Pub Date : 2015-01-01DOI: 10.1053/j.trap.2016.09.009
Steve M. Aydin DO
Regenerative medicine has demonstrated to have significant positive clinical outcomes. Its applications to multiple conditions, and potential for a healing result has caused some patients to seek out regenerative treatment options rather than considering surgical interventions once other conservative and interventional options have not been successful. In particular to the spine, much of the literature and attention has been on discogenic pain in the spine, followed by sacroiliac joint pain or syndrome. The applications of regenerative medicine in the peripheral joints, ligaments, tendons, and muscles can certainly be paralleled to many of the conditions and syndromes in the spine. Limited data and research are available; however, this is the cause for further research to be conducted.
{"title":"Regenerative medicine modalities for nondiscal spinal disorders","authors":"Steve M. Aydin DO","doi":"10.1053/j.trap.2016.09.009","DOIUrl":"10.1053/j.trap.2016.09.009","url":null,"abstract":"<div><p><span><span><span>Regenerative medicine has demonstrated to have significant positive clinical outcomes. Its applications to multiple conditions, and potential for a healing result has caused some patients to seek out regenerative </span>treatment options rather than considering surgical interventions once other conservative and interventional options have not been successful. In particular to the spine, much of the literature and attention has been on </span>discogenic pain in the spine, followed by sacroiliac </span>joint pain<span> or syndrome. The applications of regenerative medicine in the peripheral joints, ligaments, tendons, and muscles can certainly be paralleled to many of the conditions and syndromes in the spine. Limited data and research are available; however, this is the cause for further research to be conducted.</span></p></div>","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"19 1","pages":"Pages 50-53"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2016.09.009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58060774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-01-01DOI: 10.1053/j.trap.2016.09.013
Enrique Galang MD , George C. Chang Chien DO , Agnes Stogicza MD, FIPP, CIPS , Andrea Trescot MD, DABIPP, FIPP
Tendinopathy is characterized by failure of the normal tendon repair mechanism, and is a common malady that leads to chronic pain. Although pain relief is an important goal in treating the patient with tendinopathy, modalities that are intended to decrease pain in the short term do not address the underlying tissue disorder. As no current gold standard exists in the treatment of tendinopathy, physicians face a unique challenge in treating this common pathology. Regenerative medicine applications in pain medicine aim to address this unique challenge.
{"title":"Regenerative medicine techniques in the management of chronic tendinopathy","authors":"Enrique Galang MD , George C. Chang Chien DO , Agnes Stogicza MD, FIPP, CIPS , Andrea Trescot MD, DABIPP, FIPP","doi":"10.1053/j.trap.2016.09.013","DOIUrl":"10.1053/j.trap.2016.09.013","url":null,"abstract":"<div><p><span>Tendinopathy is characterized by failure of the normal </span>tendon repair<span> mechanism, and is a common malady that leads to chronic pain. Although pain relief is an important goal in treating the patient with tendinopathy, modalities that are intended to decrease pain in the short term do not address the underlying tissue disorder. As no current gold standard exists in the treatment<span> of tendinopathy, physicians face a unique challenge in treating this common pathology. Regenerative medicine applications in pain medicine aim to address this unique challenge.</span></span></p></div>","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"19 1","pages":"Pages 73-79"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2016.09.013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58060920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-01-01DOI: 10.1053/j.trap.2016.09.001
David B. Harrell PhD, DABRM, FRIPH, FAARM
The concept of tissue regeneration is ancient; the earliest known written reference to it is found in Hesiod’s Theogony. Prometheus’ liver regenerated after being consumed. This type of tissue regeneration is known as regenerative hypertrophy. Regenerative biology advanced significantly in the 18th and 19th centuries and it was during this period that the first reference to the term “stem cell” was recorded; however, the term was used significantly differently than the definition it contains today (a clonal entity able to self-renew and displays asymmetric division). Although the history of regenerative medicine, regenerative biology, and tissue regeneration is ancient, significant findings have occurred in the 18th and 19th centuries, and recently, after a period of neglect, many findings of these time frames have resurfaced and changed the way the field experts understand regenerating tissue. This translates itself into regenerative medicine regarding how to think about the technologies available to the clinician practicing regenerative medicine. That is, basic science should guide the clinical use of available methods and tools used. The tools themselves (eg, cellular therapy) are not synonymous with the practice of regenerative medicine. Rather they are tools in the arsenal of the practicing physician. The goal of this article is to provide an overview of the history of regenerative biology and medicine, the progression of the basic science of regenerative biology, and to include discussions that are focused on translating the basic science of regenerative biology into regenerative medicine. This is not a structured and comprehensive review of all the history and aspects of regenerative biology and regenerative medicine, but merely incorporates several key points to provide evidence of the topics discussed in this article.
