Analgesic Effect Of Dexmedetomidine Research Articles

Alpha 2-adrenoceptor participates in anti-hyperalgesia by regulating metabolic demand.

The α2-adrenoceptor agonist dexmedetomidine is a commonly used drug for sedatives in clinics and has analgesic effects; however, its mechanism of analgesia in the spine remains unclear. In this study, we systematically used behavioural and transcriptomic sequencing, pharmacological intervention, electrophysiological recording and ultrasound imaging to explore the analgesic effects of the α2-adrenoceptor and its molecular mechanism. Firstly, we found that spinal nerve injury changed the spinal transcriptome expression, and the differential genes were mainly related to calcium signalling and tissue metabolic pathways. In addition, α2-adrenoceptor mRNA expression was significantly upregulated, and α2-adrenoceptor was significantly colocalised with markers, particularly neuronal markers. Intrathecal dexmedetomidine suppressed neuropathic pain and acute inflammatory pain in a dose-dependent manner. The transcriptome results demonstrated that the analgesic effect of dexmedetomidine may be related to the modulation of neuronal metabolism. Weighted gene correlation network analysis indicated that turquoise, brown, yellow and grey modules were the most correlated with dexmedetomidine-induced analgesic effects. Bioinformatics also annotated the involvement of metabolic processes and neural plasticity. A cardiovascular-mitochondrial interaction was found, and ultrasound imaging revealed that injection of dexmedetomidine significantly enhanced spinal cord perfusion in rats with neuropathic pain, which might be regulated by pyruvate dehydrogenase kinase 4 (pdk4), cholesterol 25-hydroxylase (ch25h) and GTP cyclohydrolase 1 (gch1). Increasing the perfusion doses of dexmedetomidine significantly suppressed the frequency and amplitude of spinal nerve ligation-induced miniature excitatory postsynaptic currents. Overall, dexmedetomidine exerts analgesic effects by restoring neuronal metabolic processes through agonism of the α2-adrenoceptor and subsequently inhibiting changes in synaptic plasticity.

Comparative Study of Dexmedetomidine versus Fentanyl as an adjuvant to Ropivacaine (0.75%) in Epidural Anaesthesia in Lower Limb Orthopaedic Surgery

Background: Dexmedetomidine and Fentanyl both possess hypnotic, sedative, analgesic properties and have been utilised as an additive in epidural anaesthesia. The purpose of this study is to compare the sedative and analgesic effects of Dexmedetomidine and Fentanyl when added epidurally with Ropivacaine (0.75%) during lower limb orthopaedic surgery.
 Methods: The study comprised of 60 patients, both male and female, aged 18 to 60, who had ASA classification I or II for tibia fibula surgery. Two groups of patients were split up at random: Group RD contains– Ropivacaine (0.75%) 15ml + Dexmedetomidine (1microgm/kg) 0.5ml + 0.5ml sterile water (Total volume-16ml) and Group RF - Ropivacaine 15ml (0.75%) + 1ml Fentanyl (1microgm/kg) (Total volume-16 ml). The epidural space was maintained 4 cm within and situated between L3 and L4 space. Investigations were conducted on parameters such as sensory and motor block features, sedation score, hemodynamic factors and pain assessment. Using the student `t` test, statistical analysis was performed using STATAIC13 software.
 Results: Onset of sensory analgesia at L1 and Complete sensory and motor blockage occurred much earlier in the RD group. Higher sedation scores and significantly prolonged postoperative analgesia was observed in RD group.
 Conclusion: Dexmedetomidine is a safer and more effective epidural adjuvant than fentanyl because it provides stable hemodynamics, extended post-operative analgesia, early onset and development of sensory and motor effects and sedation.

Study on the inhibition of dexmedetomidine (DEX) on malignant development of breast cancer by synchrotron radiation infrared spectroscopy

