
==== Front
Interv Pain Med
Interv Pain Med
Interventional Pain Medicine
2772-5944
Elsevier

S2772-5944(22)00106-6
10.1016/j.inpm.2022.100110
100110
Commentary
Yes but no
Levin Josh jlevin49@stanford.edu

Stanford University School of Medicine, USA
18 6 2022
6 2022
18 6 2022
1 2 10011012 6 2022
13 6 2022
© 2022 The Author(s)
2022
https://creativecommons.org/licenses/by/4.0/ This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
==== Body
pmcYes but no. Coined by my nephew at the age of 4, this phrase refers to things that are and are not at the same time. Bupivacaine lasts longer than lidocaine. But as Schneider et al. demonstrated in this issue of Interventional Pain Medicine [1], it does not. Yes but no.

In the process of selecting patients for medial branch radiofrequency neurotomy, physicians perform - and perhaps more importantly interpret - diagnostic medial branch blocks. Such interpretation, while seemingly straight-forward, is most certainly not. Definitions of a positive response vary greatly among practitioners, with some advocating for a single diagnostic block with ≥50% relief in pain [2], and others recommending dual-diagnostic blocks with complete relief of pain [3]. Even triple, placebo-controlled blocks have been supported [4], yet in recognition of the logistical challenges associated with placebo-controlled procedures, the Spine Intervention Society has recommended dual comparative blocks alternating between short and long lasting local anesthetics [5]. By requiring longer-lasting relief from a longer-acting medication, the use of a placebo can be avoided, provided that the patient does not know which local anesthetic was used. All that is required is that the long-acting anesthetic lasts longer. No problem, right?

Medical reversal refers to the phenomenon of changing well-established practices due to new and contradictory evidence [6]. Treating hypertension with atenolol [7], stable coronary artery disease with stents [8], premature ventricular contractions (PVCs) with antiarrhythmic medications [9], and routine screening of woman aged 40–49 with mammography [10], are just a few examples of common practices that were reversed when new and better evidence emerged. Often times, medical reversal can have profound effects, as in the case of antiarrhythmics for PVCs, which were found to be associated with higher mortality rates [9]. Clearly, high quality science is necessary if we wish to advance our fields and provide the best care to our patients.

In the case of dual comparative medial branch blocks, one might ask why. Why would lidocaine last longer than bupivacaine? Given the pharmacokinetics, we expect it would not [11]. One might opine that local anesthetics have a more unpredictable duration of action in chronic pain states, as prolonged relief beyond the expected duration of conduction blockade often occurs [12]. But the answer to the question of why is that it is the wrong question. Instead of why, we should be asking what. What does the literature say? Schneider et al. provide an answer [1], and in the process, have contradicted years of conventional wisdom. As a result of their work, we must now question the utility of relying on concordant responses when interpreting dual diagnostic blocks.

So, does bupivacaine last longer than lidocaine? Any 4-year-old can explain it to you. Yes but no.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
==== Refs
References

1 Schneider B.J. Patient-perceived duration of effect of lidocaine and bupivacaine following diagnostic medial branch blocks; a multicenter study Interv. Pain Med. 1 2 Jun. 2022 100083 10.1016/j.inpm.2022.100083
2 Cohen S.P. Consensus practice guidelines on interventions for lumbar facet joint pain from a multispecialty, international working group Reg Anesth Pain Med 45 6 Jun. 2020 424 467 10.1136/rapm-2019-101243 32245841
3 MacVicar J. Borowczyk J.M. MacVicar A.M. Loughnan B.M. Bogduk N. Lumbar medial branch radiofrequency neurotomy in New Zealand Pain Med 14 5 May 2013 639 645 10.1111/pme.12000 23279154
4 Engel A.J. Bogduk N. Mathematical validation and credibility of diagnostic blocks for spinal pain Pain Med 17 10 Oct. 2016 1821 1828 10.1093/pm/pnw020 26995797
5 Bogduk N. International Spine Intervention Society Practice guidelines for spinal diagnostic and treatment procedures 2013
6 Prasad V. Gall V. Cifu A. The frequency of medical reversal Arch Intern Med 171 18 Oct. 2011 1675 1676 10.1001/archinternmed.2011.295 21747003
7 Carlberg B. Samuelsson O. Lindholm L.H. Atenolol in hypertension: is it a wise choice? Lancet Lond. Engl. 364 9446 Nov. 2004 1684 1689 10.1016/S0140-6736(04)17355-8
8 Boden W.E. Optimal medical therapy with or without PCI for stable coronary disease N Engl J Med 356 15 Apr. 2007 1503 1516 10.1056/NEJMoa070829 17387127
9 Echt D.S. Mortality and morbidity in patients receiving encainide, flecainide, or placebo. The Cardiac Arrhythmia Suppression Trial N Engl J Med 324 12 Mar. 1991 781 788 10.1056/NEJM199103213241201 1900101
10 Moss S.M. Effect of mammographic screening from age 40 years on breast cancer mortality at 10 years' follow-up: a randomised controlled trial Lancet Lond. Engl. 368 9552 Dec. 2006 2053 2060 10.1016/S0140-6736(06)69834-6
11 G. T. Tucker and L. E. Mather, “Clinical pharmacokinetics of local anaesthetics,” p. 38.
12 Vlassakov K.V. Narang S. Kissin I. Local anesthetic blockade of peripheral nerves for treatment of neuralgias: systematic analysis Anesth Analg 112 6 Jun. 2011 1487 1493 10.1213/ANE.0b013e31820d9787 21372279
