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OBJECTIVE:To test the hypothesis that subjective reports of pain severity, pain intensity and functional disability correlate positively with catastrophizing.PATIENTS:Adults with chronic low back pain for six months or longer presenting to a tertiary care Pain Management Unit.METHODS:Catastrophizing was measured with the Pain Catastrophizing Scale (PCS) in 40 subjects (23 males, 17 females). Functional disability was measured with the Pain Disability Index and pain severity/intensity was quantified with the McGill Pain Questionnaire. Statistical analysis included Student'sttest and Pearson correlation analysis.RESULTS:Student'sttests on all dependent variables showed no significant sex differences. Correlational analysis revealed a significant relationship between catastrophizing and pain severity (r=0.35, PCONCLUSIONS:These observations support the finding that disability in chronic pain results from various causes, and is not solely a function of pain or pathology. The helplessness component of catastrophizing is most strongly related to disability. The implication of this finding is that psychological variables need proper assessment when there is significant disability. The PCS appears to be a useful tool to delineate further psychological components of chronic pain.

OBJECTIVE: To provide clinicians with guidelines for the use of cannabinoid compounds in the treatment of chronic pain.METHODS: Publications indexed from 1990 to 2005 in the National Library of Medicine Index Medicus were searched through PubMed. A consensus concerning these guidelines was achieved by the authors through review and discussion.RESULTS: There are few clinical trials, case reports or case series concerning the use of cannabinoid compounds in the treatment of chronic pain. There are no randomized clinical trials examining the use of herbal cannabis in the treatment of chronic pain.CONCLUSIONS: A practical approach to the treatment of chronic pain with cannabinoid compounds is presented. Specific suggestions about the off-label dosing of nabilone (Cesamet, Valeant Canada limitée/Limited) and dronabinol (Marinol, Solvay Pharma Inc, Canada) in the treatment of chronic pain are provided.

In the popular press, many Canadians claim to be using herbal cannabis (marijuana) to control symptoms such as pain, nausea, muscle spasm, anorexia and anxiety that may be associated with diseases like AIDS/HIV, multiple sclerosis, epilepsy and chronic pain. Surveys of patients with chronic pain, multiple sclerosis and epilepsy suggest that approximately 10% to 12% of these patients are active cannabis users, and up to 36% have tried using herbal cannabis or its derivatives to control symptoms they experience with these diseases (1-3). On the other hand, the prescription cannabinoids available have, to date, only limited use in the management of pain. Neither nabilone (Cesamet, Valeant Canada limitee/Limited) nor dronabinol (Marinol, Solvay Pharma Inc, Canada) have pain as an indication according to the Canadian Compendium of Pharmaceuticals and Specialties (4), while Sativex (GW Pharma Ltd, United Kingdom) is only indicated for neuropathic pain in multiple sclerosis. Although there is a large and growing preclinical literature regarding potential therapeutic uses of cannabinoids, there are few studies on the clinical efficacy of natural and synthetic cannabinoids as analgesics. Previous available studies have involved only small numbers of subjects and were often of limited quality (5). An overview of the rapidly developing basic science relevant to potential analgesic actions of cannabinoids (6), which includes a review of the endogenous cannabinoid system; evidence of antinociceptive, antihyperalgesic and anti-inflammatory actions; and a review of the pharmacokinetics of cannabinoids (7) is presented in this special issue. Reviews of the current literature assist in understanding the possible toxic effects (8), safety (9) and risks of addiction (10) of cannabinoids. As with all pharmacologically active agents, currently available cannabinoids are associated with adverse effects, and it is important to be aware of these effects as clinicians begin to consider these agents in the treatment of pain. Examples include effects on drowsiness, attention and cognition, the possibility of exaggerating existing psychoses or provoking others long-term, postural hypotension and tachycardia. Further understanding the roles of the cannabinoid receptors (CB1 and CB2) and the development of new cannabinoid receptor agonists will allow us to maximize the analgesic efficacy and minimize the side effects caused by the cannabinoids. Development of novel agonists, which do not cross the bloodbrain barrier, alternative methods of delivery (ie, transdermal, buccal, rectal, etc), and further elaboration of ways to manipulate the endogenous cannabinoid system are all exciting areas of research that will lead to compounds exhibiting greater efficacy, and potentially fewer adverse effects. However, it will likely be several years before such compounds will be clinically available and, right now, we need to be familiar with the currently available compounds. The purpose of the present supplement to Pain Research & Management is to provide Canadian clinicians and researchers with comprehensive reviews of the current basic and clinical science regarding cannabinoids, along with up-to-date reviews of the literature relevant to safety, toxicity and the risk of addiction related to cannabinoids. The authors of the present supplement have developed an algorithm for use by clinicians in the assessment and treatment of chronic pain when cannabinoid compounds are considered. In addition, guidelines for the use of the two oral cannabinoid compounds that are currently available by prescription in Canada are provided. It is not possible to make recommendations about the buccal administered cannabinoid compound because information is limited. The use of smoked herbal cannabis should be discouraged; there is significant controversy regarding this route of delivery. There is no question that smoking is toxic, but can patients limit their risk by minimizing the dose? Do the benefits outweigh the risks in some cases? The answers to these questions await further study and, until inexpensive, safer and efficient methods of delivery are available, it is probable that some patients with pain and other symptoms will seek relief by smoking cannabis. Others may receive existing preparations for off-label use. It is the goal of the present supplement to assist clinicians, researchers and policy makers with these issues. EDITORIAL

