Catheters and how to pass them

Before you pass a catheter, think for a moment about what you want to do with it. If you are going to drain urine from a healthy patient, who cannot pass urine after a hernia operation, use a soft rubber Jacques catheter. If it has only to let out urine, its lumen can be narrow. If you expect bleeding, and want to irrigate a bleeding bladder, so as to dilute the blood in it and prevent it clotting, you will need a catheter with an irrigating channel. If you need to suck out clots, choose a large catheter made of stiff material which will not collapse.

If an indwelling catheter has to stay in place for 10 days or more: (1) Avoid red rubber, and use latex, plastic, or ideally silicone, because these will be less irritant. (2) Be sure that it does not fit so tightly that it blocks the mouths of the paraurethral glands. There must be plenty of room beside it for their secretions to ooze out. (3) It must be soft, because a stiff tight-fitting catheter can press on the mucosa of the urethra at the external sphincter or the penoscrotal angle, and cause a pressure sore, and finally perhaps a stricture. So use the narrowest, softest, catheter which will serve your purpose, and remove it as soon as you can. Finally, remember that passing a catheter is a sterile procedure[md]you can so easily infect a patient and cause him needless misery.


PASSING A CATHETER EQUIPMENT. 2% lignocaine gel, preferably with chlorhexidine, an antiseptic suitable for the patient's scrotum (1% chlorhexidine), the right selection of catheters, a penile clamp to retain the anaesthetic, receivers, a sterile bottle in which to send urine for culture, a syringe to blow up the Foley balloon, and a sterile connecting tube and bag to receive the urine.

METHOD. Admit him. If he is in severe pain, give him pethidine. This may help him to pass urine. Explain what you are going to do. Make sure you have help. Scrub and put on sterile gloves. Sit him comfortably in a good light with his legs apart, and a waterproof sheet under him. Drape him.

Using a syringe without a needle, put 10 ml of lignocaine gel into his urethra, and keep it there for 4 minutes with a penile clamp, or with light pressure from your finger and thumb.

CAUTION ! Allow it to act for at least 4 minutes. Half the trouble in passing a catheter comes from not doing this.

Start with a 14 or 16 Ch Foley catheter (smaller latex ones may be too supple). Hold his penis straight upwards to flatten out its folds. Take the catheter in your other gloved hand. Don't touch either your skin, or his skin. Push it gently into his meatus, and down his urethra, while keeping his penis straight.

If it sticks at the junction of his penis and scrotum, he may have a stricture, because this is the common site.

If it sticks at his external sphincter, wait, be gentle, and get him to relax it. If he tightens it, you will never get the catheter in. Force is dangerous. Be slow, gentle, and crafty. Ask him to ''Breathe in and out, and pretend to pass water''. If you can catch his sphincter off its guard, the catheter will slip in.

If it sticks in his posterior urethra, his prostate may be enlarged. Put your finger in his rectum, and press on it. You may find that the catheter will now pass onwards.

CAUTION ! Never use force.

If it still does not pass: (1) It may be too large (try a smaller one). (2) His sphincter may not be relaxed because he is frightened (try anaesthesia; see below). (3) His urethra may not be properly anaesthetized (try introducing 5[nd]10 ml more lignocaine, with KY jelly). (4) The catheter may have caught in mucosal pockets in his urethra[md]you can easily make these into a false passage, if you are not careful. (5) He may have a large prostate, which distorts his urethra, and prevents the catheter following it into his bladder.

You now have two choices:

You can do a suprapubic needle puncture (23.5). This may be your first choice for: (1) Postoperative retention. (2) Long-standing retention with overflow. (3) Retention from any cause in the middle of the night. Often, after aspirating him for 8 or 12 hours, the oedema at his bladder neck may settle, and a catheter may now pass more easily (unless he has a stricture). If a second attempt at catheterization fails, suprapubic drainage (''SPP', 23.6) would probably be wiser. This is safer than persisting with attempts to pass a urethral catheter. Be prepared to accept failure early and go straight to suprapubic catheterization, especially in areas where strictures are common. If you leave his urethra alone for two or three days, a further attempt to pass a catheter will often succeed.

Or, you can try other kinds of catheter as follows.

Try a 6, 9, or 12 Ch Gibbon catheter. This has a stiffened removable nylon stylet. Use the two plastic strips incorporated in the catheter to hold it in place in his penis.

If this fails, try a 15 Ch rubber Tiemann catheter. With a little patience, you are almost sure to succeed. If you do, strap it in, and change it for a Foley catheter a few days later. It is stiff, and can damage his urethra by pressure, if you leave it too long.

If the above methods fail on the ward, and as a last resort, and if he has an empty stomach, take him to the theatre. Give him pethidine with diazepam (A 8.8), or a general anaesthetic (seldom necessary). While he is deeply asleep, his sphincter may relax and, with luck, the catheter will slip in. If it does not, try a curved metal introducer to ''lift' a catheter into his bladder[md]taking great care. When it is in his bladder, remove the introducer.

CAUTION ! (1) Try to avoid using an introducer if you can[md]this is an instrument for the experienced. If you do use one: (a) lubricate it when you put it into the catheter, and (b) lubricate the catheter when you pass it into his urethra. This will help to prevent it being pulled out with the introducer. (2) Make sure the introducer has a smooth curve. A kinked introducer will be difficult to extract.

CAUTION ! Ask the nurses to change his urine bag at least every 48 hours, aseptically and without getting his organisms on their skin.

Fig. 23-2 PASSING A CATHETER. A, and B, straighten out the patient's urethra to remove its kinks. C, if the mucosa over his external sphincter is not well anaesthetized, it may go into spasm[md]never force a catheter past an unrelaxed sphincter. D, when it is past his relaxed sphincter, it ]]will find its way into his bladder, provided it is flexible and well-lubricated. After Blandy J, ''Operative Urology', Figs. 2.54 to 2.56 Blackwell Scientific Publications, with kind permission.

DIFFICULTIES [s7]WITH CATHETERS If the BALLOON WILL NOT DEFLATE in a Foley catheter, cut the catheter across, and leave it for 24 hours to empty. It will often deflate by itself. If it does not, inject ether up the balloon channel, and you will hear a ''pop''. Be sure to wash out the ether, and any balloon fragments which may have been left behind.

If you CANNOT REMOVE AN INDWELLING CATHETER, even though you have deflated the balloon, you have probably left it in much too long, so that crusts have anchored it to his mucosa. You will have to pull it out firmly, but in doing so you will damage his mucosa. A latex catheter becomes encrusted in 3 or 4 weeks, and a silastic one in 3 or 4 months. Be safe, and change a silastic one every 6 weeks. Note its state, and if it is good, you can extend the intervals for changing it by 2 weeks to a maximum of 4 months.

Fig. 23-3 A CONDOM CATHETER. If a patient is incontinent, you will find this very useful. You will not have a proper belt to attach it to, so you will have to use strapping, as in C. Kindly contributed by Jack Lange.