D. Norman Buckley

Epidural morphine reduces the riskof postoperative myocardial ischaemia in patients with cardiac risk factors

Perioperative myocardial ischaemia is a predictor of postoperative cardiac morbidity (PCM). Epidural anaesthesia and adequate perioperative analgesia have been shown to improve myocardial oxygen dynamics due to interruption of pain and sympathetic pathways. The aim of the present study was to compare the incidence of ischaemia after either general anaesthesia followed by parenteral analgesia with morphine or combined epidural/general anaesthesia followed by analgesia with epidural morphine. In a prospective observer-blinded analysis of the occurrence of ischaemia, 55 patients (epidural = 29/ parenteral = 26) scheduled for elective surgery with defined risks for ischaemic cardiac disease were entered and followed for 24 hr after surgery with two-lead continuous Hotter monitoring. Groups were similar with respect to age, weight, modified Goldman (Detsky) risk classification and the use of cardiac medications. Fewer patients receiving the epidural anaesthesia/ analgesia had ischaemic episodes (17.2 vs 50.0%, P = 0.01), and tachyarrhythmias (20.7 vs 50.0%, P < 0.05). Epidural patients had a four-fold reduction of the relative risk for either event (P < 0.001). All ischaemic events were asymptomatic and unrecognized (silent). All major morbid events (n = 5) (MI, congestive heart failure and death) occurred in patients who had perioperative episodes of ischaemia. There were three distinct peaks in onset of ischaemia, at 1–4 hr, 9–12 hr and 22–24 hr postoperatively. One third of postoperative ischaemic events occurred within the first four hours after operation and lasted from 1 to 31 min. Forty-two percent of ischaemic episodes were associated with a heart rate > 100 bpm, or an increase of 20% over the baseline heart rate. We conclude that epidural anaesthesia/analgesia reduces but does not eliminate the risk of myocardial ischaemia and tachyarrhythmia. We were unable to determine any associated reduction in the risk of PCM.RésuméL’ischémie myocardique périopératoire a une bonne valeur pronostique sur la morbidité cardiaque postopératoire (MCP). II a été démontré que l’anesthésie et l’analgésie post-opératoire épidurales favorisaient l’oxygénation myocardique par interruption des voies de conductions algiques et sympathiques. L’objectif de la présente étude est de comparer l’incidence de l’ischémie après l’anesthésie générale suivie d’analgésie parentérale à la morphine à l’association anesthésie générale-épidurale suivie d’analgésie à la morphine épidurale. Sont inclus dans cette étude prospective, à l’insu de l’observateur, 55 patients (29 dans le group épidural, 26 dans le groupe parentéral) programmés pour une chirurgie réglée et présentant des risques définis de maladie cardiaque ischémique. Les patients sont monitorés continuellement pendant 24 heures après la chirurgie avec un Hotter à deux dérivations. Il n’y a pas de différence entre les deux groupes pour l’âge, le poids, l’échelle de risque de Goldman (Detsky) et la médication cardiaque. Moins de patients du groupe anesthésie générale-épidurale souffrent d’épisodes ischémiques (17,2 vs 50%, P = 0,01), et de tachyarythmies (20,7 vs 50%, P < 0,05). Les patients du groupe épidural courent un risque quatre fois moins élevé de souffrir de l’une ou de l’autre complication (P < 0,001). Tous les épisodes ischémiques ont été asymptomatiques et sont passés inaperçus. Toutes les complications (n = 5) (infarctus du myocarde, défaillance cardiaque et décès) sont survenus chez des patients qui avaient présenté de l’ischémie périopératoire. On a identifié trois pointes d’incidence ischémiques postopératoires: à 1–4 hres, 9–12 hres et 22–24 hres. Un tiers des épisodes ischemiques est survenu en-deçà de quatre heures après l’opération et a duré de 1 à 31 min. Quarante-deux pourcent de ces épisodes étaient associés à une fréquence de plus de cent b · min−1 ou à une augmentation de 20% du niveau de base. Nous concluons que l’anesthésie / analgésie épidurale diminue mais n’élimine pas le risque d’ischémie cardiaque et de tachyarythmies. Nous n’avons pas démontré une réduction associée de la MCP.

