Dexmedetomidine: A Review of Its Use for Sedation in the Intensive Care Setting

An α2-adrenoceptor agonist: Dexmedetomidine induces protective cardiomyocyte hypertrophy through mitochondrial-AMPK pathway

Aims: Dexmedetomidine (Dex) as a highly selective α₂-adrenoceptor agonist, was widely used anesthetic in perioperative settings, whether Dex induces cardiac hypertrophy during perioperative administration is unknown. Methods: The effects of Dex on cardiac hypertrophy were explored using the transverse aortic constriction model and neonatal rat cardiomyocytes. Results: We reported that Dex induces cardiomyocyte hypertrophy with activated ERK, AKT, PKC and inactivated AMPK in both wild-type mice and primary cultured rat cardiomyocytes. Additionally, pre-administration of Dex protects against transverse aortic constriction induced-heart failure in mice. We found that Dex up-regulates the activation of ERK, AKT, and PKC via suppression of AMPK activation in rat cardiomyocytes. However, suppression of mitochondrial coupling efficiency and membrane potential by FCCP blocks Dex induced AMPK inactivation as well as ERK, AKT, and PKC activation. All of these effects are blocked by the α₂-adrenoceptor antagonist atipamezole. Conclusion: The present study demonstrates Dex preconditioning induces cardiac hypertrophy that protects against heart failure through mitochondria-AMPK pathway in perioperative settings.

Dexmedetomidine improves neurodevelopment and cognitive impairment in infants with congenital heart disease

Aim: Explore if dexmedetomidine (DEX) improves neurodevelopment and cognitive impairment in infants with congenital heart disease. Materials & methods: We retrospectively analyzed 256 pediatric patients aged less than 2 years with heart disease undergoing thoracic surgery. The intelligence quotient and neurodevelopment were tested. Mortality, incidence of postoperation adverse events, duration of mechanical ventilation, and length of stay were recorded and compared. Results: Compared with those not administered DEX, intelligence quotient scores and neurodevelopment evaluation scores increased in patients receiving perioperative DEX. There were no significant differences in mortality, duration of mechanical ventilation or length of stay. Conclusion: The administration of DEX might improve neural development and reduce the adverse effects of general anesthesia in infants with congenital heart disease undergoing surgery and extracorporeal circulation.

Dexmedetomidine for Acute Management of Intrathecal Baclofen Withdrawal

BACKGROUND

Intrathecal baclofen (ITB) is a mainstay of treatment for patients with chronic spasticity. Up to 40% of all patients receiving ITB experience overdose or withdrawal symptoms, which in the most severe cases can lead to multisystem organ failure and death. There is currently no well-established treatment for ITB withdrawal. One previous case report details an intubated pediatric patient who underwent baclofen pump removal in which dexmedetomidine was used in combination with other medications to prevent baclofen withdrawal.

CASE REPORT

We report a case of baclofen withdrawal where the decision was made to initiate a dexmedetomidine infusion, with subsequent improvement of the patient's hypertension and tachycardia. At no point during her stay did the patient require intubation for airway protection, and the patient was ultimately discharged to her previous nursing facility on hospital day 9 with no new neurologic deficits. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be aware of dexmedetomidine as a promising option for the treatment of ITB withdrawal in the acute setting. Although little evidence is currently present, dexmedetomidine was used successfully in this case, and should be considered as a temporizing treatment for ITB withdrawal. Dexmedetomidine holds promise in the management of ITB withdrawal compared to other previously described treatments, including oral baclofen, cyproheptadine, and dantrolene. In addition, dexmedetomidine has a superior safety profile compared to propofol or large doses of benzodiazepines. Further research will be useful in supporting the use of dexmedetomidine for this purpose.

Reconsidering Dexmedetomidine for Sedation in the Critically Ill: Implications of the SPICE III Trial

Dexmedetomidine is a sedative agent that has gained popularity for use in the intensive care unit over the past 20 years. Guidelines recommend dexmedetomidine as a first-line agent to achieve light sedation in mechanically ventilated adults. Recently, the SPICE III (Sedation Practice in Intensive Care Evaluation III) trial was published. This was a randomized controlled trial comparing initial sedation with dexmedetomidine with usual care sedation in adult patients receiving mechanical ventilation. The results of this trial have both validated and contradicted previous findings about dexmedetomidine. This editorial examines the merits of the SPICE III trial and the role of dexmedetomidine in practice following its publication.

Probing the Role of Ion-Pair Strategy in Controlling Dexmedetomidine Penetrate Through Drug-in-Adhesive Patch: Mechanistic Insights Based on Release and Percutaneous Absorption Process

The purpose of present study was to develop a controlled release drug-in-adhesive patch for transdermal delivery of dexmedetomidine (Dex) using ion-pair technique. Based on the in vitro transdermal experiment, the role of ion-pair on the Dex release behavior and percutaneous absorption process was also investigated. Fourier transform infrared spectroscopy (FTIR), molecular modeling, differential scanning calorimetry (DSC), and rheological test were conducted to probe the effect of ion-pair on the Dex release from patch. Besides, the tape stripping test, attenuated total reflectance Fourier transform infrared (ATR-FTIR), and molecular simulation were carried out to elaborate the action of ion-pair on the Dex percutaneous permeation process. Results showed that the optimized patch prepared with Dex-salicylic acid (SA) showed zero-order skin permeation profile within 24 h; Dex-SA had greater hydrogen bonding formation potential with pressure sensitive adhesive (PSA) than Dex, which resulted in the decrease in the formation ability of free volume of PSA and the increase with the improvement of mechanical strength and chain stiffness of PSA and thus controlled the release rate of Dex from transdermal patch. Besides, the physicochemical properties of Dex such as molecular weight and octanol/water partition coefficient were changed after forming ion-pair with SA, which decreased the permeation ability of Dex. In conclusion, a controlled release drug-adhesive patch for Dex was developed and the mechanism study of ion-pair on the Dex release and percutaneous permeation process was proposed at molecular level.

