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Letters to the Editor
Response to Dr. Candido et al.
Dear Editor, We concur with Doctors Knezevic, Lissounov, and Candido that pain relief resulting in the prevention of spinal surgery is one goal of interventional spine procedures. While this effect has been documented [1,2], it is a capricious outcome measure. It was serendipitous that we mentioned the avoidance of surgery as an outcome measure in our study. Our study was not designed to control for the numerous psychosocial and pathophysiologic and pathoanatomical factors that affect this particular outcome. Given the number of factors associated with the decision to undergo surgery, it is impossible to compare surgical rates between studies that do not account for all of these factors. The same factors apply to study registries and national averages, which have clearly shown great geographic variability between surgical and even injection rates [3–5]. Avoidance of surgery can only be assessed within a trial in which these local factors are evenly distributed, and cannot be completed across studies. Therefore the comparisons to other studies made in this letter are not valid. Furthermore, it is inappropriate to claim a difference in procedural techniques resulted in these differences. Implying that interlaminar injections may result in less spine surgery than transforaminal injections is simply not a valid conjecture based on the data available in these studies. Comparing the surgical rates from an interlaminar ESI approach versus a TFESI can only be done in a head to head comparison trial with similar local environments. We eagerly await completion of such a study. Lastly this commentary implied that lumbar TFESI are inherently less safe than lumbar IL injections. Unfortunately this is based upon perceptions rather than literature. It is true that an intra-arterial injection of a particulate corticosteroid has been associated with serious permanent neurologic complications. To the authors knowledge the literature has failed to demonstrate a single case of a permanent neurologic injury following a lumbar TFESI that did not also utilize a particulate corticosteroid. While the cited FDA report focused on TFESIs, a simple review of the literature shows that paralysis has been reported following lumbar IL and even caudal injections [6–8]. Even more concerning is that permanent neurologic injury has occurred following IL injections due to hematoma formations without the injection of a particulate corticosteroid [9]. Therefore, lumbar TFESI with dexamethasone may indeed be safer than an IL injection regardless of injectate. Admittedly, this is speculative, and it would be exceedingly difficult to prove requiring exceedingly large numbers of subjects given the rarity of serious complications with these injections.
DAVID J. KENNEDY, MD,* CHRISTOPHER PLASTARAS, MD,† ELLEN CASEY, MD,‡ CHRISTOPHER J. VISCO, MD,§ JOSHUA D. RITTENBERG, MD,¶ BRYAN CONRAD, PhD,** JAMES SIGLER, MD,†† and PAUL DREYFUSS, MD‡‡ *Department of Orthopaedic Surgery, Stanford University, Redwood City, California; † Department of Physical Medicine and Rehabilitation, University of Pennsylvania, Philadelphia, Pennsylvania; ‡ Drexel University College of Medicine, Philadelphia, Pennsylvania; § Department of Rehabilitation Medicine, Columbia University, New York, New York; ¶ Department of Physical Medicine and Rehabilitation, Kaiser Permanente, Oakland, California; **Nike Sport Research Lab, Beaverton, Oregon; †† Department of Physical Medicine and Rehabilitation, University of Kansas, Kansas City, Missouri; ‡‡ Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, USA
References 1 Riew KD, Yin Y, Gilula L, et al. The effect of nerve-root injections on the need for operative treatment of lumbar radicular pain. A prospective, randomized, controlled, double-blind study. J Bone Joint Surg Am 2000;82A:1589–93. 2 Riew KD, Park JB, Cho YS, et al. Nerve root blocks in the treatment of lumbar radicular pain. A minimum five-year follow-up. J Bone Joint Surg Am 2006;88: 1722–5. 3 Bederman SS, Coyte PC, Kreder HJ, et al. Who’s in the driver’s seat? The influence of patient and physician enthusiasm on regional variation in degenerative lumbar spinal surgery: A population-based study. Spine 2011; 36:481–9. 4 Wang MC, Kreuter W, Wolfla CE, Maiman DJ, Deyo RA. Trends and variations in cervical spine surgery in the United States: Medicare beneficiaries, 1992 to 2005. Spine 2009;34:955–61, discussion 962–963. 5 Friedly J, Chan L, Deyo R. Geographic variation in epidural steroid injection use in medicare patients. J Bone Joint Surg Am 2008;90:1730–7. 6 Lenoir T, Deloin X, Dauzac C, Rillardon L, Guigui P. [Paraplegia after interlaminar epidural steroid injection: A case report]. Rev Chir Orthop Reparatrice Appar Mot 2008;94:697–701. 7 Thefenne L, Dubecq C, Zing E, et al. A rare case of paraplegia complicating a lumbar epidural infiltration. Ann. Phys. Rehabil. Med. 2010;53:575–83. 1977
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Manchikanti et al. 8 Shetty SR, Shankaranarayana RU, Mehandale SG. Paraplegia following caudal block in a child with Burkitt’s lymphoma. Paediatr Anaesth 2011;21: 1087–8.