Anesthesiologists are now frequently considered specialists in perioperative medicine. This view reflects changes in practice that have evolved over the last 20 years and are currently exemplified in many departments, including those specializing in pain medicine, pain management, and perioperative medicine. Postoperatively, many patients continue to receive inadequate analgesia, and poor pain control is the leading cause of post-discharge visits to the emergency room and early re-admission to hospital after surgery. Patients with preoperative chronic pain, especially those receiving opioids, have a high rate of unsatisfactory perioperative pain control. Chronic pain in Canada affects more than one in five Canadians. Consequently, many patients who come under our care suffer from chronic pain. These patients are more likely to be opioid-dependent and receiving one or more medications that act on the central nervous system. Patients’ complex medication profiles and their concurrent anxiety and mood disruption can have a substantial impact on the perioperative care that the anesthesiologist provides. Herein, we consider some of the special issues that anesthesiologists should understand concerning the management of patients with chronic pain in the perioperative setting. Preoperative pain, anxiety, and catastrophizing

To estimate the patterns and prevalence of cannabis use among patients with multiple sclerosis (MS), 220 patients were surveyed in Halifax, Nova Scotia. Seventy-two subjects (36%) reported ever having used cannabis for any purpose; 29 respondents (14%) reported continuing use of cannabis for symptom treatment. Medical cannabis use was associated with male gender, tobacco use, and recreational cannabis use. The symptoms reported by medical cannabis users to be most effectively relieved were stress, sleep, mood, stiffness/spasm, and pain.

Our comprehension of chronic pain and its consequences continues to improve, but at the same time the complexity of the nervous system continues to confound us. This review has attempted to draw attention to some of the controversies, some of the areas of progress, some thoughts about assessing outcome and how well we do in the management of chronic pain.

Neuropathische Schmerzen betreffen etwa 7–8 % der Bevolkerung und gehen mit erheblichen Kosten fur die Allgemeinheit einher. Fur verschiedene Antidepressiva, Antikonvulsiva, Opioide und Mischpraparate konnte die Wirksamkeit bei neuropathischen Schmerzen in randomisierten kontrollierten Studien (RCTs) gezeigt werden. Aus diesen Studien wurden dann Leitlinien entwickelt, die zumeist auf einer Berechnung der NNT (number needed to treat) beruhen, also der Anzahl an Patienten, die behandelt werden mussen, damit bei mind. einem Patienten eine 50 %-ige Schmerzlinderung eintritt.

OBJECTIVE: The present randomized, double-blinded, crossover study compared the efficacy and safety of a seven-day buprenorphine transdermal system (BTDS) and placebo in patients with low back pain of moderate or greater severity for at least six weeks.METHODS: Prestudy analgesics were discontinued the evening before random assignment to 5 μg/h BTDS or placebo, with acetaminophen 300 mg/codeine 30 mg, one to two tablets every 4 h to 6 h as needed, for rescue analgesia. The dose was titrated to effect weekly, if tolerated, to 10 μg/h and 20 μg/h BTDS. Each treatment phase was four weeks.RESULTS: Fifty-three patients (28 men, 25 women, mean [± SD] age 54.5±12.7 years) were evaluable for efficacy (completed two weeks or more in each phase). Baseline pain was 62.1±15.5 mm (100 mm visual analogue scale) and 2.5±0.6 (five-point ordinal scale). BTDS resulted in lower mean daily pain scores than in the placebo group (37.6±20.7 mm versus 43.6±21.2 mm on a visual analogue scale, P=0.0487; and 1.7±0.6 versus 2.0±0.7 on the ordinal scale, P=0.0358). Most patients titrated to the highest dose of BTDS (59% 20 μg/h, 31% 10 μg/h and 10% 5 μg/h). There were improvements from baseline in pain and disability (Pain Disability Index), Pain and Sleep (visual analogue scale), Quebec Back Pain Disability Scale and Short-Form 36 Health Survey scores for both BTDS and placebo groups, without significant differences between treatments. While there were more opioid-related side effects with BTDS treatment than with placebo, there were no serious adverse events. A total of 82% of patients chose to continue BTDS in a long-term open-label evaluation, in whom improvements in pain intensity, functionality and quality of life were sustained for up to six months without analgesic tolerance.CONCLUSION: BTDS (5 μg/h to 20 μg/h) represents a new treatment option for initial opioid therapy in patients with chronic low back pain.