Co-administration of N-acetylcysteine and dexmedetomidine plays a synergistic effect on protection of LPS-induced acute lung injury via correcting Th1/Th2/Th17 cytokines imbalance

Recently both N-acetylcysteine (NAC) and Dexmedetomidine (DEX) have shown emerging roles in protection of acute lung injury (ALI). However, how their protective roles work and whether they can provide synergistic effects in ALI remain unknown. Here we explored it from the hot research viewpoint of Th1/Th2/Th17 cytokines balance. Lipopolysaccharide (LPS)-induced ALI was established and treated with NAC and/or DEX. Mice were divided into Sham group, ALI group, NAC group, DEX group and NAC+DEX group. Mice were sampled at 6, 12 and 24 hours after the model construction. Histopathology, wet to dry ratio and myeloperoxidase (MPO) activity were assessed in lung tissues. Protein concentration and cell count were assessed in bronchoalveolar lavage fluid (BALF). Th1/Th2/Th17 cytokines were assessed in plasma, BALF and lung homogenate. ALI-induced lung morphological damage, edema and aberrant MPO activity can be attenuated by NAC or DEX and mostly by NAC+DEX. NAC with DEX significantly reduced ALI-induced protein leakage and cell infiltration in BALF. Th1/Th2/Th17 cytokines imbalance aggravated with ALI progression. NAC, DEX and especially NAC+DEX can effectively correct these unbalanced cytokines. Galectin-9 and Tim-3 were transcriptionally up-regulated in ALI. Combination of NAC with DEX obtained a maximum effect on decreasing Galectin-9/Tim-3 expression. In summary, Th1/Th2/Th17 cytokines imbalance is newly found to participate in LPS-induced ALI. NAC or DEX administration can attenuate ALI by rebalancing Th1/Th2/Th17 cytokines. Their protective roles can be enhanced when co-administration, because DEX may relieve the Galectin-9/Tim-3 axis-mediated immune suppression.

Dexmedetomidine prevents septic myocardial dysfunction in rats via activation of α7nAChR and PI3K/Akt- mediated autophagy

BACKGROUND AND PURPOSE

Dexmedetomidine (Dex) has been shown to elicit cardio-protective effects in sepsis. The aim of this study was to investigate the role of autophagy in the protective effects of Dex and its possible mechanism in vivo and vitro.

EXPERIMENTAL APPROACH

6-8-week-old male Wistar rats were performed cecal ligation puncture (CLP) and administered 0.9% saline (CLP group), 50 μg/kg Dex (Dex group), Dex plus chloroquine (20 mg/kg; Dex + CQ group), or 40 μg/kg methyllycaconitin (Dex + MLA group), or 25 μM LY294002 (Dex + LY294002 group). After study, cardiac histology, cardiac function, level of autophagy, cardiomyocytes apoptosis and inflammatory mediators including protein IL-1β, IL-6, and TNF-α were measured. The LPS induced-H9C2 cardiomyocytes were treated with Dex, Dex + CQ and detected for cell apoptosis, autophagy level and cell cycle.

KEY RESULTS

CLP-induced sepsis resulted in cardiac dysfunction, apoptosis, and inflammatory response. Dex exhibited protective effects on the myocardium by the induction of myocardial autophagy and ameliorated the LPS-induced blockade of autophagic flux in H9C2 cells. CQ was found to significantly inhibit Dex-mediated protection of myocardial apoptosis and inflammation. CLP rats treated with Dex in combination with MLA, an antagonist of α7 nicotinic acetylcholine receptor (α7nAChR), exhibited decreased autophagy and increased inflammation and cell death, identifying α7nAchR was involved in the Dex-mediated pathway. In addition, we found that the PI3K/Akt pathway is involved in Dex-mediated autophagy and convergent with α7nAChR-mediated stimulation of autophagy response.

CONCLUSIONS AND IMPLICATIONS

For the first time, these data indicate that autophagy is central in Dex-mediated cardio-protection in sepsis. These observations provide the foundation for further study, and may serve as the basis for innovative therapeutic strategies against septic myocardial dysfunction.

Effect of ancillary drugs on sevoflurane related emergence agitation in children undergoing ophthalmic surgery: a Bayesian network meta-analysis

BACKGROUND

The comparative efficacy of ancillary drugs on sevoflurane related emergence agitation (EA) in children undergoing ophthalmic surgery remains controversial.

METHODS

The databases were retrieved in an orderly manner from the dates of their establishment to October, 2018, including PubMed, The Cochrane Library and Web of Science, to collect randomized controlled trials (RCT) of different anesthetic drugs combined with sevoflurane for ophthalmic surgery. Then a network meta-analysis was conducted using R and Stata 12.0 softwares.

RESULTS

The meta-analysis showed that, in reducing sevoflurane related EA, dexmedetomidine, ketamine, propofol, fentanyl, midazolam, sufentanil, remifentanil and clonidine were superior to placebo (P < 0.05). The network meta-analysis showed that the effects of ancillary drugs combine with sevoflurane in reducing risk of EA in children undergoing ophthalmic surgery was superior to placebo: dexmedetomidine (OR = 0.17, 95% CrI 0.12-0.22), ketamine (OR = 0.30, 95% CrI 0.11-0.49), propofol (OR = 0.24, 95% CrI 0.09-0.63), fentanyl (OR = 0.16, 95% CrI 0.08-0.56), midazolam (OR = 0.20, 95% CrI 0.09-0.40), sufentanil (OR = 0.27, 95% CrI 0.14-0.41), remifentanil (OR = 0.18, 95% CrI 0.08-0.54) and clonidine (OR = 0.14, 95% CrI 0.07-0.41). The SUCRA of placebo, dexmedetomidine, ketamine, propofol, fentanyl, midazolam, sufentanil, remifentanil, clonidine were respectively 0.26, 77.93, 27.71, 42.8, 69.43, 52.89, 59.83, 57.62 and 61.53%.

CONCLUSIONS

The effects of dexmedetomidine combine with sevoflurane in reducing risk of emergence agitation in children undergoing ophthalmic surgery was superior to other drugs.

Early Sedation with Dexmedetomidine in Critically Ill Patients

BACKGROUND

Dexmedetomidine produces sedation while maintaining a degree of arousability and may reduce the duration of mechanical ventilation and delirium among patients in the intensive care unit (ICU). The use of dexmedetomidine as the sole or primary sedative agent in patients undergoing mechanical ventilation has not been extensively studied.

METHODS

In an open-label, randomized trial, we enrolled critically ill adults who had been undergoing ventilation for less than 12 hours in the ICU and were expected to continue to receive ventilatory support for longer than the next calendar day to receive dexmedetomidine as the sole or primary sedative or to receive usual care (propofol, midazolam, or other sedatives). The target range of sedation-scores on the Richmond Agitation and Sedation Scale (which is scored from -5 [unresponsive] to +4 [combative]) was -2 to +1 (lightly sedated to restless). The primary outcome was the rate of death from any cause at 90 days.

RESULTS

We enrolled 4000 patients at a median interval of 4.6 hours between eligibility and randomization. In a modified intention-to-treat analysis involving 3904 patients, the primary outcome event occurred in 566 of 1948 (29.1%) in the dexmedetomidine group and in 569 of 1956 (29.1%) in the usual-care group (adjusted risk difference, 0.0 percentage points; 95% confidence interval, -2.9 to 2.8). An ancillary finding was that to achieve the prescribed level of sedation, patients in the dexmedetomidine group received supplemental propofol (64% of patients), midazolam (3%), or both (7%) during the first 2 days after randomization; in the usual-care group, these drugs were administered as primary sedatives in 60%, 12%, and 20% of the patients, respectively. Bradycardia and hypotension were more common in the dexmedetomidine group.

