We thank Fortin et al. for the letter to the editor related to our recently published article.1 We fully agree with their statements and we would like to thank them for seconding our main message: continuous noninvasive blood pressure monitoring systems are generating a lot of interest in our community and there is currently no accepted standard way to evaluate the clinical performance of these systems. We, in our meta-analysis, used the Association for the Advancement of Medical Instrumentation standards2 only because it was cited by 15 of the 28 articles included. We fully acknowledged that this is probably a misleading way to analyze these systems but we wanted to stress this point to generate discussions and provoke some changes/improvements. Even more interesting to us is the fact that studies citing the Association for the Advancement of Medical Instrumentation standards did not subsequently follow them. Here again, we agree with Fortin et al.
We believe that the next actions should be undertaken to move the field forward:
Standards are needed for the evaluation of continuous noninvasive blood pressure monitoring systems.
These standards should probably define separate benchmarks for systolic, diastolic, and mean arterial pressure. Because systolic, diastolic, and mean arterial pressure are inherently different by nature, different acceptability threshold should be applied.
These standards should probably develop a methodology for assessing the trending ability of these systems. Because these systems will be used as continuous monitors in the clinical setting, their trending ability is as important as their instantaneous accuracy.
When such standards exist, clinician scientists should follow them carefully when conducting clinical studies testing these systems.
In conclusion, we would like to thank Fortin et al. for echoing our main message and reinforcing it. We truly believe that the development and validation of this next generation of blood pressure monitoring systems is promising, but will require close collaboration between industry, clinician scientist, and regulatory agencies to make them beneficial to our patients.
Maxime Cannesson is a consultant for Edwards Lifesciences (Irvine, California), Covidien (Boulder, Colorado), Masimo Corp. (Irvine, California), ConMed (Irvine, California), and Philips Medical System (Suresnes, France). A Nexfin monitor (BMEYE B.V., Amsterdam, The Netherlands) and a CNAP monitor (CNSystems, Graz, Austria) were loaned to Maxime Cannesson and his research team in 2010. Maxime Cannesson publicly endorsed the Nexfin technology in a BMEYE newsletter. The other authors declare no competing interests.