CABG anaesthesia: on-pump and off-pump

Model answer

Core facts. Reproduce exact surveyed numbers: heparin 300 IU/kg modal with ACT 400 or 480 s, protamine 1:1 commonest surveyed ratio, CPB flows 2.2–2.5 L/min/m² and MAP 50–80 mmHg where relevant (flows/MAP taught perfusion standard).^[4]

Topic structure. Cover preoperative risk, lesion- or technique-specific goals, intraoperative sequence, TOE role per the ASE/SCA examination guideline, and the canonical crisis: haemodynamic collapse during OPCAB heart displacement (stability during enucleation plus ischaemia during grafting) requiring conversion to CPB decided on objective targets.^[2][5][6]

Close. Disposition, ICU plan within ERAS-style pathways, restrictive transfusion restraint when bleeding is controlled (TRICS III), and common traps.^[8][1]