Coronary bypass grafting on cardiopulmonary bypass in a patient with a low ejection fraction
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The stem
A 64-year-old man, 96 kg and 178 cm, is scheduled for coronary artery bypass grafting on cardiopulmonary bypass. Six days ago he presented with a non-ST-elevation myocardial infarction; angiography showed a 75% left main stenosis and severe three-vessel disease. He has had no chest pain since admission on a heparin infusion, which continues. The surgeon plans a left internal mammary artery to the left anterior descending artery and two vein grafts.
He has type 2 diabetes, hypertension and chronic kidney disease. Clopidogrel, loaded in the emergency department, was stopped five days ago; aspirin continues. He took his lisinopril this morning. He has never had surgery.
Medications: aspirin 81 mg, metoprolol succinate 50 mg, atorvastatin 80 mg, lisinopril 20 mg, insulin glargine 30 units nightly, heparin infusion at 1,400 units/h.
Allergies: none known.
- Blood pressure 124/72 mmHg, heart rate 64 in sinus rhythm, SpO2 96% on room air, temperature 36.7 °C
- Airway: Mallampati 2, full neck extension
- Hemoglobin 12.1 g/dL; platelets 186,000/µL on admission, 172,000 today; aPTT 74 s on heparin
- Creatinine 1.5 mg/dL; potassium 4.4 mEq/L; glucose 168 mg/dL; HbA1c 8.1%
- ECG: sinus rhythm, Q waves in V1–V3, lateral T-wave inversion
- Transthoracic echo: ejection fraction 30%, anterior and apical akinesis, moderate functional mitral regurgitation, normal right ventricle
- Chest radiograph: mild cardiomegaly, no edema