Continuous Infusion Of Dexmedetomidine Research Articles

Advances in the use of dexmedetomidine during the perioperative period to improve postoperative sleep quality in patients undergoing surgery.

There is a high incidence of postoperative sleep and sleep architecture disorders in patients undergoing surgery, and dexmedetomidine (DEX) is commonly used to improve postoperative sleep quality and ameliorate the adverse effects of poor sleep on various organ systems. The continuous intraoperative intravenous infusion of DEX, the addition of DEX to postoperative intravenous analgesia pumps, and the continuous infusion of DEX after admission to the intensive care unit are often used clinically to improve postoperative sleep quality at doses of 0.1 to 0.7 μg/kg/hour, but the effects of DEX on sleep quality and structure identified in these studies have been inconsistent. Thus, it is unclear whether DEX improves postoperative sleep quality. The various methods of administering DEX to improve postoperative sleep quality have differing effects, the route used modifies the effect of DEX on sleep structure, and the intrinsic mechanism whereby DEX improves sleep quality remains to be fully investigated. In the present review, we describe new directions for future research into the effects of DEX on postoperative sleep quality and the mechanisms involved, which should help guide the design of further studies. This narrative review was completed according to the Scale for the Assessment of Narrative Review Articles (SANRA).

Retrospective comparison of the effects of remimazolam and dexmedetomidine on postoperative delirium in elderly patients undergoing orthopedic surgery of the lower extremities under spinal anesthesia.

Remimazolam is often used for perioperative sedation due to its rapid onset and offset. However, the possible association between remimazolam and postoperative delirium (POD) remains undetermined. The present study evaluated whether remimazolam increased the incidence of POD compared with dexmedetomidine in elderly patients undergoing orthopedic surgery of the lower extremities. This retrospective study included patients aged ≥ 65years who had undergone orthopedic surgery of the lower extremities under spinal anesthesia from January 2020 to November 2022 and were sedated with continuous intravenous infusion of dexmedetomidine or remimazolam. The incidence of POD was assessed through a validated comprehensive review process of each patient's medical records. The effect of remimazolam on the occurrence of POD compared with dexmedetomidine was evaluated by propensity score weighted multivariable logistic models. A total of 447 patients were included in the final analysis. The crude incidence of POD within 3days after surgery was 7.5% (17/226) in the dexmedetomidine group and 11.8% (26/221) in the remimazolam group, increasing to 9.7% (22/226) and 15.8% (35/221), respectively (p = 0.073), within 5days. The multivariable models showed that, compared with dexmedetomidine, intraoperative sedation with remimazolam significantly increased the occurrence of POD within 3days (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.31 to 3.82, p = 0.003) and 5days (OR 2.10, 95% CI 1.32 to 3.40, p = 0.002). Compared with dexmedetomidine, remimazolam infusion may be associated with a higher risk of POD in elderly patients undergoing orthopedic surgery of the lower extremities under spinal anesthesia.

Determination of the ED90 of Dexmedetomidine Infusion to Prevent Emergence Agitation in Children Undergoing Dental Rehabilitation With Sevoflurane Anesthesia: A Biased-Coin Up-and-Down Sequential Allocation Trial.

Emergence agitation (EA) is an adverse complication during early recovery from sevoflurane anesthesia. Continuous intravenous infusion of dexmedetomidine (DEX) is commonly used for EA prevention. However, a wide dose range is used for preventing EA, and the optimal dose remains unknown. This study was aimed at determining the optimal dose (the 90% effective dose [ED90]) of DEX for continuous intraoperative infusion for EA prevention in children. We enrolled children aged 3 to 7 years who underwent dental treatment under sevoflurane anesthesia. DEX was continuously infused from the time of the establishment of the intravenous access until 5 minutes before the end of surgery. The initial DEX dose was 0.5 µg/kg/h, and subsequent dose adjustments were determined based on the response of the previous patient by using an up-down sequential allocation with a biased-coin design. The primary outcome was the ED90 for continuous DEX infusion based on the success or failure of the EA-preventing dose. Forty-five patients were enrolled in the study. The DEX dose ranged from 0.50 to 0.90 µg/kg/h. The estimated ED90 (95% confidence interval [CI]) for preventing EA was 0.74 µg/kg/h (0.67-1.05 µg/kg/h). The duration of surgery (mean ± standard deviation [SD]) was 113 ± 30 minutes. The times (mean ± SD) for extubation, time to emergence, and recovery time were 5 ± 2 minutes, 27 ± 9 minutes, and 39 ± 7 minutes, respectively. The ED90 for continuous intraoperative DEX infusion for EA prevention in pediatric patients receiving dental treatment under sevoflurane anesthesia was 0.74 µg/kg/h (95% CI, 0.67-1.05 µg/kg/h).

