The Effects of Meperidine and Sufentanil on the Shivering Threshold in Postoperative Patients 

1998 ◽  
Vol 89 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Pascal Alfonsi ◽  
Daniel I. Sessler ◽  
Bertrand Du Manoir ◽  
Jean-Claude Levron ◽  
Jean-Pierre Le Moing ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Oxygen Consumption ◽  
Plasma Concentrations ◽  
Potency Ratio ◽  
Clinical Observations ◽  
Mu Receptor ◽  
Target Plasma ◽  
Computer Controlled ◽  
End Tidal ◽  
Better Than

Unlabelled BACKGROUND. Meperidine (pethidine) reportedly treats postoperative shivering better than equianalgesic doses of other mu-receptor agonists. The authors' first goal was to develop a method to accurately determine postoperative shivering thresholds, and then to determine the extent to which meperidine and sufentanil inhibit postoperative shivering. Methods A computer-controlled infusion was started before operation in 30 patients, with target plasma concentrations of 0.15, 0.30, or 0.60 microg/ml meperidine or 0.1, 0.15, or 0.2 ng/ ml sufentanil targeted; patients were randomly assigned to each drug and concentration. The infusion was continued throughout surgery and recovery. Anesthesia was maintained with nitrous oxide and isoflurane. Core temperatures were approximately 34 degrees C by the end of surgery. The compensated core temperature at which visible shivering and a 20% decrease in steady-state oxygen consumption was recorded identified the shivering threshold. A blood sample for opioid concentration was obtained from each patient at this time. The ability of each opioid to reduce the shivering threshold was evaluated using linear regression. Results End-tidal isoflurane concentrations were <0.2% in each group at the time of extubation, and shivering occurred approximately 1 h later. Meperidine linearly decreased the shivering threshold: threshold (degrees C) = -2.8 x [meperidine (microg/ml)] + 36.2; r2 = 0.64, P = 0.0005. Sufentanil also linearly decreased the shivering threshold: threshold (degrees C) = -7.8 x [sufentanil (ng/ ml)] + 36.9; r2 = 0.46, P = 0.02. Conclusions At a given dose, sufentanil inhibited shivering 2,800 times better than meperidine. However, the equianalgesic ratio of these drugs is approximately 4,900. That is, meperidine inhibited shivering better than would be expected based on the equianalgesic potency ratio. These data are thus consistent with clinical observations suggesting that meperidine indeed possesses special antishivering activity.

Optimal Propofol-Alfentanil Combinations for Supplementing Nitrous Oxide for Outpatient Surgery 

1999 ◽  
Vol 91 (1) ◽  
pp. 97-108 ◽  
Author(s):  
Janet D. Pavlin ◽  
Rosalin H. Arends ◽  
Holly C. Gunn ◽  
Gail Van Norman ◽  
Meagan E. Koerschgen ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Side Effects ◽  
Outpatient Surgery ◽  
Plasma Concentrations ◽  
Emergence Time ◽  
Early Recovery ◽  
Target Plasma ◽  
Balanced Anesthesia ◽  
Eye Opening ◽  
Function Time

Background The combination of propofol and alfentanil with nitrous oxide provides balanced anesthesia with rapid recovery and minimal emetic side effects. The object of this study was to compare recovery parameters at varying proportions of propofol and alfentanil, and to determine the dosing rate and plasma concentration of propofol necessary to supplement nitrous oxide in the presence of varying concentrations of alfentanil Methods Forty-eight patients were anesthetized with nitrous oxide, targeted manual infusions of alfentanil (target plasma concentrations of 0, 50, 100, and 150 ng/ml), and propofol at rates that were varied up or down by 25% depending on the response (movement/no movement) of the preceding patient (at the same alfentanil target concentrations) to ulnar-nerve stimulation. The minimum concentrations of propofol and alfentanil required to prevent movement in 50% of patients (EC50) was determined by logistic regression. Speed of emergence and recovery of cognitive function, time to discharge, and incidence of side effects were compared for four different combinations of propofol and alfentanil with nitrous oxide. Results The EC50 for propofol alone with nitrous oxide was 6.1 microg/ml. AlfentaniL at concentrations of 41+/-17 (SD), 113+/-54, and 130+/-61 ng/mL reduced the EC50 of propofol to 3.3, 2.3, and 2.2 microg/ml, respectively, and decreased emergence time (eye opening) to 8.1, 4.9, and 3.4 min, compared with 24.3 min for propofol alone. Side effects did not differ between groups. Conclusions The authors conclude that there is a synergistic effect between propofol and alfentanil, and that combining alfentanil with propofol is associated with faster early recovery.

