If a patient has a persistent painful erection, either rigid, or merely turgid, he has priapism, which is a urological emergency. If this is secondary to sickle-cell disease (in which it is common), leukaemia, or some neurogenic cause, such as paraplegia, it usually settles with sedation and without impairing subsequent erections. The danger is that if priapism from any cause persists too long, his corpora cavernosa may become ischaemic and fibrotic, so that he becomes permanently impotent. So treat him early.

You can: (1) Sedate him; always try this first. (2) Inject an adrenergic drug. Don't persist too long with sedation and anaesthetics. Use an adrenergic drug sooner rather than later. (3) Drain his distended corpora cavernosa by making two small fistulae on each side which allow them to drain into his glans penis.

Winter CC, ''Priapism cured by creating fistulae between the glans penis and the corpora cavernosa'. Journal of Urology 1978;119:227[nd]8. Fig. 23-39 PRIAPISM. If sedation and adrenergic drugs fail (unusual), you will have to resort to surgery. Aim to create fistulae, which will allow a patient's corpora cavernosa to drain into his glans penis. In priapism his turgid corpora cavernosa project up under, and into, his glans penis. A, aspirating his corpora cavernosa through his glans. B, and C, use a sharp knife to make an incision on each side between his glans and his corpora. Alternatively, use a needle and syringe, or a special biopsy needle. After Rob C and Smith R, ''Operative Surgery: Urology'. p. 584, (Butterworth). With the kind permission of Hugh Dudley.

PRIAPISM SEDATION. First try heavy sedation with pethidine and chlorpromazine. This will usually cure a patient, especially if his priapism is due to sickle-cell disease.

If he does not respond to heavy sedation in an hour or two, give him a general anaesthetic, or intravenous pethidine and diazepam, and/or try an adrenergic drug.

ADRENERGIC DRUGS. Aspirate his corpora cavernosa with a 1 mm needle; this alone may cure him. If it does not rapidly do so, inject: (1) Metaraminol (''Aramine') 1 mg in 5 ml of saline. Or, (2) a dilute (0.001 mg/ml) solution of adrenalin. Make this by diluting the contents of a 1 mg ampoule to 100 ml in saline. Massage his penis to distribute the drug through both corpora. The venous spaces of his corpora connect, so you only need inject one of them. Repeat the procedure after 10 minutes if detumesence fails to occur.

CAUTION ! (1) Monitor his blood pressure, at 5 minute intervals. Both metaraminol and adrenalin raise it. Deaths from ruptured aneurysms have been reported with metaraminol. (2) Adrenaline is dangerous in a local anaesthetic solution when used subcutaneously as a ring block on the penis or finger (A 5.3), where it may cause gangrene, but not in the corpora cavernosa.

If this is not rapidly effective (unusual), proceed to make a fistula while he is still under general anaesthesia.

MAKE A FISTULA BETWEEN THE CORPORA AND THE GLANS. Under general anaesthesia, aspirate his corpora cavernosa through the tip of his glans penis (A, 23-39). Then, using the same needle, irrigate his corpora cavernosa with saline (preferably with some heparin). This initial aspiration and irrigation can be omitted.

Introduce a ''Travenol' biopsy needle (23.1) in the closed position through the same skin wound, and push it through his glans to the coronal septum (between his glans and his corpora cavernosa), taking care to avoid his urethra. Note that the ends of his erected corpora cavernosa project well into and under his glans. You may need considerable force. Open the biopsy needle by extending its obturator blade through the septum, and close it by pushing the sheath over the fenestrated tip, twist it, and remove it. You should withdraw tissue consisting of fibrous septum, and the contents of his corpus cavernosum. Repeat the manoeuvre in another site close by and then do the same thing with his other corpus cavernosum. By doing this you will create two fistulae on each side

His penis should now become flaccid rapidly, and remain so. Control brisk bleeding from the puncture site by pressure or with a figure of eight absorbable suture. There is no need for a pressure dressing, or an indwelling catheter.

If you don't have a ''Travenol' needle, make 2 or 3 cuts (B and C) each side with a No. 11 blade, or use a large sharp needle.

Fig. 23-40 FOURNIER'S GANGRENE OF THE SCROTUM. A, as the patient presented. He is usually much worse even than this. B, as he healed without skin grafting. After Charles Bowesman, ''Surgery and Clinical Pathology in the Tropics''. E and S Livingstone, with kind permission.