{"title":"Basic science of regenerative biology and application to regenerative medicine: Past, present, and future","authors":"David B. Harrell PhD, DABRM, FRIPH, FAARM","doi":"10.1053/j.trap.2016.09.001","DOIUrl":"10.1053/j.trap.2016.09.001","url":null,"abstract":"<div><p><span><span>The concept of tissue regeneration is ancient; the earliest known written reference to it is found in Hesiod’s Theogony. Prometheus’ liver regenerated after being consumed. This type of tissue regeneration is known as regenerative hypertrophy. Regenerative biology advanced significantly in the 18th and 19th centuries and it was during this period that the first reference to the term “stem cell” was recorded; however, the term was used significantly differently than the definition it contains today (a clonal entity able to self-renew and displays asymmetric division). Although the history of </span>regenerative medicine, regenerative biology, and tissue regeneration is ancient, significant findings have occurred in the 18th and 19th centuries, and recently, after a period of neglect, many findings of these time frames have resurfaced and changed the way the field experts understand regenerating tissue. This translates itself into regenerative medicine regarding how to think about the technologies available to the clinician practicing regenerative medicine. That is, basic science should guide the clinical use of available methods and tools used. The tools themselves (eg, cellular therapy) are not synonymous with the practice of regenerative medicine. Rather they are tools in the arsenal of the practicing physician. The goal of this article is to provide an overview of the history of regenerative biology and medicine, the progression of the basic science of regenerative biology, and to include discussions that are focused on </span>translating the basic science of regenerative biology into regenerative medicine. This is not a structured and comprehensive review of all the history and aspects of regenerative biology and regenerative medicine, but merely incorporates several key points to provide evidence of the topics discussed in this article.</p></div>","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"19 1","pages":"Pages 3-9"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2016.09.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58060096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-01-01DOI: 10.1053/j.trap.2016.09.003
Andrea Trescot MD, DABIPP, FIPP
Prolotherapy, or fibroproliferative therapy, is a regenerative injection therapy, first popularized in the 1940s and 1950s. Unfortunately, the combination of “better” surgical techniques and a series of high-profile medical catastrophes by poorly trained providers relegated the technique into the “fringe” arena. However, recent recognition of the failure of surgical interventions, combined with better technology and a burgeoning interest in the continuum of regenerative injection options, has renewed the interest and research into this “old” technique.
{"title":"Everything old is new again: New developments in prolotherapy","authors":"Andrea Trescot MD, DABIPP, FIPP","doi":"10.1053/j.trap.2016.09.003","DOIUrl":"10.1053/j.trap.2016.09.003","url":null,"abstract":"<div><p>Prolotherapy, or fibroproliferative therapy, is a regenerative injection therapy, first popularized in the 1940s and 1950s. Unfortunately, the combination of “better” surgical techniques and a series of high-profile medical catastrophes by poorly trained providers relegated the technique into the “fringe” arena. However, recent recognition of the failure of surgical interventions, combined with better technology and a burgeoning interest in the continuum of regenerative injection options, has renewed the interest and research into this “old” technique.</p></div>","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"19 1","pages":"Pages 14-18"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2016.09.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58060275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-01-01DOI: 10.1053/j.trap.2016.09.004
Matthew B. Murphy PhD , Jessica A. Terrazas BS , Don A. Buford MD, RDMS
Current best practices in regenerative medicine use cell and platelet preparations derived from a patient׳s blood or bone marrow aspirate, concentrated at the point of care, and returned to the patient during a single surgical or clinical event. As a field in its infancy, there is great confusion among many physicians, patients, regulatory agencies, and the media about what these therapies represent, their safety and efficacy, and how they are properly administered. Advances in bone marrow aspiration technique and concentration technologies have resulted in consistent significant increases in mesenchymal stem cell content in pursuit of threshold or minimum progenitor concentrations for successful outcomes described by clinical studies treating bone and soft tissues. This report reviews current preclinical and clinical data on the acquisition, processing, and administration techniques of platelet-rich plasma and bone marrow concentrate while discussing the regulatory environment around these and other cellular and regenerative medicine products.
