Does haemodynamic optimisation, as guided by Oesophageal Doppler Monitoring, produce a greater reduction in complications and length of stay, if used intra-operatively, post-operatively or both?

INTERVENTION: This will be a pilot study that will investigate/compare fluid optimisation of adult patients at different stages of their surgical experience. There will be three groups in the study: 1. Intra‐operative fluid optimisation as guided by ODM. 2. Post‐operative fluid optimisation as guided by ODM (until extubation/weaned off the ventilator). 3. Combined Intra and Post‐operative fluid optimisation as guided by ODM (until extubation). An internet and journal database search of literature on the used of ODM as a guide to fluid optimisation found that it reduces hospital stay and post‐operative complications. Most of the studies used ODM during the operation. One (involving patients having heart surgery) used ODM immediately after the operation. Therefore it would appear valid to investigate which provides the best outcome in terms of reduced hospital stay or whether a greater benefit is obtained by a combination of the two. The primary objective is to compare the three groups to see which one produces the best result in reducing length of hospital stay. The secondary objective is to compare post‐operative complications, specifically that of post‐operative nausea, arrhythmias and renal complications. Nausea or vomiting can be measured by the anti‐emetics given on the drug chart or vomiting on the fluid chart. Arrhythmias will be measured by any arrhythmia that caused haemodynamic instability and to investigate renal complications the increase in the blood creatinine and urea from routine blood results will be analysed. The Doppler probes will be inserted in theatre during surgery by a consultant anaesthetist. This will mean that the nursing staff will not be aware which group the participant is in. The participants in group one will receive standard post‐operative care when they arrive in the Intensive Care Unit (ICU). All participants will receive standard post‐operative care once they have been extubated. A flow chart will be used both during the operation and until CONDITION: Surgery: Coronary artery bypass grafting (CABG) ; Surgery ; Coronary artery bypass grafting (CABG) PRIMARY OUTCOME: Not provided at time of registration SECONDARY OUTCOME: Not provided at time of registration INCLUSION CRITERIA: Participants will be adult patients who are to undergo Coronary Artery Bypass Grafting (CABG) or valve surgery for the first time, both male and female. There will be a minimum of 21 participants in the pilot study. The small number is due to time constraints and the need for staff training. The participants will be randomly assigned to one of the three groups.