Anaesthesia & Non-cardiac Surgery Flashcards
Most common time for occurrence of perioperative MI in a patient undergoing non-cardiac surgery is?
24-48 hours
Type 1 MI?
Plaque rupture (spontaneous MI)
Type 2 MI?
Demand supply mismatch MI
Which is the most common type of MI in peri-operative period?
Demand supply mismatch (Type 2 MI)
Most occur within how many hours of surgery during the greatest postoperative stress?
24-48 hours
What is the mechanism of Type 1 MI?
Rupture of a coronary plaque leads to platelet aggregation and thrombus formation.
What is the mechanism of Type 2 MI?
Prolonged imbalance between myocardial O₂ supply and demand in the setting of CAD.
What is the predominant type of perioperative MI?
Type 2 MI
Plaque rupture occurs in how much of perioperative MI cases?
0.5
Plaque rupture is associated with which conditions?
STEMI, NSTEMI
What are the characteristics of unstable coronary plaques?
Sympathetic hyperactivity (increased plasma catecholamines), Hemodynamic instability (Tachycardia/Hypertension), Coronary vasoconstriction
What are the two outcomes of coronary vasoconstriction in unstable coronary plaques?
Plaque rupture, Plaque erosion
What does acute coronary thrombosis lead to?
Acute Coronary Thrombosis → ACS (Acute Coronary Syndrome) → Type I MI
What does DSMM stand for in the context of severe, yet stable CAD?
Demand Supply Mismatch
What factors increase myocardial O₂ demand in DSMM?
Sympathetic hyperactivity, Postoperative pain, Withdrawal of β-blockers, Hypovolemia, Cardiac decompensation, Systemic vasodilation, Increased heart rate/arrhythmia
What factors affect subendocardial O₂ supply in DSMM?
Hypotension, Myocardial wall stress, Coronary vasoconstriction, Anemia, Hypoxemia
What does prolonged ST-depression ischemia lead to?
Type II MI
What is the most common scoring method for risk stratification in patients undergoing non-cardiac surgery?
Revised Cardiac Risk Index (RCRI)
What are the 6 independent predictors of major cardiac complications in RCRI?
- High-risk type of surgery, 2. History of ischemic heart disease, 3. History of heart failure, 4. History of cerebrovascular disease, 5. Diabetes mellitus requiring insulin therapy, 6. Preoperative serum creatinine > 2.0 mg/dL
What are examples of high-risk types of surgery?
Vascular surgery, open intraperitoneal or intrathoracic procedures
What constitutes a history of ischemic heart disease?
History of myocardial infarction, positive exercise test, chest pain secondary to ischemia, nitrate therapy, pathological Q waves on ECG
What is a note regarding prior coronary revascularization procedures in ischemic heart disease?
Do not count prior coronary revascularization unless other criteria for ischemic heart disease are present
What symptoms and criteria indicate a history of heart failure?
Dyspnea > II, Framingham criteria, pedal edema, orthopnea, JVP
What constitutes a history of cerebrovascular disease?
TIA/Stroke
What is the criterion for diabetes mellitus requiring treatment with insulin?
DM with insulin therapy
What is the threshold for preoperative serum creatinine in RCRI?
Creatinine > 2.0 mg/dL (177 µmol/L)
Is Left Ventricular Ejection Fraction (LVEF) a predictor in RCRI?
No
What is the rate of cardiac death, nonfatal MI, and nonfatal cardiac arrest with no risk factors according to RCRI?
0.004
What is the rate of cardiac death, nonfatal MI, and nonfatal cardiac arrest with 1 risk factor according to RCRI?
0.01
What is the rate of cardiac death, nonfatal MI, and nonfatal cardiac arrest with 2 risk factors according to RCRI?
0.024
What is the rate of cardiac death, nonfatal MI, and nonfatal cardiac arrest with 3 or more risk factors according to RCRI?
0.054000000000000006
What is the rate of myocardial infarction and other events (excluding death) with no risk factors according to RCRI?
0.005
What is the rate of myocardial infarction and other events (excluding death) with 1 risk factor according to RCRI?
