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Aims: The association between SNPs of the human OPRM1 gene encoding the µ-opioid receptor and postoperative analgesic requirements in surgical patients remains controversial. Here, we evaluate whether any of the five tag SNPs (A118G, IVS2+G691C, IVS3+G5953A, IVS3+A8449G and TAA+A2109G) representing the four linkage disequilibrium blocks of the OPRM1 gene influences postoperative analgesic requirements. Materials & methods: We studied 138 adult Japanese patients who underwent major open abdominal surgery under combined general and epidural anesthesia and received continuous postoperative epidural analgesia with opioids. Results: The 118G homozygous (GG) patients required 24-h postoperative analgesics more than 118A homozygous (AA) and heterozygous (AG) patients. Tag SNP haplotypes also were associated with 24-h postoperative analgesic requirements. Conclusions: These results suggest that OPRM1 gene tag SNP genotypes and haplotypes can primarily contribute to prediction of postoperative analgesic requirements in individual patients undergoing major open abdominal surgery. [ABSTRACT FROM AUTHOR]

BACKGROUND AND: objectives: A novel transdermal matrix patch delivery system for fentanyl has been developed to deliver improved management of cancer pain compared with that obtained using current fentanyl reservoir patches. This study was carried out to assess the efficacy, safety and pharmacokinetic profiles of a 12.5 µg/h transdermal matrix fentanyl patch administered with the objective of replacing morphine, oral oxycodone or fentanyl injection formulations. The study also evaluated how the pharmacokinetic profiles of higher dose fentanyl patches (25, 37.5 and 50 µg/h) changed following dose adjustments to optimize management of cancer pain. METHODS: This open-label, multicentre study involved 87 patients of both sexes (≥20 years) with a confirmed diagnosis of cancer. Patients were receiving any one of the following at the time of enrolment for the management of their cancer pain: (a) morphine <45 mg/day orally, <30 mg/day as suppositories, or <15 mg/day by injection; (b) oral oxycodone <30 mg/day; or (c) fentanyl injectable preparations <0.3 mg/day. The patients were administered a 3-day course of fentanyl transdermal matrix patch application three times. The initial dose was 12.5 µg/h, which could be increased when a new patch was applied if the physician deemed this to be appropriate based on pain intensity ratings and use of rescue medications. Efficacy outcomes included patients’ global assessment scores (primary efficacy endpoint) measured on a five-step scale and dichotomous scores for physicians’ global assessment. The occurrence of adverse events and changes in laboratory tests were evaluated as safety variables. Serum fentanyl levels were measured immediately after removal of the old patch on days 4, 7 and 10 to obtain data on trough serum concentrations. RESULTS: The percentage of patients in category 3 or higher (very satisfied, satisfied, or neither satisfied nor dissatisfied) for the patient’s global assessment score was 89.4% (76/85), indicating high patient satisfaction and attainment of sufficient pain control after patients switched from their previously used opioid analgesics. Similar findings were obtained on physicians’ global assessment scores. A total of 316 adverse events occurred in 78 (90.7%) of 86 patients who were administered at least one patch. These included nausea (31 [36.0%]), somnolence (26 [30.2%]), vomiting (22 [25.6%]), diarrhoea (17 [19.8%]), constipation (14 [16.3%]), pyrexia (11 [12.8%]) and insomnia (9 [10.5%]). The mean (+/- SD) serum fentanyl concentration determined on day 4 was 169.9 +/- 103.4 pg/mL (n = 83). Serum fentanyl measurement results indicated that the same fentanyl patch dose resulted in similar serum fentanyl levels, while increased doses produced higher serum fentanyl concentrations. CONCLUSION: The fentanyl matrix transdermal patch formulation employed in this study demonstrated sufficient cancer pain control for patients switching from morphine or oral oxycodone preparations. The patch tested was well tolerated and its use did not result in any increased incidence of adverse drug reactions over those commonly found with opioid analgesics. [ABSTRACT FROM AUTHOR]

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Objectives: Several studies have demonstrated the advantages of epiduroscopy versus conservative therapies for low back pain with few studies evaluating the results in operated and non-operated back patients. We compared the effects and complications of epiduroscopy between these patients. Patients and methods: A multi-institutional, prospective, clinical study was performed in 183 patients whose low back and leg pain had failed to respond to conservative therapies. Patients were divided into an operated back (Op) group and a non-operated (Non-op) group. Japanese Orthopedic Association (JOA) score, the Japanese version of the Roland-Morris Disability Questionnaire (JRMDQ) scores, and 100-mm visual analogue scales (VAS) for leg pain, leg numbness, low back pain and dissatisfaction with ADL were recorded before and at 1 month and 3 months after epiduroscopy. Results: All scores significantly improved at 1 month and 3 months after epiduroscopy in both groups. JOA scores in the Non-op group were significantly higher than those in the Op group at 1 month and 3 months; JRMDQ scores in the Non-op group were significantly lower than those in the Op group at 1 month. VAS grades in the Non-op group were significantly lower than those in the Op group for leg pain and low back pain at 1 month and 3 months, and for leg numbness and dissatisfaction with ADL at 1 month. No permanent complications were observed in either group. Conclusions: Epiduroscopy may be effective in operated and non-operated back patients with intractable low back and leg pain, although effects and complications differed between the two groups in this study. [ABSTRACT FROM AUTHOR]