Analgesic Effect and Sleep Quality of Low-Dose Dexmedetomidine in Cardiac Surgical Patients After Ultrafast-Track Extubation: A Randomized Clinical Trial

To compare the analgesic and sleep quality effects of dexmedetomidine infusion versus placebo in patients undergoing cardiac surgery with ultra-fast track extubation. The randomized, double-blind clinical trial study. At a single academic center hospital. We included patients aged 25 to 65 scheduled for elective cardiac surgery under general anesthesia with cardiopulmonary bypass from October 2021 to December 2022. After immediate extubation in the operating room, the patients who were allocated at first after providing their consent to either the dexmedetomidine group (Dex) or the placebo group (Placebo) received continuous infusion of dexmedetomidine (0.2 μg/kg/h) or saline for 12 hours postoperatively. The groups' demographic and perioperative variables were not statistically significant. Total morphine consumption in milligrams at 12 and 24 hours after administered study drug, total sleep time in hours by BIS value ≤85, and sleep quality with the Richard-Campbell Sleep Questionnaire were compared. The analysis included 22 Dex and 23 Placebo patients. The consumption of morphine was not statistically different between the Dex and Placebo groups at 12 and 24 hours (p = 0.707 and p = 0.502, respectively). The Dex group had significantly longer sleep time (8.7 h [7.8, 9.5]) than the Placebo group (5.8 h [2.9, 8.5]; p = 0.007). The Dex group also exhibited better sleep quality (7.9 [6.7, 8.7] vs 6.6 [5.2, 8.0]; p = 0.038). Sedation with low-dose dexmedetomidine infusion for ultra-fast track extubation following cardiac surgery enhances sleep duration and quality.

Effect of dexmedetomidine on the incidence of postoperative acute kidney injury in living donor liver transplantation recipients: A randomized controlled trial.

Acute kidney injury (AKI) is one of the most common complications after living-donor liver transplantation (LDLT) that has great impact on recipient and graft outcomes. Dexmedetomidine is reported to decrease the incidence of AKI. In the current study, we investigated whether intraoperative dexmedetomidine infusion would reduce the AKI following LDLT. In total, 205 adult patients undergoing elective LDLT were randomly assigned to the dexmedetomidine group (n=103) or the control group (n=102). Dexmedetomidine group received continuous dexmedetomidine infusion at a rate of 0.4mcgּ/kg/hr after the anesthesia induction until 2 hours after graft reperfusion. The primary outcome was to compare the incidence of AKI. Secondary outcomes included serial lactate levels during surgery, chronic kidney disease, major adverse cardiovascular events, early allograft dysfunction, graft failure, overall mortality, duration of mechanical ventilation, ICU and hospital length of stay. Intraoperative hemodynamic parameters were also collected. Of 205 recipients, 42.4% (n=87) developed AKI. The incidence of AKI was lower in the dexmedetomidine group (35.0%, n=36/103) compared with the control (50.0%, n=51/102) ( P =0.042). There were significantly lower lactate levels in the dexmedetomidine group after reperfusion (4.39 [3.99-4.8] vs 5.02 [4.62-5.42], P =0.031) until the end of surgery (4.23 [3.73-4.73] vs 5.35 [4.84-5.85], P =0.002). There were no significant differences in the other secondary outcomes besides lactate. Also, intraoperative mean blood pressure, cardiac output, and systemic vascular resistance did not show any difference. Our study suggests that intraoperative dexmedetomidine administration was associated with significantly decreased AKI incidence and lower intraoperative serum lactate levels in LDLT recipients, without untoward hemodynamic effects.

Impact of a Dexmedetomidine Intravenous Infusion in Septic Dogs: Preliminary Study.