ObjectivesThe topic of the relationship between analgesia and cancer recurrence inoncology surgery is a subject of debate in the field. Administering analgesic drugs after breast cancer surgery could potentially impact the long-term outcomes for patients. During breast cancer surgery, DEX, a potent α2 adrenergic receptoragonist, is often administered as an analgesic. Despite its common use, the analgesic effect of DEX and its potential impact on the progression of breast cancer remain uncertain. MethodsTo investigate the impact of DEX on breast cancer cells, cells exposed to DEX were collected and analyzed through cell apoptosis detection and synchrotron radiation micro-infrared spectroscopy. ResultsFollowing DEX treatment, the absorption peaks of MDA-MB-231 and MCF-7 cell lines showed significant redshift at 1230–1250 cm−1 and 1380–1420 cm−1 bands (p<0.05). The absorption peak in the 1500–1700 cm−1 band decreased (p<0.05), while the 2910–2990 cm−1 absorption peak increased, along with other apoptotic characteristics (p<0.05). Our cell experiment results demonstrated that DEX was capable of protecting cell immunity via the down-regulation of TLR-4 receptor and effectively hindered the growth of breast cancer cells. ConclusionThe cell and spectrum experiments' results indicate that DEX can encourage tumor cell apoptosis. These findings suggest that DEX is safe to use for breast cancer surgery and pain management.

A comprehensive overview of clinical research on dexmedetomidine in the past 2decades: A bibliometric analysis.

Introduction: Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist with sedative, analgesic, anxiolytic, and opioid-sparing properties. A large number of dexmedetomidine-related publications have sprung out in the last 2decades. However, no bibliometric analysis for clinical research on dexmedetomidine has been published to analyze hot spots, trends, and frontiers in this field. Methods: The clinical articles and reviews related to dexmedetomidine, published from 2002 to 2021 in the Web of Science Core Collection, were retrieved on 19 May 2022, using relevant search terms. VOSviewer and CiteSpace were used to conduct this bibliometric study. Results: The results showed that a total of 2,299 publications were retrieved from 656 academic journals with 48,549 co-cited references by 2,335 institutions from 65 countries/regions. The United States had the most publications among all the countries (n = 870, 37.8%) and the Harvard University contributed the most among all institutions (n = 57, 2.48%). The most productive academic journal on dexmedetomidine was Pediatric Anesthesia and the first co-cited journal was Anesthesiology. Mika Scheinin is the most productive author and Pratik P Pandharipande is the most co-cited author. Co-cited reference analysis and keyword analysis illustrated hot spots in the dexmedetomidine field including pharmacokinetics and pharmacodynamics, intensive care unit sedation and outcome, pain management and nerve block, and premedication and use in children. The effect of dexmedetomidine sedation on the outcomes of critically ill patients, the analgesic effect of dexmedetomidine, and its organ protective property are the frontiers in future research. Conclusion: This bibliometric analysis provided us with concise information about the development trend and provided an important reference for researchers to guide future research.

Analgesic effect of dexmedetomidine in colorectal cancer patients undergoing laparoscopic surgery.

To evaluate the analgesic efficacy of intraoperative dexmedetomidine (DEX) for acute postoperative pain in colorectal cancer patients undergoing laparoscopic surgery. We retrospectively analyzed data of 190 colorectal cancer patients who had undergone laparoscopic surgery between October 2020 and May 2021 at Samsung Medical Center, Seoul, Korea, with (n=74) or without intraoperative DEX (n=85) administration. The demographic, clinical, anesthetic, and postoperative data were compared. In total, 159 patients were enrolled. Demographic and clinical data were not different between the groups. The mean arterial pressure (p<0.001) and heart rate (p<0.001) were lower in the DEX group at the end of surgery and after extubation (p=0.003, p=0.001). The minimum alveolar concentration of sevoflurane was lower in the DEX group during surgery. At the post-anesthesia care unit (PACU) admission and discharge, pain scores (p<0.001, p=0.027) and fentanyl consumption (p<0.001) were significantly lower in the DEX group. On postoperative days 1-3, pain scores and opioid consumption were not different between the groups. The incidence of postoperative complications was not different between the groups. Continuous intraoperative DEX administration had an intraoperative analgesic effect as indicated by lower hemodynamic and fentanyl consumption. Furthermore, there was immediate postoperative analgesia as suspected by the lower pain scores and fentanyl dose during the PACU. However, pain scores and opioid consumption after the PACU remained unaffected.

Applications of Dexmedetomidine in Palliative and Hospice Care.

Although the use of dexmedetomidine is currently approved by the US Food and Drug Administration in the adult population for monitored anesthesia care and sedation during mechanical ventilation, clinical experience suggests the potential application of dexmedetomidine in the palliative care arena. The medication can provide sedation with lower risk of delirium, control or minimize the adverse effects of other medications, and augment analgesia from opioids. We conducted a computerized bibliographic search of the literature regarding dexmedetomidine use for the treatment of pain and provision of sedation during palliative and hospice care in adult and pediatric patients. The objective was to provide a general descriptive account of the physiologic effects of dexmedetomidine and review its potential applications in the field of palliative and hospice care in adult and pediatric patients. The sedative and analgesic effects of dexmedetomidine have been well studied in animal and human models. Published experience from both single case reports and small case series has demonstrated the potential therapeutic applications of dexmedetomidine in palliative and hospice care. In addition to intravenous administration, case reports have demonstrated its successful use by both the intranasal and subcutaneous routes. Although these experiences have suggested its safety and efficacy, larger series and additional clinical experience with prospective comparison to other agents are needed to further define its efficacy and role in palliative and hospice care.

