Cannabis, cannabinoids, and cannabis-based medicines: future research directions for analgesia

The use of cannabis spans thousands of years and encompasses almost all dimensions of the human experience, including consumption for recreational, religious, social, and medicinal purposes. Its use in the management of pain has been anecdotally described for millennia. However, an evidence base has only developed over the last 100 years, with an explosion in research occurring in the last 20-30 years, as more states in the USA as well as countries worldwide have legalized and encouraged its use in pain management. Pain remains one of the most common reasons for individuals deciding to use cannabis medicinally. However, cannabis remains illegal at the federal level in the USA and in most countries of the world, making it difficult to advance quality research on its efficacy for pain treatment. Nonetheless, new products derived both from the cannabis plant and the chemistry laboratory are being developed for use as analgesics. This review examines the current landscape of cannabinoids research and future research directions in the management of pain.

Recommended musculoskeletal and sports ultrasound terminology: a Delphi-based consensus statement

The current lack of agreement regarding standardised terminology in musculoskeletal and sports ultrasound presents challenges in education, clinical practice and research. This consensus was developed to provide a reference to improve clarity and consistency in communication. A multidisciplinary expert panel was convened consisting of 18 members representing multiple specialty societies identified as key stakeholders in musculoskeletal and sports ultrasound. A Delphi process was used to reach consensus, which was defined as group level agreement of >80%. Content was organised into seven general topics including: (1) general definitions, (2) equipment and transducer manipulation, (3) anatomical and descriptive terminology, (4) pathology, (5) procedural terminology, (6) image labelling and (7) documentation. Terms and definitions which reached consensus agreement are presented herein. The historic use of multiple similar terms in the absence of precise definitions has led to confusion when conveying information between colleagues, patients and third-party payers. This multidisciplinary expert consensus addresses multiple areas of variability in diagnostic ultrasound imaging and ultrasound-guided procedures related to musculoskeletal and sports medicine.

The practice of regional anesthesia during the COVID-19 pandemic: an international survey of members of three regional anesthesia societies

PURPOSE

To determine the preferences and attitudes of members of regional anesthesia societies during the COVID-19 pandemic.

METHODS

We distributed an electronic survey to members of the American Society of Regional Anesthesia and Pain Medicine, Regional Anaesthesia-UK, and the European Society of Regional Anaesthesia & Pain Therapy. A questionnaire consisting of 19 questions was developed by a panel of experienced regional anesthesiologists and distributed by email to the participants. The survey covered the following domains: participant information, practice settings, preference for the type of anesthetic technique, the use of personal protective equipment, and oxygen therapy.

RESULTS

The survey was completed by 729 participants from 73 different countries, with a response rate of 20.1% (729/3,630) for the number of emails opened and 8.5% (729/8,572) for the number of emails sent. Most respondents (87.7%) identified as anesthesia staff (faculty or consultant) and practiced obstetric and non-obstetric anesthesia (55.3%). The practice of regional anesthesia either expanded or remained the same, with only 2% of respondents decreasing their use compared with the pre-pandemic period. The top reasons for an increase in the use of regional anesthesia was to reduce the need for an aerosol-generating medical procedure and to reduce the risk of possible complications to patients. The most common reason for decreased use of regional anesthesia was the risk of urgent conversion to general anesthesia. Approximately 70% of the responders used airborne precautions when providing care to a patient under regional anesthesia. The most common oxygen delivery method was nasal prongs (cannula) with a surgical mask layered over it (61%).

CONCLUSIONS

Given the perceived benefits of regional over general anesthesia, approximately half of the members of three regional anesthesia societies seem to have expanded their use of regional anesthesia techniques during the initial surge of the COVID-19 pandemic.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group

BACKGROUND

The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial.

METHODS

In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4-5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement.

RESULTS

Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation.

CONCLUSIONS

Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group

BACKGROUND

The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial.

METHODS

In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4-5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement.

RESULTS

Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation.