Continuous Intravenous Administration of Ketorolac Reduces Pain and Morphine Consumption After Total Hip or Knee Arthroplasty

The purpose of this study was to determine the analgesic efficacy, opioid-sparing effect, and tolerability of ketorolac administered as an intravenous (IV) bolus followed by a continuous infusion after total hip or knee arthroplasty. After general anesthesia, patients received either placebo or ketorolac 30 mg IV as a bolus over 15-30 s followed by a continuous IV infusion of ketorolac 5 mg/h for 24 h. All patients received patient-controlled IV morphine with no background infusion. Patients were assessed at 2, 4, 6, and 24 postoperatively with respect to analgesia, morphine consumption, side effects, and blood loss. Patients receiving ketorolac reported were less sedated and required fewer antiemetics. There was no difference in blood loss. Patients receiving ketorolac reported better analgesia and used less morphine (35% for hips and 44% for knees) than those receiving placebo. (Anesth Analg 1995;81:1175-80)

Guideline for opioid therapy and chronic noncancer pain

Chronic noncancer pain includes any painful condition that persists for at least three months and is not associated with malignant disease.[1][1] According to seven national surveys conducted between 1994 and 2008, 15%–19% of Canadian adults live with chronic noncancer pain.[2][2] Chronic

Management of Central Poststroke Pain Systematic Review of Randomized Controlled Trials

Background and Purpose— Central poststroke pain is a chronic neuropathic disorder that follows a stroke. Current research on its management is limited, and no review has evaluated all therapies for central poststroke pain. Methods— We conducted a systematic review of randomized controlled trials to evaluate therapies for central poststroke pain. We identified eligible trials, in any language, by systematic searches of AMED, CENTRAL, CINAHL, DARE, EMBASE, HealthSTAR, MEDLINE, and PsychINFO. Eligible trials (1) enrolled ≥10 patients with central poststroke pain; (2) randomly assigned them to an active therapy or a control arm; and (3) collected outcome data ≥14 days after treatment. Pairs of reviewers, independently and in duplicate, screened titles and abstracts of identified citations, reviewed full texts of potentially eligible trials, and extracted information from eligible studies. We used a modified Cochrane tool to evaluate risk of bias of eligible studies, and collected patient-important outcomes according to recommendations by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials. We conducted, when possible, random effects meta-analyses, and evaluated our certainty in treatment effects using the Grading of Recommendations Assessment, Development, and Evaluation System. Results— Eight eligible English language randomized controlled trials (459 patients) tested anticonvulsants, an antidepressant, an opioid antagonist, repetitive transcranial magnetic stimulation, and acupuncture. Results suggested that all therapies had little to no effect on pain and other patient-important outcomes. Our certainty in the treatment estimates ranged from very low to low. Conclusions— Our findings are inconsistent with major clinical practice guidelines; the available evidence suggests no beneficial effects of any therapies that researchers have evaluated in randomized controlled trials.

Management of chronic neuropathic pain: a protocol for a multiple treatment comparison meta-analysis of randomised controlled trials.

Introduction Chronic neuropathic pain is associated with reduced health-related quality of life and substantial socioeconomic costs. Current research addressing management of chronic neuropathic pain is limited. No review has evaluated all interventional studies for chronic neuropathic pain, which limits attempts to make inferences regarding the relative effectiveness of treatments. Methods and analysis We will conduct a systematic review of all randomised controlled trials evaluating therapies for chronic neuropathic pain. We will identify eligible trials, in any language, by a systematic search of CINAHL, EMBASE, MEDLINE, AMED, HealthSTAR, DARE, PsychINFO and the Cochrane Central Registry of Controlled Trials. Eligible trials will be: (1) enrol patients presenting with chronic neuropathic pain, and (2) randomise patients to alternative interventions (pharmacological or non-pharmacological) or an intervention and a control arm. Pairs of reviewers will, independently and in duplicate, screen titles and abstracts of identified citations, review the full texts of potentially eligible trials and extract information from eligible trials. We will use a modified Cochrane instrument to evaluate risk of bias of eligible studies, recommendations from the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to inform the outcomes we will collect, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to evaluate our confidence in treatment effects. When possible, we will conduct: (1) in direct comparisons, a random-effects meta-analysis to establish the effect of reported therapies on patient-important outcomes; and (2) a multiple treatment comparison meta-analysis within a Bayesian framework to assess the relative effects of treatments. We will define a priori hypotheses to explain heterogeneity between studies, and conduct meta-regression and subgroup analyses consistent with the current best practices. Ethics and Dissemination We do not require ethics approval for our proposed review. We will disseminate our findings through peer-reviewed publications and conference presentations. Trial registration number PROSPERO (CRD42014009212).

Reporting of IMMPACT-recommended core outcome domains among trials assessing opioids for chronic non-cancer pain.

