Evaluation of the Efficacy of Dexmedetomidine as an Adjuvant to Epidural Lidocaine (original) (raw)
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BMC Anesthesiology, 2022
Background: Intravenous regional anesthesia is an easy and reliable anesthetic technique, but its use is limited by tourniquet pain. Clonidine is effective in overcoming this shortcoming when used with intravenous regional anesthesia at a dose of 1 μg/kg. Dexmedetomidine has also been used successfully at a dose of 0.5 μg/kg. Objective: Based on the potency ratios of clonidine and dexmedetomidine (8 to 1) we hypothesize that a lower dexmedetomidine dose would provide patients with 50 min of pain free tourniquet time. Methods: After informed consent, patients received intravenous regional anesthesia with lidocaine and dexmedetomidine following a sequential allocation scheme. The first patient received a dose of 0.5 μg/kg of dexmedetomidine. The dose was then adjusted in 0.1 μg/kg gradients for the following patients depending on the success of the previous block. If a patient experienced tourniquet pain prior to 50 min, the next patient received a higher dose. If not, the dose was decreased. Recruitment continued until 6 independent crossovers were observed with a minimum of 20 patients. The median effective dose ED 50 of dexmedetomidine was calculated using the modified up-and-down method. Main outcome measures: The median effective dose of dexmedetomidine (ED 50) that provides 50 min of tolerance to the tourniquet during a lidocaine intravenous regional anesthesia by a sequential Dixon up-and-down allocation study. Results: The ED 50 of dexmedetomidine that provided 50 min of tolerance to the tourniquet was 0.30 ± 0.06 μg/kg. Conclusion: We determined that the dexmedetomidine dose necessary to provide 50 min of pain free tourniquet time during intravenous regional anesthesia was higher than expected based on the relative alpha-2 adrenergic receptor selectivity of dexmedetomidine compared to clonidine.
Adding Dexmedetomidine to Lidocaine for Intravenous Regional Anesthesia
Anesthesia and Analgesia, 2004
Dexmedetomidine is approximately 8 times more selective toward the ␣-2-adrenoceptors than clonidine. It decreases anesthetic requirements by up to 90% and induces analgesia in patients. We designed this study to evaluate the effect of dexmedetomidine when added to lidocaine in IV regional anesthesia (IVRA). We investigated onset and duration of sensory and motor blocks, the quality of the anesthesia, intraoperative-postoperative hemodynamic variables, and intraoperative-postoperative pain and sedation. Thirty patients undergoing hand surgery were randomly assigned to 2 groups to receive IVRA. They received 40 mL of 0.5% lidocaine and either 1 mL of isotonic saline (group L, n ϭ 15) or 0.5 g/kg dexmedetomidine (group LD, n ϭ 15). Sensory and motor block onset and recovery times and anesthesia quality were noted. Before and after the tourniquet application at 5, 10, 15, 20, and 40 min, hemodynamic variables, tourniquet pain and sedation, and analgesic use were recorded. After the tourniquet deflation, at 30 min, and 2, 4, 6, 12, and 24 h, hemodynamic variables, pain and sedation values, time to first analgesic requirement, analgesic use, and side effects were noted. Shortened sensory and motor block onset times, prolonged sensory and motor block recovery times, prolonged tolerance for the tourniquet, and improved quality of anesthesia were found in group LD. Visual analog scale scores were significantly less in group LD in the intraoperative period and 30 min, and 2, 4, and 6 h after tourniquet release. Intra-postoperative analgesic requirements were significantly less in group LD. Time to first analgesic requirements was significantly longer in group LD in the postoperative period. We conclude that the addition of 0.5 g/kg dexmedetomidine to lidocaine for IVRA improves quality of anesthesia and perioperative analgesia without causing side effects.
