The value of local dexmedetomidine as an adjuvant to ultrasound-guided wide awake local anesthesia no tourniquet (WALANT) in flexor tendon repair surgeries: a randomized controlled trial.

BACKGROUND: The Wide-Awake Local Anesthesia No Tourniquet (WALANT) technique allows intraoperative motor assessment of tendon repair integrity of the hand compared with general anesthesia or brachial plexus block. No studies have tested the effect of adding dexmedetomidine to lidocaine on the analgesic properties of the WALANT technique, which is the aim of our study. METHODS: A total of 128 patients aged more than 18 years were scheduled for surgical flexor tendon injury repair using WALANT technique. Patients were divided into two equal groups. Ultrasound-guided subcutaneous injection of lidocaine 1% with dexmedetomidine (1 µg/kg), Group D, or without dexmedetomidine, Group C, was performed at four points: proximal to the wrist joint, the distal forearm, palm region, and proximal phalanges. The primary outcome was total morphine consumption throughout the first postoperative day. Secondary outcomes included number of patients requiring rescue analgesia, time to first analgesic request, and pain score. RESULTS: Total morphine consumption was significantly (P < 0.001) lower in group D (2.66 ± 0.998) than in group C (3.66 ± 1.144) mg. Number of patients requiring rescue analgesia was significantly (P < 0.001) lower in group D (54.7% (35)) than group C (100.0% (64)). The time for first request for analgesia was significantly (P < 0.001) longer in group D (11.31 ± 6.944) than in group C (5.91 ± 4.839) h. Pain score was significantly higher in group C than D at three (P < 0.001), and six (P = 0.001) hours (P = 0.001) postoperatively. CONCLUSION: Dexmedetomidine significantly improves the analgesic quality of WALANT when added to lidocaine with less opioid consumption. TRIAL REGISTRATION: (ID: PACTR202203906027106; Date: 31/07/2023).

The influencer effect of Dexmedetomidine on radioiodine relevant to lacrimal gland impairment.

PURPOSE: To assess the potential influencing effects of Dexmedetomidine on impaired lacrimal glands after high-dose radioiodine treatment (RAI). METHODS: Thirty-six rats were arbitrarily separated into 3 groups: Sham, RAI, and Dexmedetomidine. Dexmedetomidine group was given Dexmedetomidine and RAI, the Sham group was given the same millimeters of saline, and the RAI group was given RAI only. All forms of lacrimal glands, including harderian glands (HG), extraorbital (EG), and intraorbital (IG) lacrimal glands, were evaluated for immunohistochemical, histopathologic assessments and also for tissue cytokines, oxidant and antioxidant levels. RESULTS: Dexmedetomidine significantly ameliorated histopathologic changes such as periacinar fibrosis, acinar atrophy, lymphocytic infiltration, ductal proliferation, lipofuscin-like accumulation, and nucleus changes caused by RAI in all lacrimal gland forms (p < 0.05 for all of the parameters). However, periductal fibrosis was improved significantly only in EG (p = 0.049), and mast cell infiltration was improved significantly only in IG (p = 0.038) in Dexmedetomidine groups. There was a significant decrease in the elevated caspase-3 and TUNEL levels after RAI administration in the Dexmedetomidine group in all lacrimal gland forms (p < 0.05 for all parameters). Dexmedetomidine attenuated NF-kb, TNF-α, and IL-6 levels significantly diminished total oxidant status and raised total antioxidant status levels (p < 0.05 for all parameters). CONCLUSIONS: The results of this study demonstrated that following RAI, Dexmedetomidine diminished inflammation, tissue cytokine levels, and apoptosis and ameliorated impaired histopathologic patterns of the lacrimal glands.

Dexmedetomidine supplementation for surgical field enhancement in endonasal surgery: a systematic review and meta-analysis.