The purpose of this study was to determine if a continuous rate infusion (CRI) of dexmedetomidine decreases vasopressor requirements in septic dogs undergoing surgery. Vital parameters, sequential organ failure assessment (SOFA) score, vasopressor requirement, and 28-day mortality were recorded. Dogs were randomly divided into two groups: a dexmedetomidine (DEX) (1 mcg/kg/h) group and a control group (NaCl), which received an equivalent CRI of NaCl. Dogs were premedicated with fentanyl 5 mcg/kg IV, induced with propofol, and maintained with sevoflurane and a variable rate fentanyl infusion. DEX or NaCl infusions were started 10 min prior to induction. Fluid-responsive hypotensive patients received repeated Ringer's lactate boluses (2 mL/kg) until stable or they were no longer fluid-responsive. Patients that remained hypotensive following fluid boluses received norepinephrine at a starting dose of 0.05 mcg/kg/min, with increases of 0.05 mcg/kg/min. Rescue adrenaline boluses were administered (0.001 mg/kg) if normotension was not achieved within 30 min of starting norepinephrine. The NaCl group received a significantly higher dose of norepinephrine (0.8, 0.4-2 mcg/kg/min) than the DEX group (0.12, 0-0.86 mcg/kg/min). Mortality was statistically lower in the DEX group (1/10) vs. the NaCl group (5/6). Results of this study suggest that a 1 mcg/kg/h CRI of dexmedetomidine decreases the demand for intraoperative vasopressors and may improve survival in septic dogs.

Electroencephalographic guided propofol-remifentanil TCI anesthesia with and without dexmedetomidine in a geriatric population: electroencephalographic signatures and clinical evaluation.

Elderly and multimorbid patients are at high risk for developing unfavorable postoperative neurocognitive outcomes; however, well-adjusted and EEG-guided anesthesia may help titrate anesthesia and improve postoperative outcomes. Over the last decade, dexmedetomidine has been increasingly used as an adjunct in the perioperative setting. Its synergistic effect with propofol decreases the dose of propofol needed to induce and maintain general anesthesia. In this pilot study, we evaluate two highly standardized anesthetic regimens for their potential to prevent burst suppression and postoperative neurocognitive dysfunction in a high-risk population. Prospective, randomized clinical trial with non-blinded intervention. Operating room and post anesthesia care unit at Hospital Base San José, Osorno/Universidad Austral, Valdivia, Chile. 23 patients with scheduled non-neurologic, non-cardiac surgeries with age > 69years and a planned intervention time > 60min. Patients were randomly assigned to receive either a propofol-remifentanil based anesthesia or an anesthetic regimen with dexmedetomidine-propofol-remifentanil. All patients underwent a slow titrated induction, followed by a target controlled infusion (TCI) of propofol and remifentanil (n = 10) or propofol, remifentanil and continuous dexmedetomidine infusion (n = 13). We compared the perioperative EEG signatures, drug-induced changes, and neurocognitive outcomes between two anesthetic regimens in geriatric patients. We conducted a pre- and postoperative Montreal Cognitive Assessment (MoCa) test and measured the level of alertness postoperatively using a sedation agitation scale to assess neurocognitive status. During slow induction, maintenance, and emergence, burst suppression was not observed in either group; however, EEG signatures differed significantly between the two groups. In general, EEG activity in the propofol group was dominated by faster rhythms than in the dexmedetomidine group. Time to responsiveness was not significantly different between the two groups (p = 0.352). Finally, no significant differences were found in postoperative cognitive outcomes evaluated by the MoCa test nor sedation agitation scale up to one hour after extubation. This pilot study demonstrates that the two proposed anesthetic regimens can be safely used to slowly induce anesthesia and avoid EEG burst suppression patterns. Despite the patients being elderly and at high risk, we did not observe postoperative neurocognitive deficits. The reduced alpha power in the dexmedetomidine-treated group was not associated with adverse neurocognitive outcomes.

The feasibility of dexmedetomidine-led anesthesia maintenance strategy during major abdominal surgery

