Urology - LUTS Flashcards
What are LUTS? How are they related to BPH?
LUTS are lower urinary tract symptoms that are typically caused by benign prostatic hyperplasia (BPH). There can be other causes.
Anatomically, BPH causes bladder outflow obstruction which in turn causes LUTS because of 2 reasons. First, there is a static component related to an increase in benign prostatic tissue causing narrowing of the urethral lumen. Second, there is a dynamic component related to an increase in prostatic smooth muscle tone mediated by alpha adrenergic receptors.
It is important to remember that the majority of patients with BPH will not experience either LUTS or BOO.
How common is BPH?
The incidence of BPH is age related. 50% of men over 65 have BPH rising to 90% of men over 80.
How are LUTS classified?
LUTS are divided into voiding symptoms (bladder emptying) and storage symptoms (bladder filling).
Voiding symptoms - poor flow, hesitancy, terminal dribbling, straining to void
Storage symptoms - frequency, nocturia, urgency
These symptoms can occur in varying combinations.
How are LUTS assessed?
Patients are assessed for LUTS using the IPSS scoring system or international prostate symptom score. This consists of 8 questions which can be marked from 0 to 5 regarding the various LUTS plus an additional one relating to quality of life.
The total IPSS score determines the threshold for treatment.
0-7 = mild
8-19 = moderate
20-35 = severe
How should patient with LUTS be examined?
Patients with LUTS require an abdominal and external genitalia examination. This should be followed by a DRE to assess the prostate.
Size:
- chestnut - normal
- satsuma - BPH
Consistency:
- smooth - normal
- hard and woody - may indicate cancer
- tender - prostatitis
What uroflowmetry findings are typical of BPH?
Peak flow should normally be at least 15ml/s, in BPH this is greatly reduced as is the time to void (which is increased).
Uroflowmetry is performed by plotting volume vs time. It should be combined with measurement of post void residual volume by scanning the bladder. With increased bladder outflow obstruction the residual volume increases.
When should urodynamic testing be performed?
Urodynamic testing is used if you are unsure of a patients diagnosis of BOO as a cause of LUTS. In this test, the bladder is filled with saline and the pressure generated by the bladder is measured serially. Once the bladder is filled to its capacity, the patient is asked to void into a comode where the flow can be measured. The normal bladder remains without any contraction during the filling phase, but generates pressure up to 40cmH20 during the voiding phase. If there is BOO, the bladder pressures become higher and fail to generate a normal flow rate.
Overactive bladder is the other condition that can be diagnosed using urodynamics. In this case, the bladder contracts during the filling phase.
Is the PSA raised in BPH?
The normal PSA level is < 4ng/ml. This can be mildly elevated in BPH but the majority of patients with BPH have a PSA of < 10ng/ml.
It is important to counsel a patient who is requesting a PSA about the implications of testing. For example, all patients with an abnormal PSA require a prostate biopsy which should be discussed with the patient beforehand.
What are the chances of having prostate cancer with a PSA of 10ng/ml?
The PSA level can be correlated with the chance of developing prostate cancer. A PSA of 10ng/ml indicates a >60% chance of prostate cancer. But it is important to bear in mind that PSA is not an entirely specific marker for prostate cancer.
BPH is the most common cause of LUTS, but what are some other causes?
The causes of LUTS can be divided into:
1) Outflow obstruction: BPH, urethral stricture, vesical neck obstruction
2) Infection: cystitis, bacterial prostatitis, prostatic abscess
3) Impaired detrusor function: overactive bladder, neuromuscular dysfunction, psychogenic
4) Neoplastic: prostate cancer, bladder cancer (including CIS)
What are the mandatory investigations in assessing a patient with LUTS?
- medical history
- DRE
- urinalysis: infection
- serum creatinine
- symptom questionnaire (e.g. IPSS)
NB - patients do not require imaging for initial investigation of LUTS
How should patient with BPH be mananged?
This depends on their IPSS score.
Patients with a score of 0-7 with no significant bother can have watchful waiting. Patients with a score of 0-7 with significant bother should be offered pharmacotherapy with either an alpha blocker such as doxazosin, a PDE-5 inhibitor such as sildenafil or NSAIDS such as celecoxib.
Patients who have moderate and severe IPSS scores of 8-35 should be offered pharamcotherapy first line (any of the above options) plus behavioural management programme followed by combination pharmacotherapy (alpha blocker + 5 alpha reductase inhibitors - e.g. finasteride). If this does not control symptoms then they are be offered surgery or catheters.
What are the indications for referral to hospital for patients with BPH?
- failure to respond to medical treatment
- severe urinary symptoms
- retention of urine
- other complications of BPH
- haematuria
- infection
How is the PSA value affected by 5 alpha reductase inhibitors?
The PSA value is roughly halved by 5 alpha reductase inhibitors. The effects of these drugs are also not immediate like alpha blockers are.
What are the immediate complications following TURP?
1) Haemorrhage
2) Infection/ sepsis
3) TURP syndrome - this is a rare syndrome caused by absorption of fluid in the venous sinuses of the prostate causing haemodilution leading to confusion, hypertension and reflex bradychardia