9 Kang XH, Bao FP, Xiong XX, et al. Major complications of epidural anesthesia: A prospective study of 5083 cases at a single hospital. Acta Anaesthesiol Scand 2014;58:858–66.
Cohen et al. Reach Inappropriate Conclusions on the Effect of Sedation on the Accuracy and Treatment Outcomes for Diagnostic Injections Dear Editor, In a manuscript published by Cohen et al. [1] on the effect of sedation on the accuracy and treatment outcomes for diagnostic injections, the authors presented a randomized, controlled, crossover study and concluded that the use of sedation during diagnostic injections may increase the rate of false-positive blocks and lead to misdiagnosis and unnecessary procedures. We do not believe that the study justifies the authors sweeping conclusions. The study has various deficiencies in both its design and conduct. Studies of IPM do not exist in a vacuum and can be subject to misinterpretation by the payer community and justifying their restriction of sedation in patients who need it. The authors also criticized Manchikanti et al. [2–5] for design flaws and other deficiencies. The authors’ entire literature support for their conclusions is based upon a 1966 double-blind, controlled trial wherein diazepam was used in patients experiencing backache [6]. This study included 50 patients, all suffering from acute backache, severe enough to require admission to the hospital. They were divided randomly into two groups of 25 patients each, with one group given a placebo and the other diazepam. In the placebo group, a placebo injection consisted of sterile water administered at 4-hour intervals for a total of four injections, while the treated group was given 10 mg of diazepam intramuscularly at 6-hour intervals for 24 hours. They reported that there was no significant difference between the groups and concluded that in treating acute low back pain, diazepam was not superior to a placebo. Contrary to these study findings and conclusions [6], Cohen et al. [1] described the results of this study as being an endorsement for promoting amnesia and relieving muscle-related pain. Further, the 1966 study [6] did not measure the effectiveness of diazepam on anxiety, even though a large proportion of patients in chronic pain settings suffer with generalized anxiety or other anxiety disorders [7]. In addition, the study by Cohen et al. [1] is substantially underpowered. The primary question was “Does sedation have any effect on the accuracy and treatment outcomes for diagnostic injections?” However, the authors’ attention appears to have been diverted away from this primary 1978
question to a multitude of other issues, confounding and reducing their sample size in some categories to a mere three patients! The authors relied upon a 48-year-old reference with inappropriate interpretation, even when more contemporary references were available describing false-positive results. Not surprisingly, the study by DePalma et al. [8] showed similar results as identified by multiple other studies in reference to false-positive rates [9]. The authors described that the performance of multiple blocks to enhance specificity, which may decrease sensitivity, can result in withholding effective treatments from patients [10–12]. The referenced studies had their own design issues, specifically the study utilizing 0, 1, or 2 blocks for their calculation of cost-effectiveness [11]. The authors state that the most modifiable potential cause is the use of sedation, which has generated substantial interest in the literature quoting references used for one systematic review [13], which included the studies by Manchikanti et al. [2–5] and the other references with no relevance as to the accuracy of diagnostic blocks. Compared with Manchikanti et al. [2–5], this study suffers from having a small sample size with no allocation concealment and without relevance for crossover. The authors injected large anesthetic volumes, removing the diagnostic specificity of their injections. The authors utilized midazolam in combination with fentanyl, which is not appropriate for use when performing diagnostic facet joint nerve blocks. It is also important to know how they selected the patients to either receive sedation or not. Further, Manchikanti et al.’s manuscripts [2–5] may not be relevant to this study as the authors have not assessed the role of sedation use during controlled diagnostic blocks. Cohen et al raise questions that we will answer here: 1. Patient sampling bias: Placebo responders do not respond to repeated blocks over a 2-year period. 2. Assessing pain relief: Assessing pain relief before rather than after the injections. We assessed pain relief before and after administering sedation and also included a placebo group. It is not essential to assess relief prior to making a diagnosis. In that case, one would not know who was negative and who was
Copyright of Pain Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Letters to the Editor
Response to Dr. Candido et al.