Dexmedetomidine combined with ropivacaine for erector spinae plane block after posterior lumbar spine surgery: a randomized controlled trial

PurposeDue to lumbar spinal surgery is frequently accompanied with moderate-to-severe postoperative pain, it is necessary to find an effective postoperative analgesia for patients with this surgery. This study aimed to observe the analgesic effect of dexmedetomidine combined with ropivacaine erector spinae plane block (ESPB) used in posterior lumbar spine surgery.MethodsIn this clinical trial, patients undergoing posterior lumbar spine surgery were recruited and randomly divided into two groups: intervention and control. The intervention group (Group E) received 0.375% ropivacaine with 1 µg/kg dexmedetomidine in a total of 20 ml for ESPB; the control group (Group C) received 20 ml ropivacaine 0.375% for ESPB. US-guided ESPB was performed preoperatively in all patients. Demographics, anesthesia time, surgery time, and ASA grade from the participants were recorded at baseline. The primary clinical outcome measures were 2-, 4-, 8-, 12-, 24-and 48-h visual analog scale (VAS) pain scores after surgery at rest and movement state. Other end points included opioid consumption, number of PCIA presses, flurbiprofen-axetil consumption, quality of recovery and pain management after surgery.ResultsOne hundred twenty patients were enrolled in the study (mean [SD] ages: Group E, 54.77 [8.61] years old; Group C,56.40 [7.87] years old; P = 0.280). The mean anesthesia time was 152.55 (15.37) min in Group E and 152.60 (16.47) min in Group C (P = 0.986). Additionally, the surgery time was 141.70 (15.71) min in Group E compared to 141.48 (17.13) min in Group C (P = 0.943). In addition, we found that the VAS pain scores in the resting state during the postoperative period at 8–48 h were lower in Group E than in Group C. However, the VAS pain scores in the active state were lower in Group E at 12–48 h (P < 0.05). More importantly, the consumption of opioids and flurbiprofen-axetil after surgery was also lower in Group E (P < 0.05). Subsequently, we administered questionnaires on the quality of recovery and pain management after surgery that were positively correlated with the postoperative analgesic effect. It was worth affirming that the QoR-15 scores and APS-POQ-R questionnaire results were different between the two groups, further confirming that the combination of drugs not only could obtain an ideal analgesic effect but also had no obvious adverse reactions (P < 0.05).ConclusionsAll the findings suggested that dexmedetomidine could significantly relieve postoperative pain and reduce the consumption of opioids in patients undergoing posterior lumbar spine surgery without obvious adverse reactions as a local anesthetic adjuvant. Further studies with larger sample sizes and different drug dosages may be useful in understanding the potential clinical benefits of dexmedetomidine.

Application of Dexmedetomidine Sedation Combined With Suprascapular Nerve Block and Axillary Nerve Block in Shoulder Arthroscopy, A Randomized Single-Blind Study.

Objective: The aim of the present study was to evaluate the anesthetic and analgesic effects of dexmedetomidine combined with suprascapular nerve block and axillary nerve block in shoulder arthroscopy. Methods: A total of 60 patients were randomly divided into the experimental group (DEX group) and the control group (GA group) via a random number table method. Dexmedetomidine sedation combined with suprascapular nerve block and axillary nerve block was used in the DEX group, while general anesthesia with tracheal intubation combined with interscalene brachial plexus block was used in the GA group. The perioperative indexes, intraoperative hemodynamics, cerebral oxygen saturation, and postoperative pain score, as well as any complications, were compared between the two groups. Results: The anesthesia duration (p < 0.05) and postoperative monitoring time (p < 0.05) in the DEX group were significantly shorter than those in the GA group. At most time points during the anesthesia, the cerebral oxygen saturation (p < 0.05) and mean arterial pressure (p < 0.05) in the DEX group were significantly higher than those in the GA group. Additionally, the decrease in the cerebral oxygen saturation and mean arterial pressure in the GA group was significantly higher than that in the DEX group (p < 0.05). The pain score of DEX group 12 h after operation significantly lower than that in the GA group (p < 0.05), and the incidence of postoperative hypoxemia along with nausea and vomiting in the GA group was significantly higher than that in the DEX group (p < 0.05). Conclusion: Dexmedetomidine combined with suprascapular nerve block and axillary nerve block could reduce the incidence of hypoxemia, while the approach demonstrated better hemodynamic stability, fully ensured the cerebral blood perfusion, and exhibited better anesthetic and analgesic effects, meaning it could be safely and effectively applied in shoulder arthroscopy procedures.

