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Remifentanil
Terms modified by Remifentanil Selected AbstractsAnaesthesia for endoscopic sinus surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010A. R. BAKER Endoscopic sinus surgery is commonly performed and has a low risk of major complications. Intraoperative bleeding impairs surgical conditions and increases the risk of complications. Remifentanil appears to produce better surgical conditions than other opioid analgesics, and total intravenous anaesthesia with propofol may provide superior conditions to a volatile-based technique. Moderate hypotension with intraoperative , blockade is associated with better operating conditions than when vasodilating agents are used. Tight control of CO2 does not affect the surgical view. The use of a laryngeal mask may be associated with improved surgical conditions and a smoother emergence. It provides airway protection equivalent to that provided by an endotracheal tube in well-selected patients, but offers less protection from gastric regurgitation. Post-operatively, multimodal oral analgesia provides good pain relief, while long-acting local anaesthetics have been shown not to improve analgesia. [source] Remifentanil post-conditioning attenuates cardiac ischemia,reperfusion injury via , or , opioid receptor activationACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010G. T. C. WONG Background: Ischemic pre- or post-conditioning of the heart has been shown to involve opioid receptors. Remifentanil, an ultra-short-acting selective , opioid receptor agonist in clinical use, pre-conditions the rat heart against ischemia,reperfusion injury. This study investigates whether remifentanil post-conditioning is also cardioprotective. Methods: Remifentanil post-conditioning (5-min infusion at 1, 5, 10 or 20 ,g/kg/min) or ischemic post-conditioning (three cycles of a 10 s reperfusion interspersed with a 10 s ischemia) was induced in an open-chest rat heart model of ischemia and reperfusion injury, in the presence or absence of nor-binaltorphimine, naltrindole or CTOP, specific ,, , and , opioid receptor antagonists, respectively. The same sequence of experiments was repeated in the isolated heart model using the maximal protective dose of remifentanil from the dose,response studies. Results: Both ischemic and remifentanil post-conditioning reduced the myocardial infarct size relative to the control group in both models. This cardioprotective effect for both post-conditioning regimes was prevented by the prior administration of nor-binaltorphimine and naltrindole but not CTOP. The sole administration of the antagonists had no effect on the size of myocardial infarction. Conclusions: These results indicate that remifentanil post-conditioning protects the heart from ischemia,reperfusion injury to a similar extent as of ischemic post-conditioning. This protection involves , and , but not , opioid receptor activation. This drug has great potential as a clinical post-conditioning modality as it can be given in large doses without prolonged opioid-related side effects. [source] Remifentanil and the brainACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2008V. FODALE Background and aim: Remifentanil is an ultra-short-acting opioid, increasingly used today in neuroanesthesia and neurointensive care. Its characteristics make remifentanil a potentially ideal agent, but previous data have cast a shadow on this opioid, supporting potentially toxic effects on the ischemic brain. The aim of the present concise review is to survey available up-to-date information on the effects of remifentanil on the central nervous system. Method: A MEDLINE search within the past seven years for available up-to-date information on remifentanil and brain was performed. Results: Concise up-to-date information on the effects of remifentanil on the central nervous system was reported, with a particular emphasis on the following topics: cerebral metabolism, electroencephalogram, electrocorticography, motor-evoked potentials, regional cerebral blood flow, cerebral blood flow velocity, arterial hypotension and hypertension, intracranial pressure, cerebral perfusion pressure, cerebral autoregulation, cerebrovascular CO2 reactivity, cerebrospinal fluid, painful stimulation, analgesia and hyperalgesia, neuroprotection, neurotoxicity and hypothermia. Conclusion: The knowledge of the influence of remifentanil on brain functions is crucial before routine use in neuroanesthesia to improve anesthesia performance and patient safety as well as outcome. [source] Ventriculo-arterial coupling and mechanical efficiency with remifentanil in patients with coronary artery diseaseACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2004D. Pittarello Background:, Optimum transfer of energy from the left ventricle to the arterial circulation requires appropriate matching of these mechanical systems. Left ventricular-arterial coupling describes this relationship between the ventricular elastance (Ees) and arterial elastance (Ea). The ratio of these elastances defines the efficiency of myocardium and provides in our study a useful technique for assessment of the actions of remifentanil. The purpose of this study was to evaluate the effects of remifentanil on ventriculo-arterial coupling in cardiac surgery in patients with coronary artery