Normal and Abnormal Transport of Urine After Leaving the Nephron Flashcards
Smooth muscle spasm in ureter
Or lack of smooth muscle tone
Very painful…most commonly from acute obstruction due to stone
Dec - pregnancy or chronic obstruction
ALso can have vesicouretral reflux
Stone passing through ureter
Causes renal colic
Where bladder and kidney will cause blood, reucrrent infections, pain
Renal colic
Acute, severe, worse than labor
Intermittnet
Starts in flank and can move to lower abdomen as stone moves
KIdney capsule distention —- N/V
Colic vs. peritonitis - physical exam
Peritonitis - main area of tenderness is the abdomen, guarding with or without rebound tenderness…hurts to move, pt stays still
Colic - CV angle tenderness, pt needed to keep moving
Suspected urinary stone analysis
Hematuria is classic
Main reason for doing UA is to eval for infection bc ureteral obstruction and infection is life-threatening emergency
Do not HAVE to have blood
Suspected stone - hemogram and electrolytes, BUN, creatinine
Anemia not typical for sotnes…main goal is to check WBC count
Electrolytes, BUN, and Cr normal unless abnormal kidney, dehydration from N/V, or sepsis
Imaging suspected urinary stone
Non-contrast CT
Exception - pregnancy, tones of CT, young child
Then get US or MRI
Infection with ureteral obstruction
Bacteria under pressure so pushed into ciruclation and can cause sepsis
When evaluating pt with renal colic, MUST rule out infection***
Obstruction plus infection hx and exam
Flank pain and tenderness may be worse
May have sx of bladder infection (pain while voiding or frequent voiding)
Sx and signs of sepsis
Obstruction and infection lab work
Negative UA does NO rule out UTI because trapped if completely occluded
Look at UA and hemogram together…if both are normal, probably okay…if one is not, order it STAT
Imaging obstruction and infection
CT stone protocol…if shows hydronephrosis or stone in setting of infection, call urologist STAT
Tx of obstruction with infection
Drainage - curls in kidney and bladder to hold in place
If you can’t do stent, radiologist places percutaneous nephrostomy tube
Surgery to remove stone after infection
Usual tx of stones
Observation okay if stone in kidney with no sx or obstruction
Surgery
Alpha 1 adrenergic antagonist for pt trying to pass a stone
alpha 1 antagonist
Ureter spasm distal to stone impedes its passage
alpha antagonist helps relax the smooth muscle to helpl stone to pass
Alpha 1 relevant receptor
lpha1A on urethra and ureter
Selective antgonist helps focus on fewer side effects
Oral meds for kidney stones
Uric acid stone MIGHT dissolve with oral bicarb or citrate to keep pH higher
Citrate, drugs with SH and UTI suppression (for struvite) may prevent new stoens from being formed
Which AB is best to give daily to prevent struvite stones?
