Comparison of the effect of two anaesthesia methods in preventing perioperative myocardial infarction in patients with cardiac risk undergoing total knee arthroplasty

we enrolled 50 patients of both sex of American society of Anesthesiologists (ASA) physical status II where the presence and/or risk for coronary artery disease (CAD) as well as planned lower extremity surgery was considered. Presence of CAD was ascertained by history of myocardial infarction and diagnosis of typical angina or atypical angina with a positive stress test & ECG finding. Risk for CAD included age (> 65 years old), hypertension, smoking habit, blood cholesterol (>240 mg/dL), and diabetes. who met the selection criteria were randomly allocated to 1 of the 2 groups (25 patients) each:

• Group (G): received general anaesthesia followed by IV patient-controlled analgesia (IV PCA).
• Group (F): received spinal anaesthesia followed by continuous ultrasound guided femoral never block once the anaesthesia-induced motor block resolved. We aimed to compare the effect of the two anaesthesia methods in preventing perioperative myocardial infarction in patients with cardiac risk undergoing total knee arthroplasty. The primary outcome included perioperative levels of brain natriuretic peptide & cardiac troponins. Secondary outcomes included postoperative operative pain assessment using visual analogue scale, total amount of analgesic consumption, patient satisfaction & cardiovascular complications (myocardial infarction, arrhythmias , heart failure, hypotension, hypertension & the need for inotropic agents).

Inclusion Criteria:

• presence and/or risk for coronary artery disease (CAD) as well as planned lower extremity surgery was considered. Presence of CAD was ascertained by history of myocardial infarction and diagnosis of typical angina or atypical angina with a positive stress test & ECG finding. Risk for CAD included age (> 65 years old), hypertension, smoking habit, blood cholesterol (>240 mg/dL), and diabetes.

Exclusion Criteria:

• 1) severe impairment of left ventricular function (ejection fraction < 40 %). 2) renal failure requiring hemodialysis. 3) known allergies to the drugs used in the present study. 4) contraindications to regional blocks (localized infection, and use of an antiplatelet drug within 3 days before the surgery). 5) unusual blood coagulation tests.