disease. Methods:, Fourteen patients with coronary artery disease, submitted intraoperatively to cardiac anesthesia for myocardial revascularization, were examined prospectively. With the use of transesophageal echocardiography (TEE) and different dicrotic arterial pressures, we determined the ventricle elastance (Ees), the arterial elastance (Ea) and myocardial efficiency before and after administration of a slow-bolus of remifentanil (1 µ kg,1). Results:, Remifentanil decreases significantly the ventricular elastance (from 6.09 mmHg ml,1 m,2 to 4.88) (P < 0.05), with a less, but however, significant decrease of arterial elastance (from 3.68 mmHg ml,1 m,2 to 3.13) (P < 0.05). Despite causing simultaneous declines, maintains a good myocardial efficiency (0.64,0.68) with no significant difference. Conclusion:, Although remifentanil depresses ventricular and arterial elastance, preserves a good left ventricular-arterial coupling and mechanical efficiency, despite a little increase of coupling. However, these effects are maintained only during a slow intravenous infusion and are dose-dependent with impairment of coupling, that may contribute to decline in overall cardiovascular performance, at higher anesthetic dose and rapid infusion in patients with a severe myocardial dysfunction. [source] Bispectral index, predicted and measured drug levels of target-controlled infusions of remifentanil and propofol during laparoscopic cholecystectomy and emergenceACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2000S. C. Høymork Background: Target-controlled infusions (TCI) have been launched as simple, accurate and reliable delivery systems of intravenous drugs. Bispectral index of EEG (BIS) seems promising in measuring hypnotic effect of anaesthetic drugs. The aims of this study were to evaluate the accuracy of TCI systems in patients undergoing laparoscopic cholecystectomy and to correlate measured drug levels to BIS values. Data were analysed for possible gender differences during emergence. Methods: After written informed consent, 20 patients were enrolled in an open study. Remifentanil was set at 7.5 ng/ml as target throughout the whole procedure, and propofol at 5 ,g/ml at induction and 3 ,g/ml after intubation. Values in blood samples of remifentanil and propofol were correlated to the estimated values and to systolic blood pressure and BIS. BIS values and measured drug levels during emergence and emergence time were compared for the two sexes. Results: Measured drug values varied considerably from the set target with a prediction error of ,22% for remifentanil and 49% for propofol. The anaesthesia level was regarded as quite deep with a mean BIS during stable surgery of 42±7, and at this level we found no correlation between measured values of either of the two drugs and BIS. The emergence time was significantly shorter for women (12.6±2.5 min) than for men (19.0±4.2 min) (P=0.001), with no significant differences in measured levels of propofol or remifentanil or BIS during the emergence period. Conclusion: Present systems for TCI of remifentanil and propofol result in large intra- and interindividual variations in measured drug levels, and measured levels differ from target. There may be possible interaction between the two anaesthetics at a pharmacokinetic level. Within the level of anaesthesia studied here, BIS was not an indicator of the actual drug levels. Women woke up significantly faster than men. [source] Experience with remifentanil,sevoflurane balanced anesthesia for abdominal surgery in neonates and children less than 2 yearsPEDIATRIC ANESTHESIA, Issue 6 2008FABRICE MICHEL MD Summary Background:, Few data report remifentanil use in the neonatal population. We described here our experience with remifentanil,sevoflurane balanced anesthesia in neonates and children less than 2 years who underwent general anesthesia for abdominal surgery. Methods:, We retrospectively studied the pattern of remifentanil infusion associated with sevoflurane inhalation in preterm neonates (PTN; n = 18) (born before 37 weeks of gestation and <45 weeks of postmenstrual age), full-term neonates (FTN; n = 21) (born after 37 weeks of gestation and less than 29 days old) and older children up to 2 years (CUT; n = 24). We recorded heart rate (HR), mean arterial pressure (MAP), mean remifentanil dose and sevoflurane concentration before incision and at 5, 10, 20, 30, 45, 60, 90, and 105 min after incision. Results:, We observed that remifentanil doses used during surgery were lower in PTN than in both FTN and CUT and lower in FTN than in CUT. This was because of a progressive decrease in remifentanil dose during anesthesia in PTN and FTN. Conversely, remifentanil doses increased in CUT during anesthesia. Sevoflurane concentrations were higher in CUT group than in PTN and FTN groups. MAP and HR did not vary in the three groups during anesthesia. Conclusions:, Remifentanil,sevoflurane anesthesia can be used for general anesthesia in neonates. We observed that anesthetists used lower doses of remifantanil and lower concentrations of sevoflurane in neonates compared with the older children. [source] Use of remifentanil in an infant with surgically repaired Shone's syndromePEDIATRIC ANESTHESIA, Issue 3 2004A.G. Tsiotou MD Summary We describe the use of remifentanil in an infant with a partially repaired