CONCLUSIONS

Among patients undergoing mechanical ventilation in the ICU, those who received early dexmedetomidine for sedation had a rate of death at 90 days similar to that in the usual-care group and required supplemental sedatives to achieve the prescribed level of sedation. More adverse events were reported in the dexmedetomidine group than in the usual-care group. (Funded by the National Health and Medical Research Council of Australia and others; SPICE III ClinicalTrials.gov number, NCT01728558.).

Dexmedetomidine protects aged rats from postoperative cognitive dysfunction by alleviating hippocampal inflammation

The present study investigated the effect of dexmedetomidine on hippocampal inflammation and cognitive function in rats with postoperative cognitive dysfunction (POCD). A total of 80 healthy male Sprague Dawley rats were used, 72 of which developed POCD. The rats were randomly divided into four groups: The control, model, low-dose and high-dose dexmedetomidine anesthesia groups. A POCD model was established and dexmedetomidine was administered. Cognitive function tests were performed and expression levels of interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α) and NF-κB biomarkers were evaluated on the first, third and seventh day following modeling. The cognitive function of rats was measured using a Y-maze test. The expression levels of IL-1β and TNF-α in the hippocampus were determined by ELISA. The protein expression levels of NF-κB p65 in the hippocampus were determined by western blotting. It was revealed that at 1, 3 and 7 days after surgery, there were no alterations in the exercise ability of rats in the different groups, as reflected by the number of rats passing the alternative arms in the Y-maze. On the first and third day after surgery, the cognitive dysfunction reflected by the alteration scores of the low-dose and high-dose dexmedetomidine anesthesia groups were significantly higher than those of the model group, and the increase in the high-dose group was more pronounced. Additionally, on the first day after surgery, the expression levels of IL-1β, TNF-α and NF-κB in the hippocampi of rats in the low- and high-dose dexmedetomidine anesthesia groups were significantly lower than those in the model group, and the decrease was more pronounced in the high-dose group. At 7 days after surgery, the differences in expression levels of IL-1β, TNF-α and NF-κB in the hippocampus among groups were not identified to be statistically significantly different. Taken together, the results of the present study indicated that dexmedetomidine may inhibit hippocampal inflammation induced by surgical trauma, and that dexmedetomidine may effectively improve postoperative cognitive function in rats.

Dexmedetomidine effects in different experimental sepsis in vivo models

Sepsis is a major cause of death and the most common cause of death among critically ill, non-ICU patients. Dexmedetomidine (DEX), an <alpha>₂ adrenergic receptor agonist, presents sympatholytic action in certain parts of the brain with anxiolytic, sedative, and pain killing effects. Additionally, through the activation of <alpha>₇ nicotinic acetylcholine receptor receptors, DEX reduces cytokine transcription and inhibits inflammation, rendering it beneficial during septic conditions. Moreover, there is a lot of interest in designing experimental sepsis models, where the administration of DEX is evaluated for its impact on multiple systems. This review focuses on experimental studies published between 1999 to March 2019 that were using DEX administration in sepsis in vivo models. From these, 36 articles were selected and summarized. Overall results show evidence that DEX may decrease mortality and inhibit inflammation, as it enhances the activity of the immune system while reducing its systemic reaction and lowering cytokine concentrations. Moreover DEX succeeds to alleviate heart injury during sepsis, acting beneficially for microcirculation and shows a neuroprotective role by inhibiting apoptotic pathways. In addition, DEX appears to have a protective role for liver and spleen as well as a beneficial role for the function of lungs and kidneys as it reduces sepsis-induced injuries and apoptosis in intra-abdominal experimental sepsis models.

Dexmedetomidine improves cognition after carotid endarterectomy by inhibiting cerebral inflammation and enhancing brain-derived neurotrophic factor expression

Objectives

Carotid endarterectomy (CEA) is efficient in preventing stroke for patients with significant carotid stenosis, but results in mild cognitive dysfunction. Dexmedetomidine is neuroprotective in stroke models. We hypothesized that dexmedetomidine may improve cognition after CEA.

Methods

Forty-nine patients scheduled for elective CEA were randomly assigned to intravenous dexmedetomidine treatment group (n = 25) and control group C (normal saline, n = 24). Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MOCA), as well as lactate, TNF-α, IL-6, and BDNF levels in blood, were assessed before, during, and after surgery.

Results

MMSE and MOCA scores showed subtle decline in both groups at 24 hours postoperatively; this decline remained at 48 hours postoperatively in group C. Both scores were higher in group D than in group C at 48 and 72 hours postoperatively. TNF-α and IL-6 were lower from 5 minutes post-clamping through 24 hours postoperatively in group D; lactate was lower at 5 minutes post-clamping in group D. BDNF was higher from 5 minutes post-clamping through 1 hour postoperatively in both groups, and remained high in group D at 24 hours postoperatively.

Conclusions

Dexmedetomidine improved recovery of cognition after CEA, potentially due to reduced inflammation and enhanced BDNF expression.

Safety and sedative effect of intranasal dexmedetomidine in mandibular third molar surgery: a systematic review and meta-analysis

Objective

The focus of this meta-analysis was to assess the sedative effect and safety of intranasal dexmedetomidine (Dex) in mandibular third molar surgery.

Methods

The PubMed/Medline, Web of Science, Cochrane Library, and China National Knowledge Infrastructure databases were searched for studies published until May 1, 2018. Eligible studies were restricted to randomized controlled trials (RCTs) and controlled clinical trials. The evaluation indicators mainly included the bispectral index, observer assessment of alertness/sedation scale, systolic blood pressure, and heart rate. Data for each period in the Dex and control groups were pooled to evaluate its sedative effect and safety.

Results

Five RCTs met the inclusion criteria. This study included 363 patients: 158 patients received intranasal inhalation of Dex before surgery, and 158 patients were negative controls. The pooled results showed a good sedative effect during tooth extraction when intranasal inhalation of Dex was performed 30 minutes before third molar extraction (assessment of alertness/sedation, Dex vs control SMD −1.20, 95% CI −1.73 to −0.67, I²=0, P=0.95; bispectral index, Dex vs control SMD −11.68, 95% CI −19.49 to −3.87, I²=89%; P=0.0001), and parameters returned to normal within 90 minutes after inhalation. During the operation, blood pressure and heart rate decreased to some extent, but the decreases did not exceed 20% of the baseline, and all patients returned to normal conditions within 90 minutes after inhalation.

Conclusion

Intranasal inhalation of Dex 30 minutes before third molar extraction can provide a good sedative effect, and large-sample multicenter RCTs are needed to evaluate the analgesic effect of Dex.