BACKGROUND: Dexmedetomidine has been shown to effectively control intraoperative bleeding and improve surgical field visualization. However, its value in endonasal surgeries remains a matter of debate. METHODOLOGY: We searched PubMed, Embase, and Cochrane Central Register of Controlled Trials for studies comparing dexmedetomidine with placebo in endonasal surgeries. Outcomes included bleeding, operative time (OT), surgeon’s satisfaction, postoperative pain (POP), and nausea/vomiting (PONV). For statistical analysis, we used RevMan 5.4.1, and assessed heterogeneity with I2 statistics. RESULTS: We included a total of 1386 patients from 22 studies. In the placebo group, there was higher bleeding volume, whereas the dexmedetomidine group showed lower scores on the Fromme-Boezaart scale. Additionally, the surgeon satisfaction risk ratio (RR) increased, and OT was reduced in the dexmedetomidine group. The dexmedetomidine group had lower incidences of POP and PONV. CONCLUSIONS: In endonasal surgeries, dexmedetomidine was associated with improvements in surgical field visualization as evidenced by reduced intraoperative bleeding and postoperative morbidities.

The Impact of Esketamine Combined with Dexmedetomidine on Laparoscopic Gallbladder Surgery: A Randomized Controlled Trial.

Objective: To assess the efficacy of combining esketamine with dexmedetomidine in laparoscopic gallbladder surgery. Methods: We investigated 110 laparoscopic cholecystectomy patients at Jinan Central Hospital, affiliated with Shandong First Medical University, from April 2019 to March 2020. Patients were randomly assigned to the control group (n = 55) or observation group (n = 55). The control group received dexmedetomidine intravenously at 1 µg/kg and a continuous infusion at 0.5 µg•kg-1•h-1. The observation group received esketamine and dexmedetomidine, with intravenous esketamine at 0.4 mg/kg and a continuous infusion at 0.1 mg/(kg•h). We measured heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) at four-time points: before anesthesia (T0), 30 minutes after anesthesia (T1), extubation (T2), and awakening (T3). We also assessed wake time, post-anesthesia care unit (PACU) stay, and Ramasy and visual analogue scale (VAS) scores at 2, 6, 12, and 24 hours post-surgery. Results: At T0, no significant changes occurred in HR, SBP, and DBP in both groups (P > .05). However, at T1 and T2, HR, SBP, and DBP gradually decreased, with the control group exhibiting lower levels than the observation group (P < .05). These levels returned to baseline at T3. PACU residence and wake times showed no significant differences (P > .05). At 2 hours post-operation, Ramasy scores significantly dropped in the observation group versus the control group (P < .05). At 6, 12, and 24 hours post-operation, Ramasy scores exhibited no significant differences (P > .05). Moreover, at 2, 6, and 12 hours post-operation, VAS scores in the observation group were notably lower than in the control group (P < .05). At 24 hours post-operation, VAS scores revealed no significant differences (P > .05). Adverse reactions within 3 days post-operation did not differ significantly between the groups (P > .05). Conclusions: Combining esketamine with dexmedetomidine enhances the quality of laparoscopic cholecystectomy, alleviates postoperative agitation, accelerates cognitive function recovery, reduces cognitive function impairment, and merits clinical consideration.

Sublingual vs. intranasal dexmedetomidine sedation for flexible fiberoptic bronchoscopy procedure: a retrospective comparative study.

OBJECTIVE: Flexible fiberoptic bronchoscopy (FOB) is an often-employed invasive method in diagnosing, staging, and treating lung diseases. Conventional sedative agents facilitate this process. Dexmedetomidine (DM) has low side effects and is easy to administer for trans-mucosal absorption. This study aimed to investigate trans-mucosal DM used with local anesthesia during the FOB procedure. PATIENTS AND METHODS: Fifty-nine cases were retrospectively analyzed who had undergone diagnostic flexible fiberoptic bronchoscopy (FOB) in our clinic between September 2016 and September 2019. The two methods (Group 1: Sublingual, and Group 2: Intranasal) employed during the FOB procedure for the local anesthesia were compared. RESULTS: Fifty-nine patients were included in the study, wherein forty-six were males (77.9%), and thirteen (22.1%) females had a mean age of 58.02±8.7 years (range: 39-72 years). Thirty-three patients were in Group 1 (Sublingual) and 26 in Group 2 (Intranasal). No significant differences were there between groups regarding age, gender, body mass index, or ASA physical status. Modified Aldrete Score >9 was significant to reach with time as a correlation between operator and patient satisfaction. Sedation scores for groups at 1st, 9th, 12th, and 15th min were similar. Excessive coughing was observed in two (7.7%) patients of Group 2 but in none of Group 1 (p=0.105). Patients in both groups had no complaints of swallowing, excessive body movement, or lower oxygen saturation during examination (p>0.05). There were no complications (hypotension, bradycardia, respiratory depression, allergy, permanent amnesia, nausea, and vomiting) observed in patients. CONCLUSIONS: Our study results revealed that easily administered trans-mucosal dexmedetomidine sedation is safely applied during flexible fiberoptic bronchoscopy for adequate sedation, high satisfaction, and low complication rates with no significant difference in sublingual or intranasal administration.

