Understanding Parasympathetic Blocks: Definition and Applications

A parasympathetic block is regional anesthesia inhibiting the parasympathetic nervous system (“rest and digest”). Used in surgeries (e.g., eye surgery) to reduce secretions and muscle activity in the operative area.

Parasympathetic Functions Affected

• Salivary and tear production
• Heart rate and blood pressure
• Gastrointestinal motility
• Bladder and bowel function

Methods

• Local anesthetics (lidocaine, bupivacaine) block nerve impulses.
• Anticholinergic drugs block acetylcholine, the parasympathetic neurotransmitter.

Administered by injection near parasympathetic nerves/ganglia. Duration depends on agent and dose. Generally safe; transient risks include hypotension, bradycardia, urinary retention, dry mouth, blurred vision, swallowing difficulty.