Application of Dexmedetomidine combined with Propofol Intravenous Anesthesia in Laparoscopic Day Surgery in Pediatric Urology.

ABSTRACTObjectives:To evaluate the sedative and analgesic effects of dexmedetomidine combined with propofol intravenous anesthesia in laparoscopic day surgery in pediatric urology.Methods:Eighty male children with cryptorchidism and hydrocele who underwent laparoscopic daytime surgery in our hospital from January 2019 to January 2021 were selected and randomly divided into two groups: the experimental group and the control group. Children in the experimental group ranged in age from 5.7 to 11.3, with an average of 8.52±2.17 years old, while those in the control group ranged in age from 5.3 to 12.0, with an average of 8.60±2.07 years old. There were 12 cases of cryptorchidism and 28 cases of hydrocele in the experimental group, and 14 cases of cryptorchidism and 26 cases of hydrocele in the control group. Children in the control group received conventional propofol intravenous combined anesthesia, while those in the experimental group were given dexmedetomidine (2-5 ug/kg) intranasally on the basis of conventional propofol intravenous anesthesia. The anesthetic effect, analgesic effect, serum levels of inflammatory cytokines before and after surgery and adverse drug reactions in the two groups were compared and analyzed.Results:The awakening time, extubation time and retention time in the resuscitation room of the experimental group were shorter than those of the control group, with a statistically significant difference (P<0.05); The VAS pain scores of the experimental group were significantly lower than those of the control group at 15minutes, 12hour and 24hour after awakening, with a statistically significant difference (P<0.05). In addition, the levels of TNF-a, CRP, IL-6 and other inflammatory factors in the control group were significantly higher compared with those in the experimental group 24h after surgery, with a statistical significance (TNF-a, P=0.02; CRP, P=0.00; IL-6, P=0.03); The incidence of adverse drug reactions in the experimental group was 17.5%, while that in the control group was 12.5%, which was not statistically significant (P=0.53).Conclusion:Dexmedetomidine combined with intravenous propofol anesthesia may be helpful to shorten the extubation time, the recovery time and the stay time in the anesthesia resuscative room, improve the analgesic effect, and may reduce the inflammatory response and the expression of serum inflammatory cytokines, with no significant increase in side effects.

Dexmedetomidine vs. lidocaine for postoperative analgesia in pediatric patients undergoing craniotomy: a protocol for a prospective, randomized, double-blinded, placebo-controlled trial

BackgroundPostoperative pain is a common problem that occurs in pediatric patients following neurosurgery which may lead to severe complications. Dexmedetomidine is a commonly used adjuvant medicine in craniotomy owing to its sedative, amnestic, analgesic, and neuroprotective properties. Besides, studies suggest that lidocaine has similar effects on sedation, analgesia, and neuroprotection. Both two adjuvants can reduce postoperative pain after neurosurgery in adults. However, it is still unknown whether dexmedetomidine or lidocaine can reduce postoperative pain in children undergoing craniotomy, and if yes, which is a better medicine choice. Therefore, we aimed to compare the effect of dexmedetomidine vs. lidocaine on postoperative pain in pediatric patients after craniotomy.Methods/designWe will perform a randomized (1:1:1), double-blind, placebo-controlled, single-center trial. Children aged 1–12 years scheduled for craniotomy will be eligible for inclusion. The 255 recruited participants will be stratified by age in two strata (1–6 years and 7–12 years), and then each stratum will be equally randomized to three groups: group D (infusion of dexmedetomidine [intervention group]), group L (infusion of lidocaine [intervention group]), and group C (infusion of normal saline [control group]). Patients will be followed up at 1 h, 2 h, 4 h, 24 h, and 48 h after surgery. The primary outcome will be total sufentanil consumption within 24 h after surgery.DiscussionIn this clinical trial, we expect to clarify and compare the postoperative analgesic effect of dexmedetomidine vs. lidocaine infusion on pediatric patients undergoing craniotomy. We believe that the results of this trial will provide more choices for postoperative analgesia for the pediatric population.Trial registrationChinese ClinicalTrials.gov ChiCTR1800019411. Registered on 10 November 2018

Analgesic effect of dexmedetomidine after lumbar spondylolisthesis in officers and mens

Analgesic effect of dexmedetomidine after lumbar spondylolisthesis in officers and mens

Dexmedetomidine as an adjuvant for patients undergoing breast cancer surgery: A meta-analysis.