Dexamethasone and dexmedetomidine as adjuvants to ropivacaine do not prolong analgesia in wound infiltration for lumbar spinal fusion: a prospective randomized controlled study.

BACKGROUND AND OBJECTIVES: Local anesthetics (LAs) are widely used to infiltrate into surgical wounds for postoperative analgesia. Different adjuvants like dexamethasone and dexmedetomidine, when added to LA agents, could improve and prolong analgesia. The aim of this trial was to evaluate the analgesic efficacy and opioid-sparing properties of dexamethasone and dexmedetomidine when added to ropivacaine for wound infiltration in transforaminal lumbar interbody fusion (TLIF). METHODS: We conducted a controlled study among 68 adult patients undergoing TLIF, which was prospective, randomized and double-blind in nature. The participants were divided into four equal groups at random. Group R was given 150 mg of 1% ropivacaine (15 mL) and 15 mL of normal saline. Group R + DXM received 150 mg of 1% ropivacaine (15 mL) and 10 mg of dexamethasone (15 mL). Group R + DEX received 150 mg of 1% ropivacaine (15 mL) and 1 µg/kg of dexmedetomidine (15 mL). Lastly, group R + DXM + DEX was given 150 mg of 1% ropivacaine (15 mL), 10 mg of dexamethasone and 1 µg/kg of dexmedetomidine (15 mL). The primary focus was on the length of pain relief provided. Additionally, secondary evaluations included the amount of hydromorphone taken after surgery, the numerical rating scale and safety assessments within 48 h after the operation. RESULTS: Based on the p value (P > 0.05), there was no significant variance in the duration of pain relief or the total usage of hydromorphone after surgery across the four groups. Similarly, the numerical rating scale scores at rest and during activity at 6-, 12-, 24- and 48-h post-surgery for all four groups showed no difference (P > 0.05). However, the incidence of delayed anesthesia recovery was slightly higher in group R + DEX and group R + DXM + DEX when compared to group R or group R + DXM. Furthermore, there were no significant differences between the four groups in terms of vomiting, nausea, dizziness or delayed anesthesia recovery. CONCLUSION: For wound infiltration in TLIF, the addition of dexamethasone and dexmedetomidine to ropivacaine did not result in any clinically significant reduction in pain or opioid consumption and could prompt some side effects.

Comparison of sedation with dexmedetomidine/atipamezole administered subcutaneously at GV20 acupuncture point with usual routes of administration in dogs presented for orthopaedic radiographs.

OBJECTIVES: To evaluate the efficacy of subcutaneous administration of dexmedetomidine/atipamezole at the Governing Vessel 20 (GV20) acupuncture point compared with other administration routes (intramuscular and intravenous) in dogs presented for orthopaedic radiographs. MATERIALS AND METHODS: Prospective, randomised, blinded, controlled clinical study. Sixty-four client-owned dogs were randomly injected with 200 µg/m2 of dexmedetomidine intramuscular (lumbar muscles) (n=20), intravenous (n=23) or subcutaneous at the GV20 point (n=21). Following radiographs, dogs received 2000 µg/m2 of atipamezole intramuscular (n=31), or subcutaneous at the GV20 point (n=27). Degree and time to sedation and recovery were assessed using a sedation scale and a Dynamic and Interactive Visual Analog Scale (DIVAS). Clinical physiological variables and adverse events were used. Statistical linear mixed-effect models (analysis of variance) and Cox models were performed. Significance was set at P-value <0.05. RESULTS: Sedation was insufficient to perform orthopaedic radiographs in six dogs in the intramuscular group. The time to sedation was significantly longer, and sedation scale and DIVAS scores were significantly lower in the intramuscular group. The intravenous group had significantly higher sedation scale and DIVAS scores than the GV20 group. No significant differences were observed between the intramuscular and GV20 recovery groups, although the time effect was significantly more pronounced in the GV20 recovery group. CLINICAL SIGNIFICANCE: Subcutaneous administration of dexmedetomidine and atipamezole at GV20 provided effective sedation and recovery in dogs undergoing orthopaedic radiographic studies. GV20 administration provided a clinically similar level of sedation to the intravenous route, and greater and faster sedation and similar recovery to intramuscular.

