Cateterizacion Uretral de Gatos Machos

Feline urethral obstruction is relatively common in males due to anatomical peculiarities of their penis. Prolonged urine obstruction is life threatening as a result of severe hyperkalemia and post-renal azotemia.

Obstructed patients have a palpable, hard, filled bladder and delicate but strong compression of the bladder does not produce urination.

An intravenous catheter is placed and fluid administration is started in order to reduce the azotemia and hyperkalemia and correct dehydration. The patient is lightly sedated; for this purpose I use a combination of acepromazine, ketamine and diazepam. The patient should be intubated when necessary. We proceed to inspect the penis, with the patient in lateral recumbence some pressure is applied to the sides of the foreskin the penis is easily externalized and then we should hold the penis gland firmly. To reduce the urethral spasm and disaggregate the urolith which is generally protein matrix and struvite salts we should apply xylocaine gel and proceed to massage the penis. If this does not resolve the obstruction urethral catheterization is performed.

Since it is flexible, atraumatic and has an open end unlike urethral catheters in which this end is closed, I use a 20-G intravenous catheter without its inner shaft to unblock the cat urethra. This open end is useful to infuse saline directly over the obstruction.

The lubricated catheter is inserted into the urethra with the penis stretched and parallel to the spine, so that the probe has a straight path. Then a syringe is attached to the catheter and we hold the external urethral orifice closed over the catheter and proceed to inject saline. The intention is that the sudden increase in pressure should dilate the urethral walls and retropropulse the urolith. As soon as the urolith is dislodged the catheter is removed and if urine flow is achieved we evacuate the urinary bladder. If not a urethral catheter is placed into the bladder so that we can evacuate the urine.

Complete emptying of the bladder and washing with saline is carried out. Before removing the probe I usually locally infuse bupivaine through the urethral path while proceeding to remove the probe in order to desensitize the urethra and reduce the spasm for the next 6 hours. Sometimes, in order to achieve urethral catheterization, it is necessary to reduce bladder pressure by cystocentesis. Cystocentesis should be performed in the caudal region of the bladder to prevent uroperitoneum by distention of the hole in the puncture site.

Personally, I prefer not to leave urethral catheters on because they are rigid and traumatizing. During post-obstruction treatment I prescribe acepromazine at low doses in order to keep the patient relaxed but not sedated, propantheline every 12 hours, tramadol every 8 hours and amitriptyline every 24 hours, in addition to dietary management and implementing strategies for increasing water consumption. It is important to remember that the patient will develop postobstructive polyuria so that sensitive losses will increase and greater fluid contribution is critical in the first 48 to 72 hours.