ENHANCEMENT OF SCREEN FILM MAMMOGRAM UP TO A LEVEL OF DIGITAL MAMMOGRAM: EXPERIMENTAL ANALYSIS

2013 ◽  
Vol 13 (02) ◽  
pp. 1340004
Author(s):  
APARNA NARENDRA BHALE ◽  
MANISH RATNAKAR JOSHI
Keyword(s):  
Experimental Analysis ◽  
Breast Imaging ◽  
Point Of View ◽  
Quality Analysis ◽  
Digital Mammogram ◽  
Total Recovery ◽  
Clinical Observations ◽  
Opinion Score ◽  
Better Than

Breast cancer is one of the major causes of death among women. If a cancer can be detected early, the options of treatment and the chances of total recovery will increase. From a woman's point of view, the procedure practiced (compression of breasts to record an image) to obtain a digital mammogram (DM) is exactly the same that is used to obtain a screen film mammogram (SFM). The quality of DM is undoubtedly better than SFM. However, obtaining DM is costlier and very few institutions can afford DM machines. According to the National Cancer Institute 92% of breast imaging centers in India do not have digital mammography machines and they depend on the conventional SFM. Hence in this context, one should answer "Can SFM be enhanced up to a level of DM?" In this paper, we discuss our experimental analysis in this regard. We applied elementary image enhancement techniques to obtain enhanced SFM. We performed the quality analysis of DM and enhanced SFM using standard metrics like PSNR and RMSE on more than 350 mammograms. We also used mean opinion score (MOS) analysis to evaluate enhanced SFMs. The results showed that the clarity of processed SFM is as good as DM. Furthermore, we analyzed the extent of radiation exposed during SFM and DM. We presented our literally findings and clinical observations.

scholarly journals External Evaluation of Population Pharmacokinetic Models and Bayes-Based Dosing of Infliximab

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1191
Author(s):  
Celine Konecki ◽  
Catherine Feliu ◽  
Yoann Cazaubon ◽  
Delphine Giusti ◽  
Marcelle Tonye-Libyh ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Inflammatory Diseases ◽  
Plasma Concentrations ◽  
Population Pharmacokinetic ◽  
Pharmacokinetic Models ◽  
External Evaluation ◽  
Immunomodulatory Treatment ◽  
Weighted Residuals ◽  
Prediction Distribution ◽  
Target Plasma

Despite the well-demonstrated efficacy of infliximab in inflammatory diseases, treatment failure remains frequent. Dose adjustment using Bayesian methods has shown in silico its interest in achieving target plasma concentrations. However, most of the published models have not been fully validated in accordance with the recommendations. This study aimed to submit these models to an external evaluation and verify their predictive capabilities. Eight models were selected for external evaluation, carried out on an independent database (409 concentrations from 157 patients). Each model was evaluated based on the following parameters: goodness-of-fit (comparison of predictions to observations), residual error model (population weighted residuals (PWRES), individual weighted residuals (IWRES), and normalized prediction distribution errors (NPDE)), and predictive performances (prediction-corrected visual predictive checks (pcVPC) and Bayesian simulations). The performances observed during this external evaluation varied greatly from one model to another. The eight evaluated models showed a significant bias in population predictions (from −7.19 to 7.38 mg/L). Individual predictions showed acceptable bias and precision for six of the eight models (mean error of −0.74 to −0.29 mg/L and mean percent error of −16.6 to −0.4%). Analysis of NPDE and pcVPC confirmed these results and revealed a problem with the inclusion of several covariates (weight, concomitant immunomodulatory treatment, presence of anti-drug antibodies). This external evaluation showed satisfactory results for some models, notably models A and B, and highlighted several prospects for improving the pharmacokinetic models of infliximab for clinical-biological application.

