Effect of intrathecal dexmedetomidine versus intravenous dexmedetomidine on subarachnoid anesthesia with hyperbaric bupivacaine

Effects of dexmedetomidine, fentanyl and magnesium sulfate added to ropivacaine on sensory and motor blocks in lower abdominal surgery: a randomized clinical trial

This study aimed to compare the effects of intrathecal dexmedetomidine, fentanyl and magnesium sulfate added to ropivacaine on the onset and duration of sensory and motor blocks in lower abdominal surgery. This double-blind randomized clinical trial included 90 patients scheduled for lower abdominal surgery at Vali-Asr Hospital in Arak, Iran. The enrolled patients were randomly divided into three equal groups and then underwent spinal anesthesia. The first group received 10 μg of dexmedetomidine, the second group received 50 μg of fentanyl, and the third group received 200 mg of 20% magnesium sulfate intrathecally in addition to 15 mg of 0.5% ropivacaine. In the dexmedetomidine group, the mean arterial blood pressure was lower than the other two groups (P = 0.001). Moreover, the time to onset of sensory block (P = 0.001) and the mean duration of sensory block (P = 0.001) were shorter and longer, respectively, in the dexmedetomidine group than in the other two groups. In the dexmedetomidine group, the mean time to onset of motor block (P = 0.001) and the mean duration of motor block (P = 0.001) were lower and higher than in the other two groups, respectively. There was no significant difference in visual analog scale score, heart rate, administered opioid, and drug side effects among the three groups. Dexmedetomidine caused early sensory and motor blocks while prolonging the duration of sensory and motor blocks compared with the other two groups. In addition, dexmedetomidine reduced mean arterial blood pressure in patients. Based on the findings of this study, it is recommended that dexmedetomidine can be used in order to enhance the quality of sensory and motor block in patients.

Perioperative intravenous infusion of dexmedetomidine for alleviating postpartum depression after cesarean section: A meta-analysis and systematic review

The efficacy of perioperative dexmedetomidine (DEX) infusion as a precaution against postpartum depression (PPD) in women undergoing cesarean section has not been substantiated systematically. A literature search for RCTs on DEX against PPD was retrieved in the following databases from inception to January 3, 2024: PubMed, Embase, Web of Science, the Cochrane Library, CNKI, Wanfang, CBM, VIP, etc. A total of 13 RCTs with 1711 participants were included. Meta-analysis was performed by RevMan5.3 and Stata16 using a random-effects model. EPDS scores were significantly decreased in the DEX group within one week or over one week postpartum compared to the control group (SMD = -1.25, 95 %CI: -1.73 to -0.77; SMD = -1.08, 95 %CI: -1.43 to -0.73). The prevalence of PPD was significantly inferior to the control at both time points (RR = 0.36, 95 %CI: 0.24 to 0.54; RR = 0.39, 95 %CI: 0.26 to 0.57). Univariate meta-regression suggested that age influenced the heterogeneity of the EPDS scores (P = 0.039), and DEX infusion dose was a potential moderator (P = 0.074). The subgroup analysis results of PPD scores at both time points were consistent, showing that: ① Mothers younger than 30 years old had better sensitivity to DEX for treating PPD. ② The anti-PPD efficacy of continuous infusion of DEX by PCIA was superior to both single infusion and combined infusion. ③ DEX showed a better anti-PPD effect when the total infusion dose was ≤ 2 μg/kg. Moreover, DEX improved analgesia and sleep quality, provided appropriate sedation, and reduced the incidence of nausea, vomiting, and chills. The current evidence confirmed the prophylaxis and superiority of DEX for PPD. More high-quality, large-scale RCTs are required for verifying the reliability and formulating administration methods.

Recent Advances in the Clinical Value and Potential of Dexmedetomidine

Dexmedetomidine, a highly selective α2-adrenoceptor agonist, has sedative, anxiolytic, analgesic, sympatholytic, and opioid-sparing properties and 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. Recent studies indicate several emerging clinical applications via different routes. We review recent data on dexmedetomidine studies, particularly exploring the varying routes of administration, experimental implications, clinical effects, and comparative advantages over other drugs. A search was conducted on the PubMed and Web of Science libraries for recent studies using different combinations of the words “dexmedetomidine”, “route of administration”, and pharmacological effect. The current routes, pharmacological effects, and application categories of dexmedetomidine are presented. It functions by stimulating pre- and post-synaptic α2-adrenoreceptors within the central nervous system, leading to hyperpolarization of noradrenergic neurons, induction of an inhibitory feedback loop, and reduction of norepinephrine secretion, causing a sympatholytic effect, in addition to its anti-inflammation, sleep induction, bowel recovery, and sore throat reduction effects. Compared with similar α2-adrenoceptor agonists, dexmedetomidine has both pharmacodynamics advantage of a significantly greater α2:α1-adrenoceptor affinity ratio and a pharmacokinetic advantage of having a significantly shorter elimination half-life. In its clinical application, dexmedetomidine has been reported to present a significant number of benefits including safe sedation for various surgical interventions, improvement of intraoperative and postoperative analgesia, sedation for compromised airways without respiratory depression, nephroprotection and stability of hypotensive hemodynamics, reduction of postoperative nausea and vomiting and postoperative shivering incidence, and decrease of intraoperative blood loss. Although the clinical application of dexmedetomidine is promising, it is still limited and further research is required to enhance understanding of its pharmacological properties, patient selection, dosage, and adverse effects.

The Density of Different Local Anesthetic Solutions, Opioid Adjuvants and Their Clinically Used Combinations: An Experimental Study

Various opioids are added to local anesthetic solutions for spinal anesthesia. This may change the final density of the local anestetic (LA) mixture. This effect regarding current concepts in spinal anesthesia needs to be re-evaluated. In order to re-evaluate such effects, hyperbaric and isobaric local anesthetic (LA) solutions were mixed with opioid adjuvants (A) using the equipment available in the operating room. Ten density measurements for each composition (LA-A) were performed. The density change of 0.0006 g/mL was regarded as significant. Measured densities were also compared with theoretical values calculated using Hare's. As a result, the addition of an opioid adjuvant caused a significant reduction in the final density of the LA-A solution. In hyperbaric LA mixtures, it did not change the baricity from hyperbaric to isobaric. However, the addition of highly hypobaric fentanyl 0.99360 g/mL (SD ± 0.00004) changes all isobaric LA solutions baricity to hypobaric. The comparison of measured and theoretical densities revealed significant differences (p > 0.05). However, the absolute reduction reached 0.0006 g/mL in only two LA-A compositions. We conclude that the addition of fentanyl to isobaric LA results in a hypobaric solution that may affect the distribution of the block. The inadequacy of LA-A in a clinical setting is unlikely to influence block characteristics.

Successful Management of Parkinson's Disease Dyskinesia During Local Anesthesia With Dexmedetomidine

Dyskinesia is among the most problematic issues for local anaesthesia management in Parkinson's disease (PD) patients. We present a case of a patient with PD who underwent spinal anaesthesia while utilizing dexmedetomidine (DEX) to reduce dyskinesia during urological surgery. DEX stimulates α₂-adrenergic receptors, which works to reduce the dyskinesia in PD patients.