Anesthetic Efficacy of Dexmedetomidine versus Midazolam When Combined with Remifentanil for Percutaneous Transluminal Angioplasty in Patients with Peripheral Artery Disease

Anesthesia for percutaneous transluminal angioplasty (PTA) involves a high-risk population having a broad spectrum of pain character and intensity. This study delved the anesthetic efficacy of dexmedetomidine versus midazolam, when used with remifentanil. Seventy patients scheduled for femoropopliteal PTA were randomized into two groups receiving either intermittent midazolam boluses (0.03–0.05 mg/kg) (MR group) or dexmedetomidine 0.2–0.7 μg/kg/h after a loading dose of 1.0 μg/kg for 10 min (DR group), both with remifentanil. The primary endpoint was the patients’ satisfaction (1–5, 5; extremely satisfied). Secondary endpoints included postprocedural pain scores (0–10, 10; worst imaginable pain) and adverse events. The satisfaction level of patients was significantly greater in the DR group compared with the MR group (4.0 [3.0, 5.0] versus 4.0 [2.0, 5.0] p = 0.021). The number of patients having a postprocedural pain score of at least 3 was significantly greater in the MR group compared with the DR group (10 [29%] versus 2 [6%], p = 0.013). The number of patients with hypotensive episodes was higher in the DR group (5 [14.7%] versus 0, p = 0.025), which could all be restored with ephedrine. The use of dexmedetomidine in conjunction with remifentanil may be a safe option that provides excellent patient satisfaction while potentially attenuating postprocedural pain.

Dexmedetomidine for the prevention of delirium in critically ill patients - A protocol for a systematic review

BACKGROUND

Delirium is a common complication in critically ill patients and carries an increased risk of mortality and morbidity. Dexmedetomidine can potentially prevent delirium by diminishing predisposing factors. The evidence regarding the use of dexmedetomidine in preventing delirium is conflicting. This protocol aims to identify the beneficial and harmful effects of dexmedetomidine in the prevention of delirium.

METHODS

This protocol uses the recommendations of the Cochrane Collaboration, the Preferred Report Items of Systematic Reviews with Meta-Analysis Protocols, and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess in critically ill patients, if dexmedetomidine versus placebo can reduce the incidence of delirium and improve clinical outcomes. We will include all randomised trials assessing the use of dexmedetomidine in the prevention of delirium. To identify trials, we will search the Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Latin American and Caribbean Health Sciences Literature, Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Science Journal Database, and BIOSIS. Two authors will screen the literature and extract data. We will use the Cochrane risk of bias tool to evaluate trials. Extracted data will be analysed using Review Manager 5 and Trial Sequential Analysis. We will create a "Summary of Findings"-table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using GRADE.

DISCUSSION

This systematic review can potentially aid clinicians in decision-making and benefit the many critically ill patients at risk of delirium.

Dexmedetomidine for the management of delirium in critically ill patients-A protocol for a systematic review

BACKGROUND

Delirium is a common complication in critically ill patients and carries an increased risk of mortality and morbidity. Dexmedetomidine can potentially treat delirium by diminishing predisposing factors. The evidence regarding the use of dexmedetomidine in the management of delirium is conflicting. This protocol aims to identify the beneficial and harmful effects of dexmedetomidine in the management of delirium.

METHODS

This protocol uses the recommendations of the Cochrane Collaboration, the Preferred Report Items of Systematic reviews with Meta-Analysis Protocols, and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess in critically ill patients with delirium, if dexmedetomidine vs placebo is effective in managing delirium and improving clinical outcomes. We will include all relevant randomised clinical trials assessing the use of dexmedetomidine in treating delirium. To identify trials, we will search the Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Latin American and Caribbean Health Sciences Literature, Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Chinese Science Journal Database, and BIOSIS. Two authors will screen the literature and extract data. The Cochrane risk of bias tool will be used to evaluate included trials. Extracted data will be analysed using Review Manager 5 and Trial Sequential Analysis. We will create a 'Summary of Findings'-table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using GRADE assessment.

DISCUSSION

This systematic review can potentially aid clinicians in decision making and benefit the many critically ill patients developing delirium.

[Dexmedetomidine alleviates postoperative cognitive dysfunction in aged rats probably via silent information regulator 1 pathway]

OBJECTIVE

To explore the role of silent information regulator 1 (SIRT1) signaling pathway in mediating the effect of dexmedetomidine (DEX) to alleviate postoperative cognitive dysfunction (POCD) in aged rats.

METHODS

Seventy-two healthy male Sprague-Dawley rats aged 18-20 months (weighing 500-700 g) were randomized equally into normal control group, POCD model group, DEX pretreatment group, and DEX and SIRT1 inhibitor (EX527) pretreatment group. In the latter 2 groups, DEX (25 μg/kg) was injected intraperitoneally in the rats 30 min before the operation, and normal saline was injected instead in the other 2 groups; in EX527 group, EX527 (1 μg/kg) was injected intravenously 5 min before the operation. In all but the control group, the rats were subjected to laparotomy lasting 30 min, and on days 1, 3, and 5 following the operation, 6 rats were randomly selected from each group for Morris water maze test to evaluate their cognitive functions. Immediately after the test, the rats were sacrificed and the hippocampus was collected for determination of the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) using ELISA; Western blotting was used to detect the expression of SIRT1 and nuclear factor- κB (NF-κB) in the hippocampal neurons.

RESULTS

Compared with the control rats, the rats in POCD group and EX527 group showed significantly prolonged escape latency, decreased frequency of crossing the original platform, increased TNF-α and IL-6 levels, lowered SIRT1 expression in the hippocampal neurons, and increased NF-κB expression (P &lt; 0.05), and these parameters were comparable between POCD group and EX527 group (P &gt; 0.05). DEX pretreatment significantly alleviated cognitive dysfunction and attenuated the changes in TNF-α, IL-6, SIRT1, and NF-κB expressions induced by the operation (P &lt; 0.05), and EX527 pretreatment of the rats obviously blocked the effects of DEX (P &lt; 0.05).

CONCLUSIONS

DEX alleviates POCD in aged rats probably via SIRT1 signaling pathway.

A systematic review of interventions to facilitate extubation in patients difficult-to-wean due to delirium, agitation, or anxiety and a meta-analysis of the effect of dexmedetomidine

BACKGROUND

Delirium, agitation, and anxiety may hinder weaning from mechanical ventilation and lead to increased morbidity and healthcare costs. The most appropriate clinical approach to weaning in these contexts remains unclear and challenging to clinicians. The objective of this systematic review was to identify effective and safe interventions to wean patients that are difficult-to-wean from mechanical ventilation due to delirium, agitation, or anxiety.

METHODS

A systematic review was performed using MEDLINE, EMBASE, and PubMed. Studies evaluating mechanically ventilated patients deemed difficult-to-wean due to delirium, agitation, or anxiety, and comparing the effects of an intervention with a comparator arm were sought. Time-to-extubation was the primary outcome while the secondary outcome was intensive care unit (ICU) length of stay.