The purpose of this study was to evaluate the efficacy of controlled-release (CR) tramadol and immediate-release (IR) tramadol in patients with moderate or greater intensity chronic noncancer pain.A total of 122 patients underwent washout from all opioids 2 to 7 days before randomization to 1 of 2 groups: active CR tramadol 200 mg every morning plus placebo IR tramadol 50 mg every 4 to 6 hours PRN rescue, or placebo CR tramadol 200 mg every morning plus active IR tramadol 50 mg every 4 to 6 hours PRN rescue. After 2 weeks, the doses were increased to CR tramadol 400 mg or placebo and IR tramadol 100 mg every 4 to 6 hours PRN or placebo, as rescue. After 4 weeks in the first phase, patients crossed over to the alternative treatment for another 4 weeks. Pain intensity (100-mm visual analog scale [VAS] and 5-point ordinal scales) was assessed twice daily in diaries. Pain intensity, Pain and Disability Index (PDI; 0-10 ordinal scale), Pain and Sleep Questionnaire (100-mm VAS), and analgesic effectiveness (7-point ordinal scale) were assessed at biweekly clinic visits.Sixty-five patients (35 men, 30 women) completed the study. Mean (SD) age was 56.5 (12.7) years; mean (SD) weight was 82.0 (18.5) kg. Daily diary pain intensity (mean [SD]) was significantly lower in the CR tramadol group than in the IR tramadol group in the last 2 weeks of each phase (completers: VAS, 29.9 [20.5] vs 36.2 [20.4] mm, P0.001; ordinal scale, 1.41 [0.7] vs 1.64 [0.6], P0.001; intent-to-treat [ITT] population: VAS, 32.5 [22.9] vs 38.6 [21.2] mm, P0.003; ordinal scale, 1.50 [0.8] vs 1.72 [0.7], P0.002). The overall pain intensity scores from the daily diary were also significantly better with CR tramadol for both the completers and ITT. Similar results were obtained on the biweekly VAS pain intensity questionnaire. No differences were found between treatments in total PDI or overall Pain and Sleep scores in either population. For the completers, both patients and investigators rated effectiveness higher for CR tramadol than for IR tramadol (P0.004 and P0.008 for patients and investigators, respectively).This study reports significant improvement in pain intensity with CR tramadol as compared with IR tramadol.

The Canadian Marihuana Medical Access Regulations (MMAR) program allows Health Canada to grant access to marihuana for medical use to those who are suffering from grave and debilitating illnesses. This is a report on a case series of 30 patients followed at a tertiary care pain management center in Nova Scotia who have used medicinal marihuana for 1-5 years under the MMAR program. Patients completed a follow-up questionnaire containing demographic and dosing information, a series of 11-point numerical symptom relief rating scales, a side effect checklist, and a subjective measure of improvement in function. Doses of marihuana ranged from less than 1 to 5g per day via the smoked or oral route of administration. Ninety-three percent of patients reported moderate or greater pain relief. Side effects were reported by 76% of patients, the most common of which were increased appetite and a sense of well-being, weight gain, and slowed thoughts. Limitations of the study include self-selection bias, small size, and lack of a control group. The need for further study using controlled trials is discussed along with an overview of the MMAR program.

