Cardiothoracic anaesthesia: Off pump
Anaesthesia for off pump surgery
- Before anastomoses
- Lines inserted by anaesthetist are the only means of givin rapid transfusion in the absence of the arteria cannula
- To maintain CO when the heart is position, patients are actively hydrated in the anaesthetic room
- Heparin is given at a lower dose 100-300Units/kg iv
- ST segment changes are very useful monitoring adjuncts
- Warming blankets are essential to maintaining temperature and re-warming
- During anastomoses
- Intracoronary shunts helps reduce myocardial ischaemia whilst performing distal anastomoses
- Intraoperative TOE allows assessment of whether the heart is able to tolerate particular positions
- Inotropic support is frequently needed for distal anastomoses
- Systemic pressure needs to be higher as displacement of the heart results in reduced cardiac output
- Tachycardia makes distal anastomoses more difficult
- Blood pressure and CO should return to the baseline between anastomoses
- Reduced ventilation during anastomoses can optimise surgical exposure (esp. OM vessels)
- After anastomoses
- Patients can be extubated earlier (if not bleeding, normothermic, not acidotic, adequately ventilating)
- Not all surgeons reverse heparinisation with protamine
- Adequate analgesia is important
- Post-operative acidosis develops (?mechanism related to intraoperative low cardiac output state)
- Patients are frequently hypothermic
