Cardiac Patient for Non-Cardiac Surgery

A 68-year-old male with ischemic heart disease, hypertension, and type 2 diabetes scheduled for elective laparoscopic cholecystectomy. He has a history of myocardial infarction 2 years ago and takes multiple cardiac medications.

This case is high-risk due to the combination of significant cardiac disease, diabetes, and the physiological stress of laparoscopic surgery. The primary goal is to minimize cardiac risk by ensuring hemodynamic stability throughout the peri-operative period.

Peri-Operative Anesthetic Plan

Patient Summary: 68M, Ischemic Heart Disease (IHD), Hypertension (HTN), Type 2 Diabetes Mellitus (T2DM), s/p Myocardial Infarction (MI) 2 years ago, on multiple cardiac medications. Procedure: Elective Laparoscopic Cholecystectomy.

Core Principles:

  1. Optimization: Utilize the elective nature of the surgery to optimize the patient's medical condition pre-operatively.
  2. Stability: Meticulously control heart rate, blood pressure, and myocardial oxygen supply/demand balance.
  3. Monitoring: Employ advanced monitoring to detect and treat ischemia or hemodynamic instability early.
  4. Multimodal Analgesia: Provide excellent analgesia while minimizing opioid use and its associated side effects (e.g., respiratory depression, hemodynamic swings).

I. Pre-Anesthetic Check-up & Optimization

This is the most critical phase for this patient. A thorough assessment and optimization plan can significantly reduce peri-operative complications.

A. Detailed History and Physical Examination:

  • Cardiac Review:
    • Functional Status: Quantify using METs (Metabolic Equivalents). Can he climb a flight of stairs (4 METs)? Walk on level ground (1-4 METs)? A functional capacity of <4 METs is a significant predictor of adverse cardiac events.
    • Anginal Symptoms: Has he had any chest pain, tightness, or discomfort at rest or with exertion since his MI? Any change in frequency or severity of his typical angina? This is a red flag.
    • Dyspnea: Any new or worsening shortness of breath (possible signs of congestive heart failure)?
    • Syncope/Presyncope: Any recent episodes of dizziness or fainting?
    • Physical Exam: Assess for signs of heart failure (elevated JVP, pulmonary crackles, peripheral edema), new cardiac murmurs, and baseline blood pressure control.
  • Diabetic Review:
    • Glycemic Control: What is his latest HbA1c? (Goal <7-8% is reasonable for surgery).
    • Complications: Does he have renal impairment (nephropathy), gastroparesis, or autonomic neuropathy (which can cause silent ischemia and hemodynamic lability)?
  • Medication Review (Crucial):
    • Antiplatelets: Is he on Aspirin? Clopidogrel? Ticagrelor? The decision to continue or hold these requires a multidisciplinary discussion between Anesthesia, Surgery, and Cardiology. As a general rule, for a low-bleed-risk surgery like cholecystectomy, Aspirin is usually continued. P2Y12 inhibitors (Clopidogrel, etc.) are often stopped 5-7 days pre-op, but this depends on the indication (e.g., recent coronary stent).
    • Beta-Blockers: (e.g., Metoprolol, Atenolol) Must be continued up to and including the morning of surgery. Abrupt cessation can cause rebound tachycardia, hypertension, and ischemia. If the patient is not on a beta-blocker but is high risk, one may be initiated pre-operatively (e.g., Bisoprolol) if there is adequate time (days to weeks) to titrate.
    • Statins: (e.g., Atorvastatin) Must be continued. They have pleiotropic effects, including plaque stabilization and anti-inflammatory properties, which reduce peri-operative cardiac events.
    • ACE Inhibitors/ARBs: (e.g., Lisinopril, Losartan) These are typically held on the morning of surgery due to the high risk of refractory intra-operative hypotension, especially under general anesthesia. They can be restarted post-operatively once the patient is hemodynamically stable.
    • Diabetic Medications:
      • Metformin: Hold on the day of surgery due to the risk of lactic acidosis, especially if there is potential for hemodynamic instability or renal impairment.
      • Sulfonylureas (e.g., Glipizide): Hold on the day of surgery due to the risk of hypoglycemia.
      • Insulin: The management depends on the patient's regimen. A common approach is to give half the usual dose of long-acting insulin on the morning of surgery or switch to a variable-rate insulin infusion (VRII) peri-operatively.

