Genitourinary Flashcards
What are the major functions of the Kidney?
- Filter or secrete waste/excess substances
- Retain albumin and circulating cells
- Reabsorb glucose, amino acids and bicarbonates
- Control BP, fluid status and electrolytes
- Activates 25-hydroxy vitamin D (by hydroxylating it to form 1,25 dihydroxy
vitamin D) - Synthesis erythropoietin
What is the Glomerular Filtrate rate?
The volume of fluid filtered from the glomeruli into Bowman’s space per unit
time (minutes)
What is the normal GFR?
120ml/min
What is Nephrolithiasis?
Renal Stones (calculi) commonly made from Calcium Oxalate (90%) which form in the CD and can be deposited anywhere from the renal pelvis to the urethra.
What are some other types of renal stone compared to calcium oxalate?
Calcium phosphate/oxalate (80%)
Uric Acid (10%)
Cysteine Stones
Struvite (infection often from proteus)
What are the 3 main narrowing’s where renal stones may be found?
- Pelviureteric junction
- Pelvic brim
- Vesicoureteric junction
What is the epidemiology of Renal Stones?
10-15% lifetime risk
More common in males
Peak age 20-40 yrs
Increasing Incidence
What are the risk factors for renal stones?
Chronic Dehydration
Low urine output
Primary kidney disease
HyperPTH/Hypercalcaemia
UTIs
Hx of previous renal stone
Drugs
What are the main causes for renal stones?
Anatomical:
Congenital - horseshoe kidney
Acquired - Obstruction, trauma, reflux
Urinary Factors:
Metastable urine
Increased Calcium oxalate, urate, cystine
Dehydration
What is the pathophysiology of renal stones?
Excess solute in the collecting duct
Supersaturated urine - favours crystallisation
Stones cause regular outflow obstruction - lead to hydronephrosis
Subsequent dilation of the renal pelvis will lead to lasting kidney damage
What are the 2 key complications of renal stones?
Obstruction - leading to AKI
Infection - causing obstructive pyelonephritis
What is the presentation of Renal Stones?
Maybe ASx and never cause issue
Renal colic is presenting complain in Symptomatic kidney stones:
Loin to groin pain that is colicky (peristaltic waves leading to fluctuations in severity)
LUTs (dysuria, strangury Urgency, Frequency)
Px cant lie still
What is Colicky Pain?
Pain that fluctuates in severity often due to peristalsis causing contaction of gallstones/renal stones which then settles when the contraction stops
What are the symptoms of Renal Colic?
Loin to groin pain
Px cannot lie still
Haematuria/dysuria
Nausea or vomiting
Reduced urine output (LUTS)
Symptoms of sepsis, if infection is present
What are the primary investigations for Renal stones?
1st Line - KUB (kidney, Ureter, Bladder) XR - 80% specific
Gold Standard - NCCT (non-contrast CT) KUB - 99% specific (diagnostic)
Bloods:
FBC
U&Es - raised creatinine in AKI
Urinalysis -Microscopic haematouria
Pregnancy test
Urine dipstick - UTI
What investigation would be used for hydronephrosis from a suspected renal stone for a Px who is pregnant?
Ultrasound as they cannot have CT
How can a kidney be drained if infected?
Ureteric stend
Nephrostomy
What is the Treatment for Renal Stones?
Sx management:
Strong Analgesic - IV/PR Diclofenac for severe pain (opiates in poor renal function Px)
Hydrate - oral or IV
Anti-emetics
Abx if infection present:
Cefuroxime / IV Gentamicin
Stones normally pass spontaneously if small enough (<5mm)
Elective Surgical Tx if too big to pass
What is a key complication of kidney stones?
Pyonephrosis
- Pus filled fluid caused by infection and obstruction together.
Tx with septic six
What Treatment is used if a stone is too large to pass spontaneously?
ESWL:
Extracorporeal shockwave lithotripsy - ultrasound that fragments the stones (does not clear the stone so Px still has to pass stone)
Ureteroscopy - laser
PCNL:
Percutaneous nephrolithotomy - keyhole surgery to remove large/complex stones
Nephrectomy - if kidney contributes to less than 15% renal function
What is a big issue once you have had one renal stone?
Recurrence is very common and therefore take steps to prevent it:
Overhydration
Low Ca dietary intake
Low sodium diet
Reduce BMI
Active lifestyle
Potassium Citrate and Thiazide diuretics may also help
What are some differential Diagnoses for Loin pain other than Renal Colic?
Vascular accident - Ruptured AAA
Bowel Pathology - diverticulitis, appendicitis
Gynae - Ectopic pregnancy
Testicular torsion
MSK pain
What is the treatment for bladder stones?
Conservative - asymptomatic
Endoscopic + BOO Tx
Open Laparoscopic surgery - for large stones
What is Acute Kidney Injury (AKI)?
Abrupt decline in kidney function that occurs within hrs to days.
This is characterised by a increase serum creatinine and urea and a reduced urine output due to a decline in GFR failing to maintain acid base homeostasis