RESULTS

From 10,860 studies identified, eight met the inclusion criteria: six studies assessed dexmedetomidine while the remaining two assessed loxapine and biofeedback. Pooled analysis of studies assessing dexmedetomidine showed reduced time-to-extubation (six studies, n = 303) by 10.9 hr compared with controls (95% confidence interval [CI], -15.7 to -6.1; I² = 68%) and ICU length of stay (four studies, n = 191) by 2.6 days (95% CI, 1.9 to 3.3; I² = 0%). Nevertheless, the evidence was deemed to be of low quality given the small sample sizes and high heterogeneity. Studies assessing other interventions did not identify improvements compared with controls. Safety assessment was globally poorly reported.

CONCLUSIONS

This systematic review and meta-analysis provides low quality evidence to suggest the use of dexmedetomidine in patients deemed difficult-to-wean due to agitation, delirium, or anxiety. Insufficient evidence was found regarding other interventions to provide any recommendation.

TRIAL REGISTRATION

PROSPERO (CRD42016042528); registered 15 July, 2016.

Dexmedetomidine protects against lipopolysaccharide-induced early acute kidney injury by inhibiting the iNOS/NO signaling pathway in rats

Increasing evidence has demonstrated that dexmedetomidine (DEX) possesses multiple pharmacological actions. Herein, we explored the protective effect and potential molecular mechanism of DEX on lipopolysaccharide (LPS)-induced early acute kidney injury (AKI) from the perspective of antioxidant stress. We found that DEX (30 μg/kg, i.p.) ameliorated the renal dysfunction and histopathological damage (tubular necrosis, vacuolar degeneration, infiltration of inflammatory cells and cast formation) induced by LPS (10 mg/kg). DEX also attenuated renal oxidative stress remarkably in LPS-induced early AKI, as evidenced by reduction in production of reactive nitrogen species, decreasing malondialdehyde levels, as well as increasing superoxide dismutase activity and glutathione content. DEX prevented activator protein-1 translocation, inhibited phosphorylation of I-kappa B (IκB) and activation of nuclear factor kappa B (NF-κB) in LPS-induced early AKI, as assessed by real-time quantitative polymerase chain reaction and protein levels of c-Jun, c-Fos, IκB and NF-κB. Notably, DEX pretreatment had the same effect as intraperitoneal injection of an inhibitor of inducible nitric oxide synthase inhibitor (1400W; 15 mg/kg), and inhibited the activity of renal inducible nitric oxide synthase (iNOS) and decreased the expression of iNOS mRNA and NO production. However, the protective effect of DEX on LPS-induced early AKI was reversed by the alpha 2 adrenal receptor (α₂-AR) inhibitor atipamezole, whereas the imidazoline receptor inhibitor idazoxan did not. Taken together, DEX protects against LPS-induced early AKI in rats by inhibiting the iNOS/NO signaling pathway, mainly by acting on α₂-ARs instead of IRs.

The Effect of Dexmedetomidine on the Acute Pain After Cardiothoracic Surgeries: A Systematic Review

INTRODUCTION

Acute post-operative pain remains a troublesome complication of cardiothoracic surgeries. Several randomized controlled trials have examined the efficacy of dexmedetomidine as a single or as an adjuvant agent before, during and after surgery. However, no evidence-based conclusion has been reached regarding the advantages of dexmedetomidine over the other analgesics.

OBJECTIVE

To review the effect of dexmedetomidine on acute post-thoracotomy/sternotomy pain.

METHODS

Medline, SCOPUS, Web of Science, and Cochrane databases were used to search for randomized controlled trials that investigated the analgesia effect of dexmedetomidine on post-thoracotomy/sternotomy pain in adults' patients. The outcomes were postoperative pain intensity or incidence, postoperative analgesia duration, and the number of postoperative analgesic requirements.

RESULTS

From 1789 citations, 12 trials including 804 subjects met the inclusion criteria. Most studies showed that pain score was significantly lower in the dexmedetomidine group up to 24 hours after surgery. Two studies reported the significant lower postoperative analgesia requirements and one study reported the significant lower incidence of acute pain after surgery in dexmedetomidine group. Ten studies found that the total consumption of narcotics was significantly lower in the dexmedetomidine group. The most reported complications of dexmedetomidine were nausea/vomiting, bradycardia and hypotension.

CONCLUSION

Dexmedetomidine can be used as a safe and efficient analgesic agent for reducing the postoperative pain and analgesic requirements up to 24 hours after cardiothoracic surgeries. However, further well-designed trials are needed to find the optimal dosage, route, time, and duration of dexmedetomidine administration.

Evaluation of the effects of dexmedetomidine and remifentanil on pain with the analgesia nociception index in the perioperative period in hysteroscopies under general anesthesia. A randomized prospective study

Objectives To compare analgesia nociception index (ANI) values, visual analog scale (VAS) values, and hemodynamic parameters in hysteroscopy patients who received remifentanil and dexmedetomidine during general anesthesia. Methods: In total, 30 patients who underwent hysteroscopy between March and September 2016 at the University of Health Sciences Fatih Sultan Mehmet Health Research and Application Center, Ankara, Turkey were included in this prospective study. Standard hemodynamic monitoring, ANI, and bispectral index (BIS) monitoring were applied to the patients. At 10 min prior to induction, 1 μg/kg of remifentanil was applied in Group R (n=15) and 1 μg/kg of dexmedetomidine was applied in Group D (n=15). After induction, sevoflurane was used for maintenance with dexmedetomidine at 0.2-0.7 μg/kg/hour in Group D and remifentanil at 0.05-0.5 μg/kg/minute in Group R. Perioperative and postoperative analgesia levels (ANI and VAS, respectively), hemodynamics, and complications were recorded. Results: Even though the ANI levels in Group D were lower at the perioperative 5th and 10th minutes, the ANI values were between the targeted limits, except for the measurement after I-gel insertion, in both groups. Hemodynamic parameters were within normal limits, but the mean arterial pressures in Group R after induction, following I-gel placement, and at the perioperative 5th, 10th, and 20th minutes were lower and at postoperative 30th minute were significantly higher.   Conclusion: Dexmedetomidine and remifentanil are both efficacious agents for perioperative analgesia in hysteroscopy cases.

Bradycardia Leading to Asystole Following Dexmedetomidine Infusion during Cataract Surgery: Dexmedetomidine-Induced Asystole for Cataract Surgery

Dexmedetomidine is an elective alpha-2 adrenergic agonist, being used in anesthesia practice. It offers sedative, anxiolytic, analgesic, muscle relaxant, and sympathetic lytic properties. While respiratory effects are considered minor, there are important cardiovascular side effects with bradycardia and hypotension being the most common. This article presents a case of a patient, with significant comorbidities and polypharmacy, who was scheduled for cataract surgery under dexmedetomidine sedation. During the administration, severe hemodynamic deterioration was observed with bradycardia and hypotension leading to asystole. Cardiac arrest was successfully managed in accordance with the guidelines of the European Resuscitation Council. Despite the promising role of dexmedetomidine in anesthesia practice, the associated adverse effects cannot be ignored. For this reason it is obligatory to have the minimum mandatory monitoring in accordance with the safety and quality guidelines.