B. Investigations:

  • 12-Lead ECG: Compare with previous ECGs to look for new ST/T wave changes, Q-waves, or arrhythmias.
  • Echocardiography: Essential in this patient. We need to know the Left Ventricular Ejection Fraction (LVEF), assess for regional wall motion abnormalities (indicating areas of ischemia), and rule out significant valvular disease.
  • Blood Tests:
    • Full Blood Count (FBC)
    • Electrolytes, Urea & Creatinine (to assess renal function, relevant for contrast and metformin)
    • Coagulation Profile (PT/INR, APTT)
    • HbA1c
    • Baseline Troponin: Highly recommended in a high-risk patient like this. It provides a reference point for any post-operative chest pain or ECG changes.
  • Cardiology Consultation: Mandatory. We need to discuss:
    • The patient's current cardiac status and functional capacity.
    • The results of the echocardiogram.
    • The plan for antiplatelet management.
    • Whether further cardiac investigation (e.g., stress test, coronary angiogram) is required before proceeding with elective surgery. Given he is 2 years post-MI, he is past the highest risk period, but any new symptoms would warrant a full workup.

C. Risk Stratification & Consent:

  • Use the Revised Cardiac Risk Index (RCRI). This patient has at least 3 risk factors: IHD, T2DM, and intrathoracic/upper abdominal surgery. This places him at a significant risk (>11%) of major cardiac complications.
  • Informed Consent: Have a detailed discussion with the patient and family, explaining the significantly increased risks of myocardial infarction, arrhythmia, stroke, and even death. Explain the planned measures to mitigate these risks.

II. Intra-Operative Management

A. Monitoring:

  • Standard: 5-lead ECG with continuous ST-segment analysis, Non-Invasive Blood Pressure (NIBP), Pulse Oximetry (SpO2), Capnography (EtCO2), Temperature.
  • Advanced (Essential for this patient):
    • Invasive Arterial Blood Pressure (IBP) Line: For beat-to-beat blood pressure monitoring, which is crucial for managing the rapid hemodynamic shifts during induction and pneumoperitoneum. It also allows for easy arterial blood gas (ABG) sampling to check pH, lactate, and glucose.
    • Central Venous Catheter (CVC): Considered, especially if the LVEF is <40% or if there are difficulties with fluid management. It provides central venous pressure (CVP) readings and a route for vasoactive drugs.
    • Cardiac Output Monitor: A goal-directed fluid therapy (GDFT) device (e.g., esophageal Doppler, arterial waveform analysis like LiDCO or FloTrac) is highly beneficial to guide fluid and inotrope/vasopressor use, optimizing stroke volume and preventing fluid overload.

B. Anesthetic Technique:

  • Goal: A smooth, hemodynamically stable induction and maintenance. Avoid tachycardia and hypertension.
  • Induction:
    • Pre-oxygenate well.
    • Use a gentle, titrated induction. Etomidate is an excellent choice as it has minimal cardiovascular depressant effects. If using Propofol, administer it in small, incremental doses.
    • Provide adequate analgesia before intubation with an opioid like Fentanyl (2-5 mcg/kg) to blunt the sympathetic response.
    • Use a non-depolarizing muscle relaxant with a stable hemodynamic profile, such as Rocuronium or Cis-atracurium.
  • Maintenance:
    • A balanced anesthetic technique is preferred.
    • Volatile Agent: Sevoflurane or Desflurane. Volatile agents provide myocardial preconditioning, which can be cardioprotective.
    • Opioid Infusion: A Remifentanil infusion provides excellent hemodynamic control and blunts responses to painful stimuli, with the advantage of rapid offset.
    • Adjuncts: Consider a low-dose Ketamine infusion (0.1-0.3 mg/kg/hr) for its analgesic and sympatholytic effects, or a Dexmedetomidine infusion for its sedative, anxiolytic, and opioid-sparing properties without causing respiratory depression.

