Considering the decreased duration and quality of neuro-axial block in opioids addicted patients, adjuvant medications could improve the anesthetic and analgesic properties of local anesthetics.
fifty six opioids addicted patients candidate for lower extremities surgery were randomly assigned into two groups of Dexmedetomine (5 mcg) and Midazolam (2mg) added to intratechal Bupivacaine. Sensory block, motor block, pain and sedation were evaluated using pin prick test, modified bromage scale, visual analog scale (VAS) and ramsey score respectively. Morphine consumption in 12 hour and 24 hour post operative period were recorded as well.
duration of sensory block was 175 ± 18.9 minute and 147 ± 16.3 minute in Dexmedetomidine and Midazolam groups respectively which was statistically meaningful (p 0.001). Pain in 6 and 12 hour post operative period was meaningfully higher in Midazolam group (p 0.003 and p 0.02 respectively) but not in 24 hour period (p 0.18). Morphine consumption in 24 hour post operative period was much lower in Dexmedetomidine group which was statistically meaningful (p 0.029).
Dexmedetomidine, as an adjuvant medication for spinal anesthesia in opioids addicted patients, can lengthen the sensory block more than Midazolam; moreover, it has less adverse effects andaugments sedation and analgesia.

Previous studies showed that dexamethasone and ondansetron had effect on preventing shivering in surgeries under spinal anesthesia but comparison of the two drugs was not studied. This study aimed to compare preemptive effect of intratechal fentanyl with intravenous ondansetron, dexamethasone, and dexamethasone plus ondansetron on shivering during surgeries under spinal anesthesia with bupivacaine.
In a clinical trial study, 185 patients under surgeries with spinal anesthesia were randomly divided in 5 groups of receiving 25 µg intratechal fentanyl, 4 mg intravenous ondansetron, 0.1 mg/kg intravenous dexamethasone, 0.1 mg/kg intravenous dexamethasone plus 4 mg intravenous ondansetron, and 4 ml intravenous normal saline in a bolus dose. The incidence of shivering during surgery was compared between the 5 groups.
Findings: Mean shivering scale during surgery and recovery time in control, dexamethasone plus ondansetron, ondansetron alone, dexamethasone alone, and fentanyl groups were 1.30 ± 0.33, 1.01 ± 0.04, 1.15 ± 0.20, 1.04 ± 0.07 and 1.12 ± 0.15, respectively. Shivering intensity in control group was higher and in dexamethasone plus ondansetron was lower than others significantly (P Using dexamethasone plus ondansetron have more effect on decreasing shivering during and after the surgery. In addition, this compound has not adverse effect on hemodynamic parameters.

Sedation of pediatric patients undergoing cerebral angiography is challenging. Although dexmedetomidine is used for sedation in various procedures, it has not been reported for pediatric patients undergoing cerebral angiography. Th is studycompared the safety and effi cacy of dexmedetomidine with that of propofol for cerebral angiography in pediatric patients. Sixty-two patients (6-15 years) scheduled for elective cerebral angiography were apportioned randomly and equallyto receive either propofol or dexmedetomidine sedation. Patients in the propofol group received an initial bolus of intravenous propofol (1 mg/kg) and a maintenance infusion of 100 μg/kg/min. Patients in the dexmedetomidine group received an initial bolus of intravenous d exmedetomidine (1 μg/kg over 10 min) and a maintenance infusion of 1 μg/kg/h. An additional bolus of propofol 0.5 mg/kg or dexmedetomidine 0.25 μg/kg was repeated if needed. Procedure time, time to recovery and adverse events associatedwith sedation were recorded. All cerebral angiographies were completed successfully under sedation with dexmedetomidine or propofol. Mean cerebral angiography time was 36 ± 10 min in the propofol group and 31 ± 7 min in the dexmedetomidine group (P = 0.047). Th e percentage of airway events and total adverse events were signifi cantly higher in the propofol group (P < 0.05). Heart rate decreased in the dexmedetomidine group and mean arterial pressure decreased in the propofol group (P < 0.05, each). Although cerebral angiography can be performed successfully under sedation with either propofol or dexmedetomidine, dexmedetomidine may be a better alternative because of fewer respiratory adverse events.

