What is the recommended stabilization protocol for urethral obstruction in cats?

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Stabilization of the obstructed cat prioritizes cardiac protection from hyperkalemia, IV fluid resuscitation, and pain control before urethral catheterization is attempted. Cardiovascular assessment drives the order of interventions. Cats with urethral obstruction (UO) present with varying degrees of cardiovascular instability and azotemia, with hyperkalemia-induced bradyarrhythmia representing the primary life threat. 11 In cats with severe metabolic derangements, stabilization should address hyperkalemia in three sequential steps: antagonize cardiac membrane effects with calcium gluconate, drive potassium intracellularly via sodium-potassium ATPase stimulation, and dilute extracellular potassium through IV fluid administration until renal excretion resumes. 1 IV fluid therapy is the most frequently used potassium-lowering intervention and works by increasing glomerular filtration rate to enhance potassium elimination and by dilution. 14 When hyperkalemia is moderate to severe, insulin combined with dextrose is the next most commonly employed strategy; exogenous insulin stimulates sodium-potassium ATPase pumps to drive extracellular potassium intracellularly, while dextrose prevents hypoglycemia by providing substrate or stimulating endogenous insulin release. 14 The commonly recommended dextrose-to-insulin ratio of 2 g per unit is not reliably protective against hypoglycemia in every cat, and severity of hyperkalemia is not associated with in-hospital mortality. 14 Decompressive cystocentesis (DC) is performed as part of stabilization in many institutions and offers several concurrent benefits: relief of pain, reduction of renal back pressure, improvement of bladder wall perfusion, and facilitation of subsequent retrograde urohydropropulsion by lowering intraluminal bladder pressure. 1 DC also provides a urine sample for urinalysis and culture before catheter placement contaminates the sample. 1 Concerns about DC include urine leakage into the peritoneum, bladder