Only five years ago, it was widely believed that 90 percent of erectile impotence resulted from psychogenic factors. But recent research demonstrates that many such cases may have an organic basis. And the criteria for surgical insertion of a penile prosthesis, a device that produces erections, have also changed. The extensive psychiatric counseling and requirement that the surgical candidate have a sexual partner, once considered prerequisites for undergoing the procedure, are no longer mandated. Spinal cord injury is the most publicized cause of impotence; however, many more common conditions also lead to this sexual dysfunction. It is estimated, for example, that 50 percent of diabetic men are permanently impotent and that 13 percent of this group present with impotence as an initial symptom of their diabetes(1). Arterial ischemia also leads to erectile dysfunction in many men who have atherosclerosis of the aorta and common iliac arteries(2). Extensive pelvic surgery, such as radical prostatectomy or cystoprostatectomy, can be expected to destroy the prostatovesical nerve plexus, and impotence almost invariably follows(3). Long-term use of certain drugs, such as antihypertensives, may also bring about impotence. When the cause is prostatitis or another acute infection that responds to antibiotics, impotence is usually temporary. Hormone therapy may resolve temporary impotence caused by endocrine disorders. The most frequent cause of impotence in our patients is arteriosclerotic vascular disease. Other common causes are radical pelvic surgery and diabetes mellitus. A history and physical are essential first steps in determining if impotence is organic. The physical should include a neurologic exam to determine if there is nerve damage and, if so, how extensive it is. Specific diagnostic tests then may be indicated, especially if examination reveals no obvious organic cause. One such diagnostic tool is the nocturnal penile tumescence test, in which electrodes are placed on the penis to monitor erections during sleep. A normal recording should indicate three to five involuntary erections during REM (rapid eye movement) sleep. An absence of sleep erections usually indicates that impotence is physical in origin. The Doppler ultrasound flow meter may be used to detect obstruction of blood flow through the arteries of the penis, suggesting atherosclerosis of femoral or iliac vessels. PsychoMARY CATHERINE SHORT GOOGE, RN, MSN, is the surgical patient care coordinator at WillisKnighton Medical Center, Shreveport, La. One of her responsibilities is supervision of a 32-bed urology unit.