One of the main treatments for chronic rhinosinusitis is endoscopic surgery. In this procedure, intraoperative bleeding due to limited view of the surgeon can bring about surgical complications. To have a clear operation field for endoscopic sinus surgery, bleeding management is necessary. We aimed to compare the effects of magnesium sulfate and dexmedetomidine on operation field of candidates for endoscopic sinus surgery.
In this triple-blind clinical trial, 60 candidates for endoscopic sinus surgery were randomly divided into two groups of Dexmedetomidine and Magnesium sulfate. Before anesthesia, magnesium sulfate was administered for 10 min at a dose of 50 mg/kg and at a dose 15 mg/kg/h afterwards. In the other group, dexmedetomidine was given for 10 min before anesthesia at a dose of 1 mic/kg and at a dose of 0.6 mic/kg/h thereupon. The hemodynamic status of both groups was recorded 1, 5, 15, 30, and 60 min post-tracheal intubation. The results were analyzed using SPSS, version 16.
In general, 20 (66.7%) patients in the Dexmedetomidine group and 18 (60.0%) patients in the Magnesium sulfate group were male (P=0.592). The mean ages of the Dexmedetomidine and Magnesium sulfate groups were 37.93 and 39.56 years, respectively (P=0.250). The mean surgical durations in the Dexmedetomidine and Magnesium sulfate groups were 79.03±41.8 min and 87.30± 15.09 min, respectively (P=0.003). Mean arterial pressure (MAP) in the Dexmedetomidine group was less than in the Magnesium Sulfate group at all the assessed times, except for the first time. The difference between the two groups was not significant only at first time. There was no statistical difference between the two groups in terms of mean saturation oxygen peripheral (SpO2) at all the recorded times. The mean intraoperative heart rate and mean pain intensity were lower in the Dexmedetomidine group than the Magnesium sulfate group. In the Magnesium sulfate group, odds ratio of bleeding in grade 3 to grade 2 was six times higher than the Dexmedetomidine group (OR= 6.00; 95% CI: 1.89, 19.1).
Dexmedetomidine is more beneficial for controlling hemodynamic status of sinus endoscopic surgery patients as it can provide a better operation field.

The present study was designed and carried out aiming to evaluate the effects of local Dexmedetomidine on propofol consumption in candidate patients for fiberoptic nasotracheal awake intubation.
Candidate patients were randomly divided into two groups including local Dexmedetomidine group and control group. Local anesthesia using lidocaine was performed in all patients followed by injection of Dexmedetomidine in local Dexmedetomidine group. After performing the intubation, propofol infusion was used to keep the patients on considered cerebral state index (CSI). Hemodynamic parameters and arterial blood O2 saturation (SpO2) were monitored. Propofol consumption for assessing CSI about 65-75 was measured.
A total of 64 patients with the mean age of 44.9±13.9 were evaluated (54.7% female). Baseline hemodynamic parameters and SpO2 were not significantly different between two groups. There is significant statistical difference in propofol consumption between local Dexmedetomidine group in compare with control (p It is likely that local Dexmedetomidine can be useful with the aim of propofol dose saving during awake intubation via fiberoptic.

Aims and Chronic radicular low back pain is usually temporarily relieved by transforaminal epidural(TFE) injection of steroids; our aim was to evaluate the effect of TFE dexmedetomidine injection in comparison with steroids in patients with chronic lumbar radicular pain. Patients with 3 months of low back and leg pain due to intervertebral disc herniation were randomized to receive transforaminal epidural (TFE) injection(s) of 0.2% bupivacaine and either dexmedetomidine (1 mcg/kg) or triamcinolone (20mg). Patients, investigators and study coordinators were blinded to treatment. Primary outcome was visual analogue score (VAS) after the procedure, and functional improvement according to Oswestry disability index(ODI) after 2 weeks, 1, and 6 months. Other outcomes included serum Vitamin D, fasting blood sugar, and bone densitometry which were checked before and after the treatment with an interval of 1 month,3 days, and 6 months, respectively. Twenty-two patients were screened and enrolled; 11 received dexmedetomidine and 11 triamcinolone. Both groups showed significant improvement in pain score after the injection compared to baseline (p< 0.05). The dexmedetomidine group showed additional functional improvement at 1 and 6 months relative to triamcinolonebased upon ODI (p=0.001). Fasting blood sugar was also significantly increased in triamcinolone group in comparison with dexmedetomidine group (p=0.007).However, as target enrollment was not reached in our study, we cannot say with confidence that dexmedetomidine would surely result in better outcome in patients. Regarding side-effects, there were no serious complications. Radicular pain due to disc herniation improved rapidly with TFE injection of either dexmedetomidine or triamcinolone. Dexmedetomidine resulted in greater functional improvement, with better side effect profile. Future studies however, would probably determine if dexmedetomidine is superior to placebo and of particular use in those at risk for corticosteroid complications.

