The manuscript by Lucci et al. investigates the impact of lidocaine lubricant on autonomic dysreflexia (AD) during at-home bowel care in individuals with spinal cord injury (SCI) [1]. This paper was discussed with great interest in our laboratory journal club that comprised of trainees, researchers, and clinicians. We found the topic to be clinically relevant and important in the care of individuals with SCI as episodes of AD can potentially lead to serious cardiovascular consequences when left untreated. Bowel care is a challenging daily routine and a common trigger for AD, and presents a serious burden to individuals with SCI.

Lucci et al. employed a strong study design as a double-blind, placebo-controlled crossover clinical trial to examine the efficacy of commonly prescribed 2% Xylocaine lubricant prior to bowel care routine. Furthermore, the investigators utilized state of the art cardiovascular monitoring in order to examine the severity of AD (continuous beat-to-beat finger blood pressure and ECG monitoring). Finally, this study was pragmatically designed to mimic the real world by not standardising bowel care routines and thus reflecting the diversity of bowel care routines found in a community setting.

However, we seek to share some methodological concerns that potentially limit the impact of this study and may inform future research.

Although the primary focus of the study was amelioration of AD, it was surprising that the primary outcome selected was not consistent with the current Paralyzed Veterans Association Clinical Practice Guidelines definition of AD, i.e. an increase of more than 20 mmHg systolic BP from baseline, as also indicated in the Autonomic Standards [2]. Based on the primary outcome measure selected in this study, “difference in systolic arterial pressure between the placebo and lidocaine conditions”, the results demonstrate significantly higher absolute systolic BP following lidocaine compared to placebo application. As such, the authors concluded “the use of lidocaine lubricant actually worsened the severity of AD during at-home bowel care”. However, looking at an outcome more consistent with the present definition of AD [2], reveals a different picture. The severity of AD (i.e. the difference between SBPmax and baseline), was not significantly different between the use of lidocaine vs. placebo (90.5 vs. 80 mmHg; p = 0.386). This raises a question whether the conclusions drawn using absolute SBPmax values and not using the clinical definition of AD (i.e. difference in SBP from baseline) are sufficient to contradict the current clinical recommendations regarding lidocaine use for bowel care. Certainly, there is ambiguity in literature evidence about the benefit of lidocaine as some reports show beneficial effects of lidocaine use [3], while contradicting evidence has also been reported [4]. However, since the authors are not proposing a change to the definition of AD, the BP results should be interpreted with caution and the study should be replicated to report the incidence of AD, as per the definition, following randomized, double-blinded, application of lidocaine compared to placebo.

Detailed quantitative analysis of cardiac arrhythmias during AD is another important observation reported in this study. However, at numerous occasions, the term ‘tending towards significance’ is used to emphasize a potential effect when p was >0.05, despite statistical significance being defined by the authors at p < 0.05. Although the attempt to link statistical ‘trend’ towards significance with potential clinical implications is appreciated, it is important to note that such unintentional interpretations may often be misleading [5].

In conclusion, although this study is an important contribution to the field as it rigorously addresses a major clinical problem which represents a crucial quality of life issue for individuals with SCI, we find the data insufficient, and conclusions inadequate for contradicting the current recommendations of lidocaine use during routine bowel care in individuals with SCI. More comprehensive research needs to be conducted to conclusively confirm, or contradict the present clinical recommendations for lidocaine use in bowel care following SCI.