Background:The goal of this study was to comprehensively evaluate the analgesic and antiemetic effects of adjuvant dexmedetomidine (DEX) for breast cancer surgery using a meta-analysis.Methods:Electronic databases were searched to collect the studies that performed randomized controlled trials. The effect size was estimated by odd ratio (OR) or standardized mean difference (SMD). Statistical analysis was performed using the STATA 13.0 software.Results:Twelve published studies involving 396 DEX treatment patients and 395 patients with control treatment were included. Pooled analysis showed that the use of DEX significantly prolonged the time to first request of analgesia (SMD = 1.67), decreased the postoperative requirement for tramadol (SMD = −0.65) and morphine (total: SMD = −2.23; patient-controlled analgesia: SMD = −1.45) as well as intraoperative requirement for fentanyl (SMD = −1.60), and lower the pain score at 1 (SMD = −0.30), 2 (SMD = −1.45), 4 (SMD = −2.36), 6 (SMD = −0.63), 8 (SMD = −2.47), 12 (SMD = −0.81), 24 (SMD = −1.78), 36 (SMD = −0.92), and 48 (SMD = −0.80) hours postoperatively compared with the control group. Furthermore, the risks to develop postoperative nausea/vomiting (PONV) (OR = 0.38) and vomiting (OR = 0.54) were significantly decreased in the DEX group compared with the control group. The pain relief at early time point (2, 6, 12, 24 hours postoperatively) and the decrease in the incidence of PONV were especially obvious for the general anesthesia subgroup (P < .05) relative to local anesthesia subgroup (P >.05).Conclusion:DEX may be a favorable anesthetic adjuvant in breast cancer surgery, which could lower postoperative pain and the risk to develop PONV. DEX should be combined especially for the patients undergoing general anesthesia.

Analgesic Effects of Dexmedetomidine and Remifentanil in Patients with Herniated Disc

Analgesic Effects of Dexmedetomidine and Remifentanil in Patients with Herniated Disc

Effect of ADRA2A gene polymorphisms on the anesthetic and analgesic effects of dexmedetomidine in Chinese Han women with cesarean section.

It is well known that differences in drug reactions among individuals are widespread, and therefore the study of genetic polymorphisms of drug targets has become a research hotspot. Dexmedetomidine is clinically effective by acting on α2 adrenergic receptor and the impact of the adrenoceptor α2A gene (ADRA2A) polymorphisms on the anesthetic and analgesic effects of dexmedetomidine is related to the clinical application of dexmedetomidine. The present study aimed to analyze the effects of the rs1800035, rs201376588 and rs775887911 locus single-nucleotide polymorphisms of the ADRA2A on the anesthetic and analgesic effects of dexmedetomidine in Chinese Han women. A total of 434 Chinese women undergoing cesarean section were enrolled in this study. A 3-ml fasting venous blood sample was collected from all subjects for genomic DNA extraction and genotype detection. The pre-anesthetic and post-anesthetic pain threshold (PTh), pain tolerance threshold (PTTh), mean arterial pressure, heart rate, blood oxygen saturation, cortisol (Cor) content, blood glucose (Glu) content, opioid usage, patient-controlled analgesia pressing times, surgical satisfaction and postoperative adverse reactions were recorded. The visual analogue scale (VAS) and Ramsay sedation score were evaluated. PTh and PTTh in the wild-type women were higher than those in the women with mutations (P<0.05). The postoperative VAS scores of wild-type women were lower than those of mutants (P<0.05). The Ramsay sedation scores of wild-type patients at 12 h after the operation were significantly higher than in those with mutations (P<0.05). The levels of Cor and Glu in women with mutations were significantly higher than those of wild-type women at 12, 24 and 48 h after surgery (P<0.05). The satisfaction with surgery of wild-type patients was higher than that of patients with mutations (P<0.05). Gene mutations of rs1800035, rs201376588 and rs775887911 loci in the ADRA2A gene reduced the anesthetic and analgesic effect during and after cesarean section in Chinese Han women. Postoperative analgesia of mothers with mutations may require higher doses of analgesics.

