Using millers, barasch and morgan anaesthesiology books discuss in complete detail about Anaesthetic management, classification, scores, patho physiology, diagnosis, pre op, intra op and post op management and treatment in IHD(ischemic heart disease) patients

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Anaesthetic Management of Ischemic Heart Disease (IHD)

A Comprehensive Review from Miller's Anesthesia (10e), Morgan & Mikhail's Clinical Anesthesiology (7e), and Barash's Clinical Anesthesia (9e)

1. EPIDEMIOLOGY AND OVERVIEW

Ischemic heart disease (IHD) affects approximately 20.1 million adults in the United States and 197 million people worldwide. It accounts for ~365,000 deaths annually in the US and 9 million deaths worldwide. In the perioperative context, IHD is the single most important risk factor for major adverse cardiac events (MACE) - including myocardial infarction, sudden cardiac death, and postoperative death.

Miller's Anesthesia, 10e, p. 3869

The overall incidence of coronary artery disease (CAD) in surgical patients is estimated at 5-10%. CAD is responsible for about 25% of all deaths in Western societies and is a major cause of perioperative morbidity and mortality.

Morgan & Mikhail's Clinical Anesthesiology, 7e, p. 725

2. PATHOPHYSIOLOGY OF MYOCARDIAL ISCHEMIA

2a. Core Mechanism: Oxygen Supply-Demand Imbalance

Ischemia results when metabolic oxygen demand exceeds oxygen supply to the myocardium. This can result from:

Increased myocardial metabolic demand
Reduced myocardial oxygen delivery
A combination of both

(Morgan & Mikhail, p. 725)

2b. Determinants of Myocardial Oxygen Supply

The key components, as detailed in Miller's Anesthesia (p. 7585-7586):

Factor	Detail
Coronary perfusion pressure	Aortic diastolic BP minus LV end-diastolic pressure (LVEDP). Elevated LVEDP impedes subendocardial blood flow
Duration of diastole	70-80% of coronary blood flow occurs in diastole. Tachycardia dramatically reduces diastolic time, hence oxygen supply
Arterial oxygen content	Hemoglobin concentration, SpO2, and oxyhemoglobin dissociation curve position
Coronary vascular resistance	Autoregulatory; distal to a stenosis, vessels are maximally dilated

2c. Determinants of Myocardial Oxygen Demand

Heart rate (most important - doubles as a supply determinant)
Contractility (inotropy)
Wall tension = Preload (LVEDP/EDV) + Afterload (systemic vascular resistance/BP)

2d. Causes of Ischemia

Most common: Atherosclerotic CAD (plaque causing stenosis >70% critical)
Coronary thrombosis or vasospasm (Prinzmetal's angina)
Severe hypertension or tachycardia (especially with LV hypertrophy)
Severe hypotension, hypoxemia, or anemia
Severe aortic stenosis or regurgitation (can cause ischemia without significant coronary occlusion)

(Morgan & Mikhail, p. 725)

2e. Perioperative Mechanisms of Myocardial Injury (Barash's, p. 443-444)

In noncardiac surgery, perioperative myocardial infarction (PMI) occurs via two distinct mechanisms:

Coronary plaque rupture with subsequent thrombosis - triggered by catecholamine surges, proinflammatory and prothrombotic perioperative states
Myocardial oxygen supply-demand imbalance - tachycardia, hypotension, anemia, hypertension

Additionally, inflammatory biomarkers play roles: genetic polymorphisms in IL-6, ICAM-1, E-selectin, TNF-alpha, and MBL2 influence susceptibility to perioperative cardiac injury. The incidence of PMI after cardiovascular surgery is 7-19% despite modern techniques.