Dexmedetomidine and clonidine in epidural anaesthesia: A comparative evaluation
Indian Journal of Anaesthesia, 2011
Efforts to find a better adjuvant in regional anaesthesia are underway since long. Aims and objectives are to compare the efficacy and clinical profile of two α-2 adrenergic agonists, dexmedetomidine and clonidine, in epidural anaesthesia with special emphasis on their sedative properties and an ability to provide smooth intra-operative and post-operative analgesia. A prospective randomized study was carried out which included 50 adult female patients between the ages of 44 and 65 years of (American Society of Anaesthesiologists) ASAI/II grade who underwent vaginal hysterectomies. The patients were randomly allocated into two groups; ropivacaine + dexmedetomidine (RD) and ropivacaine + clonidine (RC), comprising of 25 patients each. Group RD was administered 17 ml of 0.75% epidural ropivacaine and 1.5 μg/kg of dexmedetomidine, while group RC received admixture of 17 ml of 0.75% ropivacaine and 2 μg/kg of clonidine. Onset of analgesia, sensory and motor block levels, sedation, duration of analgesia and side effects were observed. The data obtained was subjected to statistical computation with analysis of variance and chi-square test using statistical package for social science (SPSS) version 10.0 for windows and value of P < 0.05 was considered significant and P < 0.0001 as highly significant. The demographic profile, initial and post-operative block characteristics and cardio-respiratory parameters were comparable and statistically nonsignificant in both the groups. However, sedation scores with dexmedetomidine were better than clonidine and turned out to be statistically significant (P < 0.05). The side effect profile was also comparable with a little higher incidence of nausea and dry mouth in both the groups which was again a non-significant entity (P > 0.05). Dexmedetomidine is a better neuraxial adjuvant compared to clonidine for providing early onset of sensory analgesia, adequate sedation and a prolonged post-operative analgesia.
Saudi Journal of Anaesthesia, 2015
cardio toxicity and lesser motor blockade. A slightly larger dose of ropivacaine may be required, but the addition of an adjuvant helps in the reduction of total required dose of local anesthetic and enhances the efficacy thereby providing increased duration and intensity of blockade. [6-8] The quality and duration of analgesia is improved when a local anesthetic is combined with alpha 2 adrenergic agonist. Both clonidine and dexmedetomidine are alpha 2 adrenergic agonists, which have analgesic properties and potentiate local anesthetic effects. [9-11] Neuraxial clonidine, enhances the action of local anesthetics, increases the intensity and duration of analgesia. It is known to have sedative properties and the side effects are hypotension and bradycardia. [12-15] Dexmedetomidine is about 8 times more selective towards the alpha 2 adrenoreceptor than clonidine and hence allows the use of higher doses with less α 1 effect. It has been found to have hemodynamic stability, sedative, anxiolytic, analgesic, neuroprotective and anesthetic sparing effect. It causes more intense motor blockade and cooperative sedation without increasing the incidence of side effects.
Dexmedetomidine Enhances the Local Anesthetic Action of Lidocaine via an α-2A Adrenoceptor
Anesthesia and Analgesia, 2008
BACKGROUND: Clonidine, an ␣-2 adrenoceptor agonist, is a common adjunct in both central and peripheral blocks. Dexmedetomidine, a more selective ␣-2 adrenoceptor agonist, is also known to enhance central neural blockades. Its peripheral effect, however, has not been fully elucidated. Thus, we evaluated the effect of dexmedetomidine and other ␣-2 adrenoceptor agonists on the local anesthetic action of lidocaine at the periphery and explored the mechanism involved. METHODS: ␣-2 Adrenoceptor agonists, including dexmedetomidine, clonidine, and oxymetazoline, combined with lidocaine were intracutaneously injected into the back of male guinea pigs. The test of six pinpricks was applied every 5 min until 60 min after the injection. The number of times which the prick failed to elicit a response during the 60-min period was added and the sum served as an anesthetic score indicating the degree of local anesthesia. Differences from the control value within the group were analyzed using an analysis of variance followed by a post hoc Dunnett's test. Furthermore, we evaluated the antagonism of the effect of dexmedetomidine by yohimbine, an ␣-2A, 2B, and 2C adrenoceptor antagonist, or prazosin, an ␣-1, ␣-2B, and 2C adrenoceptor antagonist, analyzed using a two-way analysis of variance. RESULTS: All ␣-2 adrenoceptor agonists enhanced the degree of local anesthesia of lidocaine in a dose-dependent manner. Furthermore, yohimbine inhibited the effect of dexmedetomidine, whereas prazosin did not. CONCLUSION: We demonstrated that ␣-2 adrenoceptor agonists enhanced the local anesthetic action of lidocaine, and suggest that dexmedetomidine acts via ␣-2A adrenoceptors.
