Pathophysiology
- Stones can form anywhere in the urinary tract, but common sites are: vesicoureteric junction (60%), ureteropelvic junction in kidney, and sacroiliac joint (where ureter crosses iliac vessels).
- 80% are calcium stones, which also contain oxalate (commonest), phosphate, or both. Other stone types include struvite (magnesium ammonium phosphate) – forming staghorn stones – and urate.
Signs and symptoms
- Sudden onset of severe, intermittent pain, due to peristalsis against the obstruction.
- Ureteric stone pain radiates from loin to groin. Midureteric stones can mimic appendicitis or diverticulitis.
- Patient writhing, trying to get comfortable, unlike peritonitis where they are still.
- Generally unwell: sweaty, nausea and vomiting.
Risk factors
- Dehydration
- Hypercalciuria (and hence hypercalcaemia).
- Family history.
- Kidney disease: renal tubular acidosis, medullary sponge kidney, polycystic kidney disease.
- Gout (urate stones).
- Proteus infection (struvite stones).
- Drugs: furosemide, steroids, acetazolamide, theophylline. Thiazides reduce the risk via tubular reabsorption of calcium.
Investigations
- Urine dip: 90% will have haematuria. Confirm on microscopy.
- CT KUB (non-contrast) is the definitive test. Will identify stones as well as other causes of renal colic – e.g. transitional cell carcinoma, retroperitoneal lymph nodes – and other differentials such as appendicitis. Shows 99% of stones vs. 60% on an XR KUB.
- XR KUB can be used to monitor passage of a stone.
Other tests:- FBC and CRP to look for infection.
- U&E
- Check Ca2+, PO43-, and urate if recurrent.
Management
- Analgesia: NSAIDs are 1st line, commonly diclofenac IM or PR.
- Antiemetics and fluids may also be needed.
- If pain resolves and no obstruction, patients can be discharged with outpatient follow up if needed.
- If pain continues or there is obstruction: ureteric stent via cystoscopy, done under general anaesthesia. Temporizing measure until definitive stone removal.
- If there is sepsis: antibiotics IV and urgent nephrostomy.
Most stones are <5 mm and pass spontaneously:- Encourage good fluid intake.
- Offer regular analgesia e.g. paracetamol or codeine.
- Try and urinate into container to catch stone.
- Usually takes 1-3 weeks to pass. Review if not passed after 3 weeks.
Stones >1 cm usually require removal:- Extracorporeal shock wave lithotripsy (ESWL) is the commonest method. Uses electromagnetic energy to destroy the stone, targeted using XR and US, with the fragments then passed in the urine.
- In rarer cases, ureteroscopy is used and the stone broken up with a laser, or percutaneous removal is used for large stones (>2 cm) in the renal pelvis.
Stones 5-10 mm are intermediate:- 50% pass spontaneously, though this is rare if ≥7 mm.
- Passage of distal ureteric stones can be aided by α-blockers, calcium channel blockers, or (for men) regular sexual intercourse (3-4 times/week).
Complications
- Obstructive nephropathy.
- Infection
- Renal failure if presentation delayed.
Baby check at birth and 6 weeks Check notes and get equipment ready: Measuring tape. Ophthalmoscope Sats probe. In notes, look at full details of pregnancy and birth, including Apgar scores at 1 and 5 minutes. Observation: Colour: pink/red, pale, jaundiced. Any rash? Erythema toxicum is a self-limiting rash of red papules and vesicles, surrounded by red blotches which sometimes give a halo appearance. Usually occurs between 2 days and 2 weeks. Behaviour and mood. Movements. Face: dysmorphism? Head: Feel fontanelle (bulging? sunken?) and sutures. Note that posterior fontanelle closes at 1-2 months, and anterior at 7-19 months. Measure circumference at widest point; take the highest of 3 measurements. Looking for hydrocephalus and microcephaly. Eyes: check red reflex with ophthalmoscope. Feel inside top of mouth with little finger for cleft palate. Also gives you the sucking reflex. Inspect ears to see if they are low-set (below eye level), have any tags or lumps, and check behind the
Comments
Post a Comment
If u have any doubt let me know.