Dear Editor, We concur with Doctors Knezevic, Lissounov, and Candido that pain relief resulting in the prevention of spinal surgery is one goal of interventional spine procedures. While this effect has been documented [1,2], it is a capricious outcome measure. It was serendipitous that we mentioned the avoidance of surgery as an outcome measure in our study. Our study was not designed to control for the numerous psychosocial and pathophysiologic and pathoanatomical factors that affect this particular outcome. Given the number of factors associated with the decision to undergo surgery, it is impossible to compare surgical rates between studies that do not account for all of these factors. The same factors apply to study registries and national averages, which have clearly shown great geographic variability between surgical and even injection rates [3–5]. Avoidance of surgery can only be assessed within a trial in which these local factors are evenly distributed, and cannot be completed across studies. Therefore the comparisons to other studies made in this letter are not valid. Furthermore, it is inappropriate to claim a difference in procedural techniques resulted in these differences. Implying that interlaminar injections may result in less spine surgery than transforaminal injections is simply not a valid conjecture based on the data available in these studies. Comparing the surgical rates from an interlaminar ESI approach versus a TFESI can only be done in a head to head comparison trial with similar local environments. We eagerly await completion of such a study. Lastly this commentary implied that lumbar TFESI are inherently less safe than lumbar IL injections. Unfortunately this is based upon perceptions rather than literature. It is true that an intra-arterial injection of a particulate corticosteroid has been associated with serious permanent neurologic complications. To the authors knowledge the literature has failed to demonstrate a single case of a permanent neurologic injury following a lumbar TFESI that did not also utilize a particulate corticosteroid. While the cited FDA report focused on TFESIs, a simple review of the literature shows that paralysis has been reported following lumbar IL and even caudal injections [6–8]. Even more concerning is that permanent neurologic injury has occurred following IL injections due to hematoma formations without the injection of a particulate corticosteroid [9]. Therefore, lumbar TFESI with dexamethasone may indeed be safer than an IL injection regardless of injectate. Admittedly, this is speculative, and it would be exceedingly difficult to prove requiring exceedingly large numbers of subjects given the rarity of serious complications with these injections.
DAVID J. KENNEDY, MD,* CHRISTOPHER PLASTARAS, MD,† ELLEN CASEY, MD,‡ CHRISTOPHER J. VISCO, MD,§ JOSHUA D. RITTENBERG, MD,¶ BRYAN CONRAD, PhD,** JAMES SIGLER, MD,†† and PAUL DREYFUSS, MD‡‡ *Department of Orthopaedic Surgery, Stanford University, Redwood City, California; † Department of Physical Medicine and Rehabilitation, University of Pennsylvania, Philadelphia, Pennsylvania; ‡ Drexel University College of Medicine, Philadelphia, Pennsylvania; § Department of Rehabilitation Medicine, Columbia University, New York, New York; ¶ Department of Physical Medicine and Rehabilitation, Kaiser Permanente, Oakland, California; **Nike Sport Research Lab, Beaverton, Oregon; †† Department of Physical Medicine and Rehabilitation, University of Kansas, Kansas City, Missouri; ‡‡ Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, USA
References 1 Riew KD, Yin Y, Gilula L, et al. The effect of nerve-root injections on the need for operative treatment of lumbar radicular pain. A prospective, randomized, controlled, double-blind study. J Bone Joint Surg Am 2000;82A:1589–93. 2 Riew KD, Park JB, Cho YS, et al. Nerve root blocks in the treatment of lumbar radicular pain. A minimum five-year follow-up. J Bone Joint Surg Am 2006;88: 1722–5. 3 Bederman SS, Coyte PC, Kreder HJ, et al. Who’s in the driver’s seat? The influence of patient and physician enthusiasm on regional variation in degenerative lumbar spinal surgery: A population-based study. Spine 2011; 36:481–9. 4 Wang MC, Kreuter W, Wolfla CE, Maiman DJ, Deyo RA. Trends and variations in cervical spine surgery in the United States: Medicare beneficiaries, 1992 to 2005. Spine 2009;34:955–61, discussion 962–963. 5 Friedly J, Chan L, Deyo R. Geographic variation in epidural steroid injection use in medicare patients. J Bone Joint Surg Am 2008;90:1730–7. 6 Lenoir T, Deloin X, Dauzac C, Rillardon L, Guigui P. [Paraplegia after interlaminar epidural steroid injection: A case report]. Rev Chir Orthop Reparatrice Appar Mot 2008;94:697–701. 7 Thefenne L, Dubecq C, Zing E, et al. A rare case of paraplegia complicating a lumbar epidural infiltration. Ann. Phys. Rehabil. Med. 2010;53:575–83. 1977
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Manchikanti et al. 8 Shetty SR, Shankaranarayana RU, Mehandale SG. Paraplegia following caudal block in a child with Burkitt’s lymphoma. Paediatr Anaesth 2011;21: 1087–8.