Meperidine and Alfentanil Do Not Reduce the Gain or Maximum Intensity of Shivering 

1998 ◽  
Vol 88 (4) ◽  
pp. 858-865 ◽  
Author(s):  
Takehiko Ikeda ◽  
Daniel I. Sessler ◽  
Farzin Tayefeh ◽  
Chiharu Negishi ◽  
Minang Turakhia ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Core Temperature ◽  
Maximum Intensity ◽  
Intensity Increase ◽  
Temperature Deviation ◽  
Kappa Agonist ◽  
Target Plasma ◽  
Opioid Administration ◽  
Venous Infusion ◽  
Lactated Ringer's Solution

Background Thermoregulatory shivering can be characterized by its threshold (triggering core temperature), gain (incremental intensity increase with further core temperature deviation), and maximum intensity. Meperidine (a combined mu- and kappa-agonist) treats shivering better than equianalgesic doses of pure mu-opioid agonists. Meperidine's special antishivering action is mediated, at least in part, by a disproportionate decrease in the shivering threshold. That is, meperidine decreases the shivering threshold twice as much as the vasoconstriction threshold, whereas alfentanil (a pure mu-agonist) decreases the vasoconstriction and shivering thresholds comparably. However, reductions in the gain or maximum shivering intensity might also contribute to the clinical efficacy of meperidine. Accordingly, we tested the hypothesis that meperidine reduces the gain and maximum intensity of shivering much more than alfentanil does. Methods Ten volunteers were each studied on three separate days: (1) control (no drug); (2) a target total plasma meperidine concentration of 1.2 microg/ml; and (3) a target plasma alfentanil concentration of 0.2 microg/ml. Skin temperatures were maintained near 31 degrees C, and core temperatures were decreased by central-venous infusion of cold lactated Ringer's solution until maximum shivering intensity was observed. Shivering was evaluated using oxygen consumption and electromyography. A sustained increase in oxygen consumption identified the shivering threshold. The gain of shivering was calculated as the slope of the oxygen consumption versus core temperature regression, and as the slope of electromyographic intensity versus core temperature regression. Results Meperidine and alfentanil administration significantly decreased the shivering thresholds. However, neither meperidine nor alfentanil reduced the gain of shivering, as determined by either oxygen consumption or electromyography. Opioid administration also failed to significantly decrease the maximum intensity of shivering. Conclusions The authors could not confirm the hypothesis that meperidine reduces the gain or maximum intensity of shivering more than alfentanil does. These results suggest that meperidine's special antishivering effect is primarily mediated by a disproportionate reduction in the shivering threshold.

scholarly journals Observational and Reported Measures of Language and Pragmatics in Young People with Autism: A Comparison of Respondent Data and Gender Profiles

2019 ◽  
Vol 50 (3) ◽  
pp. 812-830 ◽  
Author(s):  
Alexandra Sturrock ◽  
Antonia Marsden ◽  
Catherine Adams ◽  
Jenny Freed
Keyword(s):  
Autism Spectrum ◽  
Multiple Informants ◽  
Typically Developing ◽  
Accurate Identification ◽  
Clinical Observations ◽  
Self Reports ◽  
And Performance ◽  
And Gender ◽  
Performance Intelligence Quotient ◽  
Better Than

AbstractFemale children with autism spectrum disorder (FwASD) and performance intelligence quotient (PIQ) over 70 were compared with male children with ASD (MwASD) and typically developing (TD) controls (age 8–11 years) using a range of language and pragmatic measures. Functional ability was assessed using clinical observations and parent, teacher and self-reports. Results were compared between measures, and with direct assessments of language and pragmatics, in order to identify potential biases. This study found that FwASD performed better than MwASD but worse than TD controls on clinical observations of pragmatic ability. FwASD also performed worst overall on a parental measure of emotions. Additionally, there were patterns of differences between clinician, parent, teacher and self- reports and direct assessments, which indicate the need for assessment data to be collected from multiple informants. Findings also have implications for the accurate identification of ASD in females and appropriate provision of support.