3. CLASSIFICATION OF IHD / ANGINA

3a. Clinical Forms of IHD

Stable Angina (Chronic Coronary Syndrome)

Substernal, exertional chest pain/pressure radiating to neck or arm
Relieved by rest or nitroglycerin within 2-5 minutes
Fixed atherosclerotic stenosis >70% of luminal diameter
Nonexertional and silent ischemia are common, especially postoperatively
Patients with diabetes have increased incidence of silent ischemia

Unstable Angina / NSTE-ACS

Unstable angina is defined by ANY of the following (Morgan & Mikhail, p. 725):

Abrupt increase in severity, frequency (>3 episodes/day), or duration of anginal attacks (crescendo angina)
Angina at rest
New onset of angina within past 2 months with severe/frequent episodes (>3/day)

Unstable angina often reflects severe underlying CAD; critical stenosis in one or more major coronary arteries is present in >80% of cases. Plaque disruption, platelet aggregates/thrombi, and vasospasm are pathological correlates.

3b. Canadian Cardiovascular Society (CCS) Angina Classification

The CCS grading scale classifies functional limitation due to angina (Miller's, p. 3871):

Class	Description
CCS I	No angina with ordinary activity (walking, stairs). Angina only with strenuous, rapid, or prolonged exertion
CCS II	Slight limitation of ordinary activity. No angina walking >2 blocks on level ground or climbing >1 flight at normal pace. Angina precipitated by faster walking, inclines, cold, stress, post-meals
CCS III	Marked limitation of ordinary activity. Angina walking 1-2 blocks on level ground or 1 flight of stairs at normal pace
CCS IV	Inability to carry on any physical activity without discomfort. Angina may be present at rest

Perioperative Significance: CCS III-IV angina, or angina occurring at effort levels less than walking 1-2 blocks or climbing 1 flight, within 6 months preceding surgery, carries elevated 30-day postoperative mortality risk.

4. PERIOPERATIVE RISK SCORES AND CLASSIFICATION SYSTEMS

4a. Revised Cardiac Risk Index (RCRI) - Lee Index

The RCRI is the most widely recommended and validated preoperative cardiac risk tool (Miller's, p. 3884):

Component	Points
High-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular)	1
Ischemic heart disease (by any diagnostic criteria)	1
History of congestive heart failure	1
History of cerebrovascular disease	1
Diabetes mellitus requiring insulin	1
Creatinine >2.0 mg/dL (176 μmol/L)	1

RCRI Score	Risk of Major Cardiac Events*
0	1.6%
1	4.0%
2	7.9%
≥3	12.9%

*Defined as cardiac death, nonfatal MI, or nonfatal cardiac arrest (VISION Study, Roshanov et al., 2021)

The 2014 ACC/AHA, 2017 CCS, and 2022 ESC guidelines all recommend the RCRI. The ESC additionally recommends the ACS NSQIP risk calculator and Gupta MICA calculator.

4b. Surgical Risk Classification (2022 ESC Guidelines)

(Miller's, p. 3884-3885)

Low Cardiac Risk (<1% MACE)

Breast, dental, thyroid, eye, minor gynecological, minor orthopedic (meniscectomy), superficial surgery, minor urologic (TURP), minimally invasive minor lung resection

Intermediate Cardiac Risk (1-5% MACE)

Asymptomatic carotid surgery, endovascular AAA repair, head/neck surgery, hiatal hernia repair, cholecystectomy, splenectomy, non-major intrathoracic, major neurological/orthopedic (joint replacement, spine), peripheral arterial angioplasty, renal transplant, major urologic/gynecologic surgery

High Cardiac Risk (>5% MACE)

Adrenal resection, aortic/major vascular surgery, symptomatic carotid surgery, duodenal-pancreatic surgery, liver resection, esophagectomy, perforated bowel repair, open lower limb revascularization, pneumonectomy, liver transplant, lung transplant, total cystectomy

4c. Functional Capacity Assessment (METs)

Metabolic Equivalent Tasks (METs) are used to assess functional capacity:

≥10 METs: Excellent (swimming, running)
7-10 METs: Good (heavy housework, golf)
4-7 METs: Moderate (climbing stairs, light housework)
<4 METs (1-2 flights of stairs, walking on level ground): Poor - associated with increased perioperative risk

Poor functional capacity (<4 METs) triggers consideration for further noninvasive stress testing before intermediate or high-risk surgery.

