Poor Urine Output Flashcards
Reduced urine output, what simple thing do you need to check?
The trend of reduction
What’s an immediate thing to check with reduced urine output?
Blocked catheter
With reduced urine output, what are you worried about?
Sepsis
Signs of sepsis
Temperature Heart rate RR O2 sats ALL THE BASIC OBS!
Normal urine output for healthy adult
1ml/kg/hr
Untreated AKI can result in
Hyperkalaemia
Acidosis
Pulmonary oedema
All of these can kill you
What do you check on the fluid balance chart?
Adequate intake (3L/day for a normal person) The balance, is it positive or negative? Remember that often, stool and vomit are not accounted for. Also, NG tube may be documented somewhere else.
Drugs that are damaging to the kidneys
NSAIDS ACEi Diuretics Antibiotics (vancomycin and gentamicin) IV contrast
What % increase in baseline creatinine constitutes acute kidney injury?
50%
Questions to ask a patient with low urine output
Do they feel thirsty
Any symptoms of renal disease?
Signs of post-renal obstruction
Poor stream
Frequency
Terminal sribbling
Hesitancy
Signs of dehydration
Dry lips Dry, cracked tongue Tachycardic Does the patient feel DIZZY ON STANDING (a good sign of dehydration, as often no postural drop because they compensate) Cool peripheries and low BP (late stage)
Signs of heart failure
Raised JVP
Displaced apex beat
Third heart sound
Bilateral and basal crepitations
Signs of urine retention
Palpable distended bladder
BLADDER SCAN!
How does atelectasis present and what causes it?
Often caused by surgical anaesthesia
Presents as crepitations
It’s alveolar collapse
What would you expect the trend of urine output to be with a blocked catheter?
Sudden drop
But should just flush it anyway to check with low output
GENTLY push 50ml of fluid up the catheter, if there is any resistance this suggests a blockage
Quick way to get potassium measurement
VBG
Bloods to ask for in AKI
Creatinine, urea, Hb
Urea raised suggests…
Dehydration
You reckon there’s hypovolaemia, what should you initially do?
Fluid challenge of 250-500ml crystalloid solution stat
Monitor the response!
How much glucose/day to avoid starvation?
100g
How many ml/kg/day in typical patient
25ml/kg/day
Management of acute urinary obstruction
Catheterisation
IV fluids
Assess renal function (monitor urea, creatinine, Hb and electrolytes)
Assess causes = DRE, urine dipstick, ensure not constipated
TWOC in the morning (NOT AT NIGHT, because can go wrong when there are fewer staff) = alpha blocker to relax the sphincter
Which scan if you are worried about cauda equina?
MRI spine, looking for prolapsed disc or collapsed vertebrae
Cause of urine ‘spraying’
Urethral stricture
Often as a result of many cystoscopies
Patient fluid overloaded, makes pre-renal less likely unless there is obvious pathology, so consider…
Renal causes e.g. hypovolaemia in surgery leading to acute tubular necrosis
Patient with renal AKI, what do you do?
Refer to renal physicians
Assess need for dialysis
STOP nephrotoxic drugs, e.g. NSAIDs
Complications of urethral bladder catheterisation
Infection
Urethral trauma
Scarring and stricture
Bladder perforation
Complications of chronic urinary retention
Dribbling
UTI due to stasis
Bladder stones due to stasis
Hydronephrosis
Where is renin released?
Kidneys
What does renin do?
Stimulate production of angiotensin 1
What converts angiotensin 1 to angiotensin 2?
ACE
Which nerve controls voluntary micturition?
Pudendal nerve
Which muscle contracts the bladder?
Detrusor
How do you treat overactive bladder?
Anti-muscarinic = oxybutynin.
These inhibit the parasympathetic activity through the pelvic nerve
Which drugs can cause urinary retention
Antimuscarinic
Antihistamines
TCA
PSA >40 indicates?
High risk of metastatic prostate cancer
How do you confirm prostate cancer?
Transrectal prostate biopsy (painful procedure, involving needles through rectal wall)
Management of prostate cancer
Active surveillance for low risk
Radical treatment otherwise
Patient with clot retention after TURP, which catheter should you use?
3-way foley (extra port is for irrigation)
New-onset renal failure and seizures
TTP Microangiopathic haemolytic anaemia (MAHA) Thrombocytopaenia Fever Renal failure NEUROLOGICAL symptoms