Analgesic effects of dexmedetomidine and remifentanil on periprocedural pain during percutaneous ablation of renal carcinoma

Background: Percutaneous ablation of renal carcinoma is frequently a favourable treatment alternative, especially in elderly patients suffering from co-morbidities. Also, it is less resource-demanding than conventional surgery of renal carcinoma, and one may, therefore, assume that the incidence of this procedure may increase. Analgesia is necessary during this intervention. The aim of this study was to explore the possibility of analgosedation and its relation to patient comfort and safety during percutaneous ablation of renal carcinoma.Methods: Forty-six patients, sedated with dexmedetomidine and remifentanil, supplemented with infiltration anaesthesia (lidocaine 1%), underwent percutaneous (radiofrequency or microwave) ablation of renal carcinoma in this prospective study.Results: The patients expected pain intensity around the numerical rating score (NRS) 4.5 (interquartile range [IQR] 3.5–5.5), which was slightly lower than pain experienced during the procedure NRS 5 (IQR 2–7; p = 0.49). Eight percent of the patients needed supplementary morphine during the ablation procedure. Sedation score did not differ during ablation, at arrival to or discharge from the recovery ward. Median periprocedural treatment time was 12 minutes (IQR 12–16). Treatment time did not correlate with experienced pain (R2=0.000074, p = 0.96). The median length of stay in the recovery room was 120 minutes (IQR 84–154). There were seven serious adverse events.Conclusions: This proof-of-concept study has shown that analgosedation during percutaneous ablation of renal carcinoma can be performed with a generally tolerable degree of patient satisfaction. However, pain occurs and should be managed adequately. Patient safety must be a major concern for the anaesthetic care.

Comparative study of dexmedetomidine versus midazolam in monitored anaesthesia care in tympanoplasty surgery

Background: Monitored anaesthesia care (MAC) has become increasingly used for middle ear surgeries. Midazolam is most commonly used for sedation in MAC; likewise, dexmedetomidine has gained popularity for intravenous sedation for the procedures to be done under MAC. The present study was undertaken to evaluate and compare the perioperativeeffects of inj. dexmedetomidine and midazolam with respect to sedation, analgesia and hemodynamic stability. Method: Study was approved by the Institutional Medical Ethics Committee and written informed consent was obtained from all patients participating in the study. Total 60 patients of ASA Grade I and II, aged 18 - 60 years, undergoing tympanoplasty surgery under local anaesthesia with 2% Lignocaine plus adrenaline 1:200000 and sedation with infusion of either dexmedetomidine or midazolam drug. Patients were divided in two groups of 30 patients in each group by chit block method. Group D received Dexmedetomidine 1 mcg/kg IV bolus over 10 min followed by continuous IV infusion at 0.5 mcg/kg/hr. Group M received midazolam 40 mcg/kg IV over 10 min followed by continuous IV infusion at 20 mcg/kg/hr. Results: Perioperatively, sedative effects of dexmedetomidine and midazolam were almost comparable, analgesic effects of dexmedetomidine was better than midazolam IV infusion. The significant reduction in haemodynamic variables was noted with dexmedetomidine (p=0.001) provided better hemodynamic stability than midazolam. Oxygen saturation and respiratory rate were maintained within normal limits in both the groups. 80% of surgeons in either group showed significant satisfaction but the difference was not statistically significant between two groups. Conclusion: Dexmedetomidine is a safe agent as sedative in patients undergoing tympanoplasty surgery under local anaesthesia with MAC.

The efficacy of adjuvants to bupivacaine in ultrasound-guided supraclavicular block: a comparative study between dexmedetomidine, ketamine, and fentanyl