CONCLUSIONS

Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

International consensus on anatomical structures to identify on ultrasound for the performance of basic blocks in ultrasound-guided regional anesthesia

There is no universally agreed set of anatomical structures that must be identified on ultrasound for the performance of ultrasound-guided regional anesthesia (UGRA) techniques. This study aimed to produce standardized recommendations for core (minimum) structures to identify during seven basic blocks. An international consensus was sought through a modified Delphi process. A long-list of anatomical structures was refined through serial review by key opinion leaders in UGRA. All rounds were conducted remotely and anonymously to facilitate equal contribution of each participant. Blocks were considered twice in each round: for "orientation scanning" (the dynamic process of acquiring the final view) and for the "block view" (which visualizes the block site and is maintained for needle insertion/injection). Strong recommendations for inclusion were made if ≥75% of participants rated a structure as "definitely include" in any round. Weak recommendations were made if >50% of participants rated a structure as "definitely include" or "probably include" for all rounds (but the criterion for "strong recommendation" was never met). Thirty-six participants (94.7%) completed all rounds. 128 structures were reviewed; a "strong recommendation" is made for 35 structures on orientation scanning and 28 for the block view. A "weak recommendation" is made for 36 and 20 structures, respectively. This study provides recommendations on the core (minimum) set of anatomical structures to identify during ultrasound scanning for seven basic blocks in UGRA. They are intended to support consistent practice, empower non-experts using basic UGRA techniques, and standardize teaching and research.

Interests and concerns regarding medical marijuana among chronic pain patients in Ohio: an online survey

Background

Since the legalization of medical marijuana (MMJ) in Ohio in 2018, many chronic pain (CP) patients have become interested in it as an alternative or adjunct to prescription opioids. This has not only created a need for pain management specialists to learn about this potential indication for MMJ but also for them to have more detailed knowledge of patient attitudes and willingness to comply with providers’ recommendations regarding its safe use with other pain medications. For this purpose, we surveyed CP patients in a region severely affected by the opioid crisis in order to provide better education, formulate treatment plans, and develop clinical policies.

Methods

We designed and administered the Medical Marijuana Interest Questionnaire (MMIQ) online to patients of the Western Reserve Hospital Center for Pain Medicine (CPM) with a diagnosis of CP who were not yet using MMJ. Questions addressed demographic and clinical characteristics, willingness to consider MMJ, and compliance with treatment plans and concerns. We then carried out a statistical analysis including Pearson chi-square, Spearman’s rho and Kendall’s tau tests to measure associations between variables to identify factors that may influence willingness to use MMJ.

Results

After sending 1047 email invitations to complete the MMIQ, 242 (23.1%) completed questionnaires were returned. The average age range of all respondents was 51-60 years, 171 (70.7%) were female and 147 (60.7%) were current opioid users. The 204 (84.3%) respondents who were willing to consider using MMJ were given access to the entire questionnaire. Of these, 138 (67.6%) reported wanting to use less opioids after starting MMJ and 191 (93.6%) were amenable to following their pain specialists’ recommendations about using MMJ concurrently with opioids. Their greatest concern on a 0-5 scale was affordability (2.98) and there was a statistically significant negative correlation between older age and preference for inhaled forms (p = 0.023).

Conclusion

The MMIQ was successful in eliciting important data regarding patients’ attitudes about MMJ for opioid titration and potential compliance. Our study was limited by being administered online rather than in-person, which skewed the demographic makeup of the sample. The MMIQ can be used to study similar populations or adapted to patients already using MMJ. Similar surveys of MMJ-experienced patients could be combined with chart reviews to study the success of these products for pain control and opioid substitution.