BackgroundDexmedetomidine is known for its selective action on α2-adrenoceptor sites and is recognized for its neuroprotective capabilities. It can improve postoperative cognitive function. Commonly used anesthetics, such as sevoflurane and propofol, have been reported to affect postoperative cognitive function. Therefore, it could be valuable to explore dexmedetomidine-led anesthesia strategy. This study was designed to assess the performance, safety, and effective infusion rate in anesthesia maintenance, to explore a feasible dexmedetomidine-led anesthesia maintenance protocol, and to provide a foundation for potential combined anesthesia. MethodsThirty patients aged 18–60 years, classified as ASA I or II, undergoing abdominal surgery were involved. The anesthesia maintenance was achieved with dexmedetomidine, remifentanil and rocuronium. Dixon up-and-down sequential methodology was utilized to ascertain the ED50 of dexmedetomidine for maintaining Patient State Index (PSI) 25–40 (depth of stage III anesthesia). Intraoperative HR, BP and depth of anesthesia were monitored and controlled. The wake-up time from anesthesia, the incidence of intraoperative awareness and postoperative delirium, and the patients’ satisfaction were assessed. ResultsThe results indicated that dexmedetomidine-led anesthesia could maintain the depth of stage III anesthesia during abdominal surgery. The ED50 and ED95 of dexmedetomidine infusion rates during anesthesia maintenance were 2.298 μg/kg·h (95%CI: 2.190–2.404 μg/kg·h) and 3.765 μg/kg·h (95%CI: 3.550–4.050 μg/kg·h). Continuous infusion of dexmedetomidine and 0.1–0.3 μg/kg·min remifentanil could maintain PSI 25–40, and provide appropriate anesthesia depth for abdominal surgery. Perioperative bradycardia and hypertension could be rapidly corrected with atropine and nitroglycerin. The median wake-up time after anesthesia was 4.8 min, the perioperative maximum HR had significant correlation with wake-up time and intraoperative dexmedetomidine dose. No intraoperative awareness and postoperative delirium occurred; the patients were satisfied with dexmedetomidine-led anesthesia. Conclusionsdexmedetomidine-led strategy could maintain stable depth of anesthesia throughout surgery, and the ED50 of dexmedetomidine infusion rates was 2.298 μg/kg·h. Intraoperative HR, BP and depth of anesthesia require monitoring, the bradycardia and hypertension could be rapidly corrected.

The role of dexmedetomidine administered via intravenous infusion as adjunctive therapy to mitigate postoperative delirium and postoperative cognitive dysfunction in elderly patients undergoing regional anesthesia: a meta-analysis of randomized controlled trials

Study objectiveThis meta-analysis aimed to assess whether continuous intravenous administration of DEX during surgery can be part of the measures to prevent the onset of postoperative delirium and postoperative cognitive dysfunction in elderly individuals following regional anesthesia.MethodsWe searched the databases of PubMed, Embase, the Cochrane Library and China National Knowledge Infrastructure (by June 1, 2023) for all available randomized controlled trials assessing whether intravenous application of dexmedetomidine can help with postoperative delirium and postoperative cognitive dysfunction in the elderly with regional anesthesia. Subsequently, we carried out statistical analysis and graphing using Review Manager software (RevMan version 5.4.1) and STATA software (Version 12.0).Main resultsWithin the scope of this meta-analysis, a total of 18 randomized controlled trials were included. Among them, 10 trials aimed to assess the incidence of postoperative delirium as the primary outcome, while the primary focus of the other 8 trials was on the incidence of postoperative cognitive dysfunction. The collective evidence from these 10 studies consistently supports a positive relationship between the intravenous administration of dexmedetomidine and a decreased risk of postoperative delirium (RR: 0.48; 95%CI: 0.37 to 0.63, p < 0.00001, I2 = 0%). The 8 literature articles and experiments evaluating postoperative cognitive dysfunction showed that continuous intravenous infusion of dexmedetomidine during the entire surgical procedure exhibited a positive preventive effect on cognitive dysfunction among the elderly population with no obvious heterogeneity (RR: 0.35; 95%CI: 0.25 to 0.49,p < 0.00001, I2 = 0%).ConclusionAdministering dexmedetomidine intravenously during surgery can potentially play a significant role in preventing postoperative delirium and postoperative cognitive dysfunction in patients older than 60 years with regional anesthesia according to this meta-analysis.

Pediatric sedation for emergency, imaging and endoscopic procedures: a worldwide review from the last five years

Introduction: Anatomical, physiological, pharmacokinetic, pharmaco dynamic and behavioral particularities relevant to the pediatric population make its sedation challenging for quick and low-complexity procedures. Robust evidence on this subject is still scarce, and the variety of drugs available, with their multiple routes of administration and dosage schemes, makes it difficult for providers to make a decision. Methods: Through research in four databases, we found 170 articles that addressed pediatric sedation and, after applying the exclusion criteria, we selected 32 articles for analysis. Results: In sedation for invasive or painful procedures, Esketamine in monotherapy was effective, despite the significant incidence of adverse effects. Satisfactory responses were also obtained with associations between Esketamine and Propofol and Fentanyl with Propofol or Midazolam. To perform imaging tests, continuous infusions of Propofol or Dexmedetomidine were sufficient, with associations with Esketamine or opioids associated with a higher incidence of adverse effects. Endoscopic procedures have been successfully performed after administration of continuous infusion of Propofol or Dexmedetomidine, associated with Remifentanil infusion or Fentanyl bolus. Esketamine in monotherapy was also effective. Discussion: The drugs studied have an adverse effect profile compatible with safe pediatric sedation, whether administered by a specialist or not. However, alternative administration routes and dosages still need further studies before being routinely applied. Conclusion: Sedation in pediatrics is still an open field for research in our country.