Effects of dexmedetomidine on surgical site wound pain in patients undergoing laparoscopic cholecystectomy: A meta-analysis.

This study aimed to evaluate the effectiveness of dexmedetomidine as an adjuvant to local wound infiltration anaesthesia in reducing surgical site wound pain in patients undergoing laparoscopic cholecystectomy. The Cochrane Library, PubMed, EMBASE, China National Knowledge Infrastructure, and Wanfang databases were searched from the time of database creation until February 2023. We performed a randomised controlled trial on the effect of dexmedetomidine as an adjunct to local wound infiltration anaesthesia on postoperative wound pain in patients undergoing laparoscopic cholecystectomy. Two investigators independently screened the literature, extracted data, and evaluated the quality of each study. This study was performed using the Review Manager 5.4 software. Ultimately, 13 publications with 1062 patients were included. The results showed that dexmedetomidine was effective as an adjunct to local wound infiltration anaesthesia at 1 h (standardised mean difference [SMD]: -5.31, 95% confidence intervals [CIs]: -7.22 to -3.40, P < .001), 4 h (SMD: -3.40, P < .001), 12 h (SMD: -2.11, 95% CIs: -3.10 to -1.13, P < .001) and 24 h postoperatively (SMD: -1.98, 95% CIs: -2.76 to -1.21, P < .001) significantly reduced surgical site wound pain. However, there was no significant difference in the analgesic effect at 48 h postoperatively (SMD: -1.33, 95% CIs: -3.25 to -0.58, P = .17). Dexmedetomidine provided good postoperative wound analgesia at the surgical site when used for laparoscopic cholecystectomy.

Comparative review of airway anesthesia and sedation methods for awake intubation.

PURPOSE OF REVIEW: Successful awake intubation hinges upon adequate airway anesthesia and sedation for patient comfort. This review will summarize relevant anatomy and regional anesthesia techniques to achieve airway anesthesia, and compare various airway anesthesia and sedation regimens. RECENT FINDINGS: Overall, nerve blocks consistently provided superior airway anesthesia, shorter time to intubation, higher patient comfort, and higher postintubation patient satisfaction. Additionally, ultrasound guidance can further provide benefit by reducing the amount of local anesthetic administered, leading to denser blockade, and proving invaluable in challenging clinical situations. Regarding sedation methods, numerous studies supported the use of dexmedetomidine, with or without the addition of supplemental sedation, such as midazolam, ketamine, or opioids. SUMMARY: Emerging evidence has indicated that nerve blocks for airway anesthesia may be superior to other methods of topicalization. Additionally, dexmedetomidine can be useful, both as monotherapy and with supplemental sedatives, to safely provide anxiolysis for the patient and increase success. However, it is crucial to note that the method of airway anesthesia and sedation regimen should be adapted to each patient and clinical situation, and knowledge of multiple techniques and sedation regimens can best equip anesthesiologists to do so.

Neuroprotective Effect of Dexmedetomidine on Cerebral Ischemia-Reperfusion Injury in Rats.

Background: The number of patients having ischemic stroke is increasing year on year. The anesthetic adjuvant dexmedetomidine is neuroprotective in rats and has potential for use in the treatment of ischemic stroke. Objective: The neuroprotective mechanism of dexmedetomidine in cerebral ischemia-reperfusion injury was studied in relation to its regulation of the oxidative stress response, astrocyte response, microglia overactivation, and apoptosis-related protein expression. Methods: We randomly and equally divided 25 male Sprague-Dawley rats into 5 groups: a sham-operation group, an ischemia-reperfusion injury group, and low-, medium-, and high-dose dexmedetomidine groups. A rat model of focal cerebral ischemia-reperfusion injury was established by embolization of the right middle cerebral artery for 60 minutes and reperfusion for 2 hours. The volume of cerebral infarction was calculated by triphenyl tetrazolium chloride staining. The protein expression levels of caspase-3, methionyl aminopeptidase 2 (MetAP2 or MAP2), glial fibrillary acidic protein, and allograft inflammatory factor 1 (AIF-1) in the cerebral cortex were determined by Western blot and immunohistochemistry. Results: The volume of cerebral infarction in rats decreased with increasing dose of dexmedetomidine (P = .039, 95% CI = .027 to .044). The expression levels of caspase-3, glial fibrillary acidic protein, and allograft inflammatory factor 1 and the amount of 4-hydroxynonenal decreased with increasing doses of dexmedetomidine (P = .033, 95% CI = .021 to .037). Methionyl aminopeptidase 2 (MetAP2 or MAP2) expression increased with increasing doses of dexmedetomidine (P = .023, 95% CI = .011 to .028). Conclusion: Dexmedetomidine has a dose-dependent protective effect on cerebral ischemic injury in rats. The neuroprotective effects of dexmedetomidine are achieved, in part, by reducing the oxidative stress response, inhibiting glial overactivation, and inhibiting expression levels of apoptosis-related proteins.