Amoxicillin
Normal urine storage
Bladder (detrusor) smooth muscle relaxed and outlet stays closed
Normal voiding
Detrusor contracts and pushes urine out
Outlet opens - bladder neck, external urinary sphincter
PS and sympathetic NTs relevant to voiding
PS - acetylcholine…muscarinic makes bladder contract
Symp - alpha 1 - keeps outlet tight, Beta 3 - keeps bladder relaxed
How does detrusor stay relaxed
Cerebral cortex inhibits contraction - babies cannot doe this…cerebral lesions often lead to incontinence
Sympathetic system - beta 3 adrenergic receptors in detrusor keep bladder relaxed
How does outlet stay closed
Alpha 1 receptors in bladder neck
Sacral spinal cord S2-S4 - pudendal nerve…external sphincter (skeletal)…active continence…do this voluntarily
Neuro of normal voiding
Cerebral cortex stops inhibiting detrusor
Sacral cord 2-4 - efferent signals…detrusor contracts…pelvic nerves PS - pee
Acetylcholine, muscarinic receptors
External sphincter opens
Pons coordinates voiding, so external sphincter opens when bladder contracts
Bladder neck opens - pathways not worked out
Lesion above the pons
Voiding uncontrolled (urge incontinence) but otherwise normal
Common - stroke, MS in cerebral cortex, normal pressure hydrocephalus, brain tumor
At or distal to sacral spinal cord
Bladder sensation is decreased or absnet
Detrusor contraction weak or absnet…clinically incomplete empyting or can’t void at all
May lose voluntary contraction of the external sphincter
At or distal to sacral spinal cord - clinical scenarios
Lumbar spine injury or stenossi
Injury or neoplasm of scrum
Radical surgery
Between pons and sacral spinal cord
Voiding reflex occurs but is uncontrolled 9inhibiton blocked)
External shincter doesn’t relax as bladder contracts, creates functional obstruction
Coordination from pons blocker…increased voiding pressure is a health risk
Most dangerous of neuro lesions**
Detrusor-external sphincter dyssynergia
Between pons and sacral cord clinical
Cervical and most htoracic spine injuries
Neoplasm or ischemia of C or T spine
MS often affects C spine
Autonomic dysreflexia
Upper body flushing, HTN, low HR
Very high BP is life-threatening emergency
Neurologic lesion is above T6 below BS
Why autonomic dysreflia happens
Noxious stimuli increases symp system…normally, increase dampened but lesion blocks these pathways
Excess sympathetic tone below the lesion - vasoconstriction and extreme HTN
HR won’t proportionally increase
Increased BP – increase baroreceptors – increase PS…flushing/sweating and bradycardia
Hx and exam of auto dys
Spinal lesions about T6 bekow BS
Headache
Flushing/sweating
High BP with low HR
Tx of auto dys
Remove noxious stimuli…put catheter in, fecal impaction, skin lesions
Usually BP improves after this…if not, apply nitropaste or sublingual nitroglycerine while staff calls ambulance
Stress urinary incontinence
Bladder outlet not tight enough
Women - childbirth
Men - prostate surgery
Both - pelvic radiation or trauam
Hx - urine leak with cough, sneeze, lift
Exam - observe urethra, ask pt to cough and urine will come out with cough
Stress incontinence tx
Pelvic muscle exercise and physical therapy
Surgery
No meds
Urge urinary incontinence
Urge occurs and pt can’t get to bathroom in time…leaks urine
Cause - uninhibited bladder contractions
- idiopathic, due to bladder irrtation or could be nueorlogic lesion
Normal pressure hydrocephalus
Wet, wobbly, wacky
MS triad
Incontinence or difficulty voiding…can be either of these
Visual changes
Decreased hand function
Suspect MS if any 2 are present
Urge incontinence dx
Patients get urge to urinate but can’t get to bathroom fast enough
Need to distinguish why
Idio, neuro, bladder
Urge incontinence eval
Urinalysis - if pyuria, hematuria, or nitrites, send a culture
If UA abnormal and culture no growth, suspect bladder stone or cancer
Urge incontinence tx
Tx underlying cause
Muscle exercises
Surgery
Muscarinic antagonists, mirabegron
Muscarinic antagonists
Inhibit bladder contractions - oxybuynin
Come with a ton of side effects
Muscarinic antagonists in elderly
Could make dementia worse
CAN’T give donepizil bc they are opposites
Beta 3 adrenergic receptor
Expressed on bladder
Typical GPCR that works through cAMP…activated leads to smooth muscle relaxation
MIrabegron
Beta-3 adrenergic agonist
Keeps bladder relaxed
NO cognitive impairment but new so expensive
Voiding difficulty from meds
Muscarinic antagonists…decrease detrusor contractility
Alpha adrenergic agnosists - increased urethral closure pressure
Pseudophedrine
Constricts BV in nose but also constricts smooth muscle fo the urethra
Interstitial cystitis
Clinical scenario - pain with holding urine
Frequent urination
No incontinence
Urine culture no grwoth
Most are female