The oral-to-intravenous equianalgesic ratio of morphine based on plasma concentrations of morphine and metabolites in advanced cancer patients receiving chronic morphine treatment

2003 ◽  
Vol 17 (8) ◽  
pp. 673-678
Author(s):  
Masahiko Takahashi ◽  
Takeshi Ohara ◽  
Hiroyuki Yamanaka ◽  
Akira Shimada ◽  
Toshimichi Nakaho ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Advanced Cancer ◽  
Plasma Concentrations ◽  
Relative Potency ◽  
Morphine Treatment ◽  
Advanced Cancer Patients ◽  
Chronic Morphine ◽  
Potency Ratio ◽  
Palliative Care Setting ◽  
Chronic Morphine Treatment

To provide additional pharmacokinetic evidence for the oral-to-parenteral relative potency ratio of 1:2 to 1:3 for chronic morphine use in a palliative care setting, we determined the plasma concentrations of morphine and its major metabolites, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G), in hospitalized advanced cancer patients maintained on long-term oral or intravenous morphine. There were significant linear correlations between daily doses of morphine and plasma concentrations (molar base) of morphine, M3G and M6G for both routes of administration. The oral-to-intravenous relative ratios of the regression coefficients were 2.9 for morphine and 1.8 for morphine» / M6G. The morphine kinetic variables were not significantly influenced by any hepato-renal biochemical markers. These results support the commonly used oral-to-intravenous relative potency ratio of 1:2 to 1:3 in patients with cancer pain receiving chronic morphine treatment.

scholarly journals A survey of the choice of general anaesthetic agents in Australia and New Zealand

2019 ◽  
Vol 47 (3) ◽  
pp. 235-241 ◽  
Author(s):  
Forbes McGain ◽  
Jason R Bishop ◽  
Laura M Elliot-Jones ◽  
David A Story ◽  
Georgina LL Imberger
Keyword(s):  
Nitrous Oxide ◽  
New Zealand ◽  
Gas Flow ◽  
General Anaesthetic ◽  
Gas Flows ◽  
Environmental Costs ◽  
Flow Rates ◽  
Intravenous Anaesthesia ◽  
Anaesthetic Agents ◽  
End Tidal

Strategies to reduce the adverse environmental costs of anaesthesia include choice of agent and fresh gas flows. The current preferences of Australian and New Zealand anaesthetists are unknown. We conducted a survey of Australian and New Zealand anaesthetists to determine the use of volatiles, nitrous oxide and intravenous anaesthesia, lowest fresh gas flow rates, automated end-tidal volatile control, and the rationales for these choices. The survey was answered by 359/1000 (36%), although not all questions and multiple responses within single questions were answered by all respondents. Sevoflurane was preferred by 246/342 (72%, 95% confidence interval (CI) 67%–77%), followed by propofol, 54/340 (16%, 95% CI 12%–20%), desflurane 39/339 (12%, 95% CI 8%–16%) and isoflurane 3/338(1%, 95% CI 0–3%). When asked about all anaesthetics, low-risk clinical profile was the most common reason given for using sevoflurane (129/301 (43%, 95% CI 37%–49%)), reduced postoperative nausea for propofol (297/318 (93%, 95% CI 90%–96%)) and faster induction/awakening times for desflurane (46/313 (79%, 95% CI 74%–83%)). Two-thirds (226/340 (66%, 95% CI 61%–71%)) of respondents used nitrous oxide in 0–20% of general anaesthetics. Low fresh gas flow rates for sevoflurane were used by 310/333 (93%, 95% CI 90%–95%) and for 262/268 (98%, 95% CI 95%–99%) for desflurane. Automated end-tidal control was used by 196/333 (59%, 95% CI 53%–64%). The majority of respondents (>70%) preferred sevoflurane at low flows. These data allow anaesthetists to consider further whether changes are required to the choices of anaesthetic agents for environmental, financial, or any other reasons.