OBJECTIVE: Individuals with chronic pain referred to specialist chronic pain management programs frequently wait months to years for assessment and care. In the authors' pain management program, approximately 600 patients are on the waiting list. An innovative recommendation program to encourage and educate referring physicians to continue active care of pain during this waiting period was developed.METHODS: All referrals to the Queen Elizabeth II Health Sciences Centre's Pain Management Unit for a one-year period were reviewed and triaged as either 'regular waiting list' or 'fast track'. Patients in the fast track group were seen within four months and required limited interventions or were urgent in nature. The regular waiting list group waited up to 27 months for assessment and development of a treatment plan. Treatment recommendations were faxed to the referring physician. A follow-up questionnaire was sent to each physician to assess whether these treatment recommendations were useful.RESULTS: Recommendations were faxed for 297 patients. One hundred forty-nine physicians returned the follow-up questionnaire. Ninety-five physicians used the recommendations and 68 patients followed the recommendations. Seventy-nine physicians felt that the recommendations were helpful to them in their care of the patient. For 39 patients, the recommendations were helpful. The most frequently used recommendations were those on medications (eg, tricylic antidepressants, anticonvulsants, nonsteroidal anti-inflammatory drugs and controlled-release opioids). Other modalities included participation in an interdisciplinary group program and physiotherapy.CONCLUSIONS: A triage review process with recommendations faxed to referring physicians was developed and put into action for one year. The recommendations were used by 32% of the physicians (64% of responding physicians). Fifty-three per cent of responding physicians felt that the recommendations were helpful in the care of their patient. This process led to a benefit in care, as perceived by the physician, in 26% of patients (of physicians who returned the questionnaire [13% of all patients]) on the waiting list for a tertiary care pain management unit.

Twenty eight subjects with refractory, moderate to severe peripheral neuropathic pain participated in an open label prospective trial examining perceived analgesic effect, patient satisfaction, and safety of topical amitriptyline 2%/ketamine 1% cream. Outcome measures included an 11-point numerical rating scale for pain intensity (NRS-PI), a 5-point satisfaction scale, blood chemistry screen, drug and metabolite levels, urinalyses, electrocardiogram (ECG), and physical examination. Adverse events were monitored. Twenty-one subjects completed the trial. At 6 months, subjects reported an average long-term reduction in pain of 34% (standard deviation [SD] = 37%); 5 subjects (25%) achieved 50% or greater reduction in pain and 1 subject (5%) achieved 100% reduction in pain. At 12 months, the average reduction in pain was 37% (SD = 40%); 7 subjects (40%) achieved 50% or greater pain reduction. At the end of the study, 89% of subjects rated their satisfaction as 3/5 or greater and 2 subjects (10%) were pain free. Minimal adverse events were reported and there were no serious medication related adverse events. Blood levels revealed minimal systemic absorption. In conclusion, topical 2% amitriptyline/ 1% ketamine cream was associated with long-term reduction (6-12 months) in perceived pain, moderate to complete satisfaction, and was well tolerated in treatment of neuropathic pain. There was no significant systemic absorption of amitriptyline or ketamine. Perspective This study demonstrates that topical 2% amitriptyline/1% ketamine, given over 6-12 months, is associated with long-term perceived analgesic effectiveness in treatment of neuropathic pain. Antidepressants and ketamine both produce multiple pharmacologic effects that may contribute to peripheral analgesia; such actions include block of peripheral N-methyl-D-aspartate receptors, local anesthetic properties, and interactions with adenosine systems.

The objective of the present study was to examine the relative contributions of different dimensions of catastrophic thinking (i.e. rumination, magnification, helplessness) to the pain experience and disability associated with neuropathic pain. Eighty patients with diabetic neuropathy, post-herpetic neuralgia, post-surgical or post-traumatic neuropathic pain who had volunteered for participation in a clinical trial formed the basis of the present analyses. Spontaneous pain was assessed with the sensory and affective subscales of the McGill Pain Questionnaire. Pinprick hyperalgesia and dynamic tactile allodynia were used as measures of evoked pain. Consistent with previous research, individuals who scored higher on a measure of catastrophic thinking (Pain Catastrophizing Scale; PCS) also rated their pain as more intense, and rated themselves to be more disabled due to their pain. Follow up analyses revealed that the PCS was significantly correlated with the affective subscale of the MPQ but not with the sensory subscale. The helplessness subscale of the PCS was the only dimension of catastrophizing to contribute significant unique variance to the prediction of pain. The PCS was not significantly correlated with measures of evoked pain. Catastrophizing predicted pain-related disability over and above the variance accounted for by pain severity. The findings are discussed in terms of mechanisms linking catastrophic thinking to pain experience. Treatment implications are addressed.