Making a business plan for starting a transitional pain service within the US healthcare system

Chronic pain imposes a tremendous economic burden of up to US$635 billion per year in terms of direct costs (such as the costs of treatment) and indirect costs (such as lost productivity and time away from work). In addition, the initiation of opioids for pain is associated with a more than doubling of pharmacy and all-cause medical costs. The high costs of chronic pain are particularly relevant for anesthesiologists because surgery represents an inciting event that can lead to chronic pain and long-term opioid use. While the presence of risk factors and an individual patient's postoperative pain trajectory may predict who is at high risk for chronic pain and opioid use after surgery, to date, there are few interventions proven to reduce these risks. One promising approach is the transitional pain service. Programs like this attempt to bridge the gap between acute and chronic pain management, provide continuity of care for complicated acute pain patients after discharge from the hospital, and offer interventions for patients who are on abnormal trajectories of pain resolution and/or opioid use. Despite awareness of chronic pain after surgery and the ongoing opioid epidemic, there are few examples of successful transitional pain service implementation in the USA. Key issues and concerns include financial incentives and the required investment from the hospital or healthcare system. We present an economic analysis and discussion of important considerations when developing a business plan for a transitional pain service.

Radiation safety and knowledge: an international survey of 708 interventional pain physicians

INTRODUCTION

Interventional pain procedures have increased in complexity, often requiring longer radiation exposure times and subsequently higher doses. The practicing physician requires an in-depth knowledge and evidence-based knowledge of radiation safety to limit the health risks to themselves, patients and healthcare staff. The objective of this study was to examine current radiation safety practices and knowledge among interventional pain physicians and compare them to evidence-based recommendations.

MATERIALS AND METHODS

A 49-question survey was developed based on an extensive review of national and international guidelines on radiation safety. The survey was web-based and distributed through the following professional organizations: Association of Pain Program Directors, American Academy of Pain Medicine, American Society of Regional Anesthesia and Pain Medicine, European Society of Regional Anesthesia and Pain Therapy, International Neuromodulation Society, and North American Neuromodulation Society. Responses to radiation safety practices and knowledge questions were evaluated and compared with evidence-based recommendations. An exploratory data analysis examined associations with radiation safety training/education, geographical location, practice type, self-perceived understanding, and fellowship experience.

RESULTS

Of 708 responding physicians, 93% reported concern over the health effects of radiation, while only 63% had ever received radiation safety training/education. Overall, ≥80% physician compliance with evidence-based radiation safety practice recommendations was demonstrated for only 2/15 survey questions. Physician knowledge of radiation safety principles was low, with 0/10 survey questions having correct response rates ≥80%.

CONCLUSION

We have identified deficiencies in the implementation of evidence-based practices and knowledge gaps in radiation safety. Further education and training are warranted for both fellowship training and postgraduate medical practice. The substantial gaps identified should be addressed to better protect physicians, staff and patients from unnecessary exposure to ionizing radiation during interventional pain procedures.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part II: recommendations

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine Society (ASRA) commissioned this narrative review to provide recommendations for POCUS. The recommendations were written by content and educational experts and were approved by the guidelines committee and the Board of Directors of the ASRA. In part II of this two-part series, learning goals and objectives were identified and outlined for achieving competency in the use of POCUS, specifically, airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma exam, and focused cardiac ultrasound, in the perioperative and chronic pain setting. It also discusses barriers to POCUS education and training and proposes a list of educational resources. For each POCUS section, learning goals and specific skills were presented in the Indication, Acquisition, Interpretation, and Medical decision-making framework.

American Society of Regional Anesthesia and Pain Medicine expert panel recommendations on point-of-care ultrasound education and training for regional anesthesiologists and pain physicians-part I: clinical indications

Point-of-care ultrasound (POCUS) is a critical skill for all regional anesthesiologists and pain physicians to help diagnose relevant complications related to routine practice and guide perioperative management. In an effort to inform the regional anesthesia and pain community as well as address a need for structured education and training, the American Society of Regional Anesthesia and Pain Medicine (ASRA) commissioned this narrative review to provide recommendations for POCUS. The guidelines were written by content and educational experts and approved by the Guidelines Committee and the Board of Directors of the ASRA. In part I of this two-part series, clinical indications for POCUS in the perioperative and chronic pain setting are described. The clinical review addresses airway ultrasound, lung ultrasound, gastric ultrasound, the focus assessment with sonography for trauma examination and focused cardiac ultrasound for the regional anesthesiologist and pain physician. It also provides foundational knowledge regarding ultrasound physics, discusses the impact of handheld devices and finally, offers insight into the role of POCUS in the pediatric population.

