Anesthesia for Cardiac Catheterization

CCL Setup & Pre-Flight Checks - Cath Lab Conquest

• Unique CCL Environment: Radiation, remote location, shared airway, limited space/access.
• Pre-Procedural Assessment (📌 CATH):
  • Cardiac: IHD, valvular lesions, LV function (e.g., EF < 35%), arrhythmias.
  • Allergies: Esp. to contrast media (note previous contrast reaction).
  • Tests: ECG, Echo, Renal function (e.g., Serum Creatinine > 1.5 mg/dL).
  • Haemorrhage Risk: Coagulopathy; review antiplatelets, anticoagulants.
  • Comorbidities (renal, diabetes), ASA status, informed consent.
• NPO Guidelines: Solids 6-8 hrs, clear fluids 2 hrs pre-procedure.

⭐ Patients with significant renal dysfunction (e.g., eGFR < 30 mL/min/1.73 square meters) require careful consideration for contrast volume and nephroprotective strategies.

Anesthetic Modalities - Potions & Protocols

• Goals: Patient safety, comfort, immobility, hemodynamic stability, rapid recovery. 📌 SEDATe (MAC): Safety, Equilibrium (hemodynamic), Discomfort relief, Amnesia, Titratability, Emesis prevention.
• Monitored Anesthesia Care (MAC): Most common. Agents:
  • Midazolam: Anxiolysis, amnesia (0.02-0.1 mg/kg).
  • Fentanyl/Remifentanil: Analgesia.
  • Propofol: Sedation, antiemetic (Bolus: 0.25-0.5 mg/kg; Infusion: $25-75 \text{ mcg/kg/min}$). Risks: apnea, hypotension.
  • Dexmedetomidine: Sedation, minimal respiratory depression, sympatholysis.
• General Anesthesia (GA) Indications: Uncooperative/pediatric patients, prolonged/complex procedures (structural heart), hemodynamic instability, MAC refusal, difficult airway.
• Airway (GA): Remote setting considerations.

⭐ Dexmedetomidine is particularly useful in patients where respiratory depression is a major concern (e.g., severe COPD, OSA) undergoing procedures under MAC.

Vigilant Monitoring - Cath Lab Command

• Standard ASA Monitoring:
  • ECG: Continuous, leads II & V5 for ischemia detection (ST depression > 1mm).
  • NIBP: Frequent cycling.
  • SpO2, Temperature.
• Capnography (ETCO2): Mandatory for General Anesthesia (GA); highly recommended for deep Monitored Anesthesia Care (MAC) to monitor ventilation.
• Invasive Arterial Blood Pressure (IABP):
  • Indications: Anticipated large fluid shifts/blood loss, severe LV dysfunction, frequent blood sampling, vasopressor/inotrope use.
• Activated Clotting Time (ACT):
  • Crucial for procedures requiring heparinization (e.g., PCI, structural interventions).
  • Target ACT typically 250-350 seconds.
• Neuromuscular Monitoring: If muscle relaxants are administered.
• Radiation Safety: 📌 ALARA (As Low As Reasonably Achievable) for personnel - lead aprons, thyroid shields, dosimeters.

⭐ Continuous 5-lead ECG monitoring is preferred over 3-lead for better detection of myocardial ischemia during cardiac catheterization procedures.

Complication Control - Crisis Crew

• Hemodynamic Instability:
  • Hypotension: Causes (vasovagal, hypovolemia, ischemia, drugs). Mgmt:

-   Hypertension: Causes (pain, anxiety, pre-existing). Mgmt: Analgesics, anxiolytics, antihypertensives (e.g., Labetalol **5-20 mg IV**).
-   Arrhythmias: Bradyarrhythmias (Atropine **0.5-1 mg IV**, pacing), Tachyarrhythmias (ACLS guided).

• Contrast Media Reactions:
  • Types: Mild (urticaria), Moderate (bronchospasm), Severe/Anaphylactoid (shock).
  • Prophylaxis (high-risk): Steroids, antihistamines.
  • Mgmt: Mild (antihistamines); Moderate (O2, bronchodilators, steroids); Severe (Epinephrine $0.3-0.5 \text{ mg IM}$ (1:1000) or $0.05-0.1 \text{ mg IV}$ (1:10000), IV fluids, O2, airway support).
• Vascular Access Complications:
  • Hematoma, pseudoaneurysm, retroperitoneal hemorrhage.

  ⭐ Retroperitoneal hemorrhage: rare, life-threatening femoral access complication; presents with hypotension, flank pain, ↓Hb.

• Other Key Complications:
  • Thromboembolism/Stroke: Maintain anticoagulation.
  • Air Embolism: Left lateral decubitus (LLD), Trendelenburg, 100% O2.
  • Local Anesthetic Systemic Toxicity (LAST): If large LA volumes; Mgmt: Lipid emulsion therapy.
• 📌 HHAPPy Mnemonic (Common Complications): Hemorrhage, Hypotension, Arrhythmia, Pseudoaneurysm, Puncture site pain.
• Emergency Preparedness:
  • Essential: Difficult airway cart, defibrillator, emergency drugs readily available (e.g., ACLS drugs).

High-Yield Points - ⚡ Biggest Takeaways

• Monitored Anesthesia Care (MAC) is preferred, using midazolam and fentanyl for sedation.
• Vigilant airway monitoring and readiness for intervention are crucial due to sedation risks.
• Systemic heparinization is standard; target Activated Clotting Time (ACT) of 250-300 seconds.
• Key complications: cardiac arrhythmias, vascular access site bleeding, and allergic contrast reactions.
• Ensure immediate availability of reversal agents like naloxone and flumazenil.
• General anesthesia is often necessary for pediatric patients or complex interventions.