Shone's syndrome who required tendon lengthening because of congenital clubfoot. Remifentanil has unique properties, making it a potentially useful and predictable agent for infants with significant comorbidity. [source] Use of remifentanil as a sedative agent in critically ill adult patients: a meta-analysisANAESTHESIA, Issue 12 2009J. A. Tan Summary This meta-analysis examined the benefits of using remifentanil as a sedative agent in critically ill patients. A total of 11 randomised controlled trials, comparing remifentanil with another opioid or hypnotic agent in 1067 critically ill adult patients, were identified from the Cochrane controlled trials register and EMBASE and MEDLINE databases, and subjected to meta-analysis. Remifentanil was associated with a reduction in the time to tracheal extubation after cessation of sedation (weighted-mean-difference ,2.04 h (95% CI ,0.39 to ,3.69 h); p = 0.02). Remifentanil was, however, not associated with a significant reduction in mortality (relative risk 1.01 (95% CI 0.67,1.52); p = 0.96), duration of mechanical ventilation, length of intensive care unit stay, and risk of agitation (relative risk 1.08 (95% CI 0.64,1.82); p = 0.77) when compared to an alternative sedative or analgesic agent. The current evidence does not support the routine use of remifentanil as a sedative agent in critically ill adult patients. [source] Remifentanil in paediatric anaesthetic practiceANAESTHESIA, Issue 3 2009D. F. Marsh Summary Remifentanil is a synthetic opioid, first introduced into clinical practice in 1996. Its unique pharmacokinetic profile has resulted in a gradual increase in its popularity in paediatric anaesthesia. It is an opioid of high potency and rapid clearance, consequently lacking problems of accumulation. These characteristics give it a high degree of predictability and it has become an attractive choice for a wide variety of anaesthetic challenges, from premature neonates to the elderly. Neonates and infants have a higher clearance than older children and, as a result, remifentanil has additional benefits in this group. Remifentanil can be described as the only consistently predictable opioid in paediatric practice. [source] Remifentanil for fibre-optic intubation: use in difficult airwaysANAESTHESIA, Issue 2 2009C. T. D. Goodman No abstract is available for this article. [source] Remifentanil for fibre-optic intubation: dose considerationsANAESTHESIA, Issue 2 2009P. C. Hudson No abstract is available for this article. [source] Awake insertion of the laryngeal mask airway using topical lidocaine and intravenous remifentanil,ANAESTHESIA, Issue 1 2006M. C. Lee Summary We assessed the use of intravenous remifentanil for the insertion of the laryngeal mask airway in 10 healthy awake volunteers, a technique primarily developed to facilitate functional magnetic resonance imaging studies of anaesthesia. Each volunteer received 200 ,g glycopyrronium intravenously. Topical airway anaesthesia was effected by 4 ml nebulised lidocaine 4%, followed by 12 sprays of lidocaine 10%. Remifentanil was subsequently infused to achieve an initial target effect-site concentration of 2 ng.ml,1; increments of 1 ng.ml,1 were allowed with the maximum effect-site concentration limited to 6 ng.ml,1. Insertion of the laryngeal mask airway was successful on the first attempt in all cases. The median (IQR [range]) target effect-site remifentanil concentration at insertion was 2.5 (2,3 [2,4]) ng.ml,1. All volunteers were co-operative during the procedure and only one reported discomfort. Sore throat was a complication in all volunteers. We conclude that the technique allows successful insertion of the laryngeal mask airway in healthy awake volunteers under conditions that were safe and reproducible. [source] Remifentanil and intubating conditionsANAESTHESIA, Issue 5 2000A. W. Woods [source] Remifentanil in neonatal intensive care and anaesthesia practiceACTA PAEDIATRICA, Issue 10 2010Márcia Gomes Penido Abstract Remifentanil is a relatively new ultrashort action synthetic opioid. Studies on the use of remifentanil in neonatology have emerged demonstrating its effectiveness and safety in neonates. The present study describes the use of remifentanil in both full-term and premature newborns, highlighting the theoretical benefits for this population in terms of both neonatal intensive care and anaesthesia. A Medline search was undertaken of all reviews and reports about the use of remifentanil in neonates published between 1996 and 2009 using MeSH search terms ,remifentanil', ,analgesia', ,anaesthesia', ,newborn' and ,neonate'. The review points that remifentanil has been used with advantages in newborns including preterm neonates and even for foetal anaesthesia. It proved to be a good option to attenuate the hemodynamic/endocrine markers of stress related to surgery. Owing to its unique pharmacokinetic profile, shorter extubation times can be achieved what makes the drug also a good option for short duration invasive procedures in NICUs (InSurE). A concern on its use is that the hemodynamic response (hypotension) may become significant when the drug is associated to other drugs like sevoflurane. Conclusion:, Remifentanil seems to be an effective and safely used opioid for neonatal intensive care and anaesthesia practice. [source] Remifentanil for INSURE in preterm infants: