Page 2381 - Cote clinical veterinary advisor dogs and cats 4th

1176 Urethral Obstruction (Feline): Medical Management

○ Insert a lubricated, large-bore flexible urethroliths into the urinary bladder. Alternatives and Their
catheter into the distal urethra. The tip Use caution not to overdistend the Relative Merits
VetBooks.ir ○ Occlude pelvic urethra proximal to ■ If the technique is repeated, accumu- urethra (e.g., urethrotomy, urethrostomy),
bladder lumen with saline.
of the catheter should remain distal to
To minimize surgical disfigurement of the
urethroliths.
consider lithotripsy to shatter obstructing
lation of saline in the bladder lumen
urethroliths: insert a gloved index finger
into the rectum, and occlude the urethral necessitates repeating decompressive urethroliths if retrograde urohydropropulsion
is not successful.
cystocentesis.
lumen by compressing the urethra against ○ To perform this technique in female dogs,
the floor of the bony pelvis. insert the index finger into the vagina, and Pearls
○ Occlude distal urethra: with a moistened apply digital pressure; occlude the distal • This procedure should be performed only
gauze sponge, occlude the distal urethra by urethra over the catheter at the urethral in dogs that are adequately anesthetized;
compressing the distal tip of penis around papilla. Inserting the index finger in the urethral manipulation is very painful.
the catheter. rectum and applying digital pressure over • Instilling lidocaine in the flushing solution
○ Forcefully flush fluid through catheter. the catheter in the pelvic urethra can also is unlikely to be helpful because topical
Fill a large syringe (20-60 mL) with achieve distal urethral occlusion. anesthetics require prolonged contact
■
sterile isotonic solution (e.g., saline, (>5 minutes) with the urothelium to be
lactated Ringer’s solution). The normal Postprocedure effective.
bladder holds approximately 7-11 mL/ • Medical imaging
kg of the patient’s weight. ○ Radiography provides an appropriate SUGGESTED READING
With the syringe attached to the flex- method of assessing whether all radiopaque
■ Osborne CA, et al: Canine retrograde urohydropro-
ible catheter, turn it upside down, and uroliths have been flushed into the bladder pulsion. Lessons from 25 years of experience. Vet
place the top of the plunger against the lumen. Clin North Am Small Anim Pract 29:267-281,
tabletop. ○ Transurethral catheterization is not a 1999.
Hold the syringe by the barrel, and reliable method of verifying that all
■
forcefully push it down over the plunger uroliths have been flushed out of the RELATED CLIENT EDUCATION
with the goal of rapidly and forcefully urethra. SHEETS
emptying the syringe and subsequently • Pain medication (e.g., butorphanol, hydro-
dilating the urethral lumen with saline. morphone) is indicated for a short duration Consent to Perform Cystocentesis
○ Relieve occlusion of pelvic urethra: after (1-2 days). Nonsteroidal antiinflammatory Consent to Perform General Anesthesia
the urethra becomes dilated, digital pres- drugs (NSAIDs) are contraindicated in Urolithiasis
sure applied to the pelvic urethra (but animals with compromised renal function
not the penile urethra) should be rapidly or dehydration. AUTHORS: Jody P. Lulich, DVM, PhD, DACVIM; Carl A.
released. • Prevent negative fluid balance associated with Osborne, DVM, PhD, DACVIM
○ Continue flushing postobstructive diuresis by administering EDITORS: Leah A. Cohn, DVM, PhD, DACVIM; Mark S.
Thompson, DVM, DABVP
Continue flushing fluid through the parenteral fluids.
■
catheter and urethral lumen to propel

Urethral Obstruction (Feline): Medical Management

Equipment, Anesthesia
Difficulty level: ♦ ○ IV extension tubing
• The type and degree of sedation/anesthesia ○ Large syringe (12-35 mL)
Overview and Goal vary, depending on patient status and ○ Moistened gauze sponges
Complete urethral obstruction (p. 1009) is a veterinarian’s preference. • Indwelling urinary catheter placement
potentially life-threatening event, culminating in • Cardiovascular stabilization ○ Nonabsorbable suture and needle
death from uremia within 2-5 days if untreated. ○ Warming pad holders
Although most causes of urethral obstruction are ○ Intravenous (IV) catheter ○ Soft, flexible, inert sterile urinary
intraluminal (e.g., urethral plugs, urethroliths, ○ Lukewarm IV replacement fluids catheter
foreign material), mural (e.g., tumors, urethral ○ Sodium bicarbonate ○ Elizabethan collar
strictures), and extramural (e.g., pelvic fractures, ○ Insulin and glucose to manage
iatrogenic urethral ligation), they result in hyperkalemia Anticipated Time
identical clinical consequences. ○ Calcium gluconate to manage hyperka- About 20 minutes to 1 hour
lemia (p. 495)
Indications • Decompressive cystocentesis Preparation: Important
• Matrix-crystalline urethral plugs (common) ○ Sterile 1 2 -inch, 22-gauge needle Checkpoints
1
• Urethroliths (common) ○ IV extension tubing • Ensure cardiovascular stabilization before
• Blood clots ○ 3-way stopcock general anesthesia or urethral flushing.
• Intraurethral foreign bodies (i.e., buckshot) ○ Several syringes (3-20 mL) • Prevalence of potentially life-threatening
• Retrograde urethral flushing abnormalities in cats with urethral obstruction
Contraindications ○ Sterile, nonirritating isotonic solutions ○ Hypothermia (<100°F [37.8°C]) = 39%
Retrograde hydropropulsion in patients with (e.g., normal saline, lactated Ringer’s ○ Acidemia (pH < 7.2) = 16%
lower urinary tract rupture may inadvertently solution) ○ Bradycardia (<149 beats/min) = 12%
result in fluid accumulation in abdominal, ○ Sterile, open-ended catheter (e.g., Min- ○ Hyperkalemia (>8 mEq/L) = 12%
retroperitoneal, or perineal region. nesota olive-tip catheter) ○ Hypocalcemia (<0.8 mmol/L) = 6%-12%

www.ExpertConsult.com