OBJECTIVES: To measure chronic pain patient volumes seen in primary care practice; to determine what medications physicians choose for the treatment of moderate to severe chronic pain; to identify barriers to the use of opioids in the treatment of chronic pain; and to assess physicians' attitudes toward the current management of chronic pain in Canada.DESIGN: A computer-assisted telephone survey of 100 regionally representative Canadian physicians with a defined interest in palliative care (PC, n=30) or noncancer pain (GP, n=70).SETTING: A survey was conducted by Ipsos-Reid in June 2001. Only physicians who met the eligibility criteria of having written 20 or more prescriptions for moderate to severe pain in the preceding four weeks or having devoted 20% of time to palliative care were eligible to participate.RESULTS: In one month, the average number of patients with moderate to severe chronic pain seen by PCs was 94.2; the average seen by GPs was 44.7. The pain experienced by 83.3% of GP patients was noncancer related. For chronic cancer pain, an opioid analgesic was the treatment of choice of 79% of physicians (48% preferred morphine, 21% codeine, 10% other). For moderate to severe chronic noncancer pain, opioids were the first-line treatment of only 32% of physicians (16% preferred codeine, 16% major opioids) because a significant number preferred either nonsteriodal anti-inflammatory drugs (29%) or acetaminophen (16%). Thirty-five per cent of GPs and 23% of PCs would never use opioids for noncancer pain, even when described as severe. Chronic pain was deemed by 68% of physicians to be inadequately managed. Almost 60% thought that pain management could be enhanced by improved physician education. Identified barriers to opioid use included addiction potential (37%) and side effects (25%). Seventeen per cent of GPs and 10% of PCs thought that regulatory sanctions limited opioid prescribing.CONCLUSIONS: Even among physicians experienced in chronic pain treatment, there is a reluctance to use opioids for severe nonmalignant pain. One-half of the survey participants believed that there was a need for improved physician education in pain management, including the use of opioids.

OBJECTIVE: The clinical utility of guidelines for conversion of patients from a combination analgesic preparation of acetaminophen 300 mg plus codeine 30 mg every 4 h to 6h as needed to scheduled controlled-release (CR) codeine every 12 h was evaluated.METHODS: Adult patients with chronic noncancer pain underwent a two-week evaluation on acetaminophen plus codeine, followed by eight weeks of treatment with CR codeine. Patients taking four to six tablets of acetaminophen plus codeine per day were transferred to 50 mg CR codeine every 12 h; those on seven to nine tablets were transferred to 100 mg every 12 h; those on 10 to 12 tablets were transferred to 150 mg every 12 h; and those on greater than 12 tablets were transferred to 200 mg every 12 h. Subsequent dose adjustments were permitted. Acetaminophen (325 mg) was available for rescue. Pain intensity (five-point categorical and 100 mm visual analog scale), pain related disability, adverse events and acceptability were assessed.RESULTS: Of the 140 patients enrolled, 95 completed eight weeks of treatment with CR codeine. During month 1 and month 2, the mean CR codeine daily doses were 295.7±119.1 mg and 390.3±163.4 mg, respectively. Pain scores during both CR codeine month 1 and 2 were significantly lower than on acetaminophen plus codeine (53.6±20.9 mm and 49.7±23.7 mm versus 59.6±17.5 mm; P=0.0003, P=0.0001, respectively). CR codeine treatment was rated as moderately or highly acceptable by 82% of patients compared with 50% for acetaminophen plus codeine (P=0.001). Only seven patients (5.9%) discontinued CR codeine treatment because of adverse events.CONCLUSION: The results confirm the safety, efficacy and patient acceptability of the initial conversion and maintenance dosing recommendations for CR codeine from a combination opioid/nonopioid analgesic.

Objective : To investigate the effect of chronic pain on processes that generate the mismatch negativity (MMN). Methods :Twelve participants with a diagnosis of chronic intractable pain were tested before and after pain treatment. During testing, event-related potentials were recorded while participants performed tasks of varying difficulty. Results : The amplitude of the MMN was found to be greater following a nerve block procedure compared to MMN amplitude when participants were experiencing chronic pain. This effect was found to occur in the MMN for difficult-to-detect tones elicited while participants were performing a simultaneous cognitively demanding visual task. MMN amplitude was found to be greater with attention to difficult-to-detect deviants during pain but not in no pain conditions. Conclusions : These results provide an electrophysiological correlate of previous findings that high levels of pain disrupt cognition during the performance of demanding tasks.

