Case 8- Benign prostatic hyperplasia Flashcards
What zones of the prostate do BPH and prostate cancer affect?
BPH = transitional zone
Prostatic cancer = peripheral zone
What are the functions of the bladder?
- Temporary storage of urine: folded internal lining (rugae) allows it to accommodate 400-600ml of urine in healthy adults [anatomical capacity = 1L)
- Assists in expulsion of urine: the musculature (detrusor) of the bladder contracts with micturition with concomitant relaxation of sphincters
What does the prostate gland secrete? What does this fluid contain?
Slightly alkaline fluid (30% of semen volume), milky/ white colour. Mixture of sugar (energy for the sperm), enzymes and alkaline chemicals. It contains:
- Proteolytic enzymes= breaks down coagulants and proteins to liquefy the semen
- Citric acid
- PSA
- Prostaglandins
What initiates cell growth of the prostate?
Testosterone from the testicles travels to the prostate and is converted to dihydrotestosterone (DHT) via enzyme 5a-reductase. DHT is more potent than testosterone at initiating growth
What area of the brain is involved in the storage and voiding of urine?
Pontine continence centre in the pons = storage
Pontine micturition centre in pons = voiding
What innervates the bladder for storing urine? What does this nerve cause upon stimulation?
Hypogastric nerve (sympathetic)- releases NA:
- Relaxation of detrusor muscle via stimulation of B3-adrenoceptors
- Contraction of internal urethral sphincter via a-1 adrenoceptors
What is receptive relaxation?
As the bladder fills, the detrusor muscle relaxes and sphincters contract. The rugae flatten to increase volume and keep intra-vesicle pressure constant (and lower than urethral pressure).
What innervates the bladder for voiding urine? What does this nerve cause upon stimulation?
Pelvic splanchnic nerve (parasympathetic)- releases ACh:
- Contraction of detrusor muscle via M3 receptors (increases intra-vesicle pressure)
How does BPH manifest? i.e. causes
Aging associated with an enlarged prostate = non-cancerous hyperplasia. Involves proliferation of glandular tissue in the transitional zone. Forms large nodules in the transition zone.
May be due to:
- Impaired apoptosis
- Increased DHT (5a-reductase enzyme increases, so although testosterone declines, DHT is higher)
- Altered estrogen/androgen ratio (increases, i.e. more estrogen, stimulates growth of prostate)
What storage symptoms may be present with BPH?
- Going frequently to pass urine
- Feeling that the bladder is full (urgency)
- Waking up at night to pass urine (nocturia)
- Leakage of urine when you donโt get to the toilet in time (urge incontinence)
What voiding symptoms may be present with BPH?
- Needing to wait for the stream to start
- Weak stream
- Intermittent stream
- Dribbling at the end of urination
- Sensation of incomplete bladder emptying
What are some complications of BPH?
- LUTS due to bladder outlet obstruction
- High pressure retention
- UTIs
- Bladder calculi
- Haematuria
When is BPH most common (age)?
50-65
What are some risk factors for BPH?
- Age
- Family history
- Ethnicity: black African or Caribbean
- Obesity
- Lifestyle, i.e. smoking, high fat diet
- Conditions such as diabetes and CVD
What investigations may be carried out if BPH was suspected?
- Urinalysis - exclude infection
- Post-void bladder scan - check for retention
- Flow rate test
- Blood tests - inc PSA
- Rectal examination
What might you feel during a DRE for BPH?
firm, smooth, symmetrical enlarged prostate
After presenting with LUTS symptoms for the first time, should all men have a PSA test?
If aged >50 years (or >40yrs if Black African or Caribbean)
What scan may be done for a BPH diagnosis? What would indicate enlargement of the prostate?
