Monitoring of nociception: is more always more?

In this edition of the British Journal Anaesthesia (BJA), Funcke and colleagues1Funcke S. Pinnschmidt H. Brinkmann C. et al.Nociception monitor-guided opioid administration in radical retropubic prostatectomy: a randomised controlled trial.Br J Anaesth. 2020; (BJA-2020-01304-ARA036.R1 [Online ahead print])https://doi.org/10.1016/j.bja.2020.09.051Abstract Full Text PDF PubMed Scopus (5) Google Scholar describe results trial which 96 subjects were randomly assigned to have intraoperative remifentanil adjusted based on clinical judgement (control) or output one three monitors nociception: surgical pleth index (SPI), pupillary pain (PPI), nociception level (NOL). The authors found that titration PPI NOL was associated with significantly reduced dose when compared guidance by SPI judgement. fact, these used guide administration, infusion temporarily discontinued 75% 48% patients groups, respectively. also higher levels plasma stress hormones (adrenocorticotropic hormone cortisol) groups; more frequent patient movements (not statistically significant); and, consequently, doses neuromuscular blocking agents groups. Analgesia did not result any such events. None described differences had significant influence outcomes PACU. These are even remarkable those another recent publication BJA. Meijer colleagues2Meijer F. Honing M. Roor T. al.Reduced postoperative using level-guided fentanyl dosing during sevoflurane anaesthesia: 125: 1070-1078https://doi.org/10.1016/j.bja.2020.07.057Abstract (14) investigated NOL-guided versus standard opioids 50 subjects, lower less PACU after analgesia in. Within month, two studies same obtained remarkably different been published within journal. Readers seeking scientific evidence their practice might understandably be confused. However, context monitoring nociception, contradictory findings may only explained study protocols data analysis. Fundamental unknowns, as lack gold quantify consensus meaningful outcomes, best for analgesic therapy general anaesthesia, than likely obscure conclusions able draw from available trials. observed performance each ‘validated’ monitors. Unsurprisingly, quick literature search reveals multiple citations containing term ‘validation’ devices. value validation is, however, undermined fact monitor has remained an undefined process. Apart fundamental problems, trials simply prove regimes universally comparable. control group received group, resulting hormones. colleagues,2Meijer at several time points, which, end, is group. Hence, take-home message lead greater humoral response. question whether actual benefit remains unanswered. true potential well defined way devices integrated into processes. Benefits do aim replace, but assist clinician's experience. Importantly stark contrast, scenario clinicians place trust own experience fraught danger. This phenomenon known airline industry, setting frequently anaesthesia. relating over-reliance (unfamiliar) monitors, Australian Civil Aviation Safety Authority (CASA) points out introduction Global Positioning System (GPS) navigation systems resulted airplane pilots motor vehicle drivers making many grotesque errors.3Australian Government AuthorityChapter 8: human factors.2017https://www.casa.gov.au/book-page/chapter-8-human-factorsGoogle case Belgian woman meaning pick up friend Brussels, Belgium (144 km her home), being instead guided GPS Zagreb, Croatia (1300 home) without apparently raising suspicion serve extreme example. CASA familiarity device its limitations utmost importance before in-flight use. Where industry clearly appreciates dangers distraction misguidance devices, anaesthetists seem times too happy tools justified evidence. A clear expert about how validate needed. This, combined development detailed body knowledge pitfalls underlying technologies, should seen essential prerequisite prematurely embark fanciful journeys may, them farther off course. declare they no conflicts raise bias conclusions, implications, opinions stated. FvD research funding Dolosys GmbH. TL speaker honorarium travel Mediterranean Innovations, MDoloris, Philips, GE Healthcare Medasense. none aforementioned nor other third party editorial.