Effect of Immature Rubus occidentalis on Postoperative Pain in a Rat Model.

Background and Objectives: This study aimed to identify the analgesic properties of immature Rubus occidentalis extract (iROE) using a postoperative-pain rat model. We also aimed to compare the analgesic effects of iROE to those of mature R. occidentalis extract (mROE) and examine the proinflammatory cytokine response and associated underlying mechanisms. Materials and Methods: In adult male Sprague Dawley rats, acute postoperative pain was induced through plantar hind-paw incisions. After the plantar incisions were made, the rats were intraperitoneally administered with normal saline or various doses of iROE and mROE to investigate and compare the analgesic effects of iROE and mROE. The mechanisms underlying iROE-induced analgesia were investigated via post-incisional administration of yohimbine, dexmedetomidine, prazosin, naloxone, atropine, or mecamylamine, followed by iROE. Mechanical withdrawal threshold (MWT) evaluations with von Frey filaments were carried out at different time points. Serum levels of tumor necrosis factor α, interleukin (IL)-1ß, and IL-6 were measured to assess inflammatory responses. Multivariate analysis of variance (MANOVA) and linear mixed-effects model (LMEM) analysis were used to analyze the analgesic effect data. Results: The MWTs demonstrated significant increases in iROE in a dose-dependent manner up to 2 h after the plantar incisions were made. An LMEM analysis demonstrated that iROE yielded a significantly greater analgesic effect than mROE, but there was no significant difference between the two according to MANOVA. Dexmedetomidine enhanced the MWT-confirmed iROE response, while yohimbine and naloxone diminished it. Administration of iROE significantly attenuated the post-incisional increases in serum IL-1ß and IL-6 levels. Conclusions: The iROE demonstrated analgesic and anti-inflammatory effects in a rat model of incisional pain, which were more pronounced than those associated with mROE. The analgesic activity of iROE may be associated with α2-adrenergic and opioid receptors.

Nasal drip of dexmedetomidine for optimal sedation during PICC insertion in pediatric burn care.

BACKGROUND: For peripherally inserted central catheter (PICC) inserting, tranquil cooperation of children for an extended period is often required. Therefore, sedation is routinely induced clinically prior to PICC inserting. Chloral hydrate is a commonly used sedative for children. However, its clinical acceptance has remained low. And the sedation effect is non-satisfactory. Previous studies have confirmed the safety and effectiveness of intravenous/oral dosing or nasal dripping for sedation during the examinations of electrocardiography and computed tomography. Yet few studies have assessed the sedating efficacy of dexmedetomidine nasal drops for PICC inserting. METHODS: From a cohort of 40 hospitalized patients scheduled for PICC inserting, 15 children employing a novel sedative mode of dexmedetomidine nasal drops at a dose of 2 ug/kg were assigned into group A while group B included another 25 children sedated routinely via an enema of 10% chloral hydrate at a dose of 0.5 mL/kg. The Ramsay's scoring criteria were utilized for assessing the status of sedation. Two groups were observed with regards to success rate of sedation, onset time of sedation and occurrences of adverse reactions. RESULTS: Statistical inter-group differences existed in success rate and onset time of sedation. The success rate of group A was higher than that of group B (93.3% vs 64.0%, X2 = 4.302, P = .038 < 0.05). Group A had a faster onset of sedation than group B (14.86 ± 2.57 vs 19.06 ± 3.40 minutes, t = 3.781, P = .001 < 0.05). No inter-group difference of statistical significance existed in occurrence of adverse reactions (P = 1.000 > 0.05). Logistic regression analysis showed that the success rate of sedation in group A was higher than that in group B, and the difference was statistically significant (P = .036 < 0.05). CONCLUSIONS: For sedating burn children, nasal dripping of dexmedetomidine is both safe and effective during PICC inserting. Without any obvious adverse reaction, it may relieve sufferings and enhance acceptance.