BackgroundUltrasound-guided supraclavicular block is of increasing importance in upper limb surgeries as it provides excellent pain control and reduced side effects. The search for the ideal adjuvant is still present. In this study, we aim to evaluate the efficacy and safety of dexmedetomidine, ketamine, and fentanyl when added to bupivacaine in ultrasound-guided supraclavicular block.Patients and methodsA total of 60 patients with American Society of Anesthesiologists (ASA) I and II scheduled for upper limb surgeries were randomly assigned into three groups (20 patients each): group DB received 38 ml bupivacaine 0.5% with 2 ml (100ug) dexmedetomidine. Group KB received 38 ml bupivacaine 0.5% with 2 ml (100 mg) ketamine. Group FB received 38 ml of bupivacaine 0.5% with 2 ml (100ug) fentanyl. We measured sensory/motor block, sedation level, adverse effects, the total amount of rescue analgesia, and post-operative pain.ResultsThere was a significant increase in the duration of sensory and motor block in the DB group with no difference in the onset. The mean blood pressure and heart rate were lower in the DB group. Analgesic effects of dexmedetomidine were higher, followed by ketamine and lastly fentanyl. Post-operatively visual analogue scale (VAS) and rescue analgesia results indicated that dexmedetomidine and ketamine provided adequate post-operative analgesia.ConclusionAddition of dexmedetomidine was more effective in prolongation of the sensory and motor duration as well as providing adequate intra-operative analgesia when compared to ketamine and fentanyl. Dexmedetomidine and ketamine are effective and safe in post-operative analgesia.

Dexmedetomidine: present and future directions

Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist, with sedative, analgesic, anxiolytic, sympatholytic, and opioid-sparing properties. Dexmedetomidine induces a unique sedative response, which shows an easy transition from sleep to wakefulness, thus allowing a patient to be cooperative and communicative when stimulated. Dexmedetomidine may produce less delirium than other sedatives or even prevent delirium. The analgesic effect of dexmedetomidine is not strong; however, it can be administered as a useful analgesic adjuvant. As an anesthetic adjuvant, dexmedetomidine decreases the need for opioids, inhalational anesthetics, and intravenous anesthetics. The sympatholytic effect of dexmedetomidine may provide stable hemodynamics during the perioperative period. Dexmedetomidine-induced cooperative sedation with minimal respiratory depression provides safe and acceptable conditions during neurosurgical procedures in awake patients and awake fiberoptic intubation. Despite the lack of pediatric labelling, dexmedetomidine has been widely studied for pediatric use in various applications. Most adverse events associated with dexmedetomidine occur during or shortly after a loading infusion. There are some case reports of dexmedetomidine-related cardiac arrest following severe bradycardia. Some extended applications of dexmedetomidine discussed in this review are promising, but still limited, and further research is required. The pharmacological properties and possible adverse effects of dexmedetomidine should be well understood by the anesthesiologist prior to use. Moreover, it is necessary to select patients carefully and to determine the appropriate dosage of dexmedetomidine to ensure patient safety.

Evaluation of Postoperative Analgesia of DexmedetomidineAlone or Associated to Morphineas Premedicants in Bitches Undergoing Ovariosalpingohisterectomy

Background:Elective ovariossalpingohysterectomy is a common surgery that causes mild to moderate pain. Aiming at the treatment of pain in these patients, analgesia should be balanced from pre-anesthetic, transoperative and postoperative medication, with α-2-agonists and opioids being commonly used, especially dexmedetomidine that has sedation, relaxation muscle and analgesia. The aim of the present study was to evaluate the postoperative analgesic efficacy of dexmedetomidine alone and associated with morphine when used in the preanesthetic medication of bitches submitted to elective ovarian oysterectomy using the modified Glasgow pain scale and the Melbourne pain scale.Materials,Methods &amp; Results:Twenty bitches were used in this study, all of them submitted to ovarian oysterectomy, and were clinically healthy according to laboratory and clinical exams. During the experiment, bitches were randomly distributed into two groups, which received preanesthetic medication (MPA) with 5μg/kg dexmedetomidine alone (GD) or associated with 0.3 mg/kg morphine (GDM) intramuscularly (IM). In both groups, anesthetic induction with dose-effect propofol was performed and maintained with isoflurane diluted in 100% oxygen administered through a calibrated vaporizer and appropriate anesthetic system based on the weight of the animal and maintained on spontaneous ventilation. After stabilization of the patient the surgery was started, which lasted 45 min. The bitches were evaluated by the Modified Glasgow Scale (GSM), the Melbourne Scale (MS) and the Dobbins Sedation Scale (DS), previously administered MPA (T0) and the others performed in 1h (T1), 2h (T2), 4h (T3), 8h (T4), 12h (T5) and 24h (T6) after extubation. If the GSM score was greater than the value of 3.3 an analgesic rescue of 0.5 mg/kg of morphine intramuscularly would be administered. An increase in the scoring of pain scales in both groups can be observed from the T1, with significant difference only of the T1 in relation to the T0 in the GSM of the GDM. Two rescues were performed in T1 of GD and three rescues in T1 and a rescue in T3 of GDM. There was no significant difference between the groups in relation to this variable, as a result of P = 0.62.Discussion:Based on the results of this study, dexmedetomidinedoes not have adequate analgesic effect for use in preemptive analgesia of bitches submitted to elective OSH due to the high number of analgesic rescues. A small increase in GSM and MS scores from T1 can be expected compared to values prior to the surgical procedure since there was no nociceptive stimulation. This increase was only significant in T1 of GDM, moment of greatest rescue number (n = 3). The absence of significant difference between the groups proves that the analgesic effect of dexmedetomidine was not potentiated by the association with morphine at the dose and route used in this experiment. Although morphine is widely used and proven to be effective for the surgical procedure of ovariossalpingohysterectomy, both when used alone and in combination with other drugs, this fact has not been proven in the present study. This fact may have occurred due to the low dose of dexmedetomidine used or due to its short duration. Therefore, dexmedetomidine at the dose used as preanesthetic medication did not produce an adequate analgesic effect in the postoperative period of bitches submitted to elective ovariossalpingohysterectomy. The effects of the same were not potentiated by the association with morphine, at the dose used. Not being recommended for postoperative analgesic control of electiveovariossalpingohysterectomy in bitches. However, further studies are needed to better evaluate the analgesic effect of this α-2-agonist.