Effect of dexmedetomidine on the intraoperative and early postoperative complications of patients undergoing orthotopic liver transplantation

Objective: To investigate the effect of dexmedetomidine on the intraoperative and early postoperative complications of patients undergoing orthotopic liver transplantation. Methods: This is a retrospective cohort study. The clinical data of 399 patients who underwent orthotopic liver transplantation at the First Affiliated Hospital of Nanjing Medical University from January 2016 to September 2020 were retrospectively collected. There were 319 males and 80 females, aged (50.9±10.2) years (range: 10 to 73 years). These patients were divided into the control group (369 cases) and the dexmedetomidine group (30 cases) according to whether dexmedetomidine was continuously pumped intravenously during the operation until the operation ended. The 1∶2 propensity score matching was used to match the preoperative and intraoperative conditions of the two groups of patients, and the caliper width was 0.2. Outcome indicators included intraoperative postreperfusion syndrome, acute kidney injury and pulmonary complications within 7 days after surgery, length of hospital stay, time of stay in ICU, duration of assisted mechanical ventilation, rate of reintubation, 6-month and 1-year survival and recurrence-free survival rate after surgery. The independent sample t test, χ2 test, Mann-Whitney U test or Fisher exact test was used to statistically analyze the data of the two groups of patients, respectively. Survival curves of overall survival and disease-free-survival were plotted by Kaplan-Meier method, and the survival rate and recurrence-free survival rate were compared by Log-rank test. Results: A total of 78 patients were included after propensity score matching, including 26 in the dexmedetomidine group and 52 in the control group. The incidence of acute kidney injury in the dexmedetomidine group within 7 days after surgery was 0 (0/26), significantly lower than that of the control group (21.2%,11/52)(corrected χ2=4.776, P=0.029). There were no significant differences in the incidence of intraoperative postreperfusion syndrome and pulmonary complications within 7 days after surgery, length of hospital stay, ICU time, the duration of assisted mechanical ventilation, rate of reintubation, 6-month and 1-year survival, and recurrence-free survival rate after surgery between the two groups (all P>0.05). Conclusion: Continuous infusion of dexmedetomidine via intravenous pump during operation may be beneficial in reducing the incidence of acute kidney injury within 7 days after orthotopic liver transplantation.

Comparison emergence of sedation, using dexmedetomidine and remimazolam, in spinal anaesthesia - double blinded randomized controlled trial.

Background: Continuous intravenous infusion of remimazolam may be suitable for sedation in patients undergoing regional anaesthesia. However, there have been no studies comparing remimazolam and dexmedetomidine for this purpose. This study compared emergence from sedation between dexmedetomidine and remimazolam following continuous intravenous infusion in patients undergoing spinal anaesthesia. Methods: This double-blinded, randomised controlled trial assessed the sedative effects of dexmedetomidine and remimazolam. Following spinal anaesthesia, patients were sedated using continuous intravenous infusion of either dexmedetomidine (D group) or remimazolam (R group).The D group received dexmedetomidine administered at 6 mL/kg/h (6 µg/kg/h) for 10 minutes, followed by 1 mL/kg/h (1 µg/kg/h). The R group received remimazolam administered at 6 mL/kg/h (6 mg/kg/h) for 10 minutes, followed by 1 mL/kg/h (1 mg/kg/h). Sedation levels were evaluated using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. The time to reach MOAA/S ≤ 3 from the start of drug infusion and the time to reach MOAA/S = 5 from the end of infusion were recorded. Hemodynamic parameters and respiratory rate were also monitored. Results: The R group reached MOAA/S ≤ 3 significantly faster than the D group during induction of sedation (4 ± 1 minutes and 11 ± 3 minutes, respectively, p < 0.001). The R group also reached MOAA/S = 5 significantly faster than the D group during emergence from sedation (11 ± 3 minutes and 16 ± 5 minutes, respectively, p < 0.001). Both groups maintained stable hemodynamic parameters and respiratory rate without any significant differences, although the mean heart rate was significantly lower in the D group than in the R group after the start of infusion. Conclusion: Remimazolam demonstrated significantly faster induction of and emergence from sedation compared to dexmedetomidine, with no significant differences in haemodynamics or respiratory depression.