a pilot study for evaluation of efficacy and safety aspectsACTA PAEDIATRICA, Issue 9 2009L Welzing Abstract Aim:, To evaluate intubating conditions, extubation times and outcome in preterm infants receiving remifentanil as induction agent for the INSURE procedure. Methods:, In twenty-one preterm infants of 29 to 32 weeks gestation and signs of respiratory distress, we utilized remifentanil as induction agent for the INSURE procedure. Following intubation and surfactant application, the infants were mechanically ventilated until respiratory drive was judged to be satisfactory for continuing CPAP therapy. Intubating conditions were classified by our own scoring system by rating limb movements, coughing and breathing. Heart rate, blood pressure and oxygen saturation were recorded during the entire INSURE procedure. Results:, Remifentanil provided excellent or good intubating conditions in all patients. We observed no serious side effects after remifentanil infusion, in particular, no thorax rigidity, clinically significant bradycardia or arterial hypotension. Average extubation time after surfactant administration was 16.9 min (1,45 min); none of the infants had to be reintubated. Following extubation, the infants required only 3.3 days (1,8 days) of CPAP therapy. None exhibited serious complications of prematurity like periventricular leucomalacia, intraventricular haemorrhage >I°, necrotizing enterocolitis or retinopathy. Conclusion:, In this pilot study, INSURE with remifentanil was associated with good intubating conditions and early extubation resulting in an excellent neonatal outcome. [source] Remifentanil analgosedation in preterm newborns during mechanical ventilationACTA PAEDIATRICA, Issue 7 2009Carmen Giannantonio Abstract Aim:, To assess efficacy of remifentanil in preterm newborns during mechanical ventilation. Methods:, Remifentanil was administered by continuous intravenous infusion to provide analgesia and sedation in 48 preterm infants who developed respiratory distress and required mechanical ventilation. We examined the doses needed to provide adequate analgesia, extubation time after the discontinuation of opioid infusion, the presence of side effects and safety of the use. Results:, Remifentanil provided adequate analgesia, with a significant reduction of NIPS and COMFORT score since 1 h after starting the infusion of remifentanil. The drug was initially administered at a dose of 0.075 ,g/kg/min, but in 73% of newborns the latter had to be increased; at a dose of 0.094 ± 0.03 (mean ± standard deviation) ,g/kg/min, 97% of the newborns received adequate analgesia and sedation. The time elapsed between the discontinuation of remifentanil infusion and extubation was 36 ± 12 min. Treatment was started between the 1st and the 17th day of life. The mean duration of therapy was 5.9 ± 5.7 days. No side effects on the respiratory or cardiovascular system were observed. Conclusion:, Remifentanil is a manageable and effective opioid in the newborn undergoing mechanical ventilation, though randomized controlled trials and information about long-term outcomes are necessary. [source] Bilateral occipital neuropathy as a rare complication of positioning for thyroid surgery in a morbidly obese patientACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2004S. Schulz-Stübner Background:, Peripheral neuropathies in various locations are described as complications after anesthesia and surgery. This is the first case report of temporary bilateral occipital neuropathy from positioning for thyroid surgery in a morbidly obese patient. Methods:, A 48-year-old women with a history of depression, fibro-myalgia, asthma, sleep apnea, diabetes mellitus and morbid obesity (127 kg, 165 cm) underwent 4 hours anesthesia with propofol/remifentanil without muscle relaxation for thyroid surgery. The neck with a very low range of motion secondary to fat tissue needed to be extended to facilitate surgery as much as possible. The head was carefully padded and there were no episodes of hypotension or hypoxemia throughout the case or in the PACU. At post op day 1 she complained of bilateral numbness in the distribution area of both greater occipital nerves. On post op day 2 tingling sensations and improvement of numbness was noticed. The patient recovered without residual symptoms after 6 weeks. Conclusion:, Pressure or shear stress to the nerve, hypoperfusion or metabolic disturbances are discussed as the leading etiology of nerve damage during surgery in the literature. Pressure from fat tissue during prolonged head extension for surgery seems to be the cause in this case and should therefore be avoided whenever possible in morbidly obese patients, especially when other risk factors for neuropathy like diabetes are present. [source] A study of airway management using the ProSeal LMA® laryngeal mask airway compared with the tracheal tube on postoperative analgesia requirements following gynaecological laparoscopic surgeryANAESTHESIA, Issue 9 2007M. Hohlrieder Summary In a randomised double blind prospective study, we tested the hypothesis that postoperative pain is lower in patients who receive an ProSeal LMAÔ laryngeal mask airway compared with a tracheal tube. One hundred consecutive female patients (ASA I,II, 18,75 years) undergoing laparoscopic gynaecological surgery were divided into two equal-sized