There has been a surge in interest in medicinal cannabis in Canada. We conducted a questionnaire survey to determine the current prevalence of medicinal cannabis use among patients with chronic non-cancer pain, to estimate the dose size and frequency of cannabis use, and to describe the main symptoms for which relief was being sought. Over a 6-week period in mid-2001, 209 chronic non-cancer pain patients were recruited in an anonymous cross-sectional survey. Seventy-two (35%) subjects reported ever having used cannabis. Thirty-two (15%) subjects reported having used cannabis for pain relief (pain users), and 20 (10%) subjects were currently using cannabis for pain relief. Thirty-eight subjects denied using cannabis for pain relief (recreational users). Compared to never users, pain users were significantly younger (P=0.001) and were more likely to be tobacco users (P=0.0001). The largest group of patients using cannabis had pain caused by trauma and/or surgery (51%), and the site of pain was predominantly neck/upper body and myofascial (68% and 65%, respectively). The median duration of pain was similar in both pain users and recreational users (8 vs. 7 years; P=0.7). There was a wide range of amounts and frequency of cannabis use. Of the 32 subjects who used cannabis for pain, 17 (53%) used four puffs or less at each dosing interval, eight (25%) smoked a whole cannabis cigarette (joint) and four (12%) smoked more than one joint. Seven (22%) of these subjects used cannabis more than once daily, five (16%) used it daily, eight (25%) used it weekly and nine (28%) used it rarely. Pain, sleep and mood were most frequently reported as improving with cannabis use, and 'high' and dry mouth were the most commonly reported side effects. We conclude that cannabis use is prevalent among the chronic non-cancer pain population, for a wide range of symptoms, with considerable variability in the amounts used. Discussions between patients and health care providers concerning cannabis use may facilitate education and follow up, and would allow side effects and potential interactions with other medications to be monitored. Clinical trials of cannabis for chronic non-cancer pain are warranted.

Waldman’s Atlas of Common Pain Syndromes, 3 Edition has been enhanced by the addition of 18 chapters, improved visuals with more ultrasound and radiographic images, and an expanded physical examination section. The author acknowledges that the motivation for this edition is ‘‘to help practitioners move beyond the constraints of our common diagnostic constructs’’ and ‘‘to focus on diagnosis rather than treatment’’. On-line access to the book is also available through Elsevier’s ExpertConsult (www.expertconsult.com). Each of the 124 chapters details a specific pain condition and provides a step-by-step approach which progresses from signs and symptoms through physical findings, laboratory and radiographic testing, treatment options, complications and pitfalls, and clinical pearls. Diagnostic codes (ICD-9 and -10) are provided for each condition, and a brief list of suggested readings is provided for each chapter. The extensive breadth of topics is separated into 16 sections, including Headache Pain Syndromes, Shoulder Pain Syndromes, Chest Wall Pain Syndromes, Hip and Lower Extremity Pain Syndromes, Ankle Pain Syndromes, etc. Each section comprises four to 15 chapters that detail specific pain conditions relevant to the particular body area. The entire list of conditions is comprehensive and covers most common pain syndromes. This author describes each pain condition clearly and in simple terms with details of the commonly observed signs and symptoms, the appropriate diagnostic testing that can be utilized, and a differential diagnosis for the pain syndrome. Images are often provided as examples of alternative diagnostic possibilities. The use of visual aids is especially helpful and the chapters are short and to the point. The suggested treatment for each of the pain conditions is typically laid out in a hierarchical manner with no indication of ‘‘best evidence’’ for the condition. A reader can only assume that the treatment approach is that of the author. Treatment recommendations are often generic in nature, e.g., use of NSAIDs, COXIBs, physical therapy, and injections, rather than specific regarding medications and/or modalities. Frequently, injection techniques are advocated as appropriate therapy and are described in detail, giving the reader the impression that the technique might be an important part of the treatment. In some instances, the recommendation to perform injections is not supported by current guidelines or by ‘‘evidence-based’’ medicine. Examples include the use of stellate ganglion blocks for reflex sympathetic dystrophy of the face, intercostal nerve blocks for truncal diabetic neuropathy, epidural injections for post-herpetic neuralgia, and injections for acute pancreatitis. The reader should bear in mind that the evidence for the use of injections for many pain conditions is weak and sometimes extremely limited. It should also be remembered that injection therapies do have side effects and complications that can be significant. Waldman does detail possible complications of nerve blocks in most chapters where they are suggested as part of treatment. The ‘‘Clinical Pearl’’ section at the end of each chapter is a useful summary of the pain condition, issues pertaining to the condition, as well as other conditions to be considered in the differential diagnosis, investigations, treatment, complications, and pitfalls. Some outdated terms are used in the book, e.g., reflex sympathetic dystrophy, and other terms are inappropriate, e.g., fibromyalgia of the cervical musculature. A. J. Clark, MD (&) Dalhousie University, Halifax, NS, Canada e-mail: john.clark@cdha.nshealth.ca

