When the canal suddenly contracts, as from a stricture, the point of the sound often stops at the obstruction; by withdrawing the instrument a little, and diverting its point to another side or along the upper part of the urethra, a part where the obstruction is less abrupt will often be found to let the catheter glide into the stricture. The floor of the urethra should always be avoided, as false passages nearly always branch off from the floor close to the stricture.
Difficult narrow strictures are most easily overcome by injecting a drachm of warm olive oil into the urethra, and then passing fine black gum or whalebone bougies (bougies filiformes) along the urethra. These, from their fineness (their diameter is only ⅓ or ⅔ of a millimetre, about 1/100 inch), are very apt to catch in false passages; if so, the bougie should be left engaged in the false passage, and held in the left hand while another bougie is passed along the urethra; if, in its turn, this one gets into a false passage, it also should be left, and a third passed; and so on till all the false routes are occupied, or a bougie enters the stricture and reaches the bladder, which is known by the readiness with which it will pass backwards and forwards. The other bougies should then be withdrawn, and the bougie which has passed the stricture be tied in for twenty-four hours, until the passage is sufficiently dilated to allow a small catheter to replace it. If the patient is not suffering from retention of urine, there need be no anxiety about evacuating his bladder, as urine will find its way alongside the bougie when he attempts to make water. In passing to relieve retention, No. ½ English flexible catheter should be used instead of bougies; but when the stricture is too narrow for these, a bougie may still be tried, as the urine will generally dribble alongside the bougie with sufficient rapidity to relieve the patient.
English flexible Catheters should be kept on stylets curved as represented in fig. 85, that the first 3 inches of the instrument, when the stylet is withdrawn, may retain sufficient curve to ride over the impediment at the neck of the bladder. In warm weather, after being oiled, they should be dipped in cold water just before using, to render them a little stiffer, and less likely to lose their curve while traversing the urethra.
They may also be passed while the patient lies or stands, and the movements are the same as for the silver catheter.
Bulbous-ended or probe-ended Catheters and Bougies (Bougies à boule) are always straight; their suppleness, their tapering ends, and their smooth rounded point enable them to glide along the urethra, and to accommodate themselves readily to the windings of the passage; for which reason they are the easiest to pass both for the patient and the surgeon. In passing them they are slightly warmed, if the weather is cold, to restore their flexibility, and gently pushed along the canal till the bladder is reached.
Vulcanised India-Rubber Catheters (fig. 87) are used when the bladder is to be kept empty; their suppleness renders them very unirritating, and as phosphates crust on them very slowly, they may be worn for a week without being changed.
They are easily passed by threading them on a stylet with the appropriate curve, and lubricating them with white of egg or water, not with grease, which injures them. The stylet is withdrawn after they are passed.
To pass a Catheter in the Female.—The patient may lie on one side or on her back; if on her side the knees should be well drawn up; if on her back, the thighs must be somewhat separated. Before introducing the catheter, a wine bottle or narrow-necked bed urinal should be placed in the bed ready to receive the urine. If the ordinary slightly curved female catheter be not at hand, a No. 7 or 8 flexible one does just as well.
Having oiled the instrument, go to the patient’s back, and take the catheter in the right hand if the patient lies on her right side, and in the left hand if she lies on her left side; if she lies on her back, go to either side and take the catheter in the hand nearest her feet. Hold the stem of the catheter in the palm, so that the beak lies against the tip of the forefinger, while the thumb and second and third fingers grasp the stem. Then passing the hand under the bed-clothes, seek the buttock; from that pass the forefinger to the perinæum, and let it enter the vulva, keeping the back of the finger against the posterior part, then pass it between the nymphæ to the entry of the vagina. This is known by the tip of the forefinger being lightly grasped, unless the vagina is very wide. Keeping the finger just within the entry, feel for the arch of the pubes in front; having found this, withdraw the tip of the finger slightly from the vagina: in doing this, it will strike a small projection of mucous membrane hanging just at the anterior margin of the entry. Keep the finger steady against this, while the other hand pushes the catheter gently onwards, which then rarely fails to enter the urethral opening close above the projection of mucous membrane. Having penetrated the urethra, arrange the catheter in the receptacle for the urine, and push the instrument into the bladder.
To Wash out the Bladder.