groups for airway management with the ProSeal LMA or tracheal tube. Anaesthesia management was identical for both groups and included induction of anaesthesia using propofol/fentanyl, and maintenance with propofol/remifentanil, muscle relaxation with rocuronium, positive pressure ventilation, gastric tube insertion, dexamethasone/tropisetron for anti-emetic prophylaxis, and diclofenac for pain prophylaxis. All types of postoperative pain were treated using intravenous patient-controlled analgesia (PCA) morphine. Patients and postoperative staff were unaware of the airway device used. Data were collected by a single blinded observer. We found that pain scores were lower for the ProSeal LMA at 2 h and 6 h but not at 24 h. Morphine requirements were lower for the ProSeal LMA by 30.4%, 30.6% and 23.3% at 2, 6 and 24 h, respectively. Nausea was less common with the ProSeal LMA than with the tracheal tube at 2 h and 6 h but not at 24 h. There were no differences in the frequency of vomiting, sore throat, dysphonia or dysphagia. We conclude that postoperative pain is lower for the ProSeal LMA than the tracheal tube in females undergoing gynaecological laparoscopic surgery. [source] A clinical prospective comparison of anesthetics sensitivity and hemodynamic effect among patients with or without obstructive jaundiceACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010L.-Q. YANG Background: To compare isoflurane anesthesia in patients with or without hyperbilirubinemia undergoing hepatobiliary surgery. Methods: Forty-two patients with obstructive jaundice and 40 control patients with normal liver function scheduled for hepatobiliary surgery under isoflurane anesthesia were studied. Anesthesia was induced with propofol (1.5,2 mg/kg) and remifentanil (2 ,g/kg). After tracheal intubation, anesthesia was titrated using isoflurane in oxygen-enriched air, adjusted to maintain a bispectral index (BIS) value of 46,54. Ephedrine, atropine and remifentanil were used to maintain hemodynamic parameters within 30% of the baseline. The mean arterial blood pressure (MAP), heart rate (HR), drug doses and the time taken to recover from anesthesia were recorded. Results: Demographic data, duration and BIS values were similar in both groups. Anesthesia induction and maintenance were associated with more hemodynamic instability in the patients with jaundice and they received more ephedrine and atropine and less remifentanil and isoflurane (51.1±24.2 vs. 84.6±20.3 mg/min; P for all <0.05) than control patients. Despite less anesthetic use, the time to recovery and extubation was significantly longer than that in control. Conclusion: Patients with obstructive jaundice have an increased sensitivity to isoflurane, more hypotension and bradycardia during anesthesia induction and maintenance and a prolonged recovery time compared with controls. [source] Comparison of the incidence and severity of cough after alfentanil and remifentanil injectionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2010H. B. CHO Background: Intravenous administration of fentanyl derivatives can induce cough paradoxically. This study examined the incidence and severity of cough after a bolus of alfentanil and remifentanil. Methods: Four hundred and sixty-five patients, aged 18,70 years, were allocated randomly to three groups to receive alfentanil 10 ,g/kg, remifentanil 1 ,g/kg or an equal volume of 0.9% saline intravenously over 10 s. Any episode of cough was classified as coughing and graded as mild (1,2), moderate (3,4) or severe (5 or more). Results: The overall incidence of cough was higher in the opioid groups than in the saline group. The remifentanil group [39/150 patients; 26.0% (95% CI, 19.6,33.6%)] showed a higher incidence than the alfentanil group [11/152 patients; 7.2% (95% CI, 0.4,12.6%)] (P<0.001). There was no significant difference in the severity of cough between the alfentanil group and the remifentanil group. Conclusion: This study demonstrated that equipotent boluses of alfentanil and remifentanil induced coughing, even though the incidence of cough after alfentanil administration was lower than that after remifentanil administration. [source] Body positions and esophageal sphincter pressures in obese patients during anesthesiaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010A. DE LEON Background: The lower esophageal sphincter (LES) and the upper esophageal sphincter (UES) play a central role in preventing regurgitation and aspiration. The aim of the present study was to evaluate the UES, LES and barrier pressures (BP) in obese patients before and during anesthesia in different body positions. Methods: Using high-resolution solid-state manometry, we studied 17 patients (27,63 years) with a BMI,35 kg/m2 who were undergoing a laparoscopic bariatric surgery before and after anesthesia induction. Before anesthesia, the subjects were placed in the supine position, in the reverse Trendelenburg position (+20°) and in the Trendelenburg position (,20°). Thereafter, anesthesia was induced with remifentanil and propofol and maintained with remifentanil and sevoflurane, and the recordings in the different positions were repeated. Results: Before anesthesia, there were no differences in UES pressure in the different positions but compared with the other positions, it increased during the reverse Trendelenburg