4d. Cardiac Biomarkers for Risk Stratification (Miller's, p. 3886-3888)

BNP / NT-proBNP: Elevated preoperative levels predict postoperative cardiovascular events. CCS guidelines recommend natriuretic peptides; ESC recommends both natriuretic peptides AND high-sensitivity troponins
High-sensitivity troponin T: ~20-25% of inpatient noncardiac surgery patients have preoperative hsTnT above the 99th percentile. A preoperative hsTnT >14 ng/L is associated with elevated risk of death and cardiovascular complications after major noncardiac surgery. Also useful as a baseline for postoperative comparison

5. DIAGNOSIS AND INVESTIGATIONS

5a. History and Symptoms

Assess chest discomfort (pain, pressure, tightness) with respect to:

Duration, precipitating factors, associated symptoms, relieving factors
CCS angina class (I-IV)
Exertional dyspnea (may be an angina equivalent or reflect heart failure/deconditioning)
Prior MI, coronary revascularization (CABG/PCI) and its timing
Current medications: beta-blockers, statins, nitrates, antiplatelets, ACE inhibitors/ARBs, calcium channel blockers

Risk factors to document: hyperlipidemia, hypertension, diabetes, cigarette smoking, increasing age, male sex, positive family history, obesity, cerebrovascular/peripheral vascular disease, sedentary lifestyle.

(Miller's, p. 3870-3871)

5b. ECG Indications

Indicated for: patients with IHD, risk factors for IHD, age ≥65 years - especially before intermediate or high-risk procedures
NOT routinely indicated for low-risk surgery or asymptomatic patients without cardiovascular disease
A previous ECG from within 3 months is adequate if no intervening clinical change
Baseline ECG is valuable for postoperative comparison
Specific abnormalities (BBB, LVH, ST changes) increase perioperative concern

(Miller's, p. 3872)

5c. Echocardiography

Transthoracic echo (TTE): Class I recommendation for evaluation of suspected valvular heart disease; also assesses LV function (EF), regional wall motion abnormalities
Perioperative TEE: Emergency use in hemodynamically unstable patients is supported (ACC/AHA Class IIa, LOE B)
Wall motion abnormalities on echo are more sensitive than ECG for detecting ischemia

5d. Stress Testing

Noninvasive cardiac testing is considered when:

Functional capacity is poor (<4 METs)
RCRI ≥ 2 with intermediate or high-risk surgery
Results would change management

Types:

Exercise ECG: Useful if patient can exercise
Stress echo: Dobutamine stress echocardiography (DSE) - preferred when ECG is uninterpretable
Myocardial perfusion imaging (MPI): Nuclear medicine; thallium or technetium-based; detects reversible vs. fixed defects
Cardiac MRI: High-resolution assessment of perfusion and function

5e. Coronary Angiography

The gold standard for anatomical delineation of CAD. Indicated preoperatively only when revascularization is planned regardless of the need for surgery. Revascularization before elective noncardiac surgery is NOT recommended simply to reduce perioperative risk unless it would be indicated on independent grounds.