Clinical Assessment and Management of Delirium in the Palliative Care Setting

Delirium is a neurocognitive syndrome arising from acute global brain dysfunction, and is prevalent in up to 42% of patients admitted to palliative care inpatient units. The symptoms of delirium and its associated communicative impediment invariably generate high levels of patient and family distress. Furthermore, delirium is associated with significant patient morbidity and increased mortality in many patient populations, especially palliative care where refractory delirium is common in the dying phase. As the clinical diagnosis of delirium is frequently missed by the healthcare team, the case for regular screening is arguably very compelling. Depending on its precipitating factors, a delirium episode is often reversible, especially in the earlier stages of a life-threatening illness. Until recently, antipsychotics have played a pivotal role in delirium management, but this role now requires critical re-evaluation in light of recent research that failed to demonstrate their efficacy in mild- to moderate-severity delirium occurring in palliative care patients. Non-pharmacological strategies for the management of delirium play a fundamental role and should be optimized through the collective efforts of the whole interprofessional team. Refractory agitated delirium in the last days or weeks of life may require the use of pharmacological sedation to ameliorate the distress of patients, which is invariably juxtaposed with increasing distress of family members. Further evaluation of multicomponent strategies for delirium prevention and treatment in the palliative care patient population is urgently required.

Ultrasound-Guided Continuous Femoral Nerve Block with Dexmedetomidine Combined with Low Concentrations of Ropivacaine for Postoperative Analgesia in Elderly Knee Arthroplasty

OBJECTIVES

This study aims to investigate the clinical effect of dexmedetomidine (DEX) combined with low concentrations of ropivacaine in ultrasound-guided continuous fem-oral nerve block for postoperative analgesia in elderly patients with total knee arthroplasty (TKA).

MATERIALS AND METHODS

Patients were divided into three groups: group C, group D1, and group D2. For postoperative analgesia, patients in group C were given 0.15% ropivacaine, patients in group D1 were given 0.15% ropivacaine + 0.02 μg × kg-1 × h-1 DEX, and patients in group D2 were given 0.15% ropivacaine + 0.05 μg × kg-1 × h-1 DEX. The visual analogue scores in the resting state, active state (AVAS), and passive functional exercise state (PVAS), degree of joint bending, and Ramsay scores were recorded.

RESULTS

The Ramsay scores were significantly higher, AVAS scores were significantly lower, PVAS scores were significantly decreased, the degree of joint bending was significantly higher, and the time to the first postoperative ambulation was shorter in groups D1 and D2 than group C. Furthermore, the time to the first postoperative ambulation was shorter in group D2 than in group D1, patients in groups D1 and D2 were more satisfied than patients in group C, and patients in group D2 were more satisfied than patients in group D1.

CONCLUSION

The protocol of 0.05 μg × kg-1 × h-1 of DEX combined with 0.15% ro-pivacaine in ultrasound-guided continuous femoral nerve block for postoperative analgesia in elderly patients with TKA provides a better analgesic effect than without DEX performance.

X.-Y.Z. and E.-F.Z. have contributed equally to this research.

Effect of intraoperative dexmedetomidine on renal function after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: a randomized, placebo-controlled trial

INTRODUCTION

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) predispose to postoperative renal dysfunction. Dexmedetomidine is an α₂ adrenoreceptor agonist, which has renoprotective effects after cardiac surgery.

OBJECTIVE

To assess the effect of dexmedetomidine on renal function after CRS and HIPEC.

MATERIALS

Thirty-eight patients undergoing CRS and HIPEC were randomized to receive dexmedetomidine (dexmedetomidine group, n = 19, loading 1 μg/kg over 20 min followed by infusion at 0.5 μg/kg/h) or 0.9% sodium chloride (control group, n = 19) during surgery. Creatinine clearance (CrCl) was assessed daily until postoperative day 7. Urine neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule (KIM)-1 were measured for 24 h after surgery.

RESULTS

There was no difference in the lowest CrCl value during the first 7 days postoperatively, but the % change from baseline to the lowest value was lower in the dexmedetomidine group than in the control group (p = .037). Urine NGAL and KIM-1 levels were increased over time in both groups, but the increases were significantly less in the dexmedetomidine group (p = .018 and 0.038, respectively). In the dexmedetomidine group, the length of intensive care unit stay was shorter (p = .034).

CONCLUSIONS

Intraoperative dexmedetomidine infusion did not improve renal function in terms of serum Cr-related indices following CRS and HIPEC. However, as the decrease in CrCl was attenuated and early tubular-injury markers were lower in the dexmedetomidine group, dexmedetomidine may have protective effects against early tubular injury in CRS and HIPEC. Clinical Trials Registry: http://clinicaltrials.gov (NCT02641938).

Administration of Dexmedetomidine inhibited NLRP3 inflammasome and microglial cell activities in hippocampus of traumatic brain injury rats

The abnormally high nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activity is a typical characteristic of traumatic brain injury (TBI). Dexmedetomidine (Dex) is a highly selective α-2 adrenergic receptor agonist that inhibits the activation of NLRP3. Thus, it was hypothesized that Dex could attenuate TBI by inhibiting NLRP3 inflammasome activity in hippocampus. Rats were subjected to controlled cortical impact method to induce TBI, and treated with Dex. The effect of Dex treatment on the cognitive function, NLRP3 activity, and microglial activation in rat brain tissues was assessed. The administration of Dex improved performance of TBI rats in Morris water maze (MWM) test, which was associated with the increased neurone viability and suppressed microglia activity. Moreover, the administration of Dex inhibited the neuroinflammation in brain tissue as well as the expressions of NLRP3 and caspase-1. Additionally, Dex and NLRP3 inhibitor, BAY-11-7082 had a synergistic effect in inhibiting NLRP3/caspase-1 axis activity and improving TBI. The findings outlined in the current study indicated that the improvement effect of Dex on TBI was related to its effect on NLRP3 activity.

Psychotropic drug therapy in patients in the intensive care unit - usage, adverse effects, and drug interactions: a review

Managing psychological problems in patients admitted to intensive care unit (ICU) is a big challenge, requiring pharmacological interventions. On the other hand, these patients are more prone to side effects and drug interactions associated with psychotropic drugs use. Benzodiazepines (BZDs), antidepressants, and antipsychotics are commonly used in critically ill patients. Therefore, their therapeutic effects and adverse events are discussed in this study. Different studies have shown that non-BZD drugs are preferred to BZDs for agitation and pain management, but antipsychotic agents are not recommended. Also, it is better not to start antidepressants until the patient has fully recovered. However, further investigations are required for the use of psychotropic drugs in ICUs.