Abstract 18979: Calm Before the Storm: Exploring the Risk of Torsades De Pointes With Dexmedetomidine Administration

Introduction: Corrected QT interval (QTc) prolongation is the known side effect of multiple medications especially in antipsychotic and antiarrhythmic family. Patients with either inherited or secondary prolonged QTc should be monitored closely as they can develop life threatening complications like Torsades de-pointes and ventricular fibrillation. Here we present a case of cardiac arrest secondary to dexmedetomidine. Case: A 49-year-old female with history of bipolar disorder was admitted to intensive unit for seizure after intentional ingestion of uncounted amount of diphenhydramine pills. Patient was intubated for airway protection and started on propofol. Her vitals at the time of admission included the pulse rate of 76, blood pressure of 102/49 mmHg. Her urine drug screen was positive for TCA and cannabinoids. Her ECG at the time of admission was significant for prolonged QTC of 600msec that improved to 460msec in the consecutive ECGs after administration of total of 4mg intravenous magnesium. Continuous EEG was negative for seizure and she was weaned off sedation. After awakening, she became agitated, after pushes of benzodiazepines, was eventually started on dexmedetomidine. Twenty minutes after starting low dose dexmedetomidine, patient was noted to be in cardiac arrest. Reviewing telemetry prior to event, revealed the R on T phenomenon and Torsades de pointes that lasted for few seconds with progression into ventricular fibrillation. Discussion: Currently dexmedetomidine is labeled with a low to possible risk of Torsade de pointes and QTC prolongation. Dexmedetomidine induced Torsade de pointes might be explained by bradycardia in patients which causes further prolongation of QT interval. Studies have shown that continuous IV infusion of dexmedetomidine at rate of 0.3 mcg/kg/hour can worsen QTC prolongation. Conclusions: In this case we present a case of VFib arrest secondary to Torsade after twenty minutes of infusion of dexmedetomidine without any sign of bradycardia prior to the event. This carries a significant importance as it shows this drug carries a potential risk of QTc prolongation similar to previous studies. Whether this side effect is dose dependent or not requires further investigation.

Pharmacokinetics and physiologic effects of continuous rate infusion of dexmedetomidine in anaesthetized horses maintained on isoflurane, dobutamine and nitric oxide

Pharmacokinetics and physiologic effects of continuous rate infusion of dexmedetomidine in anaesthetized horses maintained on isoflurane, dobutamine and nitric oxide

Dexmedetomidine use for patients in palliative care with intractable pain and delirium: A retrospective study.

Patients seen by the palliative care team often have difficult and intractable symptoms. The current standard of practice to manage these symptoms is the deeply sedating midazolam continuous subcutaneous infusion for patients who are expected to expire within hours to days. Dexmedetomidine provides sedation but lacks evidence in palliative care use. This study describes continuous subcutaneous infusion of dexmedetomidine's effect on refractory pain and delirium. Retrospective, observational chart review and conducted in accordance with SQUIRE (quality improvement study). Twenty adult patients (18 years of age or older) with metastatic cancer disease admitted to three palliative complex care units of Fraser Health who received continuous subcutaneous infusion of dexmedetomidine between January 2017 to August 31, 2019. Average length of dexmedetomidine use was 9 days (1/3 length of stay). Eight of the 13 patients with pain symptoms exhibited an overall decline in pain. Four of the 6 patients with delirium had an initial decrease in delirium, but it did not last beyond the first day. Despite progressive clinical deterioration, adjunctive medications decreased or remained the same for 53% of as needed medications and 65% for regularly scheduled medications. Forty-five percent of patients had ≥50% days of rousable sedation. Hypotension occurred in 85% of patients. Dexmedetomidine provided benefit in managing intractable pain while allowing patients to remain rousable, but only had a short effect on delirium symptoms.

Role of dexmedetomidine in modifying immune paralysis in patients with septic shock: randomized controlled trial