9 Kang XH, Bao FP, Xiong XX, et al. Major complications of epidural anesthesia: A prospective study of 5083 cases at a single hospital. Acta Anaesthesiol Scand 2014;58:858–66.
Cohen et al. Reach Inappropriate Conclusions on the Effect of Sedation on the Accuracy and Treatment Outcomes for Diagnostic Injections Dear Editor, In a manuscript published by Cohen et al. [1] on the effect of sedation on the accuracy and treatment outcomes for diagnostic injections, the authors presented a randomized, controlled, crossover study and concluded that the use of sedation during diagnostic injections may increase the rate of false-positive blocks and lead to misdiagnosis and unnecessary procedures. We do not believe that the study justifies the authors sweeping conclusions. The study has various deficiencies in both its design and conduct. Studies of IPM do not exist in a vacuum and can be subject to misinterpretation by the payer community and justifying their restriction of sedation in patients who need it. The authors also criticized Manchikanti et al. [2–5] for design flaws and other deficiencies. The authors’ entire literature support for their conclusions is based upon a 1966 double-blind, controlled trial wherein diazepam was used in patients experiencing backache [6]. This study included 50 patients, all suffering from acute backache, severe enough to require admission to the hospital. They were divided randomly into two groups of 25 patients each, with one group given a placebo and the other diazepam. In the placebo group, a placebo injection consisted of sterile water administered at 4-hour intervals for a total of four injections, while the treated group was given 10 mg of diazepam intramuscularly at 6-hour intervals for 24 hours. They reported that there was no significant difference between the groups and concluded that in treating acute low back pain, diazepam was not superior to a placebo. Contrary to these study findings and conclusions [6], Cohen et al. [1] described the results of this study as being an endorsement for promoting amnesia and relieving muscle-related pain. Further, the 1966 study [6] did not measure the effectiveness of diazepam on anxiety, even though a large proportion of patients in chronic pain settings suffer with generalized anxiety or other anxiety disorders [7]. In addition, the study by Cohen et al. [1] is substantially underpowered. The primary question was “Does sedation have any effect on the accuracy and treatment outcomes for diagnostic injections?” However, the authors’ attention appears to have been diverted away from this primary 1978
question to a multitude of other issues, confounding and reducing their sample size in some categories to a mere three patients! The authors relied upon a 48-year-old reference with inappropriate interpretation, even when more contemporary references were available describing false-positive results. Not surprisingly, the study by DePalma et al. [8] showed similar results as identified by multiple other studies in reference to false-positive rates [9]. The authors described that the performance of multiple blocks to enhance specificity, which may decrease sensitivity, can result in withholding effective treatments from patients [10–12]. The referenced studies had their own design issues, specifically the study utilizing 0, 1, or 2 blocks for their calculation of cost-effectiveness [11]. The authors state that the most modifiable potential cause is the use of sedation, which has generated substantial interest in the literature quoting references used for one systematic review [13], which included the studies by Manchikanti et al. [2–5] and the other references with no relevance as to the accuracy of diagnostic blocks. Compared with Manchikanti et al. [2–5], this study suffers from having a small sample size with no allocation concealment and without relevance for crossover. The authors injected large anesthetic volumes, removing the diagnostic specificity of their injections. The authors utilized midazolam in combination with fentanyl, which is not appropriate for use when performing diagnostic facet joint nerve blocks. It is also important to know how they selected the patients to either receive sedation or not. Further, Manchikanti et al.’s manuscripts [2–5] may not be relevant to this study as the authors have not assessed the role of sedation use during controlled diagnostic blocks. Cohen et al raise questions that we will answer here: 1. Patient sampling bias: Placebo responders do not respond to repeated blocks over a 2-year period. 2. Assessing pain relief: Assessing pain relief before rather than after the injections. We assessed pain relief before and after administering sedation and also included a placebo group. It is not essential to assess relief prior to making a diagnosis. In that case, one would not know who was negative and who was
Copyright of Pain Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