{"title":"Bone marrow concentrate and platelet-rich plasma acquisition and preparation: Why technique matters","authors":"Matthew B. Murphy PhD , Jessica A. Terrazas BS , Don A. Buford MD, RDMS","doi":"10.1053/j.trap.2016.09.004","DOIUrl":"10.1053/j.trap.2016.09.004","url":null,"abstract":"<div><p><span><span>Current best practices in regenerative medicine use cell and platelet preparations derived from a patient׳s blood or bone marrow aspirate, concentrated at the point of care, and returned to the patient during a single surgical or clinical event. As a field in its infancy, there is great confusion among many physicians, patients, regulatory agencies, and the media about what these therapies represent, their safety and efficacy, and how they are properly administered. Advances in </span>bone marrow aspiration technique and concentration technologies have resulted in consistent significant increases in </span>mesenchymal stem cell content in pursuit of threshold or minimum progenitor concentrations for successful outcomes described by clinical studies treating bone and soft tissues. This report reviews current preclinical and clinical data on the acquisition, processing, and administration techniques of platelet-rich plasma and bone marrow concentrate while discussing the regulatory environment around these and other cellular and regenerative medicine products.</p></div>","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"19 1","pages":"Pages 19-25"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2016.09.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58060446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-01-01DOI: 10.1053/j.trap.2016.09.010
Annu Navani MD , Deepak Gupta BA, MS-II
The goal of this case review is to evaluate safety and efficacy with the use of intra-articular platelet-rich plasma (PRP) in patients with sacroiliac (SI) joint (SIJ) pain. The secondary outcomes include additional medical treatments, hospitalization, and surgery. SIJ pain contributes significantly to the social and economic burden due to its long-standing and debilitating course. Current treatments include either interventional procedures with transient benefits or invasive surgical options. PRP has been used clinically in various settings for its anti-inflammatory and tissue repair properties attributed to growth factors. Ten patients with chronic SIJ pain who tried and failed conservative treatments were administered a single injection of 4mm autologous PRP into the joint under fluoroscopic guidance after careful clinical and imaging evaluation. The patients were followed up at 1, 3, 6, and 12 months postinjection and primary and secondary outcomes were recorded. Verbal analog scale score for pain of all patients decreased more than 50% and their function increased for the period of 12 months. None of the patients presented to the hospital or clinic or received any treatments or surgery after the PRP injection. There were no adverse reactions, side effects, or complications. PRP presents as a promising option based on our preliminary observation. Larger, well-designed randomized controlled trials are warranted to understand the full breath of the efficacy, risks, and complications from the use of PRP for SIJ pain.
{"title":"Role of intra-articular platelet-rich plasma in sacroiliac joint pain","authors":"Annu Navani MD , Deepak Gupta BA, MS-II","doi":"10.1053/j.trap.2016.09.010","DOIUrl":"10.1053/j.trap.2016.09.010","url":null,"abstract":"<div><p><span>The goal of this case review is to evaluate safety and efficacy with the use of intra-articular platelet-rich plasma (PRP) in patients<span><span> with sacroiliac (SI) joint (SIJ) pain. The secondary outcomes include additional medical treatments, hospitalization, and surgery. SIJ pain contributes significantly to the social and economic burden due to its long-standing and debilitating course. Current treatments include either interventional procedures with transient benefits or invasive surgical options. PRP has been used clinically in various settings for its anti-inflammatory and </span>tissue repair properties attributed to growth factors. Ten patients with chronic SIJ pain who tried and failed conservative treatments were administered a single injection of 4</span></span> <span>mm autologous PRP into the joint under fluoroscopic guidance after careful clinical and imaging evaluation. The patients were followed up at 1, 3, 6, and 12 months postinjection and primary and secondary outcomes were recorded. Verbal analog scale score for pain of all patients decreased more than 50% and their function increased for the period of 12 months. None of the patients presented to the hospital or clinic or received any treatments or surgery after the PRP injection. There were no adverse reactions, side effects, or complications. PRP presents as a promising option based on our preliminary observation. Larger, well-designed randomized controlled trials are warranted to understand the full breath of the efficacy, risks, and complications from the use of PRP for SIJ pain.</span></p></div>","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"19 1","pages":"Pages 54-59"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2016.09.010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58060455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-10-01DOI: 10.1053/j.trap.2015.10.011
