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Anesthetic Drugs (anesthetic + drug)
Selected AbstractsThe role of peripheral Na+ channels in triggering the central excitatory effects of intravenous cocaineEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2006P. Leon Brown Abstract While alterations in dopamine (DA) uptake appear to be a critical mechanism underlying locomotor and reinforcing effects of cocaine (COC), many centrally mediated physiological and affective effects of this drug are resistant to DA receptor blockade and are expressed more quickly following an intravenous (i.v.) injection than expected based on the dynamics of drug concentration in the brain. Because COC is also a potent local anesthetic, its rapid action on Na+ channels may be responsible for triggering these effects. We monitored temperatures in the nucleus accumbens, temporal muscle and skin together with conventional locomotion during a single i.v. injection of COC (1 mg/kg), procaine (PRO, 5 mg/kg; equipotential anesthetic dose), a short-acting local anesthetic drug that, like COC, interacts with Na+ channels, and cocaine methiodide (COC-MET, 1.31 mg/kg, equimolar dose), a quaternary COC derivative that is unable to cross the blood,brain barrier. In this way, we explored not only the importance of Na+ channels in general, but also the importance of central vs. peripheral Na+ channels specifically. COC induced locomotor activation, temperature increase in the brain and muscle, and a biphasic temperature fluctuation in skin. Though PRO did not induce locomotor activation, it mimicked, to a greater degree, the temperature effects of COC. Therefore, Na+ channels appear to be a key substrate for COC-induced temperature fluctuations in the brain and periphery. Similar to PRO, COC-MET had minimal effects on locomotion, but mimicked COC in its ability to increase brain and muscle temperature, and induce transient skin hypothermia. It appears therefore that COC's interaction with peripherally located Na+ channels triggers its central excitatory effects manifested by brain temperature increase, thereby playing a major role in drug sensing and possibly contributing to COC reinforcement. [source] Direct automatic determination of free and total anesthetic drugs in human plasma by use of a dual (microdialysis,microextraction by packed sorbent) sample treatment coupled at-line to NACE,MSELECTROPHORESIS, Issue 10 2009Gabriel Morales-Cid Abstract This paper reports for the first time the use of microextraction by packed sorbent in combination with CE. The combined system was used to determine anesthetic drugs in human plasma. A microdialysis fiber was coupled on-line to the microextraction unit in order to distinguish between free and total concentrations of drugs. The system was automated by connecting the microextraction unit to a syringe pump and interfacing it to a computer. The ensuing method allows the determination of 10,,g/L concentrations of free drugs and 1,,g/L concentrations of total drugs from only 200,,L of sample with an RSD of less than 9%. [source] Effects of isoflurane, pentobarbital, and urethane on apoptosis and apoptotic signal transduction in rat kidneyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2006N. Aravindan Background:, Renal cell apoptosis contributes significantly to the pathogenesis of acute renal failure. Anesthetic agents have been shown to modulate apoptotic signal transduction in various tissues. We examined the effects of 6 h of different general anesthetic techniques on renal cell apoptosis in rat kidneys. Methods:, Twenty-one male Sprague,Dawley rats were randomly allocated into four groups: (i) control, non-anesthetized rats (n= 3) and rats anesthetized with (ii) inhaled isoflurane (n= 6), (iii) intraperitoneal pentobarbital (n= 6), and (iv) intraperitoneal urethane (n= 6). Animals were sacrificed 6 h after the induction of anesthesia. Results:, Apoptosis was assessed by terminal deoxynucleotidyl transferase-fluorescein end-labeling analysis. RNA was extracted from the left kidney to probe cDNA microarrays. Gene expression was measured as a percentage of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and subsequently confirmed using reverse transcriptase-polymerase chain reaction (RT-PCR). Compared with the control (no anesthesia), urethane significantly (P < 0.001) induced apoptosis in both the renal cortex and medulla. Isoflurane significantly (P < 0.001) inhibited apoptosis in the medulla. Microarray analysis revealed that urethane up-regulated more (74) genes than pentobarbital (16) and isoflurane (10). Isoflurane down-regulated more genes (85) than pentobarbital (74) and urethane (12). These anesthetic-induced modulations were significant (P < 0.05) for 60 isoflurane-, 30 pentobarbital- and 4 urethane-modulated genes. Conclusion:, Our results suggest that general anesthetic drugs have an effect on renal cell apoptosis and apoptotic signal transduction, and thus may potentially affect the risk of subsequent acute renal failure. [source] Gender differences in drug effects: implications for anesthesiologistsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2003H. Pleym Background:, The gender aspect in pharmacokinetics and pharmacodynamics of anesthetics has attracted little attention. Knowledge of previous work is required to decide if gender-based differences in clinical practice is justified, and to determine the need for research. Methods:, Basis for this paper was obtained by Medline searches using the key words ,human' and ,gender' or ,sex,' combined with individual drug names. The reference lists of these papers were further checked