Close this window to return to IVIS www.ivis.org Proceedings of the Congreso Ecuatoriano de Especialidades Veterinarias CEEV 2011 Nov. 15-17, 2011 Quito, Ecuador Reprinted in IVIS with the permission of CEEV
URETHRAL OBSTRUCTION - BLOCKED CAT Helio Autran de Morais, DVM, PhD, ACVIM (Small Animal Internal Medicine & Cardiology) Oregon State University Very common in cause of acute post-renal failure in cats o Urethral plugs o Stones o Others? Signs o Pollakiuria, dysuria o Uremia 24 48 h o Vomit 48 h o Moribund 72 h Radiographs o May be normal o Radiopaque stones o Thick bladder wall (contrast studies) Complications o Hypovolemia o Metabolic Acidosis o Hypocalcemia o Hypercalemia o Hyperphosphatemia o Azotemia What is going to kill your patient first? o Hypovolemia o Tissue Perfusion o Actions Catheter Blood sample Fluids ECG First steps (lab) o Blood BUN, Creatinine Calcium and Phosphorus Sodium and Potassium Glucose PCV and TP Venous blood gas o The worst the patient looks the higher BUN, Creatinine Calcium and Phosphorus? Sodium and Potassium (stethoscope?)
Glucose PCV and TP (???) Venous blood gas ( acidosis) o The worst the patient looks the worst Hypothermia Tissue perfusion Bradicardia Dehydration Decrease in consciousness o Can you predict? Hypothermic patients Acidosis 80% Hyperkalemia 41% Hypocalcemia 19% Temperature < 95 o F => 86% hyperkalemia First steps (Medicine) o Line o Fluids Don t worry, bladder WILL NOT rupture NaCl 0.9%, 20 30 ml/kg immediately See what happens Patient is o Better Unblock Same or worst o Stabilization o More fluids o Address complications Complications o Hyperkalemia Bradicardia Not as pronounced as in dogs ECG changes Functional assessment of hyperkalemia Weakness Therapy Calcium 50 100 mg/kg in 2 3 min o With ECG monitoring o Advantage treats hypocalcemia Insulin + Glucose o Regular: 0.1 0.25 U/Kg + Glucose: 1 2 g/u of insulin o Problem: Risk of hypoglycemia Too much insulin o Advantage: Treats hypoglycemia Bicarbonate o 1 2 meq/kg
o Problems: Hyperosmolar, decrease ionized calcium o Advantage: Improves acidosis o Metabolic Acidosis ph < 7.1 Bicarbonate o Ionized hypocalcemia Worsen clinical manifestations of hyperkalemia Give calcium o Hypoglycemia Glucose Unblocking o Cystocentesis? Allows for obtaining and uncontaminated sample Easier to pass the catheter later Less chance of bladder rupture Reestablish renal function o Chemical Restraint + Analgesia Painful Need full cooperation May decreased urethral tone? Comatose patients may not need anesthesia o Catheterization On occasion, the obstruction will be at the distal tip of the penis and can be massaged out to relieve the obstruction USE STERILE TECHNIQUE Be a real doctor Wear gloves Shave the perineum especially long-haired cats Use a gentle antiseptic Start with a well lubricated, open-ended polypropylene (Tom cat) catheter Extrude the penis by pushing the prepuce back. A strong pinch is necessary to keep it out of the prepuce Insert the catheter while your assistant flushes (use saline or saline & lube mix) After placing catheter, lavage bladder with saline to remove debris Leave indwelling catheter in place Use a soft catheter (red rubber) Use a closed-ended catheter Attach a sterile, closed-collection system again, be a real doctor Management after Unblocking o Transfusion Urinary PCV > 5% and PCV dropping o Fluids High rate Post-obstructive diuresis is rare but can be severe
o Tends to be proportional to the initial azotemia o Can lead to severe dehydration o Usually self-limiting Urine output should never exceed fluid input Fluid? Any replacement solution with adequate amounts of potassium o Hypokalemia Common Add potassium to the fluids o Pain management o Tranquilizers Ace Watch for hypotension o Steroids NEVER o Antibiotics Catheter increases risk of infection Culture post-removal of catheter Antibiotics DO NOT prevent catheter-induced UTI o Removal of the catheter Clear Urine 36 48 h Dark urine??? o Removed the Catheter Tries to urinate all the time Empty bladder: Urethritis/cystitis Full bladder: BLOCKED o Rapid Re-obstruction Recurrence Edema Urethral Spasm Blood clots Stones Urate Does not try to urinate at all Empty bladder: Probably leaking constantly Full bladder: ATONY o Bladder Overdistention may lead to Bladder Atony Separation of tight juntions Act immediately to prevent irreversible damage Avoid manual expression Keep bladder empty (catheterization) for at least 7 days Bethanecol: 2.5 mg BID