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Instrumental Methods of Examination, X-rays and Radioisotopic diagnostics in Urological diseases

por Herbert Daugherty (2020-07-15)


id="mod_12149806">Preliminary procedures

Hello everyone! This is the second Urological Hub I am publishing in a day. Whew! As much as it is an achievement, its also a challenge, taking up the mantle just immediately after exams. Well, this hub is published to give each and everyone of us an idea of the instruments and tools used in urological analysis. Sometimes, we need to have an idea of such things so that whenever we approach the Doctor in related situations, we will can easily comprehend and blend with what the doctor is saying.

Diagnostic imaging is a dynamic recent development in medical practice with great potential for benefiting patient care. Nothing has contributed more to the improvement of existing anatomic imaging devices and the development of new ones than digital computers and their related electronics. With computers, the vast numbers of data collected in analog fashion by the basic imaging  mechanics of radiography, Ultrasonography, computerized tomography (CT scanning), tomography are converted electronically into digits corresponding to the different intensities of the original bits of information. These \digits are store in the computer and can be recalled, combined, and manipulated in various ways to achieve reconverted analog images. Hard copies of selected images can be made at the time of the study, or the information can be stored permanently in digital form for subsequent retrieval and conversion to analog images.

Radiography (roentgenography) is the oldest method of urologic imaging, having been used to demonstrate radiopaque urinary calculi shortly after the discovery of X-rays by Wilhelm Roentgen in 1895. Since then, it has continued to be used for diagnosis in every branch of medicine, and it is currently the most widely available method of medical imaging. More recently and other body imaging procedures still in their very early development, eg, magnetic resonance tomography- are competing with, complementing, and in some instances, replacing long established uroradiographic tachniques.

Aseptic Technique

Although bacteria are present in the distal urethra, the urinary tract is considered sterile. Therefore, any instrument entering the tract should be sterile. Instruments made of metal, rubber, and plastic may be autoclaved, but those containing optical devices must be gas-sterilized or soaked for a sufficient time in an approved solution of glutaraldehyde and then thoroughly rinsed in sterile water. The foreskin should be retracted and the glans penis washed thoroughly with cleansing solution. Th vulva must be cleansed and the labia held apart as the instrument is introduced.

Lubrication of Urethra

All transurethral maneuvers require lubrication. In women, application of lubricant to the instrument is sufficient. However, this method does not provide adequate lubrication for the entire male urethra, because the meatus tends to remove most of the lubricant as the instrument is passed. The male urethra should be lubricated by instilling at least 15 mL of a sterile, water soluble lubricant by means of a blunt, cone-tipped syringe. Oils (e.g, mineral or Olive oil) must not be used, since fatal oil emboli may result. The syringe allows introduction of the lubricant with constant, low, steady pressure, which helps overcome the normal tone of the external sphincter. This resistance may be markedly increased in apprehensive patients, leading the inexperienced instrumentalist to an erroneous diagnosis of urethral stricture.

Anesthesia

A simple procedure such as passage of a urethral catheter may be done without anesthesia. If more complex or painful manipulations are planned, sedation or topical, regional, or general anesthesia will be necessary. Sedation may be achieved with barbiturates, tranquilizing agents, or narcotics. Topical anesthesia of the urethral mucosa may be obtained with cocaine, tetracaine, or lidocaine. In females, a cotton applicator moistened with the anesthetic may be placed in the urethra for 5 minutes. In males, these agents in liquid form are rapidly absorbed into the circulation through the posterior urethra. Contact with traumatized mucosa or injection under pressure increases the absorption. This can lead to seizures, circulatory collapse, and cardiopulmonary arrest. Dyclonine, 0.5% has been used without toxicity in males. Wherever these drugs are used as topical anesthetics for the urethra, resuscitation equipment should be available. Lidocaine as a 2% solution in carboxymethylcellulose gel provides lubrication as well as safe topical anesthesia. The drug is less readily absorbed in this form and can be used in both the male and female urethra. In females, approximately 3-5mL of the jelly is instilled into the urethra. To occlude the meatus, a cotton swab lubricated with jelly may be placed in the distal urethra or a sponge may be placed in the distal vagina. In males, 15-30mL of the jelly is instilled 5-10 minutes prior to the procedure, a penile clamp is placed at the corona; and a small amount of jelly is instilled in the distal urethra. Topical anesthesia is effective on the mucosa only and will not prevent pain from pressure or from distortion of underlying structures during manipulation. Regional or general anesthesia should be planned if more painful procedures (eg, resection or bipsy) are contemplated or if the patient is very apprehensive. The regional anesthetic must reach the third lumbar segment to provide the necessary sensory ablation during transurethral resection; thus, spinal or epidural anesthesia rather than a sacral block must be used. General anesthesia must be used when cystourethroscopy is done in pediatric patients.

Warning to Patients

Instrumentation is uncomfortable and may be painful. A forewarned, cooperative patient will be of help. Explaining the proposed maneuvers as one proceeds may reduce the patient's anxiety. The instrument must be introduced gently and advanced gradually. Gentle, sure maneuvering with adequate lubrication is essential. No movement should be rough or abrupt. Discomfort will increase as the instrument passes through the prostatic urethra, and men must be warned to anticipate some discomfort as this area is approached. Once spasm of the external sphincter develops, it may be impossible to complete the instrumentation. A very high bladder neck will cause marked angulation of the urethra that may preclude instrumentation under topical anesthesia.