Clint E. Elliott MD, Salman Thobhani MD
Analgesia for total knee arthroplasty (TKA) is not a new topic; however, some newer approaches to peripheral nerve blocks for control of postoperative pain have been developed. The femoral nerve block plus or minus a sciatic nerve block has been shown to provide effective analgesia, but not without some degree of motor block. The adductor canal block provides analgesia not inferior to a femoral with less motor weakness, and a continuous catheter technique can be used to prolong its effects. Blocking the sciatic nerve has been a subject of controversy, in part because of the motor weakness but also because of the inclusion of the common peroneal nerve, a nerve that can potentially be damaged by TKA. An infiltration of the interspace between the popliteal artery and the capsule of the posterior knee, provides analgesia for the posterior knee without motor effects or common peroneal block. The combination of an adductor canal catheter and an interspace between the popliteal artery and the capsule of the posterior knee provides a balance of effective postoperative analgesia and preservation of motor function, ultimately shortening length of stay following TKA.
{"title":"The adductor canal catheter and interspace between the popliteal artery and the posterior capsule of the knee for total knee arthroplasty","authors":"Clint E. Elliott MD, Salman Thobhani MD","doi":"10.1053/j.trap.2015.10.011","DOIUrl":"10.1053/j.trap.2015.10.011","url":null,"abstract":"<div><p><span>Analgesia for total knee arthroplasty<span><span> (TKA) is not a new topic; however, some newer approaches to peripheral nerve blocks<span> for control of postoperative pain have been developed. The </span></span>femoral nerve block plus or minus a </span></span>sciatic nerve<span><span> block has been shown to provide effective analgesia, but not without some degree of motor block. The adductor canal block provides analgesia not inferior to a femoral with less motor weakness, and a continuous catheter technique can be used to prolong its effects. Blocking the sciatic nerve has been a subject of controversy, in part because of the motor weakness but also because of the inclusion of the common peroneal nerve, a nerve that can potentially be damaged by TKA. An infiltration of the interspace between the </span>popliteal artery<span> and the capsule of the posterior knee, provides analgesia for the posterior knee without motor effects or common peroneal block. The combination of an adductor canal catheter and an interspace between the popliteal artery and the capsule of the posterior knee provides a balance of effective postoperative analgesia and preservation of motor function, ultimately shortening length of stay following TKA.</span></span></p></div>","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"18 4","pages":"Pages 126-129"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2015.10.011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58059987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-10-01DOI: 10.1053/j.trap.2015.10.012
Dmitri Souzdalnitski MD, PhD , Glenn R. Rech RPh , Aleksandr Naydinskiy BSc , Daria Suzdalnitskaya , Roman V. Isakov , Maged Guirguis MD
Successful perioperative analgesia for knee surgeries results in improved patient satisfaction and promotes successful rehabilitation. However, effective perioperative pain control is commonly a challenging task for knee surgeries. Such surgical procedures as total knee replacement or knee arthroscopy may be accompanied by severe postoperative pain. As opioids and nonsteroidal anti-inflammatory drugs are commonly used, the side effects of these types of medicines are quite common as well, especially in patients with chronic pain, as they are commonly dissatisfied with regular analgesia. Patients with chronic pain tend to have lower tolerance to pain, and be dependent and tolerant to opioids. These patients typically require higher doses of analgesics, which further negatively affect patients’ safety and the overall perioperative experience. Multimodal perioperative analgesia helps to spare opioids and promote successful rehabilitation. Ketamine is a noncompetitive N-Methyl-d-aspartate (NMDA) receptor antagonist that has been used for multimodal perioperative analgesia as an adjunct to opioids and nonsteroidal anti-inflammatory drugs. Despite the significant number of papers evaluating the role of ketamine in perioperative analgesia, the feasibility of ketamine for perioperative pain control in knee surgeries remains a subject of debate. There are only a limited number of high-quality studies on the topic. We used a systematic approach