Coronary Artery Bypass Grafting (CABG)
Updated On: July 23, 2026
Anesthetic Approaches
Induction - the first high-stakes phase. Tachycardia raises oxygen demand and shortens diastolic filling time across stenosed coronaries; hypotension drops coronary perfusion pressure - either one can produce ischemia before the chest is open. Titrated, opioid-balanced induction with the arterial line already in place.
Lines - arterial line before induction; central line (± PA catheter per institution) for pressors and post-bypass management; large-bore IV access.
TEE - standard of care: ventricular function, valve pathology, de-airing, and post-graft assessment.
Heparin - 300-400 units/kg before cannulation, target ACT ≥480 sec. Known or suspected heparin-induced thrombocytopenia (HIT) - bivalirudin is the described alternative.
On bypass - MAP typically 50-80 mmHg. The anesthetic must continue via the oxygenator vaporizer or a propofol drip - awareness is a real risk if this handoff is missed.
Weaning from CPB - rewarm fully, optimize rhythm with pacing ready, TEE-guided volume, inotropes and pressors as ventricular function dictates.
Protamine - 1 mg per 100 units of heparin, given slowly. Rapid administration causes hypotension; watch for anaphylactoid reactions and catastrophic pulmonary hypertension.
Bleeding - post-bypass coagulopathy is common; guide products with ACT, TEG, and labs rather than empirically.
Glucose and temperature - hyperglycemia and hypothermia both worsen outcomes; actively control each.
Disposition - fast-track extubation vs sedated ICU transport per institution; transport fully monitored with pressors running.
Tucked Arms (general considerations): Consider a second IV – once the procedure has started, it's going to be VERY difficult to handle IV issues – especially if your only IV has problems. Ensure the IV is running and monitors are still functioning after tucking the patient's arms.
High Blood Loss (general considerations): Type and cross, CBC, and CMP should be done prior to the procedure. Consider having an A-line, blood tubing, and extra push-lines. Depending on the fragility of the patient, you may want to have blood in the room and available.
Long procedure (general considerations): Procedures anticipated to last longer than 2 hours generally require a urinary catheter. Also, consider checking lines and positioning regularly as the risks of infiltration and nerve damage are increased with procedure time. Consider an IV fluid warmer and a forced air warmer to keep the patient euthermic.
Arterial line (general considerations): Preoperatively check pulses to gauge the best side to attempt the A-line. Perform an Allen test to ensure adequate blood flow. Have the A-line equipment set up and ready in the room.
High Blood Loss RISK (general considerations): Though most of these cases don't result in a high blood loss, there is a high blood loss RISK. Type and cross, CBC, and CMP should be done prior to the procedure. Consider having an A-line, blood tubing, and extra IV push-lines. Depending on the fragility of the patient, you may want to have blood in the room and available.
Bispectral Index Scale (BIS) monitor (general considerations): The recommended values under general anesthesia are 40-65. Values of 65-85 are recommended for sedation.
Atherosclerotic coronary artery disease (CAD) narrows the coronary arteries until myocardial oxygen supply cannot meet demand, producing angina, ischemia, and infarction. CABG bypasses the obstructions with harvested conduits — the left internal mammary artery (LIMA) to the LAD is the gold-standard graft, supplemented by saphenous vein or radial artery grafts. Indicated for left main disease, three-vessel or complex multivessel disease (especially with diabetes or reduced EF), and anatomy unsuitable for PCI. Nearly 400,000 are performed annually, making it the most common cardiac surgical procedure in the US.
Sternotomy and conduit harvest — median sternotomy; LIMA takedown and endoscopic saphenous vein (± radial artery) harvest proceed concurrently.
Heparinization and cannulation — heparin given, then aortic and right atrial cannulation once target ACT is confirmed.
Bypass and arrest — cardiopulmonary bypass (CPB) initiated, aortic cross-clamp applied, cardioplegic arrest.
Anastomoses — distal anastomoses to the target vessels, then proximal anastomoses to the aorta.
Weaning — rewarming, de-airing, separation from CPB with pacing and inotropes as needed.
Closure — protamine reversal, hemostasis, chest tubes, sternal wires.
Off-pump variant (OPCAB) — stabilizer on the beating heart, no CPB; used selectively.
OPCAB - positioning the beating heart for lateral and posterior targets causes profound transient hypotension; treat with table position, volume, and pressors in communication with the surgeon rather than deepening the anesthetic.
Redo sternotomy - adhesions put the RV and patent grafts at risk on chest entry; have checked blood in the room and external defibrillator pads on before incision.