Lower
urinary Infection and cystitis
Infection of the bladder gives rise to symptoms of frequency, urgency,
suprapubic discomfort, dysuria and cloudy offensive urine. These symptoms are
often known as ‘cystitis’. Lower urinary tract infections (UTI) are much
more common in women than in men, particularly in the under 50s. Recurrent lower
urinary infection occurs in some healthy women after
Predisposing
causes
• Incomplete emptying of the
bladder which may be secondary to bladder outflow obstruction caused by
prostatic obstruction, urethral stricture or meatal stenosis, bladder
diverticulum, neurogenic bladder dysfunction or decompensation of the detrusor
muscle.
• The presence of a calculus, foreign body or neoplasm.
• Incomplete emptying of the upper
tract caused by dilatation of the ureters associated with pregnancy or vesico
ureteric
reflux. In childhood, the mainstay of treatment of vesicoureteric reflux is
antibiotic therapy; operation is reserved for those with recurrent infection
despite antibiotics or severe upper tract dilatation.
• Oestrogen deficiency which may give rise to lowered local
resistance.
• Colonisation of the perineal skin
by strains of Escherichia coli expressing molecules that facilitate
adherence to mucosa.
Avenues
of infection
Ascending
infection from the urethra is the commonest route (see Chapter 66). The organisms
originate in the bowel, contaminate the vulva and reach the bladder because of
the shortness of the female urethra. The passage of urethral instruments may
cause urinary infection in either sex, especially when the bladder contains
residual urine. This happens because it carries organisms from the urethra into
the bladder (Fig. 65.40).
Other
routes are less common. These include: descending from the kidney
(tuberculosis), haematogenous spread, lymphogenous and from adjoining
structures (fallopian tube, vagina or gut).
Bacteriology
Escherichia
coli is the commonest organism, followed by Proteus mirabilis,
Staphylococcus epidermidis and Streptococcus faecalis. Infection
with other organisms or mixed organisms is found in patient with neurogenic
bladder dysfunction or those with a long-standing indwelling urethral catheter.
These organisms include Pseudomonas, Klebsiellae, Staphylococcus aureus and
various streptococci. Tuberculous infection is considered below. The presence of pus cells without organism calls for repeated
examination for Mycobacterium tuberculosis and Neisseria gonorrhoeae. Having
eliminated these possibilities, the underlying condition may be abacterial
cystitis, carcinoma in situ, renal papillary necrosis, stones or
incomplete treatment of a urinary infection.
Clinical
features
Symptoms
The severity of the symptoms varies greatly.
Frequency.
This occurs during the day and night, it may occur every few minutes and may
cause incontinence.
Pain.
Pain varies from mild to severe. It may be referred to the suprapubic region,
the tip of the penis, the labia majora or the perineum.
Haematuria.
The passage of a few drops of blood-stained urine or blood-stained debris at the
end of micturition is a frequent accompaniment. Less often the whole specimen is
blood stained.
Pyuria.
This is usually present.
Examination
On examination there is tenderness over the bladder. Initial and
midstream urine specimens should be collected in a male as acute prostatitis may
be present (see below) which will lead to threads in the initial specimen. The
midstream specimen must be subjected to microscopy and culture, and the
sensitivity of any organisms assessed.
Treatment
Treatment should be commenced forthwith, and modified if necessary when
the bacteriological report is to hand. The patient is urged to drink.
Appropriate first-line antibiotics include trimethoprim, amoxycillin or one of
the quinolones. Failure to respond indicates the necessity for further
investigation
to exclude predisposing factors.
Investigation
Cystoscopy. This is not necessary in the acute phase.
Other
investigations. These include measurement of urinary flow rates and
post-void
residual urine. An IVU will usually be carried out together with cystoscopy.
Difficult cases may require urodynamic investigation.