Erectile dysfunction

Question 1

Risk factors for ED?

Answer 1

• smoking
• obesity
• lack of exercise
• hypercholesterolemia
• hypertension
• metabolic syndrome
• diabetes mellitus

Question 2

Describe the normal erection physiology

Answer 2

1. Dilatation of the arterioles and arteries by increased blood flow in both the diastolic and the systolic phases
2. Trapping of the incoming blood by the expanding sinusoids
3. Compression of the subtunical venular plexuses between the tunica albuginea and the peripheral sinusoids, reducing the venous outflow
4. Stretching of the tunica to its capacity, which occludes the emissary veins between the inner circular and the outer longitudinal layers and further decreases the venous outflow to a minimum
5. An increase in PO2 and intracavernous pressure, which raises the penis from the dependent position to the erect state (the full-erection phase)
6. A further pressure increase with contraction of the ischiocavernosus muscles (rigid-erection phase)

Question 3

What does neurogenic, arteriogenic and venogenic ED mean?

Answer 3

Neurogenic = failure to initiate erection

Arteriogenic = failure to fill as arterial flow is affected so erection is not sustained

Venogenic = failure to store through inadequate venous occlusion

Question 4

Name some causes of erectile dysfunction

• vascular factors
• hormonal factors
• anatomical
• central causes
• drugs
• peripheral causes
• psychiatric causes

Answer 4

• vascular factors
  CVD, DM, trauma, smoking, hyperlipidemia, atherosclerosis
• hormonal factors
  hypogonadism, thyroid disease, cushings
• anatomical
  micropenis or other abnormalities
• central causes
  parkinson’s, MS, traumatic brain injury, spinal. cord injury
• drugs
  antihypertensives, diuretics, beta blockers, anti-depressants (SSRIs), anti-psychotics, anti-convulsants, recreational drugs
• peripheral causes
  DM, alcoholism, surgery, peripheral neuropathy
• psychiatric causes
  generalised anxiety states, depression, psychosis, alcoholism

Question 5

Questions to ask someone with erectile dysfunction

Answer 5

sexual history
current and past sexual relationships
erectile symptoms - is it sudden or gradual and how long does it last for?
Early morning erections present?
Quality of the erections
Arousal, ejaculation and orgasmic difficulties
Medical and past medical history - medications

Question 6

Examination of a patient with ED?

Answer 6

Height, weight, BMI - determine metabolic state
Thyroid exam, pulmonary status, cardiac rhythm
Abdominal exam and mid waist circumference
Peno-scrotal exam
Rectal exam if accompanied by LUTS

Question 7

Tests to consider in someone with ED?

Answer 7

Urinalysis
Fasting BF
Lipids
total testosterone
PSA in men over 40/50
Prolactin levels
Penile ultrasound to look for. plaques in arteries

Question 8

First line treatment for ED? Name a few drugs in this class and how they work.

Answer 8

Phosphodiesterase PDE-5 inhibitors
Sildenafil, tadalafil, vardenafil
They improve the relaxation of smooth muscle to improve blood flow to sustain erections.

Question 9

Second line therapy for ED?

Answer 9

1. Intraurethral suppository
   → Alprostadil - noninjectable prostaglandin pellet which improves vascular flow by causing vasodilation via increased cAMP and increased blood flow
2. Intracavernous injection
   → Syringe of alprostadil injected into corposa cavernosa to produce an erection
   → Can cause penile pain (50% patients)
3. Vacuum assisted devices
   → An external cylinder is fitted over the penis to allow air to be pumped out, resulting in engorgement of penis with blood.
4. Shockwave therapy
   → Shock wave into cavernosa to improve blood flow

Question 10

Third line therapy for ED

Answer 10

Implants - fluid flows into pump and cylinders to achieve an erection. Pump button pressed to inflate and deflate.