to evaluate randomized controlled trials with perioperative ketamine used for knee surgeries. The majority of the studies confirmed that the utilization of ketamine in perioperative analgesia was associated with lower pain scores, reduced opioid use, improved knee joint mobility, and an increase in patient tolerance for physical therapy and rehabilitation. The techniques for ketamine administration and dosing varied significantly, which may explain the inconsistencies between the reports. In addition, some of the studies, even those of high quality, used nitrous oxide in both the study and control groups. Nitrous oxide has NMDA receptor antagonist properties, as does ketamine. None of the studies reported whether patients were taking methadone, dextromethorphan, memantine, or magnesium sulfate, which are NMDA receptor antagonists too. The concomitant use of NMDA receptor antagonists, other than ketamine, may have interfered with the realization of analgesic effects of ketamine. Although it is largely accepted that NMDA receptor antagonism at the spinal level explains most of the analgesic effects of ketamine, it also interacts at other multiple receptors centrally, including, cholinergic receptors, nicotinic and muscarinic, adrenergic, central NMDA, and non-NMDA glutamate receptors. These influences may potentially explain why patients tr
{"title":"Ketamine in perioperative analgesia for knee surgeries: Review of evidence from randomized controlled trials","authors":"Dmitri Souzdalnitski MD, PhD , Glenn R. Rech RPh , Aleksandr Naydinskiy BSc , Daria Suzdalnitskaya , Roman V. Isakov , Maged Guirguis MD","doi":"10.1053/j.trap.2015.10.012","DOIUrl":"10.1053/j.trap.2015.10.012","url":null,"abstract":"<div><p><span><span>Successful perioperative analgesia for knee surgeries results in improved patient satisfaction and promotes successful rehabilitation. However, effective perioperative pain control is commonly a challenging task for knee surgeries. Such surgical procedures as total knee replacement<span><span> or knee arthroscopy may be accompanied by severe </span>postoperative pain. As opioids and nonsteroidal anti-inflammatory drugs are commonly used, the side effects of these types of medicines are quite common as well, especially </span></span>in patients<span><span> with chronic pain, as they are commonly dissatisfied with regular analgesia. Patients with chronic pain tend to have lower tolerance to pain, and be dependent and tolerant to opioids. These patients typically require higher doses of analgesics, which further negatively affect patients’ safety and the overall perioperative experience. Multimodal perioperative analgesia helps to spare opioids and promote successful rehabilitation. </span>Ketamine is a noncompetitive N-Methyl-</span></span><span>d</span><span><span>-aspartate (NMDA) receptor antagonist that has been used for multimodal perioperative analgesia as an adjunct to opioids and nonsteroidal anti-inflammatory drugs. Despite the significant number of papers evaluating the role of ketamine in perioperative analgesia, the feasibility of ketamine for perioperative pain control in knee surgeries remains a subject of debate. There are only a limited number of high-quality studies on the topic. We used a systematic approach to evaluate </span>randomized controlled trials<span><span> with perioperative ketamine used for knee surgeries. The majority of the studies confirmed that the utilization of ketamine in perioperative analgesia was associated with lower pain scores, reduced opioid use, improved knee joint mobility, and an increase in patient tolerance for physical therapy and rehabilitation. The techniques for ketamine administration and dosing varied significantly, which may explain the inconsistencies between the reports. In addition, some of the studies, even those of high quality, used nitrous oxide in both the study and control groups. Nitrous oxide has NMDA receptor antagonist properties, as does ketamine. None of the studies reported whether patients were taking methadone, </span>dextromethorphan<span><span>, memantine<span>, or magnesium sulfate, which are NMDA receptor antagonists too. The concomitant use of NMDA receptor antagonists, other than ketamine, may have interfered with the realization of </span></span>analgesic effects<span><span> of ketamine. Although it is largely accepted that NMDA receptor antagonism at the spinal level explains most of the analgesic effects of ketamine, it also interacts at other multiple receptors centrally, including, cholinergic receptors, nicotinic and muscarinic, adrenergic, central NMDA, and non-NMDA glutamate receptors. These influences may potentially explain why patients tr","PeriodicalId":93817,"journal":{"name":"Techniques in regional anesthesia & pain management","volume":"18 4","pages":"Pages 130-136"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1053/j.trap.2015.10.012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58059995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}