for other relevant studies. Results:, Females have 20,30% greater sensitivity to the muscle relaxant effects of vecuronium, pancuronium and rocuronium. When rapid onset of or short duration of action is very important, gender-modified dosing may be considered. Males are more sensitive than females to propofol. It may therefore be necessary to decrease the propofol dose by 30,40% in males compared with females in order to achieve similar recovery times. Females are more sensitive than males to opioid receptor agonists, as shown for morphine as well as for a number of kappa (OP2) receptor agonists. On this basis, males will be expected to require 30,40% higher doses of opioid analgesics than females to achieve similar pain relief. On the other hand, females may experience respiratory depression and other adverse effects more easily if they are given the same doses as males. Conclusion:, These examples illustrate that gender should be taken into account as a factor that may be predictive for the dosage of several anesthetic drugs. Moreover, there is an obvious need for more research in this area in order to further optimize drug treatment in anesthesia. [source] Effect of alkalinization and/or hyaluronidase adjuvancy on a local anesthetic mixture for sub-Tenon's ophthalmic blockACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2002M. M. Moharib Background and objectives: pH adjustment and/or addition of hyaluronidase to local anesthetic drugs decrease the time to onset and prolong the duration of regional anesthetic techniques for ocular surgery. The objective of this study was to investigate whether these factors are effective also in sub-Tenon's block. Methods: Sixty patients were randomly assigned to four groups in a double blind, prospective fashion, and received 5.125 ml mixtures as follows: 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5% and 0.125 ml isotonic saline (group LB); 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5%, 15 IU hyaluronidase/ml and 0.125 ml isotonic saline (group LBH); 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5% and 0.125 ml sodium bicarbonate 8.4% (group LBpH); and 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5%, 15 IU hyaluronidase/ml and 0.125 ml sodium bicarbonate 8.4% (group LBHpH). This measurement was based on one quadrant sub-Tenon's block. Akinesia was assessed every 30 s. Results: No statistically significant differences were found between the groups regarding mean times to onset and to complete akinesia. Group LBH displayed a significantly lower frequency of patients experiencing pain and a lower need for rescue medication during surgery than the other groups. Conclusion: pH adjustment and/or addition of hyaluronidase to a mixture of lignocaine and bupivacaine did not shorten the time to onset of akinesia following sub-Tenon's technique. However, the addition of hyaluronidase was associated with a lower fraction of patients experiencing pain during surgery. [source] Supplementing desflurane with intravenous anesthesia reduces fetal cardiac dysfunction during open fetal surgeryPEDIATRIC ANESTHESIA, Issue 8 2010ANNE BOAT MD Summary Objective:, To lower the incidence and severity of fetal cardiovascular depression during maternal fetal surgery under general anesthesia. Aim:, We hypothesized that supplemental intravenous anesthesia (SIVA) with propofol and remifentanil would lower the need for high-dose inhalational anesthesia and provide adequate maternal depth of anesthesia and uterine relaxation. SIVA technique would minimize prolonged fetal exposure to deep inhalational anesthetics and significant intraoperative fetal cardiovascular depression. Background:, Fetal hypoxia and significant fetal hemodynamic changes occur during open fetal surgery because of the challenges such as surgical manipulation, hysterotomy, uterine contractions, and effects of anesthetic drugs. Tocolysis, a vital component of fetal surgery, is usually achieved using volatile anesthetic agents. High concentrations of volatile agents required to provide an appropriate degree of uterine relaxation may cause maternal hypotension and placental hypoperfusion, as well as direct fetal cardiovascular depression. Methods:, We reviewed medical records of 39 patients who presented for ex utero intrapartum treatment and mid-gestation open fetal surgery between April 2004 and March 2009. Out of 39 patients, three were excluded because of the lack of echocardiographic data; 18 patients received high-concentration desflurane anesthesia and 18 patients had SIVA with desflurane for uterine relaxation. We analyzed the following data: demographics, fetal medical condition, anesthetic drugs, concentration and duration of desflurane, maternal arterial blood pressure, intraoperative fetal echocardiogram, presence of fetal bradycardia, and need for intraoperative fetal resuscitation. Results:, Adequate uterine relaxation was achieved with about 1.5 MAC of desflurane in the SIVA group compared to about 2.5 MAC in the desflurane only anesthesia group (P = 0.0001). More fetuses in the high-dose desflurane group compared to the SIVA group developed moderate-severe left ventricular systolic dysfunction over time intraoperatively (P = 0.02). 61% of fetuses in the high-dose desflurane group received fetal resuscitative interventions compared to 26% of fetuses in the SIVA group (P = 0.0489). Conclusion:, SIVA as described provides adequate maternal anesthesia and uterine relaxation, and it allows for decreased use of desflurane during open fetal surgery. Decreased use of desflurane may better preserve fetal cardiac function. [source] | |||||||||||||