0.013000000000000001
What is the rate of myocardial infarction and other events (excluding death) with 2 risk factors according to RCRI?
0.036000000000000004
What is the rate of myocardial infarction and other events (excluding death) with 3 or more risk factors according to RCRI?
0.091
What are the components of the AUB-HAS2 cardiovascular risk index related to heart disease?
History of heart disease, Symptoms of heart disease (Angina or dyspnea)
What are the components of the AUB-HAS2 cardiovascular risk index related to age or anemia?
Age ≥ 75 years, Anemia (Hemoglobin < 12 mg/dl)
What types of surgery are included in the AUB-HAS2 index?
Emergency Surgery, Vascular Surgery
How does the AUB-HAS2 index stratify patients into risk groups?
Low risk (score 0-1), Intermediate risk (score 2-3), High risk (score > 3)
What makes the AUB-HAS2 index superior to the RCRI?
The AUB-HAS2 index was shown to be superior in performance to RCRI.
Who can effectively use the AUB-HAS2 cardiovascular risk index?
Busy physicians in clinics or nurses in preadmission units
What surgeries are considered high risk for cardiac events (reported cardiac risk >5%)?
Aortic and other major vascular surgery, Peripheral vascular surgery
What surgeries are considered intermediate risk for cardiac events (reported cardiac risk 1%-5%)?
Intraperitoneal and intrathoracic surgery, Carotid endarterectomy, Head and neck surgery, Orthopedic surgery, Prostate surgery
What surgeries are considered low risk for cardiac events (reported cardiac risk <1%)?
Endoscopic procedures, Superficial procedure, Cataract surgery, Breast surgery, Ambulatory surgery
What is the cardiac risk for patients undergoing non-cardiac surgery classified as high risk?
> 5%
What is the cardiac risk for patients undergoing non-cardiac surgery classified as intermediate risk?
1%-5%
What is the cardiac risk for patients undergoing non-cardiac surgery classified as low risk?
<1%
What is the risk of intraperitoneal surgery according to Braunwald/ESC?
Intermediate risk
How is intraperitoneal/intrathoracic surgery classified according to RCRI?
High risk
What surgeries are considered low risk for cardiac events (reported cardiac risk <1%)?
Superficial surgery, Breast surgery, Dental surgery, Endocrine (thyroid surgery), Eye surgery, Reconstructive surgery, Carotid asymptomatic (CEA or CAS), Gynecology (minor surgery), Orthopedic (minor, meniscectomy), Urological (minor, TURP), Endoscopic procedures, Cataract surgery
What surgeries are considered intermediate risk for cardiac events (reported cardiac risk 1%-5%)?
Intraperitoneal surgery, Splenectomy, Hiatal hernia repair, Cholecystectomy, Carotid symptomatic (CEA or CAS), Peripheral arterial angioplasty, Endovascular aneurysm repair, Head and neck surgery, Neurological or orthopedic (major, hip and spine surgery), Urological or gynecological (major), Renal transplant, Intrathoracic surgery (non-major)
What surgeries are considered high risk for cardiac events (reported cardiac risk >5%)?
Aortic and major vascular surgery, Open lower limb revascularization or amputation or thrombo-embolectomy, Duodeno-pancreatic surgery, Liver resection, bile duct surgery, Esophagectomy, Repair of perforated bowel, Adrenal resection, Total cystectomy, Pneumonectomy, Pulmonary or liver transplant
What was the effect of administering aspirin before surgery and throughout the early postsurgical period?
Had no significant effect on the rate of a composite of death or nonfatal myocardial infarction.
What trial studied the administration of aspirin before surgery and throughout the early postsurgical period?
POISE-2 trial
What is the recommendation for aspirin before surgery according to the POISE-2 trial?
Class 2a
What was the outcome of the POISE-2 trial regarding aspirin administration?
Neutral (+ve)
What was the effect of spironolactone according to the TOPCAT trial?
Significantly reduced the incidence of the primary composite in patients with heart failure and a preserved ejection fraction.
What was the outcome of the TOPCAT trial for spironolactone?
Positive (+ve)