C. Managing Laparoscopic Surgery-Specific Challenges:

  • Pneumoperitoneum (CO2 Insufflation):
    • Cardiovascular Effects: Increased intra-abdominal pressure pushes the diaphragm up, increasing intrathoracic pressure, which decreases venous return and cardiac output. Simultaneously, it increases systemic vascular resistance (afterload). This is a double-hit on the heart.
    • Management:
      • Keep insufflation pressure as low as possible (ideally 12-15 mmHg).
      • Communicate with the surgeon before insufflation and deflation to anticipate hemodynamic changes.
      • Use vasopressors (e.g., Phenylephrine) to manage increases in afterload and inotropes (e.g., low-dose Epinephrine) if cardiac output falls significantly.
  • CO2 Absorption:
    • Leads to hypercapnia (increased PaCO2), which causes sympathetic stimulation, tachycardia, and arrhythmias.
    • Management: Increase minute ventilation to maintain normocapnia (EtCO2 35-40 mmHg). Monitor ABGs if prolonged surgery or significant CO2 retention is suspected.
  • Positioning: Reverse Trendelenburg position can cause hypotension due to venous pooling in the lower extremities. Manage this with fluid boluses or vasopressors as needed.

D. Fluid Management:

  • Goal: Maintain euvolemia. Avoid hypovolemia (causes hypotension, tachycardia, and reduced coronary perfusion) and hypervolemia (risk of pulmonary edema in a patient with compromised LV function).
  • Strategy: Use a Goal-Directed Fluid Therapy (GDFT) protocol guided by the cardiac output monitor. Administer small, titrated fluid boluses (e.g., 250ml of crystalloid) and assess the response in stroke volume.

E. Emergence and Extubation:

  • Goal: A smooth, controlled emergence without coughing, straining, hypertension, or tachycardia, as this can cause myocardial ischemia.
  • Technique:
    • Ensure the patient is fully reversed, warm, and hemodynamically stable.
    • Provide adequate analgesia before emergence (e.g., IV Fentanyl, local anesthetic infiltration at port sites).
    • Consider IV Lidocaine (1.5 mg/kg) or a short-acting beta-blocker like Esmolol 30-60 seconds before extubation to blunt the sympathetic response.
    • Extubate when the patient is awake and following commands. Deep extubation is contraindicated in this patient.

III. Post-Operative Management

A. Location and Monitoring:

  • The patient should be managed in a High Dependency Unit (HDU) or a step-down area for the first 24 hours.
  • Monitoring: Continue continuous ECG with ST analysis, frequent NIBP or IBP monitoring, SpO2, urine output, and temperature.
  • Investigations: Obtain a 12-lead ECG and a cardiac troponin level 6-12 hours post-operatively, or immediately if any symptoms of ischemia or hemodynamic instability occur.

B. Analgesia:

  • Continue a multimodal analgesia regimen to minimize opioid requirements.
  • Regimen: Regular IV Acetaminophen, consider NSAIDs if renal function is acceptable, and a low-dose Ketamine infusion can be continued post-op. A Patient-Controlled Analgesia (PCA) with morphine can be used, but with a low basal rate and careful monitoring for sedation and respiratory depression. A Transversus Abdominis Plane (TAP) block performed by the anesthesiologist can provide excellent analgesia and reduce opioid needs.

C. Glycemic Control:

  • Maintain tight but safe glycemic control (e.g., blood glucose 140-180 mg/dL or 7.8-10 mmol/L).
  • Use a structured insulin protocol (e.g., Variable Rate Insulin Infusion or a subcutaneous sliding scale) and monitor blood glucose frequently.

D. Resumption of Medications:

  • Beta-Blockers and Statins: Restart as soon as the patient can take oral medications (usually on the evening of surgery or the next morning).
  • ACE Inhibitors/ARBs: Restart once the patient is hemodynamically stable, euvolemic, and has good renal function.
  • Antiplatelets: Restart Aspirin as soon as hemostasis is secured (often within 24 hours). The timing for restarting P2Y12 inhibitors should be confirmed with the surgical and cardiology teams.

E. Thromboprophylaxis:

  • Start mechanical prophylaxis (TED stockings) intra-operatively.
  • Start pharmacological prophylaxis (e.g., LMWH like Enoxaparin) as soon as it is deemed safe by the surgical team, balancing the risk of bleeding with the risk of venous thromboembolism.

F. Discharge Planning:

  • Ensure the patient and family have clear instructions on resuming all home medications.
  • Arrange for appropriate follow-up with their primary care physician and cardiologist.

Conclusion:

Managing this patient requires a proactive, systematic, and multidisciplinary approach. The key to a successful outcome lies in meticulous pre-operative optimization, vigilant intra-operative monitoring and management to maintain a delicate myocardial oxygen supply/demand balance, and careful post-operative care to detect and treat any complications promptly.

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