6. PREOPERATIVE MANAGEMENT

6a. Risk Assessment Algorithm

The 2014 ACC/AHA, 2017 CCS, and 2022 ESC guidelines all share a common algorithmic approach:

Step 1: Assess urgency of surgery

Emergency surgery (<6 hours): Proceed directly to OR; postoperative surveillance with serial ECGs, enzymes, hemodynamic monitoring
Urgent surgery (6-24 hours): Proceed with perioperative risk mitigation
Time-sensitive surgery (1-6 week delay would affect outcomes - e.g., cancer): Individualize risk vs. delay
Elective surgery: Full preoperative assessment

Step 2: Active cardiac conditions Defer elective surgery and treat first:

Acute MI (<30 days) or recent MI with ongoing ischemia
Unstable or severe angina (CCS III-IV at rest)
Decompensated heart failure
Significant arrhythmias (Mobitz II/III AV block, symptomatic VT)
Severe valvular disease (severe AS or symptomatic MS)

Step 3: Surgical risk

Low risk (<1% MACE): Proceed without further testing
Intermediate/high risk: Proceed to functional capacity assessment

Step 4: Functional capacity

Moderate-excellent (≥4 METs without symptoms): Proceed with surgery
Poor (<4 METs) or indeterminate: Consider pharmacological stress testing if results would change management

(Miller's, p. 3873-3874)

6b. Timing After Myocardial Infarction

One of the most important decisions in preoperative management:

Recent MI dramatically increases perioperative risk
Current ACC/AHA guidelines recommend deferring elective noncardiac surgery for at least 60 days after a STEMI or NSTEMI
After PCI with bare metal stent (BMS): delay at least 30 days (preferably 3 months) before stopping aspirin + P2Y12
After PCI with drug-eluting stent (DES): delay at least 6 months (ideally 12 months) before elective surgery while on dual antiplatelet therapy

6c. Preoperative Medications

Continue perioperatively (do NOT withdraw acutely):

Beta-blockers: Abrupt withdrawal precipitates rebound increase in ischemic episodes, tachycardia. Must be continued. However, do NOT acutely START new beta-blocker therapy in patients not previously on them - evidence shows increased risk of stroke and death when newly initiated perioperatively (Morgan & Mikhail, p. 732)
Statins: Must be continued perioperatively. Acute perioperative withdrawal is harmful - associated with increased cardiovascular events
Nitrates (long-term therapy): Continue if on chronic nitrate therapy. Prophylactic IV/transdermal nitroglycerin in patients NOT on chronic nitrates provides no benefit (Morgan & Mikhail, p. 2196)
Aspirin: Generally continue for most surgical procedures. Stop only if bleeding risk is unacceptably high (e.g., intracranial surgery, posterior eye surgery)
ACE inhibitors/ARBs: Variable recommendations - many guidelines suggest holding on the morning of surgery to reduce risk of intraoperative hypotension, particularly for elective noncardiac surgery
Calcium channel blockers: Continue

Review carefully:

P2Y12 inhibitors (clopidogrel, prasugrel, ticagrelor): Timing of discontinuation depends on surgery type and stent type. Stopping early increases stent thrombosis risk; continuing increases bleeding. Cardiologist consultation mandatory

6d. Premedication

Allaying fear, anxiety, and pain preoperatively is critical - sympathetic activation adversely affects the myocardial oxygen supply-demand balance. Small doses of IV midazolam immediately before procedures or transport to the OR is the standard approach.

Avoid overmedication (hypoxemia, respiratory acidosis, hypotension are all harmful).

(Morgan & Mikhail, p. 2194)

7. INTRAOPERATIVE MANAGEMENT

7a. Goals and Priorities

The overarching intraoperative goal is maintaining a favorable myocardial oxygen supply-demand balance (Morgan & Mikhail, p. 739):

Target	Approach
Heart rate	50-70 bpm ideal; avoid tachycardia (reduces diastolic time and increases demand); use beta-blockers, adequate depth
Blood pressure	Avoid hypotension (reduces CPP) and hypertension (increases demand); maintain diastolic BP to perfuse coronary arteries, especially with high-grade stenoses
LVEDP/Preload	Avoid excessive volume loading (raises LVEDP, reduces subendocardial perfusion)
Hemoglobin	Most clinicians reluctant to allow Hb <7 g/dL in CAD patients; no fixed transfusion trigger but anemia worsens supply-demand
SpO2/PaO2	Maintain adequate oxygenation