More than Drug Fever: Dexmedetomidine-Induced Hyperthermia in a Critically Ill Patient.

Dexmedetomidine is a selective alpha-2 adrenergic agonist utilized for sedation in critically ill patients.1 We present the case of a morbidly obese critically ill patient who experienced profound hyperthermia, with a maximum temperature of 41.4°C, hours after starting a dexmedetomidine infusion that was otherwise not explained by her clinical diagnoses. The hyperthermia resolved hours following cessation of the infusion. Dexmedetomidine was assessed as probable in terms of causing this adverse effect. Dexmedetomidine may be associated not only with low-grade fever, but as demonstrated in our case, it may be associated with significant temperature elevations requiring cessation of therapy to restore normothermia.

Physical compatibility of remimazolam with opioid analgesics, sedatives, and muscle relaxants during simulated Y-site administration.

PURPOSE: There is a lack of information on the compatibility of remimazolam with opioid analgesics, muscle relaxants, and other sedatives. This study aimed to evaluate the physical compatibility of remimazolam with these drug classes. METHODS: Remimazolam was combined with 1 or 2 target drugs (remifentanil, fentanyl, rocuronium, vecuronium, dexmedetomidine, and midazolam). Ten physical compatibility tests were conducted, including four 3-drug compatibility tests. Remimazolam was dissolved in 0.9% sodium chloride injection to a final concentration of 5 mg/mL. Other medications were diluted in 0.9% sodium chloride injection to obtain clinically relevant concentrations. Compatibility tests were conducted with 3 test solutions, wherein remimazolam and the target drugs were compounded at equal volume ratios (1:1 or 1:1:1). Visual appearance was assessed and testing of Tyndall effect, turbidity, and pH was performed immediately after mixing and then again 1 hour and 4 hours after mixing. Appearance and turbidity were evaluated by comparison with the control solution of each target drug diluted with 0.9% sodium chloride injection to the same concentration as the test solution. RESULTS: All drugs tested were determined to be compatible with remimazolam. The drug combination with the highest change of turbidity was remimazolam and vecuronium (a mean increase of 0.16 NTU relative to the remimazolam control solution), 4 hours after mixing. The combination with the highest pH was remimazolam, fentanyl, and vecuronium (mean [SD], 3.76 [0.01]), 4 hours after mixing. The combination of remimazolam and fentanyl showed a larger change in pH at 4 hours after mixing (a mean increase of 2.6%) than immediately after mixing. CONCLUSION: Remifentanil, fentanyl, rocuronium, vecuronium, dexmedetomidine, and midazolam are physically compatible with remimazolam during simulated Y-site administration.

Ketamine-dexmedetomidine combined with local anesthesia, with or without different doses of atipamezole in the postoperative period, for orchiectomy in cats.

OBJECTIVE: To evaluate the anesthetic and cardiopulmonary effects of ketamine-dexmedetomidine combined with local anesthesia, associated or not in the postoperative period with different doses of atipamezole, for orchiectomy in cats. ANIMALS: 24 healthy cats. PROCEDURES: Cats received ketamine (7 mg/kg) combined with dexmedetomidine (10 µg/kg) IM, and 1 mL of saline (group KDSAL), 25 µg/kg (group KDAT25), or 50 µg/kg (group KDAT50) of atipamezole IV, postoperatively. All cats received local anesthesia (2 mg/kg of lidocaine) intratesticular and SC. Physiologic variables were recorded at baseline and at time points during anesthesia. Ketamine rescue dose (1 mg/kg) was recorded. The quality of recovery, the degree of sedation, and side effects were evaluated postoperatively. RESULTS: 2 cats received a single additional bolus of ketamine to perform local anesthesia. Heart rate was lower in KDSAL, KDAT25, and KDAT50 during anesthesia, compared with baseline. Hypertension was observed intraoperatively in all groups. The time to head up, pedal reflex regained time, time to sternal recumbency, and time to standing were shorter in KDAT25 and KDAT50 compared to KDSAL. Lower sedation scores were assigned sooner to KDAT25 and KDAT50 than KDSAL. All groups resulted in low recovery quality scores and no side effects. CLINICAL RELEVANCE: At the doses used, ketamine-dexmedetomidine combined with local anesthesia allowed the performance of orchiectomy. Rescue dose of ketamine for performing local anesthesia may be required. This combination can result in hypertension. Both atipamezole doses shortened the anesthetic recovery, without differences among them, and side effects.