during anesthesia. LES pressure decreased in all body positions during anesthesia. The LES pressure increased during the Trendelenburg position before but not during anesthesia. The BP remained positive in all body positions both before and during anesthesia. Conclusion: LES pressure increased during the Trendelenburg position before anesthesia. This effect was abolished during anesthesia. LES and BPs decreased during anesthesia but remained positive in all patients regardless of the body position. [source] Remifentanil post-conditioning attenuates cardiac ischemia,reperfusion injury via , or , opioid receptor activationACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2010G. T. C. WONG Background: Ischemic pre- or post-conditioning of the heart has been shown to involve opioid receptors. Remifentanil, an ultra-short-acting selective , opioid receptor agonist in clinical use, pre-conditions the rat heart against ischemia,reperfusion injury. This study investigates whether remifentanil post-conditioning is also cardioprotective. Methods: Remifentanil post-conditioning (5-min infusion at 1, 5, 10 or 20 ,g/kg/min) or ischemic post-conditioning (three cycles of a 10 s reperfusion interspersed with a 10 s ischemia) was induced in an open-chest rat heart model of ischemia and reperfusion injury, in the presence or absence of nor-binaltorphimine, naltrindole or CTOP, specific ,, , and , opioid receptor antagonists, respectively. The same sequence of experiments was repeated in the isolated heart model using the maximal protective dose of remifentanil from the dose,response studies. Results: Both ischemic and remifentanil post-conditioning reduced the myocardial infarct size relative to the control group in both models. This cardioprotective effect for both post-conditioning regimes was prevented by the prior administration of nor-binaltorphimine and naltrindole but not CTOP. The sole administration of the antagonists had no effect on the size of myocardial infarction. Conclusions: These results indicate that remifentanil post-conditioning protects the heart from ischemia,reperfusion injury to a similar extent as of ischemic post-conditioning. This protection involves , and , but not , opioid receptor activation. This drug has great potential as a clinical post-conditioning modality as it can be given in large doses without prolonged opioid-related side effects. [source] The potential for ,-opioid receptor agonists to be anti-emetic in humans: a review of clinical dataACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2010KEVIN D. JOHNSTON In animal models of vomiting, ,-opioid (MOP, OP3) receptors mediate both emesis and anti-emesis. ,-receptors within the blood,brain barrier, mediating anti-emesis, are more rapidly accessible to lipid-soluble ,-opioid receptor agonists such as fentanyl than to morphine, and fentanyl has broad-spectrum anti-emetic effects in a number of species. Whether a similar situation exists in humans is not known. A search was performed for clinical studies comparing the emetic side effects of opioids administered peri-operatively in an attempt to identify differences between morphine and more lipid-soluble ,-receptor-selective agonists such as fentanyl. Overall, the evidence appears to suggest that fentanyl and other phenylpiperidines are associated with less nausea and vomiting than morphine, but not all studies support this, and fentanyl-like drugs are associated with nausea and vomiting per se. Good evidence, however, exists to show that fentanyl and alfentanil do not cause more nausea and vomiting than the ultra fast-acting remifentanil. Because remifentanil is cleared rapidly post-operatively, such trials suggest that the emetic side effects of fentanyl and alfentanil are minimal. The clinical evidence, although limited, is at least consistent with the possibility that central ,-opioid receptors may mediate anti-emesis in humans. It is possible that the role of ,-opioid agonists in anti-emesis may become clearer in the future as a result of the use of peripheral ,-opioid receptor antagonists. [source] An anaphylactic reaction to transdermal delivered fentanylACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 8 2009P. DEWACHTER Immediate allergic hypersensitivity reactions with fentanyl are rarely reported. We diagnosed a presumably IgE-mediated allergic hypersensitivity reaction comprising generalized erythema and bronchospasm 4 h after the first-time application of transdermal fentanyl. Prick test remained negative with fentanyl whereas an intradermal test (IDT) with fentanyl was positive (dilution 10,2). Cross-reactivity was found with sufentanil but not with remifentanil. The diagnosis was supported by the clinical history and a positive IDT with fentanyl. This case report confirms the need for a systematic allergological investigation in case of immediate hypersensitivity reactions for all drugs and all modes of administration. [source] Depth of anaesthesia monitoring in obese patients: a randomized study of propofol,remifentanilACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009C. S. MEYHOFF Background: In obese patients, depth of anaesthesia monitoring could be useful in titrating intravenous anaesthetics. We hypothesized that depth of anaesthesia monitoring would reduce recovery time and use of anaesthetics in obese patients receiving