What is the role and dosage of lignocaine (lidocaine) in a patient undergoing percutaneous transluminal coronary angioplasty (PTCA)?

Lignocaine in PTCA Patients

Lignocaine (lidocaine) is not routinely indicated for patients undergoing PTCA, as the primary pharmacological focus during percutaneous coronary intervention is antiplatelet therapy (aspirin, clopidogrel/ticlopidine) and anticoagulation (heparin with target ACT 300-350 seconds), not local anesthetic administration. 1

Primary Medications for PTCA

The evidence-based pharmacological management during PTCA centers on:

• Aspirin: 80-325 mg given at least 2 hours before PCI to reduce ischemic complications 1
• Thienopyridines: Clopidogrel 300 mg loading dose followed by 75 mg daily, or ticlopidine as alternatives for antiplatelet therapy 1
• GP IIb/IIIa Inhibitors: Should be considered particularly in patients with unstable angina or high-risk characteristics to reduce abrupt closure and periprocedural MI rates 1
• Heparin: Weight-adjusted dosing with target ACT of 300-350 seconds during the procedure, with initial bolus of 100 units/kg recommended 1

When Lignocaine Might Be Relevant

Lignocaine has no established role in the PTCA guidelines from the American College of Cardiology/American Heart Association 1. The only potential scenarios where lignocaine might be encountered are:

Local Anesthesia for Vascular Access

• For arterial sheath insertion: Standard local infiltration with lignocaine 1-2% (maximum 4.5 mg/kg without epinephrine) may be used at the femoral or radial access site 2, 3
• Dosing considerations: Use ideal body weight for calculation: (height in cm - 100) for men; (height in cm - 105) for women 1
• Safety precautions: Avoid in patients <40 kg; maximum infusion rate should not exceed 120 mg/h if used systemically 1

Antiarrhythmic Use (Separate Indication)

• Lignocaine may be used as an antiarrhythmic agent for ventricular arrhythmias complicating acute MI, but this is a distinct indication from the PTCA procedure itself 4
• This would be managed separately from the procedural anticoagulation protocol 4

Critical Pitfalls to Avoid

• Do not confuse local anesthetic needs for vascular access with the core pharmacological management of PTCA, which focuses on antiplatelet and anticoagulation therapy 1
• Avoid concurrent use of multiple local anesthetic sources (IV lidocaine should not be started within 4 hours of nerve blocks or local infiltration) 1
• Monitor for toxicity if lignocaine is used: signs include circumoral numbness, facial tingling, metallic taste, and in severe cases seizures or cardiac complications 2
• Reduce doses in elderly, debilitated patients, and those with hepatic disease or cardiac failure, as lignocaine is metabolized by the liver and clearance is significantly reduced in these conditions 2, 4

Hemodynamic Considerations

• Patients undergoing PTCA often have compromised cardiovascular status where lignocaine with epinephrine should be used cautiously, as cardiac arrhythmias may occur, particularly during or following potent general anesthetic agents 2
• Epinephrine-containing solutions (1:200,000 concentration) cause less cardiovascular disturbance than higher concentrations (1:80,000) and are recommended for cardiac patients if vasoconstriction is needed 5