Published Online:
January 21, 2009
This is the protocol for a review and there is no abstract. The objectives are as follows:
Our main objectives are to determine:
- whether tight-glycaemic-control (TGC) through intensive insulin therapy reduces mortality and morbidity among critically ill patients (attempted or omitted);
- if myocardial protection can be enhanced by metabolic support (investigating the effects of administering glucose-insulin-potassium solutions).
We will combine studies with varying methods of insulin administration in diverse clinical settings.
- 'Normoglycaemia' has been variously defined. We will, therefore, accept the author's definition of conventional and experimental glycaemic control (conventional control being defined as intravenous insulin solely administered to those exceeding pre-determined glycaemic blood levels).
- Measurements to evaluate cardiac injury will include cardiac enzyme profiles for Creatine Kinase (creatine phosphokinase (CK-MB) found in heart muscle and troponin I, after induction of anaesthesia (base line) and 4, 6, 12 and 24 hours after initial distal coronary occlusion; as well as 12-lead electrocardiograms (ECGs).
Serial plasma non-esterified fatty acid (NEFA) concentrations will be measured preoperatively and at 1, 3, 6, 12 and 24 hours after reperfusion of the heart muscle.
Cardiac performance will be assessed using continuous cardiac output and total tissue oxygen balance, where the relationship between oxygen delivery and oxygen consumption (SVO2) varies directly with cardia output, Hb, and SaO2,, and inversely with V02 (oxygen consumption), heart rate (including reoccurrence of arrhythmias and the treatment assigned) and systemic and pulmonary artery pressures.