7b. Choice of Anesthetic Technique

General vs. Regional Anesthesia:

No definitive evidence that one technique is superior for IHD patients

ACC/AHA Recommendations (Morgan & Mikhail, p. 740):

Recommendation	Class	LOE
Use of either volatile anesthetic or TIVA is reasonable for noncardiac surgery	IIa	A
Neuraxial anesthesia for postoperative pain relief can reduce MI in abdominal aortic surgery	IIa	B
Preoperative epidural analgesia may be considered to decrease preoperative cardiac events in hip fracture	IIb	B
Prophylactic IV nitroglycerin is NOT effective in reducing myocardial ischemia	III: No Benefit	B

Regional/Neuraxial Anesthesia Considerations:

Epidural anesthesia reduces stress response, catecholamine surges, and hypercoagulability
Particularly beneficial for high-risk vascular and abdominal aortic surgery
Hypotension from sympathetic blockade must be promptly treated (reduces coronary perfusion pressure)

7c. Specific Anesthetic Agents

Volatile Anesthetic Agents:

Isoflurane, sevoflurane, desflurane provide "anesthetic preconditioning" (mimics ischemic preconditioning)
Dose-dependent vasodilation and myocardial depression require careful titration
Coronary vasodilation with volatile agents: isoflurane was historically implicated in "coronary steal" but clinical significance is debated at modern doses
Desflurane: may cause tachycardia and sympathetic activation during induction - avoid rapid increases in concentration

Opioids:

Fentanyl, sufentanil, remifentanil: cardiostable, reduce sympathetic response to laryngoscopy and surgery; preferred in high-risk IHD
High-dose opioid technique historically used for cardiac surgery (blunts stress response)
Remifentanil infusion: excellent control of HR and BP, but context-sensitive half-life requires transition to longer-acting analgesia

Induction Agents:

Propofol: Vasodilation and mild myocardial depression; can cause significant hypotension - use cautiously and slowly in IHD; titrate dose
Etomidate: Minimal cardiovascular effects; preferred for hemodynamically unstable patients; suppresses adrenal function with repeated doses
Ketamine: Increases HR, BP, and myocardial oxygen demand - generally avoided in IHD unless patient is hypotensive/shocked (catecholamine-depleted state)

Neuromuscular Blocking Agents:

Pancuronium: vagolytic - causes tachycardia; avoid in IHD
Vecuronium, rocuronium, cisatracurium: relatively cardiostable; preferred

Vasopressors/Vasoactive Drugs:

Phenylephrine: pure alpha-1 agonist; raises BP via vasoconstriction; can cause reflex bradycardia - useful for hypotension without tachycardia
Norepinephrine: alpha + beta; good for maintaining CPP in severe hypotension
Vasopressin: useful in refractory vasodilatory shock
Nitroglycerin (IV): indicated for treatment of intraoperative ischemia, hypertension, or coronary vasospasm; reduces preload and coronary vasodilation; NOT recommended as prophylaxis
Esmolol: ultra-short acting IV beta-blocker; ideal for treating intraoperative tachycardia/hypertension

7d. Intraoperative Monitoring

Standard (all IHD patients):

5-lead ECG with ST-segment analysis (II + V5): Lead V5 alone detects ~75% of ischemic episodes; adding II increases sensitivity to 80%; II + V4 + V5 gives 96% sensitivity
Continuous SpO2, capnography, temperature
Invasive arterial line: recommended for major/high-risk surgery in IHD patients (beat-to-beat BP monitoring, arterial blood gases)

Advanced Monitoring:

Central venous pressure (CVP): limited accuracy as LV preload surrogate
Pulmonary artery catheter (PAC): considered for patients with poor LV function, pulmonary hypertension, or major hemodynamic instability. Contentious - no proven mortality benefit but provides filling pressures and CO data
Transesophageal Echocardiography (TEE): Emergency use in hemodynamically unstable patients - Class IIa, LOE B. Regional wall motion abnormalities appear earlier than ECG changes in ischemia; most sensitive intraoperative ischemia monitor. Assesses volume status, wall motion, valvular function in real-time
BIS/depth of anesthesia monitoring: avoids awareness and prevents excessive depth (which causes hypotension) or light depth (which causes hypertension/tachycardia)

(Morgan & Mikhail, p. 740)

7e. Hemodynamic Management

Key Hemodynamic Events to Prevent:

Event	Why Harmful	Management
Tachycardia (HR >100)	Reduces diastolic time, increases O2 demand	Esmolol IV bolus (0.5 mg/kg) or infusion; deepen anesthesia
Hypertension (SBP >20% above baseline)	Increases wall stress and O2 demand	Deepen anesthesia, nitroglycerin, labetalol, esmolol
Hypotension (SBP <20% below baseline)	Reduces CPP (especially diastolic BP)	Phenylephrine, norepinephrine, reduce volatile agent, optimize volume
Bradycardia	Reduces CO and potentially increases filling pressures	Atropine, glycopyrrolate; reduce beta-blockade if excessive

Critical rule: In patients with high-grade coronary occlusions, higher diastolic pressures may be preferred to maintain adequate coronary perfusion.

(Morgan & Mikhail, p. 739)

7f. Airway Management in IHD

Laryngoscopy/intubation is a major sympathetic stimulus - attenuate with:
- Adequate depth of anesthesia at induction
- IV lidocaine (1.5 mg/kg) or fentanyl (2-3 mcg/kg) before laryngoscopy
- IV beta-blocker (esmolol or metoprolol) pre-induction if anticipated difficult/prolonged laryngoscopy
- Minimize laryngoscopy duration

8. SPECIFIC SCENARIOS AND TREATMENT

8a. Intraoperative Ischemia Detection and Treatment

Diagnostic Criteria:

ECG: New ST depression >1 mm horizontal or downsloping, or ST elevation >1 mm in 2 contiguous leads
New regional wall motion abnormalities on TEE (more sensitive than ECG)
Hemodynamic changes (new hypotension, new arrhythmias)

Treatment Protocol:

Verify and increase FiO2 to 1.0
Check and correct hemoglobin (transfuse if <7-8 g/dL with active ischemia)
Treat tachycardia first: IV esmolol (0.5 mg/kg bolus) or metoprolol (2.5-5 mg IV)
Treat hypertension: IV nitroglycerin 50-100 mcg bolus; isosorbide dinitrate
Treat hypotension: Phenylephrine or norepinephrine; reduce volatile agent
IV nitroglycerin infusion (0.5-5 mcg/kg/min) for sustained ischemia or coronary vasospasm
Notify surgeon - consider whether to abort or expedite surgery
Emergent cardiology consultation if ischemia persists
Post-procedure: serial 12-lead ECGs, troponins, echocardiography

8b. IHD Patients for Cardiac Surgery (CABG)

(Miller's, p. 7587)

Preoperative assessment for CABG should document:

Coronary artery anatomy: left main stenosis, proximal LAD disease, triple-vessel disease
LV function: EF (assessed by angiography or echo)
Concurrent valvular abnormalities (MR, AS, AI, ASD, VSD)

On-pump CABG (Cardiopulmonary Bypass):

Myocardial protection strategies: cardioplegia, hypothermia, venting
Vigilant monitoring of ischemia during aortic cross-clamping and reperfusion
Management of systemic inflammatory response from CPB

Off-pump CABG:

Avoids CPB-related complications but requires careful hemodynamic management during coronary positioning
Heparin still required; TEE monitoring essential