The treatment of cocaine toxicity is an important subject for emergency physicians. We investigated the effects of dexmedetomidine, moxonidine and alpha-methyldopa on acute cocaine toxicity in mice.. The aim of this study was to evaluate the effects of dexmedetomidine, moxonidine and alpha-methyldopa in a mouse model of acute cocaine toxicity.. We performed an experiment consisting of four groups (n = 25 each). The first group received normal saline solution, the second group received 40 µg/kg of dexmedetomidine, the third group received 0.1 mg/kg of moxonidine and the fourth group received 200 mg/kg of alpha-methyldopa, all of which were intraperitoneally administered 10 minutes before cocaine hydrochloride (105 mg/kg). All animals were observed for seizures (popcorn jumping, tonic-clonic activity, or a loss of the righting reflex) and lethality over the 30 minutes following cocaine treatment.. The ratio of animals with convulsions was lower in all treated groups when compared to the control (P < 0.001). Furthermore, 68% (n = 17) of animals in the dexmedetomidine group, 84% (n = 21) of the alpha-methyldopa group, 92% (n = 23) of the moxonidine group and 100% (n = 25) of the control group showed evidence of seizure activity (P = 0.009). Cocaine-induced lethality was observed in 12% (n = 3) of the dexmedetomidine group, 48% (n = 12) of the alpha-methyldopa group, 52% (n = 13) of the moxonidine group, and 72% (n = 18) of the control group (P < 0.001). All treatments prolonged the time to seizure, which was longest in the dexmedetomidine group (P > 0.05). In addition, the time to lethality was also longer in the same group (P < 0.001).. The present study provides the first experimental evidence in support of dexmedetomidine treatment for cocaine-induced seizures. Premedication with dexmedetomidine reduces seizure activity in a mouse model of acute cocaine toxicity. In addition, while dexmedetomidine may be effective, moxonidine and alpha-methyldopa did not effectively prevent cocaine-induced lethality..

Medetomidine and dexmedetomidine are the two new alpha-2 agonists available for use in veterinary anesthesia. These drugs are employed for sedation and premedication in small animals. The present study aimed to investigate the effects of medetomidine and dexmedetomidine alone and in combination with acepromazine on sedation, cardiovascular function and electrocardiography in dogs. Sixty dogs were randomly divided into four equal groups. The dogs received one of the treatments of medetomidine (10 μg/kg), dexmedetomidine (5 μg/kg), medetomidine (10 μg/kg) with acepromazine (0.05 mg/kg) and dexmedetomidine (5 μg/kg) with acepromazine (0.05 mg/kg) intramuscularly. Sedation levels, heart rate, non-invasive arterial blood pressure, respiratory rate, body temperature and electrocardiogram were carefully recorded in dogs up to 20 minutes after administration. Sedation scores were significantly higher in groups of medetomidine with acepromazine and dexmedetomidine with acepromazine, at 5 and 20 minutes in comparison to groups of medetomidine and dexmedetomidine alone. Comparison of sedation scores in each group showed a significant increase over time. The comparison of heart rate, within the groups, showed a significant decrease when compared with the baseline value. The respiratory rate showed a decreasing trend in all groups over time. The amplitude of the P wave decreased and the P-R and Q-T intervals increased during the evaluation period in all groups. Sinus arrhythmia, AV-block grade 1, and sinus arrest were seen after the administration of sedative drugs in all groups. In conclusion, it is inferred that the addition of acepromazine to medetomidine and dexmedetomidine increases the sedation level. Heart rate decreased in medetomidine and dexmedetomidine groups and the addition of acepromazine exacerbated this decrease. The combination of acepromazine with medetomidine and dexmedetomidine did not also reduce the occurrence of arrhythmias in the dog.

