The Alfred Dept of Anaesthesia & Perioperative Medicine undertakes and coordinates a number of trials, both single centre and large multi-centre and international collaborative trials.
Some trials include:
To investigate the effectiveness of fluid restriction (vs. liberal), and the possible effect-modification of goal-directed therapy (eg. oesophageal Doppler, Flotrac®). The first will be randomly assigned; the latter will be measured covariates according to local practices and beliefs.
The optimal fluid regimen and haemodynamic (or other) targets for patients undergoing major surgery are based on rationales that are not supported by strong evidence. Practices vary substantially; guidelines are vague, small trials and meta-analyses are contradictory. The strongest and most consistent evidence, and biological plausability regarding tissue oedema, supports a restrictive fluid strategy. There is less (and more contradictory) evidence supporting goal-directed therapy using a flow-directed device and/or dopexamine, and use and choice of colloids. A large, definitive clinical trial evaluating perioperative fluid replacement in major surgery is required.
Dexamethasone is widely used by anaesthetists in the perioperative period, principally as an effective antiemetic to prevent postoperative nausea and vomiting (PONV). The molecular mechanisms underlying dexamethasone’s antiemetic action are not fully understood. However, because it is a potent glucocorticosteroid, it is has immunosuppressive and hyperglycaemia effects. It is hypothesised that these actions may increase the risk of perioperative infections, particularly in patients with diabetes mellitus, who are already at increased risk of complications. Whether the use of dexamethasone in the perioperative period increases the risk of surgical site and other infections, has not been definitively established. This is an important health priority as in Australia alone up to one million patients will receive dexamethasone as part of their anaesthesia care annually.
Monitors that use the electroencephalogram (EEG) to assess anesthetic depth in patients undergoing surgery are now widely available. General anesthesia that is performed without depth of anesthesia monitoring, tends to be relatively deep to ensure a lack of awareness. Five of six recent observational studies have shown a 20% increase in mortality in moderate or high risk patients undergoing major surgery who receive relatively deep anesthesia but this needs to be balanced against a possible increase in the risk of awareness if patients are given lower doses of anesthetic drugs. The optimal depth at which anesthetics should be administered is unknown.