propofol and remifentanil. Methods: We investigated 38 patients with a body mass index ,30 kg/m2 scheduled for an abdominal hysterectomy. Patients were randomized to either titration of propofol and remifentanil according to a cerebral state monitor (CSM group) or according to usual clinical criteria (control group). The primary end point was time to eye opening and this was assessed by a blinded observer. Results: Time to eye opening was 11.8 min in the CSM group vs. 13.4 min in the control group (P=0.58). The average infusion rate for propofol was a median of 516 vs. 617 mg/h (P=0.24) and for remifentanil 2393 vs. 2708 ,g/h (P=0.04). During surgery, when the cerebral state index was continuously between 40 and 60, the corresponding optimal propofol infusion rate was 10 mg/kg/h based on ideal body weight. Conclusion: No significant reduction in time to eye opening could be demonstrated when a CSM was used to titrate propofol and remifentanil in obese patients undergoing a hysterectomy. A significant reduction in remifentanil consumption was found. [source] The use of desflurane or propofol in combination with remifentanil in myasthenic patients undergoing a video-assisted thoracoscopic-extended thymectomyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009P. GRITTI Background: Although several studies of the use of desflurane in anesthesia have revealed many desirable qualities, there are no data on the use and effects especially on the neuromuscular function of desflurane on myasthenia gravis (MG) patients. The purpose of this study was to evaluate the use of either desflurane or propofol, both combined with remifentanil, in patients with MG undergoing a video-assisted thoracoscopic-extended thymectomy (VATET). Methods: Thirty-six MG patients who underwent VATET were enrolled. Nineteen patients were anesthetized with remifentanil and propofol infused with a target-controlled infusion plasma model, and 17 patients with desflurane and remifentanil. No muscle relaxant was used. The intubating conditions, hemodynamic and respiratory changes, neuromuscular transmission and post-operative complications were evaluated. Results: Neuromuscular transmission was significantly decreased in the desflurane group (6.7%, from 3% to 9% during anesthesia P=<0.05). The intubating conditions were good in all 36 patients and 35 patients were successfully extubated in the operating room. The time-to-awakening, post-operatory pH and base excess were significantly different in the two groups, with a decreasing mean arterial pressure in the group administered with desflurane. No patients required reintubation due to myasthenic or cholinergic crisis, or respiratory failure. No other significant differences between the two groups studied were observed. Conclusion: Our experience indicates that anesthesia with desflurane plus remifentanil in patients with MG could determine a reversible muscle relaxation effect, but with no clinical implication, allowing a faster recovery with no difference in extubation time and post-operative complications in the two groups. [source] Safety of laryngeal mask airway and short-stay practice in office-based adenotonsillectomyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009R. GRAVNINGSBRÅTEN Background: It is still disputed whether laryngeal mask airway (LMA) is safe and convenient for adenotonsillectomy, and whether these procedures can be safely undertaken in an office-based short-stay ambulatory setting. We report the result of this practice in 1126 consecutive children <16 years of age. Methods: The patients received general anaesthesia with propofol and remifentanil. For analgesic prophylaxis, they received paracetamol, fentanyl and local anaesthetic administration. NSAIDs were given to patients weighing above 15 kgs. A surgical technique with elevation, scissors and electrocoagulation was used. Post-operatively, the tonsillectomies were observed in the unit for at least 1.5 h and the adenoidectomies for at least 15,20 min. Results: Conversion from LMA to an endotracheal tube was carried out in six patients (0.5%), mostly due to airway leakage during ventilation. One patient had a pulmonary atelectasis and was re-intubated. No re-operation was needed in the clinic after surgery, and all patients, except for the one with atelectasis (0.1%), were discharged home as planned. In 122 patients answering a questionnaire, after discharge, two patients (1.6%) were admitted to hospital and re-operated due to bleeding; a further six patients (4.9%) were admitted for observation. In 25% of the patients, nausea and vomiting occurred after discharge, including 21% vomiting of swallowed blood during home travel. Only 5.6% reported significant post-discharge pain. Conclusion: With a well-trained team, adenotonsillectomy on children can be carried out safely in an office-based setting with LMA and a short post-operative stay. [source] Morphine, opioids, and the feline pulmonary vascular bedACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2008A. D. KAYE Background: Opioid-induced vasodepressor responses have been reported in a variety of species and laboratory models. The aim of this study was to ascertain the relative potencies of different clinically relevant opioids compared with traditional vasodepressor agents in the feline pulmonary vascular bed. A second aim was to