A physician survey of perioperative neuraxial anesthesia management in patients on a direct oral anticoagulant

BACKGROUND

The perioperative management of patients taking a direct oral anticoagulant (DOAC) who require a high-bleed-risk surgery and/or neuraxial anesthesia is uncertain. We surveyed clinician practices relating to DOAC interruption and related perioperative management in patients having high-bleed-risk surgery with neuraxial anesthesia, and assess the suitability of a randomized trial of different perioperative DOAC management strategies.

METHODS

We surveyed members of the American Society of Regional Anesthesia and Pain Medicine, the Canadian Anesthesia Society and Thrombosis Canada. We developed four clinical scenarios involving DOAC-treated patients who required anticoagulant interruption for elective high-bleed-risk surgery. In three scenarios, patients were to receive neuraxial anesthesia, and in one scenario they were to receive general anesthesia. We also asked about the merit of a randomized trial to compare a 2-day versus longer (3- to 5-day) duration of DOAC interruption.

RESULTS

There were 399 survey respondents of whom 356 (89%) were anesthetists and 43 (11%) were medical specialists. The responses indicate uncertainty about the DOAC interruption interval for high-bleed-risk surgery and/or neuraxial anesthesia; anesthetists favor 3- to 5-day interruption whereas medical specialists favor 2-day interruption. Anesthetists were unwilling to proceed with neuraxial anesthesia in patients with a 2-day DOAC interruption interval, preferring to cancel the surgery or switch to general anesthesia. There is general agreement on the need for a randomized trial in this field to compare a 2-day and a 3- to 5-day DOAC interruption management strategy.

CONCLUSIONS

There is variability in practices relating to the perioperative management of DOAC-treated patients who require a high-bleed-risk surgery with neuraxial anesthesia; this variability relates to the duration of DOAC interruption in such patients.

Topical intranasal lidocaine is not a sphenopalatine ganglion block

There is renewed interest in the central role of the sphenopalatine ganglion (SPG) in cerebrovascular autonomic physiology and the pathophysiology of different primary and secondary headache disorders. There are diverse neural structures (parasympathetic, sympathetic and trigeminal sensory) that convene into the SPG which is located within the pterygopalatine fossa (PPF). This makes the PPF an attractive target to neuromodulatory interventions of these different neural structures. Some experts advocate for the nasal application of local anesthetics as an effective route for SPG block with the belief that the local anesthetic can freely access the PPF. It is time to challenge this historical concept from the early 1900s. In this daring discourse, I will review anatomical studies, CT and MRI reports to debunk this old myth. Will provide anatomical evidence to explain that all these assumptions are untrue and the local anesthetic has to magically 'travel' a distance of 4-12 mm of adipose and connective tissue to reach the SPG in sufficient concentration and volume to effectively induce SPG blockade. Future research should focus on assessing a clinical biomarker to confirm SPG blockade. It could be regional cerebral blood flow or lacrimal gland secretion.