Although most patients suffering from pain related to upper urinary tract stones feel the discomfort on the same side as the stone, rarely it is perceived on the opposite side. We sought to identify the prevalence of this clinical scenario and to review possible explanations. The charts and x-rays of all patients with unilateral, symptomatic, radiologically identifiable upper urinary tract stones, seen at an outpatient clinic between June 1993 and August 1996, were reviewed retrospectively in terms of the side of the discomfort in comparison to the side of the stone. Three of 631 patients presented with contralateral or "mirror pain" secondary to a renal or ureteric calculus. In each case the symptoms resolved completely following successful extracorporeal shock wave lithotripsy or spontaneous passage of the stone.

A comprehensive peer review programme for anaesthesia departments in Nova Scotia was implemented in 1987 by the anaesthesia community. Departments are reviewed by peers at the request of the Head, Department of Anaesthesia, and the President of the Medical Staff. A confidential report with recommendations is written. Twenty-six reviews have been completed (to June 1993) and have most often documented deficiencies in: design of the anaesthesia record, anaesthesia staff recruitment, inadequate documentation of policies for anaesthesia and post-anaesthesia care, peer review/quality assurance processes, organizational structure of hospital medical staffs and operating room committees, and use of anaesthesia equipment that does not meet current (at date of review) CSA standards. In the four hospitals that have been reviewed twice, 24 of the 30 deficiencies noted on the first review had been corrected before the second review which occurred three to five years later. Nine new deficiencies were noted. Departments are encouraged to request a review every four or five years.

Pain causes considerable disability and discomfort in HIV (Human Immunodeficiency Virus) infected individuals. A large number of patients infected with HIV suffer from one or more pain-related syndromes. Pain is under-reported and suboptimally managed in these patients. An outline of the different pain syndromes, including headache, oral cavity pain, chest pain, abdominal pain, anorectal pain, musculoskeletal pain and peripheral neuropathic pain, and their aetiologies are discussed. Current pain management modalities, including non-narcotic and narcotic analgesics, tricyclic antidepressants, anticonvulsants, physical therapy and psychological techniques, are outlined. Treatment should be based on the same principles applied to the management of cancer-related pain. A multi-disciplinary, comprehensive approach to pain management will assist these individuals to achieve improved levels of comfort, function and quality of life in this ultimately terminal illness.

Acutepain ischaracterizedbyrapidonset,unpredictableandvariable intensity confounded by highly variable patient responses to analgesics. Consequently, a successful dose is difficult to predict and maintain. AeroLEF, a proprietary combination of free and liposome-encapsulated fentanyl for inhalation provides micro-doses of fentanyl per breath designed to allow real-time patientcontrolled dose selection. In this study, nineteen post-surgical patients with moderate to severe pain following ACL surgery, were instructed to self-administer AeroLEF via breath actuated nebulizer until they had achieved analgesia, experienced dose-limiting side effects, or completed the maximum available dose (1000 g emitted per nebulizer, 2 nebulizers allowed). Eighteen (95%) of the patients achieved analgesia following self-administration of AeroLEF. The median time to first perceptible analgesia was 2.7min. Mean plasma fentanyl concentration at first perceptible analgesia was 0.801ng.mL. Median time to effective analgesia was 17min. At analgesia, the mean plasma fentanyl level was 1.30ng.mL but varied widely among patients, covering a 6.5-fold concentration range (0.39 to 2.5 ng.mL) The mean duration of analgesia was 3.7h and the request for additional analgesics was associated with a decrease in mean plasma fentanyl levels to 0.887ng.mL (ranging from o.36ngmL to 1.584ngmL), comparable to the concentrations at first perceptible analgesia and consistent with reported ranges for minimal effective plasma fentanyl in post-surgicalpatients (0.34 to1.58ng.mL).A9-folddosingrangewas selected by patients in order to obtain analgesia with AeroLEF, emphasizing the inter-patient variability associated with opioid use. AeroLEF, at doses sufficient to establish analgesia, was well tolerated with no serious adverse events were reported. Adverse events were generally mild and commonly associated with opioid use in the post-operative period. These data suggest that selftitration to analgesia with AeroLEF offers a novel and effective approach to address the variability inherent in pain. Industry support provided by YM BioSciences Inc.