Effects of electroacupuncture with dexmedetomidine on myocardial ischemia/reperfusion injury in rats.

BACKGROUND: To investigate the protective effect of electroacupuncture combined with dexmedetomidine (EA + Dex) on oxidative stress injury in myocardial ischemia/reperfusion (I/R) rats. METHODS: A total of 50 male Sprague-Dawley (SD) rats were randomly divided into 5 groups: sham operation (sham group); I/R group; dexmedetomidine group (Dex group); electroacupuncture group (EA group); and EA + Dex group. The myocardial I/R model was established. The EA group received EA at the Neiguan acupoint [pericardium 6 (PC6)] every day for 1 week before modeling. Rats in the EA + Dex group received EA at PC6 every day for 1 week before modeling, and intraperitoneal injection of Dex was performed 15 minutes before modeling. Dex was injected intraperitoneally in the Dex group 15 minutes before modeling. The rats were sacrificed 1 hour after reperfusion, and myocardial tissue was obtained to measure the myocardial infarction area. The myocardial tissue pathologic changes were shown by hematoxylin and eosin (HE) staining, and the superoxide dismutase (SOD), malondialdehyde (MDA), adenosine triphosphate (ATP), and reactive oxygen species (ROS) content in serum was determined. RESULTS: Compared with the sham group, the myocardial infarction area was significantly increased (P<0.01), SOD and ATP content was significantly decreased (P<0.01), and MDA and ROS content was significantly increased (P<0.01) in the I/R group; this change was significantly reduced in the Dex, EA, and EA + Dex groups (P<0.01). The indicators in the EA + Dex group were better than those in the EA and Dex groups (P<0.05). There was no significant change in the above indices in the Dex group compared with the EA group (P>0.05). CONCLUSIONS: EA + Dex pretreatment improved the damage of myocardial I/R by increasing SOD and ATP content and reducing the generation of MDA and ROS in an oxygen-free radical system.

Dexmedetomidine suppresses the isoflurane-induced neurological damage by upregulating Heme Oxygenase-1 via activation of the mitogen-activated protein kinase kinase 1/extracellular regulated protein kinases 1/nuclear factor erythroid 2-related factor 2 axis in aged rats.

Dexmedetomidine (DEX) displays a neuroprotective role in aged rats with isoflurane (ISO)-induced cognitive impairment through antioxidant, and anti-inflammatory, and anti-apoptotic effects. Therefore, the present study was performed to define the molecular mechanism of DEX on ISO-induced neurological impairment in aged rats in relation to the MEK1/ERK1/Nrf2/HO-1 axis. The study enrolled elderly patients undergoing ISO anesthesia. Patient cognitive function following treatment with DEX was evaluated using mini-mental state examination (MMSE). The results revealed that DEX supplementation of anesthesia contributed to higher MMSE scores in patients one week post treatment. Rat model of neurological impairment was also induced in 18-month-age Wistar rats by ISO, followed by DEX treatment. Based on the results of Morris water maze experiment, ELISA, and TUNEL and hematoxylin-eosin staining, in vivo experiments confirmed that DEX could reduce the oxidative stress and neurological damage induced by ISO in rats. DEX activated the nuclear factor erythroid 2-related factor (Nrf2)/Heme Oxygenase 1 (HO-1) pathway. DEX upregulated the expression of Nrf2 and HO-1 by activating the MEK1/ERK1 pathway, whereby attenuating the ISO-caused oxidative stress and neurological damage in rats. Collectively, DEX suppresses the ISO-induced neurological impairment in the aged rats by promoting HO-1 through activation of the MEK1/ERK1/Nrf2 axis.

Dexmedetomidine Mitigates Myocardial Ischemia/Reperfusion-Induced Mitochondrial Apoptosis through Targeting lncRNA HCP5.