Hypoxemia raises muscle sympathetic activity but not norepinephrine in resting humans

1989 ◽  
Vol 66 (4) ◽  
pp. 1736-1743 ◽  
Author(s):  
L. B. Rowell ◽  
D. G. Johnson ◽  
P. B. Chase ◽  
K. A. Comess ◽  
D. R. Seals
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous Activity ◽  
Plasma Concentrations ◽  
Random Order ◽  
Sympathetic Nervous Activity ◽  
Severe Hypoxemia ◽  
Arterial Blood ◽  
End Tidal ◽  
Venous Plasma

The experimental objective was to determine whether moderate to severe hypoxemia increases skeletal muscle sympathetic nervous activity (MSNA) in resting humans without increasing venous plasma concentrations of norepinephrine (NE) and epinephrine (E). In nine healthy subjects (20–34 yr), we measured MSNA (peroneal nerve), venous plasma levels of NE and E, arterial blood pressure, heart rate, and end-tidal O2 and CO2 before (control) and during breathing of 1) 12% O2 for 20 min, 2) 10% O2 for 20 min, and 3) 8% O2 for 10 min--in random order. MSNA increased above control in five, six, and all nine subjects during 12, 10, and 8% O2, respectively (P less than 0.01), but only after delays of 12 (12% O2) and 4 min (8 and 10% O2). MSNA (total activity) rose 83 +/- 20, 260 +/- 146, and 298 +/- 109% (SE) above control by the final minute of breathing 12, 10, and 8% O2, respectively. NE did not rise above control at any level of hypoxemia; E rose slightly (P less than 0.05) at one time only with both 10 and 8% O2. Individual changes in MSNA during hypoxemia were unrelated to elevations in heart rate or decrements in blood pressure and end-tidal CO2--neither of which always fell. We conclude that in contrast to some other sympathoexcitatory stimuli such as exercise or cold stress, moderate to severe hypoxemia increases leg MSNA without raising plasma NE in resting humans.

scholarly journals The Efficacy of Once-Daily Dose of Phenobarbital in Children with Generalized Tonic-Clonic Epilepsy

2018 ◽  
Vol 35 (7-8) ◽  
pp. 172-9
Author(s):  
Amril A. Burhany ◽  
Sofyan Ismael ◽  
Hardiono Pusponegoro
Keyword(s):  
Clinical Trial ◽  
Plasma Concentrations ◽  
Serum Levels ◽  
Control Group ◽  
Controlled Clinical Trial ◽  
Study Group ◽  
Once Daily ◽  
Daily Dose ◽  
Plasma Measurements ◽  
Better Than

In spite of its long half life, phenobarbital is still given twice-daily in the treatment of generalized tonic-clonic epilepsy. This study aims to determine if daily dose of phenobarbital given once differs to that given twice daily. Subjects of this unblinded controlled clinical trial were generalized tonic-clonic epilepsy patients ranging in age from 1-15 years. There were 40 study cases and 42 controls. We gave phenobarbital 4-6 mg/kg/day once-daily for study group and twice-daily dose for control group. History, physical and EEG examination and phenobarbital plasma measurements were obtained a t the beginning of the study and four weeks later. The ratio of the second to first phenobarbital plasma concentrations in the study group was 0.99 while in the control group it was 1.02. The proportion of seizure-free patients in the study group increased from 70% at the beginning to 85% at the end of study, and in the control group from 64.3% to 83.3%. Hyperactivity and irritability increased in both groups, and there were no significant differences in mean serum levels, seizures control, hyperactivity and irritability in both groups. Drowsiness was found in 50% of cases, but statistically significant decrease were found in study group. The compliance of the study group (92.5%) was significantly better than that of the control group (71.4%).

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