26 - urethra

complete urinary obstruction

metabolic acidosis

hyperkalemia → tx with 0.9% NaCl

azotemia

death in 65-70 hrs

increased renal intratubular pressure → decrease GFR → reversible if relieved in 24-36 hrs

post-obstructive diuresis → temp loss of concentrating ability + refractory hypokalemia

FLUTID

feline lower urinary tract inflammatory disease

aka feline interstitial cystitis

inflammatory condition related to stress

dysuria, hematuria, stranguria

often copmlicated by recurrent UTIs and urolithiasis

hyperkalemia

stretched ECG strip

affects cardiac conduction

tall T-waves

widened QRS

flattened P waves

treatment

calcium gluconate → stop if bradycardia worsens, QT interval shortens

dextrose ± insulin → long-term control, stimulates endogenous insulin → intracellular translocation of plasma potassium

insulin + dextrose → never give insulin w/o dextrose

blocked cat

correct hyperkalemia

start IVF

decompress bladder

catheterize

sedation: opioid, benzo, alfaxalone

use slippery sam catheter

post-obstructive diuresis

leave in place for 48 hrs

can lead to hypokalemia

urethral relaxants

acepromazine, phenoxybenzamine, prazosin → alpha-1 antagonists → relaxes sphincters

perineal urethrostomy

amputation of penis and urethra

up to bulbourethral glands → 2x the width of penile urethra

may not fully control FLUTD

goal: reduce risk of life threatening urethral obstruction

technique

dissect penis free of distal attachments

at ischium, ligate ischiocavernosus muscles

break ventral attachments → avoid dorsal → nervous/arterial supply

transect retractor penis at apex

cease dissection at bulbourethral glands

appose urethra to skin

bury remnant penis subcutaneously

no u-cath post-op → don’t touch it!!

post-op

use only shredded paper in litter box for 2 weeks

check incision BID → don’t disturb

E-collar for 2 weeks

complications

urine extravasion

stricture

hemorrhage

wound dehiscence

recurrent UTIs

urine scald

incontinence

scrotal urethrostomy

urethra very superifical in scrotum

indications

failure of urohydropulsion

stricture

neoplasua

trauma

technique

extend incision to longer than expected → up to half of length lost during healing

tack SQ to tunica albuginea → tension-free positioning

appose urethral mucosa to skin → engage mucosa

post-op care

monitor PCV → slow leakage of blood

E collar for 3 weeks

watch for stricture, subcutaneous urine leakage

urethral trauma

anuria

bruising indicating urine leakage

conservative management

cather past lesion → 5-7 days

surgical anastomosis

for full thickness urethral stransection

risk fo structure

maintain catheter 3-5 days post-op