Abstract The Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) has recommended that trialists evaluating treatments for chronic pain should consider reporting 9 patient-important outcome domains. We examined the extent to which clinical trials evaluating the effect of opioids for chronic non-cancer pain (CNCP) report outcome domains recommended by IMMPACT. We systematically searched electronic databases for English-language studies that randomized patients with CNCP to receive an opioid or a non-opioid control. In duplicate and independently, reviewers established the eligibility of each identified study and recorded all reported outcome domains from eligible trials. We conducted a priori regression analyses to explore factors that may be associated with IMMPACT-recommended outcome domains. Among 156 eligible trials, reporting of IMMPACT-recommended outcome domains was highly variable, ranging from 99% for pain to 7% for interpersonal functioning. Recently published trials were more likely to report the effect of treatment on physical functioning, emotional functioning, role functioning, sleep and fatigue, and participant disposition. Trials for which the corresponding author was from North America were more likely to report treatment effects on physical functioning and participant ratings of improvement and satisfaction with treatment. Trials published in higher impact journals were more likely to report treatment effects on emotional function, but less likely to report participant ratings of improvement and satisfaction with treatment. Most IMMPACT domains showed an increased rate of reporting over time, although many patient-important outcome domains remained unreported by over half of all trials evaluating the effects of opioids for CNCP.

Development of an algorithm to identify preoperative medical consultations using administrative data.

Background:Preoperative consultation by internal medicine specialists may help improve the care of patients undergoing major surgery. Population-based administrative data are an efficient approach for studying these consultations at a population-level. However, administrative data in many jurisdictions lack specific codes to identify preoperative medical consultations, as opposed to consultations for nonoperative indications. Objective:To develop an accurate claims-based algorithm for identifying preoperative medical consultations before major elective noncardiac surgery. Research Design:We conducted a multicenter cross-sectional study in Ontario, Canada. Preoperative medical consultations identified by medical record abstraction were compared with those identified by linked administrative data (physician service claims, hospital discharge abstracts). Subjects:We randomly selected 606 individuals, aged older than 40 years, who underwent elective intermediate-to-high-risk noncardiac surgery at 8 randomly selected hospitals between April 1, 2002 and March 31, 2004. Results:Medical record abstraction identified preoperative medical consultations in 317 patients (52%). The optimal claims-based algorithm for identifying these consultations was a physician service claim for a consultation by a cardiologist, general internist, endocrinologist, geriatrician, or nephrologist within 4 months before the index surgical procedure. This algorithm had a sensitivity of 90% (95% confidence interval [CI]: 86–93), specificity of 92% (95% CI: 88–95), positive predictive value of 93% (95% CI: 89–95), and negative predictive value of 90% (95% CI: 86–93). Conclusions:A simple claims-based algorithm can accurately identify preoperative medical consultations before major elective noncardiac surgery. This algorithm may help enhance population-based evaluations of preoperative care, provided that the requisite linked administrative healthcare data are present.

Prophylactic Diclectin reduces the incidence of postoperative vomiting.

BackgroundDiclectin® (DCL) is an effective antiemetic used for relief of nausea and vomiting in pregnancy. It is unknown whether DCL is effective in the prevention of postoperative nausea and vomiting (PONV).MethodsWe conducted a randomized, stratified, double-blind placebo-controlled trial to examine the incidence of PONV in women undergoing elective laparoscopic tubal ligation in the day surgery setting. DCL (doxylamine succinate 10 mg and pyridoxine hydrochloride 10 mg) was administered orally the night before surgery, the morning of surgery, and upon hospital discharge.ResultsWe enrolled 146 women in the trial, 127 of whom were included in the effectiveness analysis and 102 of whom were included in the efficacy analysis. We did not detect a difference in the incidence of nausea and vomiting in the first six hours postoperatively after adjusting for additional antiemetics administered. Patients receiving DCL as compared with placebo were significantly less likely to experience vomiting six to 24 hr postoperatively [5/59 (8.5%)vs 14/55 (25.4%),P < 0.0 17], Treated patients tended to return to work earlier than those who received placebo (1.74vs 3.7 daysP = NS).ConclusionPerioperative oral DCL reduces the incidence of postoperative vomiting in women undergoing elective laparoscopic tubal ligation, and may accelerate return to work.RésuméContexteLe Diclectin® (DCL) est un antiémétique efficace contre les nausées et les vomissements pendant la grossesse. On ne sait pas s’il peut prévenir les nausées et vomissements postopératoires (NVPO).MéthodeNous avons réalisé une étude randomisée, stratifiée et à double insu contre placebo pour vérifier l’incidence de NVPO chez des femmes qui subissent une ligature des trompes laparoscopique réglée en chirurgie d’un jour. Le DCL (10 mg de succinate de doxylamine et 10 mg de chlorhydrate de pyridoxine) a été administré oralement le soir avant l’opération, le matin de l’opération et lors du départ de l’hôpital.RésultatsNous avons recruté 146 femmes, dont 127 pour l’analyse d’efficacité et 102 pour l’analyse de l’activité. Nous n’avons pas noté de différence d’incidence de nausées et de vomissements pendant les six premières heures postopératoires après ajustement pour les antiémétiques supplémentaires administrés. Les patientes recevant le DCL, comparé au placebo, ont eu signifcativement moins de vomissements de six à 24 h après l’opération [5/59 (8,5 %) vs 14/55 (25,4 %), P < 0,017]. Les patientes traitées sont retournées plus tôt au travail que celles qui ont reçu le placebo (1,74 vs 3,7 jours P = NS). Conclusion: Le DCL périopératoire oral réduit l’incidence de vomissements postopératoires chez les femmes qui subissent une ligature des trompes laparoscopique réglée et il peut hâter le retour au travail.