Antinociception mechanisms of action of cannabinoid-based medicine: an overview for anesthesiologists and pain physicians

Cannabinoid-based medications possess unique multimodal analgesic mechanisms of action, modulating diverse pain targets. Cannabinoids are classified based on their origin into three categories: endocannabinoids (present endogenously in human tissues), phytocannabinoids (plant derived) and synthetic cannabinoids (pharmaceutical). Cannabinoids exert an analgesic effect, peculiarly in hyperalgesia, neuropathic pain and inflammatory states. Endocannabinoids are released on demand from postsynaptic terminals and travels retrograde to stimulate cannabinoids receptors on presynaptic terminals, inhibiting the release of excitatory neurotransmitters. Cannabinoids (endogenous and phytocannabinoids) produce analgesia by interacting with cannabinoids receptors type 1 and 2 (CB1 and CB2), as well as putative non-CB1/CB2 receptors; G protein-coupled receptor 55, and transient receptor potential vanilloid type-1. Moreover, they modulate multiple peripheral, spinal and supraspinal nociception pathways. Cannabinoids-opioids cross-modulation and synergy contribute significantly to tolerance and antinociceptive effects of cannabinoids. This narrative review evaluates cannabinoids' diverse mechanisms of action as it pertains to nociception modulation relevant to the practice of anesthesiologists and pain medicine physicians.

Consensus practice guidelines on interventions for lumbar facet joint pain from a multispecialty, international working group

BACKGROUND

The past two decades have witnessed a surge in the use of lumbar facet blocks and radiofrequency ablation (RFA) to treat low back pain (LBP), yet nearly all aspects of the procedures remain controversial.

METHODS

After approval by the Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, letters were sent to a dozen pain societies, as well as representatives from the US Departments of Veterans Affairs and Defense. A steering committee was convened to select preliminary questions, which were revised by the full committee. Questions were assigned to 4-5 person modules, who worked with the Subcommittee Lead and Committee Chair on preliminary versions, which were sent to the full committee. We used a modified Delphi method, whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chair, who incorporated the comments and sent out revised versions until consensus was reached.

RESULTS

17 questions were selected for guideline development, with 100% consensus achieved by committee members on all topics. All societies except for one approved every recommendation, with one society dissenting on two questions (number of blocks and cut-off for a positive block before RFA), but approving the document. Specific questions that were addressed included the value of history and physical examination in selecting patients for blocks, the value of imaging in patient selection, whether conservative treatment should be used before injections, whether imaging is necessary for block performance, the diagnostic and prognostic value of medial branch blocks (MBB) and intra-articular (IA) injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for a prognostic block, how many blocks should be performed before RFA, how electrodes should be oriented, the evidence for larger lesions, whether stimulation should be used before RFA, ways to mitigate complications, if different standards should be applied to clinical practice and clinical trials and the evidence for repeating RFA (see table 12 for summary).

CONCLUSIONS

Lumbar medial branch RFA may provide benefit to well-selected individuals, with MBB being more predictive than IA injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of more false-negatives. Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Neuraxial anaesthesia and peripheral nerve blocks during the COVID-19 pandemic: a literature review and practice recommendations

Coronavirus disease 2019 (COVID‐19) has had a significant impact on global healthcare services. In an attempt to limit the spread of infection and to preserve healthcare resources, one commonly used strategy has been to postpone elective surgery, whilst maintaining the provision of anaesthetic care for urgent and emergency surgery. General anaesthesia with airway intervention leads to aerosol generation, which increases the risk of COVID‐19 contamination in operating rooms and significantly exposes the healthcare teams to COVID‐19 infection during both tracheal intubation and extubation. Therefore, the provision of regional anaesthesia may be key during this pandemic, as it may reduce the need for general anaesthesia and the associated risk from aerosol‐generating procedures. However, guidelines on the safe performance of regional anaesthesia in light of the COVID‐19 pandemic are limited. The goal of this review is to provide up‐to‐date, evidence‐based recommendations or expert opinion when evidence is limited, for performing regional anaesthesia procedures in patients with suspected or confirmed COVID‐19 infection. These recommendations focus on seven specific domains including: planning of resources and staffing; modifying the clinical environment; preparing equipment, supplies and drugs; selecting appropriate personal protective equipment; providing adequate oxygen therapy; assessing for and safely performing regional anaesthesia procedures; and monitoring during the conduct of anaesthesia and post‐anaesthetic care. Implicit in these recommendations is preserving patient safety whilst protecting healthcare providers from possible exposure.