Ultrasound: if prostate >30ml then enlarged (normal 20-25ml /g)
What medication may patients with BPH be started on? (with moderate-severe symptoms)
- Alpha blockers: alpha-1 or alpha-1A
- Phosphodiesterase-5 (PDE-5) inhibitors: if have erectile dysfunction
- 5-alpha-reductase inhibitor: if larger prostate (>30g), but possibly in combination with alpha blockers for symptomatic relief
For alpha-1a blockers, give an example, their MOA, contraindications and side effects
Tamulosin or silodosin
MOA: blocks alpha-1a adrenoceptors in the smooth muscle of prostate and bladder. Reduces obstruction; dynamic component of BPH
Side effects: headaches, postural HTN, retrograde ejaculation, dizziness, sexual dysfunction
Contraindications: history of postural hypotension
Give the benefits of alpha-1a selective blockers over alpha-1 blockers
Less likely to cause heart failure (the predominant receptor in the prostate and bladder neck is 1A so its more specific)
Give an advantage of alpha blockers over 5a-reductase inhibitors
Quick, symptomatic relief within a few days, whereas 5a reductase inhibitors can take months to improve symptoms
For 5a-reductase inhibitors, give an example, their MOA, contraindications and side effects
Finasteride or dutasteride
MOA: inhibit 5a-reductase to reduce the conversion of testosterone to DHT, thereby reducing size of the prostate (static component)
Side effects: sexual dysfunction
Dutasteride: contraindicated in liver disease
How do phosphodiesterase-5 inhibitors work?
Relax smooth muscle by prolonging NO (dynamic component of BPH)
What medications may be used if the patient has moderate-severe storage symptoms?
- Anticholinestergic therapy: such as tolterodine, festerodine, oxybutynin (alone or adjunct)
- Beta-3 adrenergic agonists: mirabegron, used as an adjunct with alpha blockers
What scale may be used to assess symptom severity? Give the boundaries for mild/ mod/ severe
IPSS: 0-7 mild, 8-19 moderate, 20+ severe.
What surgical treatments can be offered for BPH? When would each be used?
- Transurethral resection of the prostate (TURP): removes a little at a time. For men with prostate <80g.
- Holmium enucleation of prostate (HoLEP): removes the prostate via laser. Should be considered in patients at high risk of bleeding (i.e. on anticoagulants)
- Laparoscopic-assisted prostatectomy: only if prostate is signficiantly enlarged (>80g)
What is a risk of transurethral resection of the prostate?
Significant risk of sexual side effects, i.e. ejaculatory dysfunction
What are some minimally invasive surgical options for BPH?
- Radical steam therapy: vaporisation of the prostate, fires steam to kill excess tissue, allowing the bladder to drain freely
- Prostatic artery embolization (PAE)
- Stent: opens up the urethra. However, can increase urination and can become dislodged
- Phytotherapy
How does prostatic artery embolisation help to treat BPH?
Blocks the blood supply of the prostate to reduce LUTS, makes the gland shrink and allows better flow of urine
Compare effective and preference-sensitive interventions for decision making
Effective: one choice is supported by evidence as being optimal/ the best, but still needs to be supported by patient choice
Preference-sensitive: evidence doesnt suggest one choice as โbestโ
What are 2 possible negative outcomes of preference-sensitive decision making?
Decisional conflict
Post-decision regret
What is the difference between procedural and sensory information?
Procedural - about what to expect on the day/ process of it
Sensory - pain, how things might feel, taste after chemo etc.
When explaining to a patient about their surgery, how should we explain the pain expected?
Accurately - NOT optimistically. If patients feel more pain than expected it can cause feelings of worry, and reduce trust in HCPs
What cognitive interventions can be used to prepare patients for surgery? How do they work?
Aim to change how a person thinks โ the goal is to reduce negative thinking and/or anxiety.
- Reframe cognitions
- Distraction
What 2 models could be used for preparing a patient to surgery?
Mastery model = model is calm and relaxed
Coping model = model finds it challenging but successfully copes
Should HCPโs tell parents to reassure their children about an upcoming surgery? Why?
No - leads to further distress of the child. 3 possible reasons:
1) Might suggest that a parent is worried or that something bad is about to happen
2) Could reinforce distress/ anxiety
3) Could encourage children to communicate anxiety/ distress (i.e. same level of distress but more likely to say they are)
What are the risk factors for prostate cancer?
- Age
- Race โ more common in African American
- Family history
- Nationality: most common in North America and North West Europe (compared to Asia or Africa)
- Genetics: i.e. HOXB13
- Diet, exercise and obesity โ likely only a small risk
What might patients with prostate cancer present with?
Local: LUTS/ lower urinary tract symptoms:
- Obstructive โ not emptying properly, terminal dribbling, weeing in the night, or flow isnโt strong
- Irritative โ frequency, discomfort (possibly blood)
- Metastatic: pain etc. from lymph node or bone metastases
- Systemic: fatigue, weight loss