A randomised controlled trial of median Sternotomy versus anterolateral left Thoracotomy on morbidity and healthcare resource use in patients having off-pump coronary artery bypass surgery

The primary outcome is the time until patients are classified as ‘fit for discharge’. A patient must have a chest X-ray with no evidence of pleural effusion requiring drainage, lung collapse/consolidation or pneumothorax, no suspected infection, normal routine blood tests and temperature in order to be classified as fit for discharge. Susceptibility to bias of these components of the primary outcome will be minimised by documenting objective clinical signs and measurements.

1. Intraoperative measurement of cardiac output measured by Swan-Ganz catheter, when each distal anastomosis is being carried out on the target coronary arteries (consecutive sub-sample only, n = 40)
2. A participant’s judgement about his or her readiness for discharge when the above criteria are met (too soon, about right, could have been discharged earlier)
3. Biochemical inflammatory markers, i.e. complement activation (C3a and C5), interleukin (Interleukin 6 [IL6], Interleukin 8 [IL8] and Interleukin 10 [IL10]); these will be assessed at five time points, i.e. preoperatively, at the end of the operation, and 4, 12 and 24 hours post-operatively (consecutive sub-sample only, n = 60)
4. Alveolar/arterial gradient measured preoperatively (in the anaesthetic room), after extubation, and 1 day after extubation, from arterial blood samples taken through an existing arterial line 5 minutes after administering oxygen by mask, for each of three different oxygen concentrations (consecutive sub-sample only, n = 40)
5. Pulmonary function tests (PFTs) preoperatively and at discharge
6. Pain score measured with a 10 cm (0 to 100 mm) visual analogue scale, or by verbal response (0 to 100) if a participant is not well enough to use the visual analogue scale at 2, 12, 24 and 36 hours after extubation and on discharge
7. The total amount (volume and dose) of local anaesthetic (paravertebral block) and patient-controlled analgesia administered; post-operative days on which paracetamol and non-steroidal anti-inflammatory drugs were dispensed
8. Intensive Care Unit (ICU) and post-operative hospital stay
9. In-hospital mortality and other standard measures of morbidity, e.g. post-operative myocardial infarction (MI), stroke, arrhythmia, need for haemodynamic support, renal failure and wound infection
10. Use of healthcare resources and associated costs, e.g. duration of operation, ICU/High Dependancy Unit (HDU) and ward stay, additional interventions to treat complications, readmissions
11. Coronary Revascularisation Outcome Questionnaire (CROQ) preoperatively (preoperative version) and at 3 months (postoperative version)