:

  • UTI
  • diuresis
  • constipation
  • drugs
  • postoperaive
  • bleeding (clot retention)
5
Q

What are the causes of acute urinary retention in females?

A

Reflex AUR:

  • urethritis
  • UTI

Intrinsic compression:

  • meatal stenosis or stricture
  • tumour
  • urethral diverticulum or stone

Extrinsic compression:

  • severe prolapse
  • pelvic space-occupying lesion
6
Q

What are the main physiological roles of the kidney?

A
  1. Maintain salt and water balance
  2. Excrete solutes and waste products
  3. Acid/base homeostasis
  4. EPO and Vitamin D
7
Q

What are the features of kidney disease?

A
  1. Inability to excrete OR conserve salt and water
  2. Accumulation of solutes and waste products
  3. Accumulation of acids
  4. Anaemia and renal bone disease
8
Q

What are the causes of acute kidney injury?

A

Pre-renal causes:

  • haemorrhage
  • hypovolaemia
  • hypotension

Intra-renal:

  • tubular injury (common) - ischaemia/prolonged hypoperfusion (ATN) or toxins
  • interstitial nephritis (common) - drugs, infection, infiltration
  • glomerular injury (uncommon) - inflammation (i.e. glomerulonephritis), thrombosis
  • vascular disease (uncommon) - inflammation (vasculitis), occlusion (thrombosis or embolism)

Post-renal:

  • tumour
  • kidney stones
  • enlarged prostate
  • trauma
9
Q

What are the three key assessments in the clinical assessment of AKIs?

A
  1. volume status to detect pre-renal cause
  2. urine studies to differentiate between pre-renal cause and ATN
  3. renal ultrasound to detect post-renal cause

Note: if pre-renal cause, urine will be concentrated (high Na). If ATN, urine will not be concentrated.

10
Q

What is the definition of acute kidney injury?

A

Rapid decrease in kidney function over 48 hours

OR urine output less than 0.5 mL/kg/hour over 6 hours

11
Q

What is the most common cause of acute kidney injury in the community and in hospitalised patients?

A

In the community, pre-renal AKI is the most common with obstruction (ureteric, bladder neck or urethral) the 2nd most common.

In hospitalised patients, pre-renal AKI is the most common.

12
Q

What is the pathophysiology of acute tubular necrosis (ATN)?

A
Ischaemic depletion of ATP 
> release of ROS
> apoptosis
> cell desquamination
> obstructive casts 
> back-leak of tubular fluid
> reversible with regeneration of tubular endothelial cells
13
Q

What are the three main clinical stages of acute tubular necrosis (ATN)?

A
  1. Initiation phase: acute decrease in GFR to low or very low levels, an increase in serum Cr and urea
  2. Maintenance phase: sustained reduction in GFR - urea and Cr continue to rise
  3. Recovery phase: tubular function is restored with increase in urine volume (if oliguria was present) and a gradual decrease in Cr and urea.
14
Q

What are some considerations in the clinical evaluation of AKI?

A
  1. Is the renal impairment acute or chronic?
  2. Has obstruction been excluded? (often complete anuria with palpable bladder, renal U/S shows hydronephrosis)
  3. What is the patient’s volume status? (may suggest pre-renal)
  4. Is there evidence of other intrinsic renal disease apart from ATN? (history, exam, urinalysis)
  5. Has a major vascular occlusion occurred? (history and risk factors)
15
Q

What are some risk factors for acute kidney injury?

A

Background:
Elderly, CKD, cardiac failure liver disease, diabetes, vascular disease, background nephrotoxic medications

Acute insult:
Sepsis and hypoperfusion, toxicity, obstruction, parenchymal kidney disease

16
Q

How do we prevent an acute kidney injury (AKI)?

A
  1. Monitor patient
    - obs, blood tests, fluid charts, urine volume
  2. Maintain circulation
    - euvolaemia, resuscitation, oxygenation
  3. Minimise kidney insults
    - drugs, contrast, high risk interventions, hospital-acquired infections
  4. Manage the acute illness
    - sepsis, heart failure, liver failure
17
Q

How do we investigate AKI?

A
  1. Causes - think STOP (sepsis, toxicity, obstruction, parenchymal disease)
  2. Urine dipstick
  3. Renal ultrasound
18
Q

What is the purpose of dialysis in the context of AKI?

A
  1. Fluid balance - for those with AKI, urine output may not be preserved.
  2. Solute removal - the removal of waste products and solutes, electrolytes and excess acid