Landiolol hydrochloride is a new ultra-short-acting β1-adrenergic receptor blocking agent that is used for patients with tachycardia during general anesthesia. The hemodynamic response to a β-adrenergic receptor blocking agent is generally dependent on the subject. In the present investigation we investigated the effects of age and sex on the hemodynamic response to different doses of landiolol. Following a persistence of tachycardia for more than 1 min, landiolol was infused at 0.03125, 0.0625 and 0.125 mg kg−1 min−1 for 1 min followed by 0.01, 0.02 and 0.04 mg kg−1min−1 for 10 min in groups L, M and H, respectively. Heart rate (HR), systolic (sBP) and diastolic blood pressure (dBP) were recorded each minute during the procedure. The respective changes were evaluated using logistic analysis with the equation $$ Y{\left( t \right)} = {p + {\left( {q - p} \right)}} \mathord{\left/ {\vphantom {{p + {\left( {q - p} \right)}} {{\left[ {1 + \exp {\left\{ {{\left( {{4m} \mathord{\left/ {\vphantom {{4m} {{\left( {q - p} \right)}}}} \right. \kern-\nulldelimiterspace} {{\left( {q - p} \right)}}} \right)}{\left( {k - t} \right)}} \right\}}} \right]}}}} \right. \kern-\nulldelimiterspace} {{\left[ {1 + \exp {\left\{ {{\left( {{4m} \mathord{\left/ {\vphantom {{4m} {{\left( {q - p} \right)}}}} \right. \kern-\nulldelimiterspace} {{\left( {q - p} \right)}}} \right)}{\left( {k - t} \right)}} \right\}}} \right]}} $$ , where p, q, m and k indicate the upper asymptote, lower asymptote, maximum slope and time at the maximum slope. Parameters q and k for HR in group H were smaller than those in group L, whereas the parameters for sBP and dBP were unchanged among the three groups. Parameter q for HR in group H decreased with age of the patient. There was no significant difference in the landiolol-induced change in HR between males and females. The hemodynamic response to landiolol is reliably modeled by the logistic function, especially in terms of HR. Landiolol causes a rapid and dose-dependent decrease in HR, whereas landiolol-induced changes in sBP and dBP are independent of dose. The landiolol-induced decrease in HR becomes larger with aging, but shows no sex difference. The logistic model may be useful for studying hemodynamic responses to landiolol based on age and sex differences, and may allow development of an improved monitoring system. The logistic function reliably represents the hemodynamic responses to landiolol. Landiolol reduces HR rapidly and in a dose-dependentl manner whereas landiolol-induced changes in sBP and dBP are independent of dose. A larger decrease in HR is caused by landiolol in elderly patients, but there is no sex difference in the landiolol-induced change in HR. [ABSTRACT FROM AUTHOR]

Objective: No systematic study has been conducted to investigate effects of deep hypothermic circulatory arrest (DHCA) on electroencephalographic bispectral index (BIS) and suppression ratio (SR). Thus, the effects of DHCA were evaluated on BIS and SR. Design: A prospective clinical study. Setting: University hospital (single institute). Participants: Twenty consecutive patients undergoing thoracic aortic surgery using DHCA under narcotics-sevoflurane anesthesia. Interventions: BIS and SR were monitored during cardiopulmonary bypass, simultaneously with nasopharyngeal temperature (NPT). Measurements and Main Results: BIS decreased to 0 with induction of deep hypothermia and rose again with rewarming, although rates of BIS changes in response to cooling and rewarming varied widely among patients. Typically, BIS decreased slowly until NPT reached 26°C during cooling and then it began to decrease rapidly and reached 0 at 17°C, in inverse proportion to SR, which increased rapidly with deep hypothermia and reached 100% at 17°C. When SR was 50% or more, BIS was determined by SR according to the expression: BIS = 50 − SR/2. With rewarming, BIS rose again and returned to precooling baseline levels. Time to the beginning of the BIS recovery significantly correlated with duration of DHCA. Conclusions: With induction of deep hypothermia, BIS decreased in a biphasic manner to 0 at rates varying among patients. With rewarming, BIS rose again at rates extremely widely varying among patients. The rate of BIS recovery was related to duration of DHCA. BIS may be capable of conveniently tracing suppression and recovery of a part of cerebral electrical activity before, during, and after DHCA. [Copyright &y& Elsevier]

Copyright of Canadian Journal of Anaesthesia / Journal Canadien d'Anesthésie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Discusses a study which compared the analgesic effect of intravenous adenosine triphosphate (ATP) on postherpetic neuralgia (PHN) responses to intravenous ketamine and lidocaine. Means by which the intensity of spontaneous pain and tactile allodynia was assessed; Statistics of patients who responded to ketamine, lidocaine and ATP; Subtype of PHN that would respond to ATP; Mechanism of adenosine in alleviating neuropathic pain.