What is the recommended pre-procedure regimen for patients undergoing catheterization (cath) lab procedures?

Pre-Procedure Regimen for Cardiac Catheterization

All patients undergoing cardiac catheterization must have a thorough pre-procedure assessment including informed consent, laboratory evaluation with renal function testing, adequate hydration protocols, and appropriate antiplatelet/anticoagulation management based on their specific clinical scenario. 1

Patient Assessment and Risk Stratification

The performing physician must critically review the patient's complete history, physical examination, and laboratory data ideally the day before the procedure 2. This review should specifically identify:

• High-risk features requiring inpatient observation: congestive heart failure, unstable angina, acute MI, renal insufficiency (creatinine >2.0 mg/dl), frequent ventricular arrhythmias, severe COPD, bleeding diathesis, uncontrolled hypertension, recent stroke (<1 month), severe pulmonary hypertension, ejection fraction ≤35%, and age >75 years 2

• Timing considerations: The procedure should be performed when arrhythmias, heart failure, or azotemia are stable or improving, as unstable conditions yield misleading data and increase procedural risk 2

Informed Consent

The physician performing the procedure must personally obtain informed consent, not delegate this entirely to others 2, 1. This discussion must include:

• Reasons for the study, potential benefits, and specific complications 2, 1
• For coronary procedures, the potential need for ad hoc PCI with its additional risks 2
• All elective PCI procedures must mention possible need for surgical intervention 2
• A "time-out" must occur before sedation to verify correct patient and procedure 2

Laboratory Testing and Checklist

Use a standardized checklist that includes: patient identification, procedure planned, consent status, physical exam findings, ASA classification, planned access site, medications, allergies, laboratory findings (especially creatinine clearance), and proposed contrast limit 2, 1

Essential laboratory evaluation:

• Estimate glomerular filtration rate and adjust renally cleared medications accordingly 1
• Assess bleeding risk before the procedure 1
• Evaluate risk for contrast-induced acute kidney injury 1, 3

Hydration Protocol

All patients must receive adequate preparatory hydration to prevent contrast-induced nephropathy 1. This is one of the three pillars of prevention, along with identifying high-risk patients and eGFR-based contrast dosing 3.

Common pitfall: Inadequate hydration before contrast administration significantly increases nephropathy risk 1

Antiplatelet Management

For patients already on aspirin: Continue with 81-325 mg before the procedure 1

For patients not on aspirin: Administer non-enteric aspirin 325 mg before the procedure 1

Statin therapy: For patients requiring high-dose statins, pre-procedure administration is reasonable to reduce periprocedural MI risk 1

Important consideration: Opioid medications reduce absorption of oral antiplatelet loading doses, which should factor into sedation decisions 4

Anticoagulation Management

For patients on warfarin: Can be continued at modified doses for most cardiac catheterizations 1

For high-risk procedures (trans-septal catheterization, direct LV puncture, pericardial drainage): Stop oral anticoagulants and perform bridging anticoagulation 1

Bridging protocol when required:

• Last dose of LMWH should be >12 hours before procedure 1
• UFH should be discontinued 4 hours before procedure 1
• Resume effective anticoagulation as soon as possible post-procedure based on bleeding risk 1

Contrast Nephropathy Prevention

For patients with chronic kidney disease (creatinine clearance <60 mL/min): Minimize contrast volume 1

N-acetylcysteine is NOT useful for preventing contrast-induced AKI 1

Use ultra-low contrast volume techniques in high-risk patients 3

Allergy Prophylaxis

Patients with prior anaphylactoid reaction to contrast: Must receive appropriate prophylaxis before repeat contrast administration 1

Common misconception: Shellfish/seafood allergy does NOT require anaphylactoid prophylaxis for contrast 1

Sterile Technique and Infection Control

Standard procedures: Gloves, gowns, and laboratory coats are required 2, 1

For complex/lengthy procedures (PTCA, valvuloplasty): More rigorous sterile technique should be followed 2, 1

For high-risk infectious cases: Use surgical caps, masks, eye protection, and consider double gloving (reduces inner glove perforation by 60%) 2

Hepatitis B vaccination should be mandatory for all catheterization laboratory personnel 2

Procedural Anticoagulation

Heparin should be routinely administered when nonionic contrast agents are used for angiography, as these agents inhibit blood clotting and platelet aggregation less than ionic agents 2, 1

Post-Procedure Planning

Standard orders should include:

• Blood pressure, pulse, distal pulses, and bandage site checks every 15-30 minutes for 2 hours, then hourly 1
• Catheterization team member examination later that day and subsequently as indicated 1
• Adequate post-procedural holding area, especially for ambulatory patients 1

Key Exclusions from Ambulatory Catheterization

Absolute contraindications (Class III): Geographic remoteness (>1 hour drive), interventional procedures, fever/active infection, severe anemia/electrolyte imbalance, bleeding diathesis, recent stroke (<1 month), suspected severe pulmonary hypertension, severe peripheral vascular disease, severe insulin-dependent diabetes 2