Urinary stones

Introduction

Urinary stones are usually divided into 2 types :

1) Infective

These stones are usually whitish and chalky, and they crumbles easily.

Usually due to impaired drainage of urine, for eg, in cases of prolonged immobilisation or even bladder diverticulum.

Main constituents includes calcium, ammonia, and magnesium phosphate.

2) Metabolic

80% of these stones are calcium-oxalate stones.

Usually due to abnormal concentration of normal constituents (dehydration) Or

presence of abnormal constituents in urine (homocystinuria) Or

excessive amount of normal constituents in urine (hypercalcemia secondary to hyperparathyroidism or hyperuricemia due to gout)

Hence, any recurrent renal/ureteric colic is an indication for such metabolic screening.

Renal and ureteric stones

More common in males, aged in between 30-50 years of age.

The predominant symptom here is pain, which is dependent on the site of the stones.

If it's a renal stone, it causes a dull, sometimes severe fixed renal pain at the loin (region in between the 12th rib and iliac crest)

Once it has entered into the ureter, the pain changes it's nature.

It becomes colicky (in fact, a true colic), radiating from the loin to groin, testes, labia, and even to the tip of penis.

And of course, the pain might be the worst pain ever experience by the patient.

The patient will be jolting around, rolling, in attempt to relieve the pain.

And it's associated with nausea and vomiting.

Macroscopic hematuria is usually not seen.(although evidence of microscopic hematuria more common)

Bear in mind that the first presentation might be in the form of acute pyelonephritis (triad = fever, loin pain, dysuria)

Or some stones can be clinically silent, till it produces significant renal impairment where the patient first presents with features of uraemia.

It's not possible to examine the patient while he/she is having acute pain. Hence, diagnosis is mostly from history.

Bladder stones

Bladder stones are more commonly seen in middle-age and elderly patients.

Most of them are having prostatic diseases.

Common symptoms include increased frequency of micturition, which sometimes can be related to posture.

While standing up, the stones fall onto the bladder trigone.
Hence, there's a stabbing lower abdominal pain or intense desire to micturate.
While lying down supine, symptoms subsided since the stones fall away from the trigone.
There might be intermittent cessation of urinary flow due to the same reason.
Other symptoms includes : hematuria, features of cystitis (suprapubic pain, burning micturition)

Investigations

A pain abdominal X-ray may reveal a radio-opaque lesion seen along the course of ureter.
Usually, an intravenous urogram reveals obstruction caused by the stones.

Midstream urine is sent for urine culture to rule out any infection.
Renal profile is evaluated

Management

First of all, IM diclofenac is to be given to relief pain (pethidine is an alternative)
In case where the stones are <0.5cm in diameter, as it passes out spontaneously, and the patient's condition improves, there's no further interventions required.
However, if there's evidence of hydroureter, hydronephrosis, increasing pain/fever, treatment is required.
Management of choice nowadays is the extracorporal shock wave lithotripsy.

Alternatively, a ureteroscope is inserted to break the stones.
Or in case where the above 2 interventions fails, go for percutaneous nephrolithotomy.