GU Problems Flashcards
Define AKI
A syndrome of decreased renal function, measured by serum creatinine or urine output, occurring over hours to days
- Rise in creatinine >26 within 48h
- Rise of creatinine >1.5x baseline within 7 days
- Urine output <0.5ml/kg/h for >6 consecutive hours
What are the limitations of serum creatinine? But why is serum creatinine superior to urea?
Limitations:
- Muscle mass - lower in elderly, females, amputees; higher in body builders
- Dilution
- eGFR can fall to half before creatinine rises past upper limit
Superior:
- Urea is easily influenced by protein turnover (diet, etc) and hydration status
Name the 7 commonest causes of AKI
- Sepsis
- Major surgery
- Cardiogenic shock
- Other hypovolaemia
- Drugs
- Hepatorenal syndrome (renal deterioration secondary to cirrhosis)
- Obstruction
How can the aetiology of AKI be divided up?
Pre-renal = decreased perfusion to kidneys Renal = intrinsic renal disease Post-renal = obstruction to urine
What are some pre-renal causes of AKI?
Hypovolaemia
- Haemorrhage
- Severe D&V
- Burns
- Pancreatitis
Decreased cardiac output
- Cardiogenic shock
- MI
Systemic vasodilation
- Sepsis
- Drugs
- Anaphylaxis
Renal vasoconstriction -> hypoperfusion
- NSAIDs
- ACEi
- Hepatorenal syndrome
- Renal artery stenosis
What are some renal causes of AKI?
Glomerular
- Glomerulonephritis
- Acute tubular necrosis
Interstitial
- Drugs
- Sarcoidosis
- Infection
Vessels
- Vasculitis
- HUS
- Thrombosis
- DIC
What are some post-renal causes of AKI?
Within renal tract
- Stone
- Malignancy
- Stricture
- Clot
Extrinsic compression
- Pelvic malignancy
- BPH
- Retroperitoneal fibrosis
Which medications are nephrotoxic?
DIAMOND + Li
Diuretics (especially potassium sparing) Iodine contrasts/immunosuppressants Antibiotics e.g. aminoglycosides Metformin Opioids NSAIDs Digoxin Lithium
What investigations should be done in AKI?
Urgent VBG to check K+
Bloods
- U&Es - serum creatinine, derange electrolytes
- LFTs - hepatorenal syndrome
- FBC - platelets (if low do blood film), signs of infection, anaemia in HUS
- Blood film - HUS
Urinalysis - protein, haematuria, signs of infection
Ultrasound scan within 24 hours unless cause obvious
Monitor urine output
How do you treat AKI?
STOP AKI
- Sepsis - BUFALO
- Toxins - stop nephrotoxins
- Optimise blood pressure - 500ml 0.9% sodium chloride given over 15 min (if hypovolaemic)
- Prevent harm
- Treat complications e.g. hyperkalaemia, pulmonary oedema, pericarditis, acidosis
- Identify cause
- Review drug chart
- Renal replacement therapy?
- Monitor fluids and U&Es
What ECG changes would you see in hyperkalaemia?
Tall tented T waves
Increased PR interval
Small/absent P wave
Widened QRS complex
How do you treat hyperkalaemia?
- Calcium chloride 10ml of 10% OR Calcium gluconate 30ml of 10% - stabilises myocardium but doesn’t reduce K+
- Insulin (10 units actrapid) in 50ml 50% dextrose IV over 20 minutes – lowers K+ by driving it into cells
- Salbutamol 10-20mg NEB – drives potassium into cells
- If they don’t respond to above start haemofiltration/dialysis
What is a complication of uraemia?
Pericarditis
What is renal colic?
Type of pain that occurs when urinary stones block part of the urinary tract
The pain is produced by ureteric obstruction, increased intraluminal pressure and muscle spasm
Describe the pain caused by a stone in the renal pelvis
Dull ache in the loin
What are the different types of calculi in order of how common they are?
- Calcium oxalate (75%)
- Struvite - magnesium ammonium phosphate (15%)
- Urate
- Hydroxyapatite (usually do to UTI)
- Cysteine (usually due to renal tubular defect)
What metabolic disorders predispose you to urinary tract calculi?
Hypercalcaemia (hyperthyroidism, hyperparathyroidism, malignancy, sarcoidosis, lithium)
Renal tubular acidosis
Gout
Cysteinuria
What signs might you find on examination of renal stones?
Renal angle tenderness - especially on percussion if there is retroperitoneal inflammation
Reduced bowel sounds (as in any severe pain)
Severe pain in testis/tip of penis/labia but not tender on palpation
What is the investigation choice for imaging stones?
Non-contrast CT (99% visible, whilst excluding other causes of acute abdomen)
What investigation for renal stones can be done in pregnant patients?
