DM3 Pt4-5 Urethral Obstruction Flashcards
hat is urethral obstruction often associated with in cats?
Urethral obstruction is commonly associated with idiopathic cystitis, urethral spasm, and urethral plugs.
What are other potential causes of urethral obstruction?
Urolithiasis, urethral stricture, urethral trauma, and urethral neoplasia.
Why is the time period of obstruction significant in feline urethral obstruction cases?
The time period affects the clinical status and management of the cat.
What should be assessed in a cat with urethral obstruction during a clinical exam?
Hydration status, hypovolaemia (peripheral pulse quality, blood pressure), and presence of bradycardia.
What might bradycardia indicate in a cat with urethral obstruction?
Bradycardia may be indicative of significant hyperkalaemia or hypovolaemia.
What precautions should be taken when assessing bladder size and tone?
Avoid applying significant pressure to the bladder to prevent bladder rupture.
What should be measured after the physical examination of a cat with urethral obstruction?
Blood pressure, an ECG if possible, and blood samples for urea, creatinine, electrolytes, and acid-base status.
Is the degree of elevated urea and creatinine a prognostic indicator in urethral obstruction cases?
No, the degree of elevation is not a prognostic indicator. Post-renal azotaemia can be dramatic but may resolve with fluid therapy and relief of the obstruction.
Why is fluid therapy important in stabilizing cats with urethral obstruction?
Fluid therapy reduces hyperkalaemia and maintains renal perfusion, helping avoid acute renal failure.
What type of fluids are initially administered during stabilization?
Crystalloids are given as a 10-20ml/kg bolus over 10-15 minutes, repeated if necessary to improve blood pressure and pulse quality.
How should fluid deficits be corrected in a cat with urethral obstruction?
Fluid deficits should be corrected over 12-24 hours.
What is the primary treatment for hyperkalaemia in urethral obstruction cases?
Relief of the obstruction and IV fluid therapy are the primary treatments.
When is IV calcium gluconate used during stabilization?
IV calcium gluconate is used in severe cases to counteract the cardiac effects of hyperkalaemia.
What is administered if potassium remains high despite aggressive fluid therapy?
Glucose saline, with or without soluble insulin, may be given.
Is bicarbonate often needed to manage acidosis in urethral obstruction cases?
No, bicarbonate is rarely needed as acidosis usually resolves with fluid therapy alone.
What type of analgesia is appropriate for cats with urethral obstruction?
Opioid analgesia, such as buprenorphine, is appropriate. NSAIDs should only be used when the cat is non-azotaemic with normal blood pressure and hydration.
Why is anaesthesia required for urethral catheterisation?
Anaesthesia is required to avoid urethral trauma, which is a high risk when catheterizing a conscious or inadequately sedated cat.
What anaesthetic agents are recommended for urethral catheterisation?
Ketamine with midazolam for induction, or propofol with isoflurane/sevoflurane for maintenance, are recommended.
What preparation should be done before urethral catheterisation?
The perineal area should be clipped and cleaned to avoid iatrogenic infection.
What techniques can be used if an obstruction is encountered during catheterization?
Gentle flushing with saline or dilute lubricant, palpating the penis, and retrograde hydropulsion can help remove the obstruction.
What steps should be taken when catheterization is proving unsuccessful?
Consider deepening anaesthesia, ensuring adequate analgesia, checking for a urethral stricture, altering the cat’s position, and making sure the urethra is straightened.
What alternative catheters can be tried if the initial catheter fails?
Open-ended Slippery Sam, lacrimal catheter, or IV catheter can be tried.
What is the risk of being forceful when attempting catheterization?
Being too forceful can cause significant urethral trauma, leading to complications.
What should be considered if catheterization remains unsuccessful?
Referral to a specialist should be considered if catheterization is still unsuccessful.
What is cystocentesis and when is it considered in urethral obstruction cases?
Cystocentesis is the decompression of the bladder using a needle, considered to buy time for systemic stabilization before relieving the obstruction.
What is the advantage of cystocentesis in urethral obstruction cases?
It reduces bladder pressure, making catheterization easier, and provides time for systemic stabilization.
What is the main risk of cystocentesis in cats with urethral obstruction?
The main risk is iatrogenic bladder injury, especially if the bladder wall is compromised.
How can the risk of bladder injury during cystocentesis be reduced?
Perform cystocentesis under sedation, use a small gauge needle, an extension T connector, or a butterfly needle with a 3-way tap, and avoid excess pressure on the bladder.
What is the direction of the needle during cystocentesis to minimize risks?
The needle should be directed caudally, and as much urine as possible should be drained out.
What should be done after a catheter is successfully placed?
The bladder should be flushed with warmed 0.9% saline until the fluid runs clear.
Why should Walpole’s solution not be used after catheterization?
It is highly irritant and acidic, which can increase bladder inflammation, exacerbate cystitis, and slow recovery.
What diagnostic procedures are recommended while the cat is still anesthetized?
Radiographs should be taken to check for uroliths, and a retrograde urethrogram should be performed to assess for urethral rupture or strictures.
What kind of analgesia and anti-spasmodic treatment should be used after catheterization?
Continued opioid analgesia and a combination of smooth muscle antispasmodics (e.g., prazosin, phenoxybenzamine) and skeletal anti-spasmodic (e.g., dantrolene) are recommended.
Why should intravenous fluid therapy be continued post-catheterization?
Many cats develop post-obstructive diuresis, so fluid requirements may be higher, and close monitoring of urine output is important.
When should an indwelling urinary catheter be placed after relieving urethral obstruction?
If the case involved systemic complications, difficult catheterization, penile inflammation, or severely haemorrhagic urine, an indwelling catheter is advisable for at least a couple of days.
What type of catheter is recommended for cases with severe penile inflammation or recurrent obstruction?
Mila tom cat catheters are recommended as they are silicone-based and less irritant, with a longer design to prevent irritation at the bladder neck.
What should be done when an indwelling catheter is in place to prevent infections?
The catheter should be placed as aseptically as possible with a closed collection system, and antibiotics should be avoided. The catheter tip should be cultured on removal to check for iatrogenic infections.
When should surgery be considered in urethral obstruction cases?
Surgery is a last resort, particularly indicated for urethral trauma or stricture identified on retrograde studies, or when catheterization is unsuccessful.
What is a cystotomy tube used for in urethral obstruction cases?
A cystotomy tube may be placed to allow swelling and inflammation to reduce before performing perineal surgery.
What are the main chronic problems associated with urethrostomies?
Recurrent urinary tract infections and incontinence are the main chronic problems, especially with pre-pubic urethrostomies.
