Stones and UTI

Karina and Cameron

Name some common stone sites..

Stones

Renal tract (urolithiasis)

Appendix (faecolith)

Salivary glands

(sialolithiasiss)

Gallbladder/ biliary tree

(cholelithiasis)

Prostate

Veins (phleboliths)

Gallstones

• How do they present? – Asymptomatic, abdo pain

(epigastric and right shoulder pain due to irritation of diaphragm C1-C5), positive murphy’s sign, jaundice and fever

• What investigations would you do? – Bloods: LFTs/amylase, USS and

ERCP/MRCP

Renal Stones• How do they present?

– Loin to groin pain (Can’t get comfortable and may radiate to testicles)

– Sweating– Haematuria – Vomiting – Irritative voiding

• Why do you get this loin to groin pain?

• What initial investigations would you carry out? – Urine dipstick (haematuria)– Imaging: KUB – Do this immediately

if there is also fever present as it could be pylonephrosis.

Renal plexus

Abdomino-aortic plexus

Hypogastric plexus (superior)

T12

L1/2

Sensory nerve route

Renal Stones

• What are the types of renal stone? – Calcium (oxalate and phosphate),

Urate, Struvite, Cystine and Others• Which are the most common?

– Ca oxalate (60%)• They can be seen in different

radiolucencies. What order are they seen in on xrays? – Ca> struvite > cystine> urate (urate are

not seen on xray but can be seen on US and CT)

• What stone causes this classic pattern? – Staghorn calculi of struvite stones

Risk factors

Calcium stones• What are the two main causes of hypercalciuria?

– Hyperparathyroidism and malignancy are most common. Rare genetic disorders and sarcoidosis/TB also come into play.

• What are the causes of hyperoxaluria?– Primary hyperoxaluria, caused by genetic defects; Secondary

hyperoxaluria, caused by increased ingestion of eg spinach/rhubarb/tea or enteric causes.

Struvite stones• What is the usual cause of struvite stones?

– Chronic UTI with urea-splitting bacteria

• …and hence what are the risk factors for this type of stone?– Female, catheters, neurogenic bladders, urinary tract abnormalities,

stagnant urine

Risk factors IICystine stones• What causes the formation of cystine stones?

– Autosomal recessive disorder, resulting in failure of renal tubular reabsorption of cystine. It then crystallises in the urine.

Uric acid stones• What other condition might a patient with uric acid stones

have?– Gout – both result from accumulation of urate, an end product of purine

metabolism.

• What are some common dietary sources of purines which should be avoided with these two conditions?– Alcohol, red meat, liver/sweetbreads/kidney, fish

Renal stones

• Where do renal stones get stuck? – Pelvic ureteric junction (PUJ)

– Pelvic brim

– Vesicoureteric junction (VUJ)

– Bladder urethra outlet

• When would you need to remove the stones? – Pain/ failure to pass

– Recurrent infection

– Bleeding

– Renal impairment

– Some jobs e.g. pilot

UTI • What are the risk factors for UTI?

– Female, sex, exposure to spermicide in females, diabetes, pregnancy (often not picked up until pylonephritis – so routine dipstick), menopause, immunosuppression, stones, catheter (nearly always infected so pointless sending off a sample), malformation.

• A UTI infection can affect any part of the urinary tract. Bladder: cystitis (most common); Prostate: prostatitis; Renal pelvis: pyelonephritis

• What is the clinical presentation of a UTI? – Frequency, pain on voiding (dysuria), suprapubic pain and tenderness, haematuria, smelly

urine, pyuria. – Loin pain, fever, oliguria and systemic symptoms suggest involvement of pelvis of the kidney

pylonephitis. • What is the most common UTI pathogen?

– E coli (>70%)• What tests would you use to confirm UTI?

– MSU: dipstick: nitrites (gram negative bacteria will reduce nitrates to nitrites) and leukocytes.– If the patient also presents with loin pain, fever and tenderness send for US to exclude

obstructed pyelonephrosis.• Which antibiotic are simple/uncomplicated UTI’s treated with?

– Trimethoprim

UTI• How would acute pyelonephritis present?

– Loin to groin pain, vomiting, malaise, fever, rigors

– There may be small renal abscess and streaks of pus in the renal medulla. CT scams will often show wedge shaped areas of inflammation.

• What is reflux nephropathy (aka chronic pyelonephitis)? – Normally the vesicouteric valve and junction

acts to allow urine to enter from above, but not leave the bladder via this route when the bladder contracts. If this valve is compromised urine will go up the ureters and into the kidney – leading to kidney damage. This is more common in children and when the base of the bladder grows it may stop being a problem.

Questions

i. Dysuria, frequency, cloudy urine ii. Nitrites and leukocyte esterases present in the urineiii. Short urethraiv. Clean the peri-uthreal region and take a mid stream sample.

i. E coli ii. Frequent sexual intercourse, female, older age, diabetes, reduced

immunity, poor hygiene

Questions?