Dexmedetomidine nebulization as adjuvant to lignocaine during awake flexible fiberoptic intubation

Sir, Awake fiberoptic intubation (AFOI) is recommended for patients with anticipated difficult airway, failed intubation, and unstable cervical spine injury where optimum positioning for laryngoscopy is difficult to achieve. Preparation includes obtundation of airway reflexes, adequate sedation, and anxiolysis along with preservation patent airway and adequate ventilation. Dexmedetomidine produces hypnosis, amnesia, analgesia, anxiolysis, sympatholysis, and antisialogogue effects; all of them are desired during AFOI.[1] Administration of dexmedetomidine through inhalational route could be a new promising noninvasive method. The bioavailability of dexmedetomidine is 65% and 82% through nasal and buccal mucosa, respectively, following nebulization.[2] Here, we reported a series of four cases of patients with difficult airway in which dexmedetomidine was used as adjuvant to lignocaine nebulization before awake fiberoptic bronchoscope-guided nasotracheal intubation. Written consent was taken from all patients. All these patients were scheduled for mandibular excision and reconstruction under general anesthesia. After shifting the patients to operating room, standard ASA monitor was connected and baseline was taken. Injection glycopyrrolate 0.2 mg i.m., intranasal xylometazoline 0.1%, was given 15 min prior to nebulization to each patient. Patients were nebulized with mixture of 4% lignocaine 10 ml and dexmedetomidine 1 μg/kg by using ultrasonic nebulizer for 15 min followed by fiberoptic bronchoscope-guided nasotracheal intubation. All patients received supplemental oxygen (2 l/min) through the working channel of the bronchoscope. Following intubation, general anesthesia was induced. The parameters observed include heart rate, mean arterial pressure, oxygen saturation at 0, 5, 10, 15 (end of nebulization), and 20 min (just after intubation). Other parameters were observed such as cough and gag reflexes [severity graded as no cough, slight ≤2 coughs, moderate (3–5 coughs), severe (>5 coughs)], patient comfort (cooperative, restless/minimal resistance, severe resistance/requirement for immediate general anesthesia), and signs of lignocaine toxicity. Discussion There were bradycardia and hypotension noted during nebulization in case 2 and 3 as shown in Table 1. Tachycardia was noted at 20 min in case 2 and 4. One episode of cough and gag reflex was noted in case 2. No cough, gag, and other adverse effects such as bronchospasm, seizures due to lignocaine toxicity, and oversedation were recorded in rest of cases as shown in Table 1. Patients were comfortable throughout the procedure.Table 1: Shows vitals parameter and cough/gag reflexes during intubationBrummett et al.[3] studied the effect after perineural dexmedetomidine injection and they attributed to the increased duration of analgesia to the local action of dexmedetomidine. The analgesic effect of dexmedetomidine was not reversed by a ∞2-adrenoceptor antagonist (prazosin or idazoxan), hence confirming its local site of action. Hence, we hypothesize that dexmedetomidine nebulization provides surface analgesia to airway mucosa in addition to its systemic effect due to its effects on peripheral nerve endings. We could not measure systemic levels of the drugs due to lack of this facility in our institute. Hence, we limited the maximum dose of lignocaine to 400 mg and dexmedetomidine 1 μg/kg. For validation of our hypothesis, we further require randomized controlled studies. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.