8c. Perioperative Antiplatelet Management in PCI Patients

Bare metal stent (BMS): Minimum 30 days of DAPT (aspirin + P2Y12) required to prevent stent thrombosis; ideally 3 months before elective surgery
Drug-eluting stent (DES): Minimum 6 months DAPT; ideally 12 months
Bridge therapy: No proven benefit with IV antiplatelet agents (eptifibatide, tirofiban) for perioperative bridging
If surgery MUST proceed while on DAPT (e.g., bleeding emergency): continue aspirin, stop P2Y12 5-7 days before surgery (clopidogrel), 7 days (prasugrel), or 3-5 days (ticagrelor)
Cardiology/surgeon collaboration is mandatory

9. POSTOPERATIVE MANAGEMENT

9a. Priority of Postoperative Period

The early postoperative period carries high risk because:

Catecholamine surges from pain, hypothermia, and emergence agitation
Hypercoagulable state (increased thromboxane, decreased fibrinolysis)
Fluid shifts and anemia
Intermittent hypoxemia (atelectasis, hypoventilation, OSA)
Sympathetic activation causing tachycardia

9b. Postoperative Monitoring

Surveillance for MACE:

Serial 12-lead ECGs at 24 and 48 hours (or immediately if symptoms arise)
Serial high-sensitivity troponin I or T measurements at baseline (preop), 24h, 48h postoperatively for high-risk patients or those with high RCRI
Continuous ECG telemetry monitoring for the first 24-48 hours in intermediate/high-risk patients
In patients with preoperative troponin elevation, postoperative values must be compared to the established baseline

Key Point from Miller's (p. 3887): Comparing postoperative troponin to preoperative baseline is essential - a preoperative hsTnT measurement prevents misclassification of chronic elevation as acute injury.

9c. Myocardial Injury After Non-cardiac Surgery (MINS)

MINS is defined as troponin elevation (hsTnT ≥65 ng/L, OR a delta of ≥5 ng/L if baseline was elevated) in the postoperative period - even without symptoms or ECG changes. MINS carries a significant mortality risk (~10% at 30 days) and requires:

Cardiology consultation
Optimization of antiplatelet and anticoagulant therapy
Assessment with echo/imaging
Aspirin and statin therapy initiation if not already present

9d. Analgesia and Pain Management

Pain control is paramount - inadequately treated pain causes:

Tachycardia and hypertension (increases O2 demand)
Splinting (atelectasis, hypoxemia)
Hypercoagulability

Preferred approaches:

Neuraxial (epidural) analgesia: Particularly effective for abdominal aortic surgery (Class IIa, LOE B per ACC/AHA); provides excellent analgesia, reduces stress response, sympathetic block may decrease cardiac events
Multimodal analgesia: Combining paracetamol + NSAIDs (use with caution - NSAIDs have cardiovascular risks in IHD) + opioids + regional techniques
IV opioids (PCA) when neuraxial not feasible
Avoid NSAIDs (especially COX-2 inhibitors) in high-risk IHD patients - associated with increased MI risk

9e. Hemodynamic Control Postoperatively

Hypertension: Common postoperatively (pain, anxiety, fluid overload, bladder distension, hypothermia). IV labetalol is particularly useful (controls HR + BP). Vasodilators useful if bradycardic. Restart oral antihypertensives as soon as oral intake resumes (Morgan & Mikhail, p. 1966)
Hypotension: Assess and treat cause (bleeding, cardiac tamponade, PE, hypovolemia, vasodilation); optimize volume status
Tachycardia: IV esmolol or metoprolol; treat underlying cause (pain, fever, hypovolemia)

9f. Resumption of Medications Postoperatively

Medication	Postoperative Action
Beta-blockers	Resume immediately when oral intake/NG access available - do NOT miss doses
Statins	Resume as soon as oral intake possible
Aspirin	Resume within 24 hours if bleeding risk acceptable
P2Y12 inhibitors	Resume as per stent-specific protocol (cardiologist guidance)
ACE inhibitor/ARB	Resume when hemodynamically stable and renal function acceptable
Nitrates	Resume if on chronic therapy