USS with doppler
Which stones are radio-opaque and would be seen on KUBXR?
Calcium oxalate stones
Struvite stones
Hydroxyapatite stones
How do you treat stones <5mm?
Increase fluid intake - 90% pass spontaneously
Analgesia - diclofenac IV/PR
Antibiotics - penicillin/gentamicin if infection
How do you treat stones >5mm?
Medical expulsive therapy
- Nifedipine (calcium-channel blocker) or tamsulosin (alpha blocker)
- Extracorporeal shockwave lithotripsy (ultrasound waves shatter the stone)
- Uteroscopy
Percutaneous nephrolithotomy = keyhole surgery to remove stones if complex
What is a risk factor for testicular torsion?
Undescended testis
Bell Clapper deformity = abnormally mobile mesentery of testis within tunica vaginalis - bilateral
What becomes twisted in testicular torsion?
The spermatic cord which brings blood to the scrotum
How does testicular torsion classically present?
Sudden onset severe scrotal pain that may radiate to the groin or lower abdomen
Nausea & vomiting
How can you differentiate testicular torsion from hydrocele?
Trans-illumination
What signs may be found on examination of testicular torsion?
Red, tender, swollen testis
Deming’s sign = affected testicle lies high up
Angell’s sign = opposite testicle lies horizontally
Absent cremaster reflex
How do you treat testicular torsion?
Emergency surgery within 6-12h to preserve testicle
Orchidopexy = fixation of the testis
Orchidectomy if the testis is non-viable
What is the difference between complicated/uncomplicated UTIs?
Uncomplicated = normal renal tract structure + function
Complicated = structural/functional abnormality of genitourinary tract e.g. obstruction, catheter, stones, renal transplant, neurogenic bladder
What are the most common organisms to cause a UTI?
E. Coli = most common (75-95% in community)
- Staphyloccous saprophyticus (skin commensal)
- Proteus mirabilis
- Klebsiella pneumonia
What are the symptoms of cystitis?
- Frequency
- Dysuria
- Urgency
- Suprapubic pain
- Haematuria
What are the symptoms of pyelonephritis?
- Fevers and rigors
- Nausea and vomiting
- Loin tenderness
- Septic shock
- Associated cystitis symptoms
What indicates a UTI on urinalysis?
Leucocytes
Nitrites
What investigation should be done for UTIs in catheterised patients?
MSU cultures
Dipstick would almost always be positive so is not useful
In which patients should urine cultures be done?
Immunosuppressed Pregnant women Renal tract anomaly Failed to respond to empirical treatment Men with history suggestive of UTI
Which organism causes hospital/catheter acquired UTI?
Pseudomonas
What is the treatment for non-pregnant women with a lower UTI?
3-6 day course of trimethoprim/ nitrofurantoin
Can only give nitrofurantoin if eGFR > 30
What is the treatment for pregnant women with a UTI? Which antibiotics must be avoided?
Penicillins (e.g. amoxicillin)/cephalosporins
Avoid:
- Trimethoprim (1st trimester)
- Nitrofurantoin (term)
- Quinolones e.g. ciprofloxacin (all pregnancy)
- Sulphonamides (all pregnancy)
How do you treat men with lower UTI?
1-2 week course of trimethoprim/nitrofurantoin
How do you treat men with prostatitis?
4 week course of ciprofloxacin because it penetrates prostatic fluid
What is the treatment for upper UTI?
- 7-10 day course of ciprofloxacin/gentamicin
- Co-amoxiclav and cefalexin can be used
Which antibiotics should be avoided in renal impairment?
- Nitrofurantoin
- Tetracyclines
- Gentamicin
Which antibiotics are best for long-term treatment or prophylaxis of UTIs?
Trimethoprim 100mg
Nitrofurantoin 50-100mg
What can cause urinary retention in men/women?
Both
- Bladder calculi
- Bladder cancer
- Faecal impaction
- Urethral strictures
Women
- Prolapse
- Pelvic mass e.g. malignancy, cyst, fibroid
- Retroverted gravid uterus
Men
- BPH
- Prostate cancer
- Phimosis
What drugs increase the risk of acute urinary retention?
Anticholingergics Opioids Benzodiazepines NSAIDs Calcium-channel blockers Antihistamines Alcohol
What is by far the most common cause of urinary retention?
BPH
What is important to screen for in a patient presenting with urinary retention?
Cauda equina syndrome
- Check lower limb peripheral nervous system
- DRE for anal tone and prostate
How does acute urinary retention present?
Painful, distended bladder
Anuria
Possible associated delirium
How do you manage acute urinary retention?
Immediate and complete bladder compression with catheter