Neuroprotective effect of dexmedetomidine in a murine model of traumatic brain injury

No FDA approved pharmacological therapy is available that would reduce cell death following traumatic brain injury (TBI). Dexmedetomidine (Dex) is a highly selective agonist of alpha-2 adrenergic receptors and has demonstrated neuroprotective effects in hippocampal slice cultures undergoing direct impact. However, no one has tested whether Dex, in addition to its sedative action, has neuroprotective effects in an animal model of TBI. Thus, in the present study, we investigated the effects of Dex on an animal model of TBI. Mice received different doses of Dex (1, 10, or 100 µg/kg bodyweight, n = 10 each group) or saline as control at 1 hour and 12 hours following TBI. The mice treated with Dex lost less cortical tissue than the control mice. Further analysis found that Dex treatment reduced cell death in the cortex and the hippocampus measured by Fluoro-Jade B (FJB) staining, prevented axonal degeneration detected by immunostaining with antibody against β-amyloid precursor protein (β-APP), and protected synapses from elimination with synaptophysin staining. Taken together, in an in vivo murine model of TBI, Dex at the dose of 100 µg/kg not only prevented tissue lesion and cell death, but also reduced axonal injury and synaptic degeneration caused by TBI.

Use of Dexmedetomidine in Cardiothoracic and Vascular Anesthesia

Dexmedetomidine is a highly selective α₂-adrenergic agonist with analgesic and sedative properties. In the United States, the Food and Drug Administration approved the use of the drug for short-lasting sedation (24 h) in intensive care units (ICUs) in patients undergoing mechanical ventilation and endotracheal intubation. In October 2008, the Food and Drug Administration extended use of the drug for the sedation of nonintubated patients before and during surgical and nonsurgical procedures. In the European Union, the European Medicine Agency approved the use of dexmedetomidine in September 2011 with a single recognized indication: ICU adult patients requiring mild sedation and awakening in response to verbal stimulus. At present, the use of dexmedetomidine for sedation outside the ICU remains an off-label indication. The benefits of dexmedetomidine in critically ill patients and in cardiac, electrophysiology-related, vascular, and thoracic procedures are discussed.

Exploring Opioid-Sparing Multimodal Analgesia Options in Trauma: A Nursing Perspective

Challenges with opioids (e.g., adverse events, misuse and abuse with long-term administration) have led to a renewed emphasis on opioid-sparing multimodal management of trauma pain. To assess the extent to which currently available evidence supports the efficacy and safety of various nonopioid analgesics and techniques to manage trauma pain, a literature search of recently published references was performed. Additional citations were included on the basis of authors' knowledge of the literature. Effective options for opioid-sparing analgesics include oral and intravenous (IV) acetaminophen; nonsteroidal anti-inflammatory drugs available via multiple routes; and anticonvulsants, which are especially effective for neuropathic pain associated with trauma. Intravenous routes (e.g., IV acetaminophen, IV ketorolac) may be associated with a faster onset of action than oral routes. Additional adjuvants for the treatment of trauma pain are muscle relaxants and alpha-2 adrenergic agonists. Ketamine and regional techniques play an important role in multimodal therapy but require medical and nursing support. Nonpharmacologic treatments (e.g., cryotherapy, distraction techniques, breathing and relaxation, acupuncture) supplement pharmacologic analgesics and can be safe and easy to implement. In conclusion, opioid-sparing multimodal analgesia addresses concerns associated with high doses of opioids, and many pharmacologic and nonpharmacologic options are available to implement this strategy. Nurses play key roles in comprehensive patient assessment; administration of patient-focused, opioid-sparing, multimodal analgesia in trauma; and monitoring for safety concerns.

Clinical Assessment and Management of Delirium in the Palliative Care Setting

Delirium is a neurocognitive syndrome arising from acute global brain dysfunction, and is prevalent in up to 42% of patients admitted to palliative care inpatient units. The symptoms of delirium and its associated communicative impediment invariably generate high levels of patient and family distress. Furthermore, delirium is associated with significant patient morbidity and increased mortality in many patient populations, especially palliative care where refractory delirium is common in the dying phase. As the clinical diagnosis of delirium is frequently missed by the healthcare team, the case for regular screening is arguably very compelling. Depending on its precipitating factors, a delirium episode is often reversible, especially in the earlier stages of a life-threatening illness. Until recently, antipsychotics have played a pivotal role in delirium management, but this role now requires critical re-evaluation in light of recent research that failed to demonstrate their efficacy in mild- to moderate-severity delirium occurring in palliative care patients. Non-pharmacological strategies for the management of delirium play a fundamental role and should be optimized through the collective efforts of the whole interprofessional team. Refractory agitated delirium in the last days or weeks of life may require the use of pharmacological sedation to ameliorate the distress of patients, which is invariably juxtaposed with increasing distress of family members. Further evaluation of multicomponent strategies for delirium prevention and treatment in the palliative care patient population is urgently required.

The Benefit of Neuromuscular Blockade in Patients with Postanoxic Myoclonus Otherwise Obscuring Continuous Electroencephalography (CEEG)

Introduction. Myoclonus status epilepticus is independently associated with poor outcome in coma patients after cardiac arrest. Determining if myoclonus is of cortical origin on continuous electroencephalography (CEEG) can be difficult secondary to the muscle artifact obscuring the underlying CEEG. The use of a neuromuscular blocker can be useful in these cases. Methods. Retrospective review of CEEG in patients with postanoxic myoclonus who received cisatracurium while being monitored. Results. Twelve patients (mean age: 53.3 years; 58.3% male) met inclusion criteria of clinical postanoxic myoclonus. The initial CEEG patterns immediately prior to neuromuscular blockade showed myoclonic artifact with continuous slowing (50%), burst suppression with myoclonic artifact (41.7%), and continuous myogenic artifact obscuring CEEG (8.3%). After intravenous administration of cisatracurium (0.1 mg–2 mg), reduction in artifact improved quality of CEEG recordings in 9/12 (75%), revealing previously unrecognized patterns: continuous EEG seizures (33.3%), lateralizing slowing (16.7%), burst suppression (16.7%), generalized periodic discharges (8.3%), and, in the patient who had an initially uninterpretable CEEG from myogenic artifact, continuous slowing. Conclusion. Short-acting neuromuscular blockade is useful in determining background cerebral activity on CEEG otherwise partially or completely obscured by muscle artifact in patients with postanoxic myoclonus. Fully understanding background cerebral activity is important in prognostication and treatment, particularly when there are underlying EEG seizures.