Dexmedetomidine Enhances the Local Anesthetic Action of Lidocaine via an a-2A Adrenoceptor
Anesth Analg, 2008
BACKGROUND: Clonidine, an ␣-2 adrenoceptor agonist, is a common adjunct in both central and peripheral blocks. Dexmedetomidine, a more selective ␣-2 adrenoceptor agonist, is also known to enhance central neural blockades. Its peripheral effect, however, has not been fully elucidated. Thus, we evaluated the effect of dexmedetomidine and other ␣-2 adrenoceptor agonists on the local anesthetic action of lidocaine at the periphery and explored the mechanism involved. METHODS: ␣-2 Adrenoceptor agonists, including dexmedetomidine, clonidine, and oxymetazoline, combined with lidocaine were intracutaneously injected into the back of male guinea pigs. The test of six pinpricks was applied every 5 min until 60 min after the injection. The number of times which the prick failed to elicit a response during the 60-min period was added and the sum served as an anesthetic score indicating the degree of local anesthesia. Differences from the control value within the group were analyzed using an analysis of variance followed by a post hoc Dunnett's test. Furthermore, we evaluated the antagonism of the effect of dexmedetomidine by yohimbine, an ␣-2A, 2B, and 2C adrenoceptor antagonist, or prazosin, an ␣-1, ␣-2B, and 2C adrenoceptor antagonist, analyzed using a two-way analysis of variance. RESULTS: All ␣-2 adrenoceptor agonists enhanced the degree of local anesthesia of lidocaine in a dose-dependent manner. Furthermore, yohimbine inhibited the effect of dexmedetomidine, whereas prazosin did not. CONCLUSION: We demonstrated that ␣-2 adrenoceptor agonists enhanced the local anesthetic action of lidocaine, and suggest that dexmedetomidine acts via ␣-2A adrenoceptors.
Introduction: Sedation has been shown to increase patient satisfaction during regional anesthesia and may be considered as a means to increase the patient’s acceptance of regional anesthetic techniques. For surgery under regional anesthesia, sedation is a valuable tool to make it more convenient for the patient, the anesthetist, and the surgeon. This study focuses sedative property of Dexmedetomidine in regional anesthesia. Material and Method: This study was conducted in the Department of anaesthesiology, Banaras Hindu University. A randomized prospective study was conducted on 60ASA grade I and II patients of age 20 to 60 years undergoing elective gynaecological surgery. Dexmeditomidine was administered intravenously for sedation. Group A sedation was monitored by BIS and Group B by Ramsay sedation score (RSS). Results: The induction, maintenance and total dose of Dexmedetomidine in group A was significantly less than in group B (28.77±4.44 vs 35.43±6.90, 12.24±2.70 vs 18.57±4.74, and 41.01±5.97 vs 54.00±9.62 mcg p< 0.001). Recovery time was prolonged in group B in comparison to group A (37.87±3.35 vs 22.17±3.19 mins p<0.001). Vitals like heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure were significantly less than baseline in both groups. Respiratory rate and SPO2 did not change significantly from baseline in both groups. Conclusions: Dexmedetomidine provides effective sedation. Use of BIS during Dexmedetomidine infusion reduces the dose required for sedation.