In order to induce sedation during cataract surgery, various medications such as midazolam propofol and narcotics with different side effects are used in separation or in combination. Dexmedetomidine has no effect on the respiratory  system, but being dependent on dosage, it may cause cardiovasculardisorders . The present study aims to compare hemodynamic and sedative effects of dexmedetomidine and the combination of sufentanil-midazolam on patients undergoing cataract surgery. In a randomized clinical trial study, 60 patients were randomly divided into two dexmedetomidine and sufentanil-midazolam groups. In sufentanil – midazolam group,  dexmedetomidine  (DEX infusion at 0.5 μg/ kg for 10 minutes, then adjusted to 0.2 µg/kg/h) was prescribed.  In the sulfentanil-midazolam group,  sufentanil (0.1 μg /kg for 5  minutes )  and midazolam(0.2µg/kg) was injected five minutes before the operation.  Hemodynamic variables (Systolic blood pressure, diastolic blood pressure, heart rate), complications (nausea, vomiting, hypoxia), sedation level and pain intensity were recorded  (in the beginning of the study, 5, 10 minutes after anesthesia, at the start of surgery, 5, 10, 15 minutes after the surgery) as well as patient’s satisfaction, surgeon's satisfaction and complications.Results suggest that apart from gender, other primary characteristics of patients including age, history of blood pressure, diabetes history, ASA score, mean of systolic, diastolic blood pressure, heart rate and SPO2 levels were similar in both groups (P> 0.05). Systolic blood pressure   patients receiving dexmedetomidine  declined significantly more than that of patients receiving sufentanil-midazolam (P> 0.5). Diastolic blood pressure suddenly fell 5 minutes after the infusion of sufentanil-midazolam (P> 0.05), but then a relative increase and finally a relative decrease occurred  , while diastolic blood pressure in patients receiving dexmedetomidine decreased steadily . The mean heart rate in patients receiving dexmedetomidine and sufentanil-midazolam declined gently (P> 0.05). SPO2 reduced significantly in the sufentanil-midazolam group (P <0.05). drugs used  in both groups reduced pain intensity equally  (P> 0.05). From the beginning of the study, dexmedetomidine produced a relatively stable sedation level (score 2) based on Ramsay's criteria, while the combination of sufentanil-midazolam-medications cause deeper sedation (score 3) in patients (P <0.05). Despite this fact , 23.33% of the patient receiving sufentanil-midazolam could have movements during the surgerywhich was 6.66%  higher in patients receiving dexmedetomidine (P = 0.071). The satisfaction of patients receiving dexmedetomidine was significantly higher (P = 0.044), while the surgeon's satisfaction was almost identical in both anesthesia procedures (P = 0.94).In the end, the results of the present study showed that although dexmedetomidine is associated with few respiratory problems and higher satisfaction of patients, it decreases blood pressure and heart rate progressively. However, it seems that this medicine is more effective than a combination of midazolam-sufentanil  because of more patient satisfaction, lack of hypoxia, fewer complications, and more suitable immobility.

Postoperative cognitive dysfunction is a common postoperative neurological complication in elderly patients, and has some relationship with neuroinflammation. some studies have shown ability of dexmedetomidine to improve cognitive performance in elderly individuals who underwent thoracic surgery. Therefore, our study hypothesized that dexmedetomidine treatment may reduce the incidence of POCD in elderly patients.In addition,this study detected the antineuroinflammatory effects of dexmedetomidine by β-amyloid aggregation inhibitors and release of cytokines in elderly patients . The results show that dexmedetomidine used during operation can inhibit the postoperative release of Aβ and cytokines in elderly patients, and dexmedetomidine used during operation can reduce the incidence of postoperative cognitive dysfunction, with dose-dependence. These results provide a clinical application direction for clinical anesthesiologists and ICU physicians.