9g. Treatment of Postoperative Myocardial Infarction

If postoperative MI is confirmed:

STEMI: Emergency coronary angiography/PCI as rapidly as possible (surgical bleeding risk must be carefully weighed). Thrombolytics generally contraindicated in early postoperative period
NSTEMI/MINS: Aspirin + anticoagulation (heparin - weigh bleeding risk), beta-blockers, statins; cardiology-guided decision re: early invasive strategy vs. conservative management
Continuous ECG monitoring, ICU care
Treat complications: arrhythmias, acute HF, cardiogenic shock

Cardiogenic Shock Management:

Vasopressors: norepinephrine (first-line for MAP support)
Inotropes: dobutamine for impaired contractility
Intra-aortic balloon pump (IABP): reduces afterload, increases diastolic BP and coronary perfusion
Emergent revascularization when feasible

10. LONG-TERM MEDICAL THERAPY FOR IHD (Perioperatively Relevant)

(Miller's, p. 3869)

Drug Class	Agents	Mechanism	Perioperative Role
Antiplatelet	Aspirin, P2Y12 inhibitors (clopidogrel, ticagrelor, prasugrel)	Reduce thrombotic events	Continue vs. hold based on stent timing and bleeding risk
Beta-blockers	Metoprolol, atenolol, carvedilol, esmolol	Reduce HR and myocardial O2 demand	Continue; do not acutely start or withdraw
Statins	Atorvastatin, rosuvastatin	Plaque stabilization, lipid reduction, anti-inflammatory	Continue throughout; do not withdraw
RAAS inhibitors	ACE inhibitors, ARBs	Reduce wall stress, prevent remodeling	Hold morning of surgery to prevent hypotension; resume postop
Nitrates	Isosorbide mononitrate/dinitrate, GTN	Venodilation, coronary dilation	Continue if on chronic therapy; not for prophylaxis
Calcium channel blockers	Amlodipine, diltiazem, verapamil	Reduce afterload, HR (non-DHP); coronary vasodilation	Continue
Newer therapies	Canakinumab (anti-IL-1β), low-dose rivaroxaban, PCSK9 inhibitors	Anti-inflammatory, antithrombotic, LDL reduction	Growing role; increasingly perioperative relevant

11. SUMMARY TABLE: ANAESTHETIC MANAGEMENT OF IHD

Phase	Key Goals	Key Actions
Preoperative	Risk stratify; optimize; plan	RCRI score; assess CCS class; ECG; echo if EF unknown; continue beta-blockers/statins; hold ACEi day of surgery; ensure adequate antiplatelet timeline for stents; stress test if <4 METs + intermediate-high risk surgery
Induction	Attenuate sympathetic response	Slow IV induction (propofol or etomidate); opioid pre-laryngoscopy (fentanyl 2-3 mcg/kg); lidocaine 1.5 mg/kg; esmolol for predicted difficult airway; avoid ketamine in stable IHD
Maintenance	O2 supply-demand balance	5-lead ST monitoring; volatile agents (preconditioning benefit); titrate depth; keep HR 50-70, MAP within 20% of baseline; avoid tachycardia >100 bpm; have nitroglycerin and esmolol ready
Emergence	Minimize hemodynamic swings	Extubate with adequate analgesia; treat hypertension (labetalol/esmolol); smooth emergence; avoid coughing/straining
Postoperative	Detect and treat MACE; optimal analgesia	Serial ECG/troponins (24h, 48h); resume all cardiac medications; multimodal analgesia; neuraxial preferred for major abdominal/vascular; ICU monitoring for high-risk patients

Sources:

Miller's Anesthesia, 2-Volume Set, 10th Edition - pp. 3869-3888, 7585-7588
Morgan & Mikhail's Clinical Anesthesiology, 7th Edition - pp. 725-740, 1966-2196
Barash, Cullen & Stoelting's Clinical Anesthesia, 9th Edition - pp. 443-445

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