Our study aimed to explore the function and mechanism of Dexmedetomidine (Dex) in regulating myocardial ischemia/reperfusion (I/R)-induced mitochondrial apoptosis through lncRNA HCP5. We demonstrated Dex suppressed I/R-induced myocardial infarction and mitochondrial apoptosis in vivo. Dex induced the expression of lncRNA HCP5 and MCL1, inhibited miR-29a expression and activated the JAK2/STAT3 signaling. Dex attenuated hypoxia/reoxygenation (H/R)-induced mitochondrial apoptosis by upregulating lncRNA HCP5 in cardiomyocytes. Overexpression of lncRNA HCP5 sponged miR-29a to suppress H/R-induced mitochondrial apoptosis. Knockdown of miR-29a also alleviated cardiomyocyte apoptosis by upregulating MCL1. Overexpression of lncRNA HCP5 activated the JAK2/STAT3 signaling through sponging miR-29a and enhancing MCL1 expression in cardiomyocytes. Dex mitigated myocardial I/R-induced mitochondrial apoptosis through the lncRNA HCP5/miR-29a/MCL1 axis and activation of the JAK2/STAT3 signaling.

Effects of dexmedetomidine on cardiac electrophysiology in patients undergoing general anesthesia during perioperative period: a randomized controlled trial.

BACKGROUND: Dexmedetomidine has controversial influence on cardiac electrophysiology. The aim of this study was to explore the effects of dexmedetomidine on perioperative cardiac electrophysiology in patients undergoing general anesthesia. METHODS: Eighty-one patients were randomly divided into four groups: groups D1, D2, D3 receiving dexmedetomidine 1, 1, 0.5 µg/kg over 10 min and 1, 0.5, 0.5 µg/kg/h continuous infusion respectively, and control group (group C) receiving normal saline. Twelve-lead electrocardiograms were recorded at the time before dexmedetomidine/normal saline infusion (T1), loading dose finish (T2), surgery ending (T6), 1 h (T7) after entering PACU, 24 h (T8), 48 h (T9), 72 h (T10) and 1 month (T11) postoperatively. Cardiac circulation efficiency (CCE) were also recorded. RESULTS: Compared with group C, QTc were significantly increased at T2 in groups D1 and D2 while decreased at T7 and T8 in group D3 (P < 0.05), iCEB were decreased at T8 (P < 0.05). Compared with group D1, QTc at T2, T6, T7, T9 and T10 and iCEB at T8 were decreased, and CCE at T2-T4 were increased in group D3 significantly (P < 0.05). Compared with group D2, QTc at T2 and iCEB at T8 were decreased and CCE at T2 and T3 were increased in group D3 significantly (P < 0.05). CONCLUSIONS: Dexmedetomidine at a loading dose of 0.5 µg/kg and a maintenance dose of 0.5 µg/kg/h can maintain stability of cardiac electrophysiology during perioperative period and has no significant adverse effects on CCE. TRIAL REGISTRATION: ClinicalTrials.gov NCT04577430 (Date of registration: 06/10/2020).

The Impact of Dexmedetomidine-loaded Nano-microsphere Combined with Percutaneous Acupoint Electrical Stimulation on the Postoperative Cognitive Function of Elderly Patients with Hip Fracture.

To explore the impact of nano-microsphere loaded with dexmedetomidine (DEX) combined with percutaneous acupoint electrical stimulation on the postoperative cognitive function of elderly patients with hip fracture. The free base was prepared by the alkali precipitation method in this research, and then the drug was loaded into PLGA microspheres to construct the drug sustained-release system. The PLAG microspheres loaded with DEX (MS/DEX) were prepared by the O/W emulsion volatilization method and then Gel-(DEX-MS/BUP) suspension was obtained. A scanning electron microscope (SEM) was used to analyze the characterization of the prepared drug-loaded nano-microsphere, rheological analysis was performed on the copolymer solution, and in vivo release and degradation, experiments were carried out. Wistar rats were randomly divided into four groups (n=ten). After the sciatic nerve block model was established, the block time was observed after the injection of each sustained-release agent. The results showed that the gel-forming temperature of Gel and Gel-(DEX-MS/BUP) were 27.3°C and 26.3°C, respectively. Both MS/BUP and Gel-(DEX-MS/BUP) drugs could completely enter the blocking state. There was no loss of motor function in the rats after GEL-DEX. The clinical trials showed that Gel-(DEX-MS/BUP) system had good in situ and sustained release effects, and the analgesic effect of local anesthesia was significantly improved.