The objective of the study was to evaluate the effect of intravenous dexmedetomidine on the duration of subarachnoid block and sedation in patients undergoing surgeries under spinalanaesthesia with 5% lidocaie. 80 ASA physical status I/II patients undergoing elective surgeries under spinal anaesthesia were randomized into two groups of 40 each. Immediately after subarachnoid block with 2 ml of 5% hyperbaric lidocaine, group D patients received a loading dose of 1 μg/kg of dexmedetomidine intravenously by infusion pump over 10 mins followed by a maintenance dose of 0.5 μg/kg/hr till the end of surgery whereas group C received an equivalent quantity of normal saline by infusion pump. Time taken for regression to Modified Bromage Scale 0, level of sensory block, two dermatomal regression of sensory blockade, duration of sensory block and intraoperative Ramsay sedation scores were higher in group D compared to group C (p values < 0.001). In conclusion, intravenous dexmedetomidine significantly prolongs the duration of sensory and motor block of lidocaine spinal anaesthesia with good hemodynamic stability.
Panacea Journal of Medical Sciences
Background: Requirement of anesthetic agents is reduced due to addition of adjuvants in epidural anaesthesia as they augment the local anesthetic action and have analgesic properties as well. Effective epidural analgesia ensures stable hemodynamics and satisfactory perioperative period. Objective: To evaluate efficacy of epidural clonidine compared to dexmedetomidine as adjuvants in postoperative analgesia Materials and Methods: Comparative, randomized clinical study was carried out among 100 subjects undergoing abdominal and vaginal hysterectomies of age 44-65 years with ASA grade I and II. They were divided randomly into two group of 50 each. Group A received 17ml of 0.5% of bupivacaine with 2mcg per kg clonidine. Group B received 17ml of 0.5% of bupivacaine with 1.5mcg per kg dexmedetomidine. Various parameters related to sensory and motor blockade, Ramsay sedation scale for sedation score, Hemodynamic parameters were monitored continuously and recordings were made at regular intervals. Results: Both groups were comparable in terms of age, weight, duration of surgery, ASA grades and type of surgery. Parameters pertaining to time for onset of sensory and motor block were significantly higher in clonidine group compared to the dexmedetomidine group (p<0.05). Postoperative block duration was significantly higher in dexmedetomidine group compared to clonidine group (p<0.05). The hemodynamic parameters and Ramsay sedation score at pre-operative and at 120min were comparable (p>0.05) between two groups except for heart rate which was significantly less in dexmedetomidine group at 120min compared to clonidine group (p<0.05). Conclusion: Dexmedetomidine added to bupivacaine epidurally prolonged postoperative analgesia longer than clonidine.
ragijain5@gmail.com, 2017
Introduction: Spinal anaesthesia is the anesthesia of choice for patients undergoing lower abdominal and lower limb surgeries. However its use is restricted by the limited duration of its action. Aim: To study the comparative evaluation of clinical efficacy of dexmedetomidine when used either by intravenous or intrathecal route in patients undergoing surgeries under spinal anaesthesia. Materials and Methods: 60 American Society of Anaesthesiologists Grade I and II were randomized to receive dexmedetomidine by either intravenous (0.5µgm/kg) (Group I) or intrathecal (0.5µgm) (Group II) routes, in patients scheduled for surgeries under spinal anaesthesia. Primary outcomes studied were the duration of sensory and motor blocks. Secondary outcomes were the time for first request of analgesia, sedation levels and incidence of bradycardia and hypotension. Results: Group II patients showed significant prolongation of sensory and motor block as compared to Group I (p= 0.009, ˂0.000 respectively). Similarly the time of rescue analgesia is greater in Group II (p= 0.0001). However mean sedation levels were greater in Group I (p=0.02). There was no significant difference in the incidence of bradycardia and hypotension between two groups. Conclusion: Intrathecal dexmedetomidine as an adjuvant in spinal anaesthesia, showed significant prolongation of duration of sensory and motor blocks as compared to its intravenous counterpart, without significant increase in incidence of adverse effects.