BackgroundImmune paralysis can be defined as a hypoinflammatory state associated with the incapacity of the immune system to release proinflammatory mediators despite the clearance of pathogens by antimicrobials. Persistent immune paralysis leads to failure to eradicate primary infections with a substantial increase in the risk of multiorgan dysfunction and mortality. The state of immune paralysis is caused mainly by the diminished ability of monocytes to release proinflammatory cytokines in response to endotoxin. This phenomenon is known as endotoxin tolerance. This study aimed to assess the role of dexmedetomidine in modifying immune paralysis in septic shock patients.MethodsTwenty-four patients with septic shock were randomized into two groups of 12 patients. A continuous intravenous infusion of dexmedetomidine started at 0.15 µg kg−1 hr−1 and adjusted by 0.15 µg kg−1 h−1 to a maximum of 0.75 µg kg−1 h−1 (10 ml h−1), while midazolam was started at 1 mg h−1 (2 mL hr−1) and adjusted by 1 mg h−1 to a maximum of 5 mg h−1 (10 mL h−1). All infusions were adjusted by increments of 2 mL/hr−1 to maintain blinding. Serum levels of CD42a+/CD14+, HLADR+/CD14+, CRP, IL-6, IL-10 and TNF-α were measured at baseline (T1), 12 h (T2), and 24 h (T3).ResultsTreatment with dexmedetomidine yielded no significant difference in CD42a+/CD14+, HLADR+/CD14, CD24b-MFI, HLADR-MFI, IL6 and TREM1 at all time points when compared with midazolam treatment. There was no significant difference in TLR levels between the two groups. Cardiac output in the dexmedetomidine group showed a significant decrease at 6, 12 and 24 h (P = 0.033, 0.021, and 0.005, respectively) compared with that in the midazolam group.ConclusionOur results indicated that dexmedetomidine did not affect CD42a+/CD14+ and HLA-DR+/CD14+ expression in septic patients. Furthermore, cytokine production and inflammatory biomarkers did not change with dexmedetomidine infusion.Trial registration Clinical trial.gov registry (NCT03989609) on June 14, 2019, https://register.clinicaltrials.gov.

Feasibility of the pupillary pain index as a guide for depth of analgesia during opioid-sparing anesthesia with continuous infusion of dexmedetomidine

BackgroundThe pupillary dilation reflex (PDR) is an objective indicator of analgesic levels in anesthetized patients. Through measurement of the PDR during increasing tetanic stimulation (10–60 mA), it is possible to obtain the pupillary pain index (PPI), a score that assesses the level of analgesia.ObjectivesThe depth of analgesia during opioid-sparing anesthesia (OSA) with continuous infusion of dexmedetomidine in addition to general anesthesia was assessed.DesignObservational prospective feasibility pilot studySettingThis study was performed in the operating rooms of the Spedali Civili University-affiliated hospital of Brescia, Italy.PatientsForty-five adults who underwent elective open (5-cm incision) surgery under general anesthesia (78% inhalation anesthesia), from Feb. 18th to Aug. 1st, 2019, were enrolled. Exclusion criteria were as follows: implanted pacemaker or ICD, ophthalmological comorbidities, chronic opioid use, peripheral neuropathy, other adjuvant drugs, epidural analgesia, or locoregional block.Main outcome measuresThe first aim was to verify the feasibility of applying a study protocol to evaluate the depth of analgesia during intraoperative dexmedetomidine administration using an instrumental pupillary evaluation. The secondary outcome was to evaluate appropriate analgesia, drug dosage, anesthesia depth, heart rate, blood pressure, transient side effects, postoperative nausea and vomiting (PONV), and pain numerical rating scale (NRS) score.ResultsThirty out of 50 patients (60%) treated with dexmedetomidine during the study period were included in the DEX group (8 males, age 42 ± 13 years, BMI 45 ± 8), and 15 other patients were included in the N-DEX group (8 males, age 62 ± 13 years, BMI 26 ± 6). Patients who underwent bariatric, abdominal, or plastic surgery were enrolled. At least 3 pupillary evaluations were taken for each patient. PPI ≤ 3 was observed in 97% of patients in the DEX group and 53% in the N-DEX group. Additionally, the DEX group received less than half the remifentanil dose than the N-DEX group (0.13 ± 0.07 vs 0.3 ± 0.11 mcg kg−1 min−1). The average dose of dexmedetomidine administered was 0.17 ± 0.08 mcg kg−1 h−1.ConclusionThe feasibility of applying the protocol was verified. An OSA strategy involving dexmedetomidine may be associated with improved analgesic stability: a randomized controlled trial is necessary to verify this hypothesis.Trial registrationTrial.gov registration number: NCT05785273

Metaraminol in reverting hypotension in equine anesthesia with isoflurane and dexmedetomidine: Case report