To the Editor: We read with interest the paper by Mak et al.1 concerning the use of methadone and tramadol for chronic pain in an actively employed police officer. It is well established that the use of potent opioid medications in chronic non-cancer pain is appropriate and comprises good clinical care. Several Canadian provincial Colleges of Physicians and Surgeons and the Canadian Pain Society have published guidelines for such use2 as well as those noted in this report. What we think is unique and important in this report are that works reports were prepared regularly by this officer’s employer for performance analysis. This individual was able to return to and function effectively in a demanding position. To our knowledge this is the first report of this type of evaluation in an individual using opioids for chronic noncancer pain. This finding lends support to what we frequently see in clinical practice; patients who are prescribed opioids for chronic non-cancer pain can and do return to productive life styles with control of their pain and with minimal impairment in psychomotor functioning. Zacny has reviewed the effects of opioids in opioid dependent users on psychomotor and cognitive functioning and shown little effect.3 The same is true for the driving ability of individuals with cancer pain who are treated with opioids.4 Within the patients followed at our pain management unit we have more than 20 who use the equivalent of 300 mg or more of morphine per day, who lead productive lives and are able to perform everyday activities safely, such as driving. Some also continue to hold fulltime positions effectively. The use of an opioid on a chronic basis can be safe and effective.

Neuropathic pain (NeP), generated by disorders of the peripheral and central nervous system, can be particularly severe and disabling. Prevalence estimates indicate that 2% to 3% of the population in the developed world suffer from NeP, which suggests that up to one million Canadians have this disabling condition. Evidence-based guidelines for the pharmacological management of NeP are therefore urgently needed. Randomized, controlled trials, systematic reviews and existing guidelines focusing on the pharmacological management of NeP were evaluated at a consensus meeting. Medications are recommended in the guidelines if their analgesic efficacy was supported by at least one methodologically sound, randomized, controlled trial showing significant benefit relative to placebo or another relevant control group. Recommendations for treatment are based on degree of evidence of analgesic efficacy, safety, ease of use and cost-effectiveness. Analgesic agents recommended for first-line treatments are certain antidepressants (tricyclics) and anticonvulsants (gabapentin and pregabalin). Second-line treatments recommended are serotonin noradrenaline reuptake inhibitors and topical lidocaine. Tramadol and controlled-release opioid analgesics are recommended as third-line treatments for moderate to severe pain. Recommended fourth-line treatments include cannabinoids, methadone and anticonvulsants with lesser evidence of efficacy, such as lamotrigine, topiramate and valproic acid. Treatment must be individualized for each patient based on efficacy, side-effect profile and drug accessibility, including cost. Further studies are required to examine head-to-head comparisons among analgesics, combinations of analgesics, long-term outcomes, and treatment of pediatric and central NeP.

Instrumental climate data are only available for the last few hundred years. To extend this record back in time, climate proxies are used. However, on the geological timescale, the temporal resolution of most paleoclimate records does not provide information about seasonality, let alone events on the weather-timescale. These weather-timescale events are becoming more frequently integrated in models to predict future climate change, but reconstructions of variability with such short timescales in the geological record are extremely rare.A recent study by de Winter et al. (2020) has revealed that the Eocene giant marine gastropod Campanile giganteum (Lamarck, 1804) had growth rates exceeding 600 mm/year along the helix, far exceeding those of most other modern and fossil molluscs. With such high growth rates, these giant gastropods have the unique potential to record weather-timescale variability in the Eocene greenhouse world. Therefore, we generated a high-resolution (mm-scale) δ18O record on a well-preserved specimen of C. giganteum from the Paris Basin in Fleury-la-Rivière, France, in order to generate a unique ultra-high resolution record of intra-annual, weather-timescale variability in the Eocene. Our preliminary results show a clear seasonal pattern with δ18O values ranging between 0.1‰ and -2.5‰, superimposed by weekly variations of up to 0.5‰. This could provide insights in weather patterns in the Eocene greenhouse climate and potentially allow the identification of extreme weather events. Referencede Winter N.J., Vellekoop J., Clark A.J., Stassen P., Speijer R.P., Claeys P., (2020) The Giant Marine Gastropod Campanile Giganteum (Lamarck, 1804) as a High‐Resolution Archive of Seasonality in the Eocene Greenhouse World., Geochemistry, Geophysics, Geosystems, 21(4), https://doi.org/10.1029/2019GC008794