Emergent catheterization in acute urinary retention may cause which hemodynamic change?

• A. Hypertension and tachycardia
• B. Hyperglycemia
• C. Hypotension and bradycardia
• D. No significant change

Answer: (C)

Relief of bladder distension from emergent catheterization can trigger a vagal response, causing bradycardia and hypotension. When the bladder is suddenly decompressed, parasympathetic activity increases and sympathetic activity decreases, leading to a slower heart rate and lower blood pressure. This reflex, sometimes called a vasovagal response to bladder emptying, explains why the expected hemodynamic change is a drop in both heart rate and blood pressure. Hyperglycemia isn’t induced by catheterization, and hypertension or tachycardia would reflect sympathetic activation rather than the parasympathetic surge seen here. There is indeed a notable change in hemodynamics with this procedure.