Oesophageal Doppler monitoring: a misguided editorial

Abstract

Ghosh and colleagues raise a series of concerns regarding the guidelines from the National Institute for Health and Clinical Excellence (NICE) on the use of the oesophageal Doppler monitor (ODM) [1]. Firstly, they state the current evidence base is insufficient to justify publication of the guideline, although it has recently been added to regarding major urology surgery [2]. No guideline is perfect, and many treatments in current practice have an imperfect evidence base – one estimate is that 50% of clinical practice guidelines are opinion- rather than evidence-based [3]. The question that Ghosh et al. should address, therefore, is ‘how much evidence is enough?’ The level of evidence for the use of the ODM is greater than for high frequency oscillatory ventilation, extracorporeal membrane oxygenation, and inotropes in heart failure, not to mention other common interventions in anaesthesia and critical care. We live in an imperfect, uncertain world, and waiting for ‘perfect evidence’ risks decision-making stasis. Their second concern relates to links between industry and experts. In general, this is a valid concern, but the apparently dichotomous view that ‘industry link = bad, non-industry link = good’ is, we feel, naive. Most commentators are biased in one way or another [4, 5]. Thirdly, their view appears to be that guidelines should not be produced for specific technologies unless a similar level of information is available for competitor devices. In this case, the comparator is generally ‘current accepted practice’ rather than other cardiac output monitors. The lack of evidence from other devices is not relevant in this instance; indeed, it is consistently the case that despite NICE guidance, use of ODM or similar technologies remains low (personal observation). Such studies of other monitors against ODM are certainly valid, but we doubt that ethics committees would allow a control arm where stroke volume was not estimated and managed; equivalence studies are probably all that would be allowed. Ghosh et al. also suggest that one result of NICE guidance is an inappropriate pressure on managers and clinicians to adopt technologies and treatments. The NICE guidance documents do not state that clinicians are obliged to use ODM technology and many such innovations are routinely debated within departments. In many cases, they will choose not to follow specific recommendations for a variety of reasons. Ghosh et al. also express disbelief that a short-lived intervention can save the NHS £1100 per patient. Nevertheless, an unpublished cost analysis of our study [2] demonstrated a saving in excess of £1900 per patient. This came predominantly from a reduction in bed-days and requirement for total parenteral nutrition, due to a reduction in gastrointestinal complications and the number of long-stay patients. It does not come from a reduction in stay in every treated patient. Finally, Ghosh et al. suggest that one should simply dispense with the ODM and give all patients an extra 500 ml colloid bolus. We presume this is a deliberately tongue-in-cheek remark, rather than their belief after reading the available clinical evidence.