Comparative evaluation of midazolam, dexmedetomidine, and propofol as Intensive Care Unit sedatives in postoperative electively ventilated eclamptic patients

Background and Aims:

Eclampsia is a common hypertensive disorder of pregnancy and treatment often includes termination of pregnancy with elective postoperative mechanical ventilation. The present study was aimed to compare midazolam, propofol, and dexmedetomidine for sedation and antihypertensive requirements of such patients admitted to Intensive Care Unit (ICU) after termination of pregnancy.

Material and Methods:

A total of ninety eclamptic patients administered general anesthesia for the termination of pregnancy through cesarean section and who also required postoperative ventilation were taken up for the study and were randomly allocated into three groups. All patients received MgSO4 (loading dose, 4 g intravenous) following first seizure episode followed by a continuous infusion for next 24 h. Midazolam group (GrM) received 0.05 mg/kg loading dose of midazolam, followed by infusion of 0.05–0.3 mg/kg/h, propofol group (GrP) received 1 mg/kg loading dose of propofol followed by infusion of 2–8 mg/kg/h, and dexmedetomidine group (GrD) received dexmedetomidine loading dose at 1 mcg/kg followed by infusion of 0.2–1.2 mcg/kg/h. Postoperatively, patients were assessed for hemodynamic stability, requirement of antihypertensive and analgesics, duration of sedation and stop sedation-discharge, and total time spent in the ICU.

Results:

Mean heart rate and mean arterial pressure recorded at different time intervals were lowest in GrD. Nearly 70% (n = 21) patients in the GrM required antihypertensive, 50% (n = 15) in GrP, and 36.6% (n = 11) in the GrD (P < 0.05). Duration of stop sedation-discharge from ICU was least in GrD. A number of patients demanding additional analgesics was also least in GrD.

Conclusion:

Sedation with dexmedetomidine produced better hemodynamic stability in eclamptic patients, and there was a significant reduction in requirement of additional analgesics (P = 0.035) and antihypertensive (P = 0.004). Total duration of ICU stay was also less in this group of patients.

The protective and hemodynamic effects of dexmedetomidine on hypertensive cerebral hemorrhage patients in the perioperative period

The aim of the present study was to analyze the protective and hemodynamic effects of dexmedetomidine in hypertensive cerebral hemorrhage (HCH) patients during perioperative period. In total, 50 HCH patients were selected and randomly divided into two groups, one group was administered with dexmedetomidine and the other groups with midazolam. The mean arterial pressure (MAP), heart rate (HR) and blood oxygen saturation (SpO₂) were monitored in the two groups of patients before and during the operation. The MAP, HR, SpO₂ and P_ETCO₂ recorded 5 min after admission into the operation room was considered T₁, the same parameters recorded 10 min after drug administration were considered T₂, just after starting the operation were considered T₃ and 30 min after start of operation were considered T₄. The preoperative sedation and analgesia were evaluated by the Ramsay scoring method and the neuron-specific enolase (NSE) and S100 protein (S100β) were estimated using ELISA. The patients of the midazolam group experienced mild respiratory depression during the period of sedation. Levels of, MAP, HR and P_ETCO₂ were significantly increased whereas SPO₂ was decreased (P<0.05). The MAP, HR, SPO₂ and P_ETCO₂ were stable during the period of sedation (P>0.05). The plasma concentrations of epinephrine and norepinephrine at T₁ were similar in the two groups (P>0.05), but decreased after drug administration. This decrease was more prominent in the dexmedetomidine group patients (P<0.05) than midazolam group patients. The epinephrine and norepinephrine concentrations just after starting operation (T₃) were higher than the basal level (T₁) in the midazolam group, but close to the basal level in the dexmedetomidine group (P<0.05). The serum concentration of NSE and S100β in the two groups showed no difference (P>0.05) at the end of operation (T₅), but after 24 h of operation (T₇) NSE and S100β in the dexmedetomidine group were significantly lower compared to the midazolam group (P<0.05). In conclusion, the administration of dexmedetomidine for patients with HCH during perioperative period is safe and serves as an effective sedative, without causing respiratory depression and does not influence stable haemodynamics with certain brain protective effect.

Pharmacy-Driven Dexmedetomidine Stewardship and Appropriate Use Guidelines in a Community Hospital Setting

BACKGROUND

Dexmedetomidine is a widely utilized agent in the intensive care unit (ICU) because it does not suppress respiratory drive and may be associated with less delirium than midazolam or propofol. Cost of dexmedetomidine therapy and debate as to the proper duration of use has brought its use to the forefront of discussion.

OBJECTIVE

To validate the efficacy and cost savings associated with pharmacy-driven dexmedetomidine appropriate use guidelines and stewardship in mechanically ventilated patients.

METHODS

This was a retrospective cohort study of adult patients who received dexmedetomidine for ICU sedation while on mechanical ventilation at a 433-bed not-for-profit community hospital. Included patients were divided into pre-enactment (PRE) and postenactment (POST) of dexmedetomidine guideline groups.

RESULTS

A total of 100 patients (50 PRE and 50 POST) were included in the analysis. A significant difference in duration of mechanical ventilation (11.1 vs 6.2 days, P = 0.006) and incidence of reintubation (36% vs 18% of patients, P = 0.043) was seen in the POST group. Aggregate use of dexmedetomidine 200-µg vials (37.1 vs 18.4 vials, P = 0.010) and infusion days (5.4 vs 2.5 days, P = 0.006) were significantly lower in the POST group. Dexmedetomidine acquisition cost savings were calculated at $374 456.15 in the POST group. There was no difference between the PRE and POST groups with regard to ICU length of stay, expected mortality, and observed mortality.

CONCLUSIONS

Pharmacy-driven dexmedetomidine appropriate use guidelines decreased the use of dexmedetomidine and increased cost savings at a community hospital without adversely affecting clinical outcomes.

Post-operative cardiac arrest induced by co-administration of amiodarone and dexmedetomidine: a case report

We firstly report a postoperative hemodialysis patient who was co-administered with amiodarone and dexmedetomidine and developed severe bradycardia followed by cardiac arrest. A 79-year-old male patient underwent an amputation of the right lower extremity. The electrocardiogram of the patient showed a complete right bundle branch block with left anterior fascicular block before the anesthesia, and paroxysmal atrial tachycardia over 200 beats/min lasting 15 min was observed during surgery. After admission to the intensive care unit, the intensivist and the consultant cardiologist decided to treat tachycardia using amiodarone. The initial dosing of amiodarone and the maintenance infusion succeeded to decrease the heart rate. Approximately 2 h and a half after the start of dexmedetomidine infusion for sedation, the heart rate gradually declined and severe bradycardia suddenly followed by cardiac arrest was observed. Resuscitation was promptly initiated and the patient regained sinus rhythm without delay. In retrospective analysis, the monitoring record of the electrocardiogram revealed the marked atrioventricular conduction abnormalities. This is the first case report concerning a cardiac arrest induced by amiodarone and dexmedetomidine.