study the effects of morphine and to identify the receptors involved in the mediation or the modulation of these effects. Methods: This was a prospective vehicle-controlled study involving an intact chest preparation of adult mongrel cats. The effects of various opioids, morphine, fentanyl, remifentanil, sufentanil, and meperidine were compared with other vasodepressor agents. Additionally, the effects of l - N5 -(1-iminoethyl) ornithine hydrochloride (l -NIO) (nitric oxide synthase inhibitor), nimesulide [selective cyclooxygenase (COX)-2 inhibitor], glibenclamide (ATP-sensitive K+ channel blocker), naloxone (non-selective opioid receptor antagonist), and diphenhydramine (histamine H1 -receptor antagonist) were investigated on pulmonary arterial responses to morphine and other selected agonists in the feline pulmonary vascular bed. The systemic pressure and lobar arterial perfusion pressure were continuously monitored, electronically averaged, and recorded. Results: In the cat pulmonary vascular bed of the isolated left lower lobe, morphine, remifentanil, fentanyl, sufentanil, and meperidine induced a dose-dependent moderate vasodepressor response and it appeared that sufentanil was the most potent on a nanomolar basis. The effects of morphine were not significantly altered after administration of l -NIO, nimesulide, and glibenclamide. However, the vascular responses to morphine were significantly attenuated following administration of naloxone and diphenhydramine. Conclusion: The results of the present study suggest that sufentanil appears to have slightly more potency and morphine the least of the five opioid agonists studied on a nanomolar basis. Morphine-induced vasodilatory responses appeared to be mediated or modulated by both opioid receptor and histamine-receptor-sensitive pathways. [source] Remifentanil and the brainACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2008V. FODALE Background and aim: Remifentanil is an ultra-short-acting opioid, increasingly used today in neuroanesthesia and neurointensive care. Its characteristics make remifentanil a potentially ideal agent, but previous data have cast a shadow on this opioid, supporting potentially toxic effects on the ischemic brain. The aim of the present concise review is to survey available up-to-date information on the effects of remifentanil on the central nervous system. Method: A MEDLINE search within the past seven years for available up-to-date information on remifentanil and brain was performed. Results: Concise up-to-date information on the effects of remifentanil on the central nervous system was reported, with a particular emphasis on the following topics: cerebral metabolism, electroencephalogram, electrocorticography, motor-evoked potentials, regional cerebral blood flow, cerebral blood flow velocity, arterial hypotension and hypertension, intracranial pressure, cerebral perfusion pressure, cerebral autoregulation, cerebrovascular CO2 reactivity, cerebrospinal fluid, painful stimulation, analgesia and hyperalgesia, neuroprotection, neurotoxicity and hypothermia. Conclusion: The knowledge of the influence of remifentanil on brain functions is crucial before routine use in neuroanesthesia to improve anesthesia performance and patient safety as well as outcome. [source] Skin conductance or entropy for detection of non-noxious stimulation during different clinical levels of sedationACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2007A. C. Gjerstad Background:, State entropy (SE) measures electroencephalographic signals, whereas response entropy (RE) also includes frontal electromyographic activity. In the presence of electromyographic activity, the RE index is larger than the SE index, the difference being denoted as RE-, (RE-,= RE , SE). Skin conductance (SC) may be expressed by a slow reacting variable, the mean SC level, the derivate of the mean SC level (D-SC), the number of SC fluctuations (NSCF) or the amplitude of the SC fluctuations (ASCF), which directly shows skin sympathetic nerve activity. The goal of this study was to evaluate whether these SC and entropy variables could differentiate between the responses obtained to load sound stimuli at different sedation levels before the induction of general anaesthesia. Methods:, Twenty women scheduled for gynaecological laparotomy were studied. The modified observer's assessment of alertness sedation (OAAS) was used to classify the patients' hypnotic levels. White sounds (98 dB) were given at OAAS level 5 without propofol, at OAAS levels 4,3 and 3,2 with propofol and at OAAS levels 3,2 and < 2 with propofol and remifentanil. Results:, RE and SE showed a steady decline from OAAS level 5 to level < 2 (P < 0.01). RE-, did not discriminate between any of the OAAS levels (P= NS). The mean SC level discriminated between OAAS levels 4,3 to < 2 (P < 0.01). D-SC discriminated between all the different OAAS levels (P < 0.01). NSCF discriminated between OAAS levels 5 to 3,2 (P < 0.05), but did not discriminate at OAAS level 3,2 between propofol alone or combined with remifentanil, or between OAAS level 3,2 and < 2. ASCF differentiated between OAAS levels 5 and 4 (P < 0.001) and OAAS levels 3,2 and < 2 (P < 0.05) only. Conclusion:, RE, SE and D-SC showed a similar discrimination between sound responses at the different sedation levels. [source] | ||||||||||