Best evidence in anesthetic practice Prevention: Intraoperative neuraxial blockade reduces some postoperative complications

Structured abstractQuestionWhat are the effects of neuraxial blockade with epidural or spinal anesthesia on postoperative morbidity and mortality?Data sourcesStudies were identified by computerized searches of Current Contents (1995–6), EMBASE (1980–96), MEDLINE (1966–96), and the Cochrane Library (1988) using the keywords “regional anesthesia”, “regional anaesthesia”, “spinal”, or “epidural” and the Cochrane Collaboration search terms for randomized trials. Citation review of reference lists and hand search of conference proceedings were also performed.Study selectionStudies were selected if they were trials of patients randomized to intraoperative neuraxial blockade (epidural or spinal anesthesia) or general anesthesia. The neuraxial anesthesia group could also receive general anesthesia concurrently; the general anesthesia group could also receive postoperative neuraxial blockade.Data extractionData were extracted on trial design, interventions, patient characteristics, and events. The main outcomes were all cause mortality, deep vein thrombosis (DVT), pulmonary embolism (PE), myocardial infarction (MI), transfusion requirements, pneumonia, other infections, respiratory depression, and renal failure.Main resultsOne hundred forty-one trials with a total of 9559 patients met the inclusion criteria. Neuraxial blockade significantly reduced 30-day all cause mortality, DVT, PE, transfusion requirements, and respiratory depression (Table I). Reductions were noted in MI, stroke, wound infections, and renal failure, but these were not statistically significant. There were no differences in the number of deaths between 30 days and six months after surgery.ConclusionsIntraoperative neuraxial blockade reduces 30-day all cause mortality, thromboembolic events, transfusion requirements, and respiratory depression.FundingHealth Research Council of New Zealand, Astra Zeneca.

Somatosensory rehabilitation for allodynia in complex regional pain syndrome of the upper limb: A retrospective cohort study

Study Design: Retrospective cohort study. Introduction: Somatosensory rehabilitation is a standardized method of evaluation and conservative treatment of painful disorders of vibrotactile sensation, including the mechanical allodynia and burning pain of complex regional pain syndrome (CRPS). Purpose of the Study: The purpose of this study was to examine the effectiveness of somatosensory rehabilitation for reducing allodynia in persons with CRPS of 1 upper limb in a retrospective consecutive cohort of patients. Methods: An independent chart review of all client records (May 2004‐August 2015) in the Somatosensory Rehabilitation Centre (Fribourg, Switzerland) identified 48 persons meeting the Budapest criteria for CRPS of 1 limb who had undergone assessment and treatment. Outcomes of interest were the French version of the McGill Pain Questionnaire (Questionnaire de la Douleur St‐Antoine [QDSA]), total area of allodynia as recorded by mapping the area of skin where a 15‐g monofilament was perceived as painful, and the allodynia threshold (minimum pressure required to elicit pain within the allodynic territory). Results: This cohort was primarily women (70%), with a mean age of 45 years (range: 18‐74). Mean duration of burning pain was 31 months (range: 1 week‐27.5 years), and baseline QDSA core was 48. The average primary area of allodynia was 66 cm2 (range: 2.6‐320), and the most common allodynia threshold was 4.0 g. The average duration of treatment was 81 days. At cessation of treatment, the average QDSA score was 20 (effect size Cohens d = 1.64). Allodynia completely resolved in 27 persons (56% of the total sample where only 58% completed treatment). Discussion: This uncontrolled retrospective study suggests that somatosensory rehabilitation may be an effective treatment with a large effect size for reducing the allodynia and painful sensations associated with CRPS of the upper limb. More work is in progress to provide estimates of reliability and validity for the measurement tools for allodynia employed by this method. Level of Evidence: 2c.