Oesophageal Doppler monitoring – the emperor's new clothes?

I wish to congratulate Dr. Morris on his editorial 1. I admire his honest views that make a lot of sense, and find myself increasingly sceptical of many things that were taught by mantra. I believe the oesophageal Doppler monitor (ODM), whilst useful to a degree 2, has been oversold as a panacea to all our ills. I did use it myself for 6–7 years but now our ODMs lie gathering dust, superceded by less ‘high-maintenance’ arterial line-based systems. No single monitor is the answer for high-risk patients, and none are any use if the anaesthetist lacks training to interpret the data. The paper by Challand et al. 3 neatly demonstrates that slavish adherence to the ODM protocol may allow the unwary practitioner to overload the circulation of colorectal surgical patients, particularly fitter ones with their compliant ventricles, and actually delay recovery of patients, with consequent increased length of stay in hospital. We have performed many studies at my institution into aspects of haemodynamic optimisation of surgical patients. The latest, currently undergoing peer review, is a double-blind comparison of hydroxyethyl starch and crystalloid in 202 moderate to high-risk colorectal patients, using stroke volume variation as the optimisation parameter, but our best results in the highest-risk patients are in those who received human albumin and pulmonary artery catheters 4. What is also becoming clear in our peri-operative practice is that there is tremendous variation in patients' risk within any given type of major surgical procedure. Using data obtained from cardiopulmonary exercise testing alone (and there is much more to that than just the anaerobic threshold), we can identify five different risk categories for colorectal surgery, with a smooth gradation in mortality from robust patients to the highest-risk group with poor functional capacity and gas exchange evidence of cardiac abnormality, in whom mortality approaches 7% despite our very best efforts. The lowest-risk group would probably do just as well with no goal-directed monitoring, whilst those at highest risk will surely benefit from the extra information that arterial and central venous (or even pulmonary artery) catheterisations offer, and the access for inotropic support that may be required. The notion that one monitoring parameter will improve the outcome of all these patients is fanciful. The good news for our specialty is that as the population gets older and surgical demands increase, the emerging complexity of individual risk assessment and appropriate tailor-made treatment will help cement our position as peri-operative physicians. I hope that the coming generations will retain the degree of equipoise that Dr. Morris calls for, and not be seduced by the ‘one drug/technique cures all’ mentality.