Neurogenic bladder dysfunction Flashcards
What are the muscles associated with the bladder?
- Smooth muscles: detrusor muscle and urethral muscle
- Skeletal muscle: external sphincter
Describe the autonomic function of the bladder
- Parasympathetic = peeing
- Sympathetic = storage
- When your fleeing you shouldn’t be peeing!!
What receptors are found in the detrusor muscle?
- Muscarinic cholinergic (parasympathetic)
- Beta adrenergic (sympathetic)
What receptors are found in the urethral muscle?
-Alpha adrenergic (sympathetic)
What receptors are found in the external sphincter?
-Nicotinic cholinergic (parasympathetic)
What nerve is important in voiding?
Pelvic nerve (parasympathetic, cholinergic)
Where are the pre-ganglionic cell bodies of neurons that control bladder filling and closure of the urinary sphincter in dogs? In cats?
Dogs: L1-L4
Cats: L2-L5
Where are the alpha receptors (sympathetic) located? What are they stimulated to do during the storage and emptying phase?
Bladder neck; they are stimulated during the storage phase to contract and keep bladder neck closed, and blocked during the emptying phase to relax and open the bladder neck and urethra
Where are the beta receptors (sympathetic) located? What are they stimulated to do during the storage and emptying phase?
They are located in the bladder body, and stimulated during the storage phase to relax muscle and blocked during the emptying phase to contract the bladder
Where are the parasympathetic cholinergic receptors located?
They are located throughout the bladder. They are blocked during the storage phase to relax muscles (for filling) and stimulated during the emptying phase to strengthen the contraction of the bladder muscle
What drugs are used to block sympathetic alpha receptors to facilitate bladder emptying?
Phenoxybenzamine and Prazosin (more popular)
What drugs are used to block striated urethral muscle to facilitate bladder emptying?
Diazepam (more popular) and dantrolene
What drugs are used for cholinergic stimulation of the detrusor muscle to facilitate bladder emptying?
Bethanechol (NO LONGER AVAILABLE)
What drug is used as alpha agonist to increase internal sphincter tone to facilitate urine storage?
Phenylpropanolamine
What drug is used as an anticholinergic to decrease bladder tone to facilitate urine storage?
Propantheline
What estrogen drug is used to increase sphincter tone to facilitate urine storage?
Diethylstilbestrol (only used in dogs)
What testosterone drug is used to increase sphincter tone to facilitate urine storage?
Testosterone cypionate (only used in dogs)
What are the aims for bladder management?
- Patient welfare (paramount)
- Aid voiding or manual expression
- Prevent urine scalding
- Prevent cystitis
- Prevent muscle tight junctions over-stretching and causing permanent damage
What is the problem with an UMN bladder? How is it solved?
- Problem: increased sphincter tone, makes bladder difficult to express
- Solution: diazepam +/- prazosin
What procedure is contraindicated with UMN bladder?
Cystocentesis if bladder is very full; repeated catheterization should be avoided