Systemic hypotension is the most frequent complication of inhalational anesthesia in horses and is directly related to increased post-anesthetic morbidity and mortality. The treatment of hypotension depends on the physiological cause and can be performed with positive chronotropic, inotropic and vasopressor drugs, individually or combined. However, there are few drugs used in horses and the effects of these drugs on cardiovascular support in these animals during anesthesia are poorly described. For this reason, this study aimed to report the action of metaraminol (Aramin®), a vasopressor with direct and indirect action on adrenergic receptors, in the correction of hypotension in a horse submitted to elective orchiectomy, anesthetized with isoflurane and continuous infusion of dexmedetomidine. Cardiovascular changes with different infusion rates of 1, 2 and 4 µg/kg/min are described. Metaraminol reversed hypotension at a rate of 4 µg/kg/min, increasing systolic blood pressure by 93 mmHg, mean blood pressure by 74 mmHg, diastolic blood pressure by 66 mmHg, and reduced cardiac output by 7.1 L/min and heart rate to 32 bpm, in relation to mean arterial pressure of 58 mmHg, cardiac output of 13.4 L/min and heart rate of 36 bpm at the expired rate of 1.3% isoflurane. Furthermore, it improved cardiac contractility at the rate of 2 and 4 µg/kg/min and did not cause arrhythmia at any infusion rates.

Endotoxic kidney injury in Beagle dogs assessed by serum creatinine and symmetric dimethylarginine, and urinary neutrophil gelatinase-associated lipocalin and clusterin

Sepsis of Gram negative bacterial origin results in lipopolysaccharide-induced endotoxemia. This often leads to acute kidney injury (AKI) and its recognition remains a challenge and delays treatment. As renal damage occurs before a rise in serum creatinine is detected, new early biomarkers of kidney injury need to be explored. The aim of this study was to determine changes in serum parameters of renal function and urine biomarkers of renal injury. This was a descriptive study. Endotoxemia was induced intravenously in six anaesthetized Beagles (T1). To achieve normotension, dogs received fluids (T2), followed by a continuous infusion of noradrenaline and dexmedetomidine or 0.9% NaCl (T3). Ten minutes later, the dogs received fluids (T4) and noradrenaline and dexmedetomidine or 0.9% NaCl in a crossover manner (T5). At each timepoint, blood and urine were collected for serum creatinine, urea, symmetric dimethylarginine, urine protein/creatinine (UPC) ratio, urine neutrophil-gelatinase-associated lipocalin (U-NGAL), U-NGAL/creatinine ratio, urine clusterin (U-clusterin) and U-clusterin/creatinine ratio. Data were analyzed using a mixed-effect model taking into account time and stage of veterinary AKI (VAKI). Three of six dogs had a VAKI stage ≥1; one with anuria and elevated creatinine. Serum creatinine (P < 0.001), U-NGAL/creatinine ratio (P = 0.01) and U-clusterin/creatinine ratio increased over time (P < 0.01). The UPC ratio (mean (range) 0.68 (0.35–2.3) versus 0.39 (0.15–0.71) P < 0.01) and U-NGAL (3164 pg/mL (100–147,555) versus 100 (100–14,524), P = 0.01) were higher in VAKI stage ≥1 versus stage 0, respectively. Endotoxemia induced VAKI stage ≥1 in half of the dogs. Repeated measurement of selected parameters could detect AKI early.

Determination of the effective dose of dexmedetomidine to achieve loss of consciousness during anesthesia induction.

Dexmedetomidine (DEX) is a sedative with greater preservation of cognitive function, reduced respiratory depression, and improved patient arousability. This study was designed to investigate the performance of DEX during anesthesia induction and to establish an effective DEX induction strategy, which could be valuable for multiple clinical conditions. Patients undergoing abdominal surgery were involved in this dose-finding trial. Dixon's up-and-down sequential method was employed to determine the effective dose of DEX to achieve the state of "loss of consciousness", and an effective induction strategy was established with continuous infusion of DEX and remifentanil. The effects of DEX on hemodynamics, respiratory state, EEG, and anesthetic depth were monitored and analyzed. Through the strategy mentioned, the depth of surgical anesthesia was successfully achieved by DEX-led anesthesia induction. The ED50 and ED95 of the initial infusion rate of DEX were 0.115 and 0.200 μg/kg/min, respectively, and the mean induction time was 18.3 min. The ED50 and ED95 of DEX to achieve the state of "loss of consciousness" were 2.899 (95% CI: 2.703-3.115) and 5.001 (95% CI: 4.544-5.700) μg/kg, respectively. The mean PSI on the loss of consciousness was 42.8 among the patients. During anesthesia induction, the hemodynamics including BP and HR were stable, and the EEG monitor showed decreased α and β powers and increased θ and δ in the frontal and pre-frontal cortices of the brain. This study indicated that continuous infusion of combined DEX and remifentanil could be an effective strategy for anesthesia induction. The EEG during the induction was similar to the physiological sleep process.