The safety and efficacy of dexmedetomidine versus propofol for patients undergoing endovascular therapy for acute stroke: A prospective randomized control trial

Research progress of propofol in alleviating cerebral ischemia/reperfusion injury

Ischemic stroke is a leading cause of adult disability and death worldwide. The primary treatment for cerebral ischemia patients is to restore blood supply to the ischemic region as quickly as possible. However, in most cases, more severe tissue damage occurs, which is known as cerebral ischemia/reperfusion (I/R) injury. The pathological mechanisms of brain I/R injury include mitochondrial dysfunction, oxidative stress, excitotoxicity, calcium overload, neuroinflammation, programmed cell death and others. Propofol (2,6-diisopropylphenol), a short-acting intravenous anesthetic, possesses not only sedative and hypnotic effects but also immunomodulatory and neuroprotective effects. Numerous studies have reported the protective properties of propofol during brain I/R injury. In this review, we summarize the potential protective mechanisms of propofol to provide insights for its better clinical application in alleviating cerebral I/R injury.

The Role of Intravenous Anesthetics for Neuro: Protection or Toxicity?

The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine (Dex), propofol, ketamine, etomidate, midazolam, and remimazolam. Apart from their established sedative, analgesic, and anxiolytic properties, an increasing body of research has uncovered neuroprotective effects of intravenous anesthetics in various animal and cellular models, as well as in clinical studies. However, there also exists conflicting evidence pointing to the potential neurotoxic effects of these intravenous anesthetics. The role of intravenous anesthetics for neuro on both sides of protection or toxicity has been rarely summarized. Considering the mentioned above, this work aims to offer a comprehensive understanding of the underlying mechanisms involved both in the central nerve system (CNS) and the peripheral nerve system (PNS) and provide valuable insights into the potential safety and risk associated with the clinical use of intravenous anesthetics.

Sedation with propofol/remifentanil versus dexmedetomidine / remifentanil for patients undergoing transcatheter aortic valve implant: A retrospective study between 2012 and 2019

BACKGROUND AND OBJECTIVES

Percutaneous implantation of an aortic valve prosthesis is a therapeutic alternative for patients with severe aortic stenosis. The procedure is traditionally performed under general anaesthesia; however, sedation is now gaining in popularity because it reduces the need for vasoactive drugs and shortens the patient's stay in the critical care unit and on the ward. The aim of this study is to evaluate the clinical efficacy, safety and potential benefits of sedation with dexmedetomidine in patients undergoing percutaneous implantation of an aortic valve prosthesis in terms of haemodynamic and respiratory complications.

MATERIALS AND METHODS

We performed a retrospective study of 222 patients that had undergone percutaneous implantation of an aortic valve prosthesis between 2012 and 2019 under sedation with either dexmedetomidine plus remifentanil (DEX-RMF) or propofol plus remifentanil (PROPO-RMF). We collected data on complications, mainly haemodynamic and respiratory, during and after the procedure.

RESULTS

No significant differences were found between sedation with dexmedetomidine and propofol (in combination with remifentanil) in terms of haemodynamic stability and intraprocedural cerebral blood oxygen. In the DEX-RMF group, however, mean blood pressure, midazolam dose, and duration of anaesthesia were lower compared with the PROPO-RMF group, but the incidence of haemodynamic and respiratory complications did not differ significantly between groups.

CONCLUSIONS

Our results show that sedation, particularly with adjuvant dexmedetomidine, is a valid anaesthetic techniques in percutaneous aortic valve prosthesis implantation.

A retrospect and outlook on the neuroprotective effects of anesthetics in the era of endovascular therapy

Studies on the neuroprotective effects of anesthetics were carried out more than half a century ago. Subsequently, many cell and animal experiments attempted to verify the findings. However, in clinical trials, the neuroprotective effects of anesthetics were not observed. These contradictory results suggest a mismatch between basic research and clinical trials. The Stroke Therapy Academic Industry Roundtable X (STAIR) proposed that the emergence of endovascular thrombectomy (EVT) would provide a proper platform to verify the neuroprotective effects of anesthetics because the haemodynamics of patients undergoing EVT is very close to the ischaemia–reperfusion model in basic research. With the widespread use of EVT, it is necessary for us to re-examine the neuroprotective effects of anesthetics to guide the use of anesthetics during EVT because the choice of anesthesia is still based on team experience without definite guidelines. In this paper, we describe the research status of anesthesia in EVT and summarize the neuroprotective mechanisms of some anesthetics. Then, we focus on the contradictory results between clinical trials and basic research and discuss the causes. Finally, we provide an outlook on the neuroprotective effects of anesthetics in the era of endovascular therapy.

Type of anaesthesia for acute ischaemic stroke endovascular treatment

BACKGROUND

The use of mechanical thrombectomy to restore intracranial blood flow after proximal large artery occlusion by a thrombus has increased over time and led to better outcomes than intravenous thrombolytic therapy alone. Currently, the type of anaesthetic technique during mechanical thrombectomy is under debate as having a relevant impact on neurological outcomes.

OBJECTIVES

To assess the effects of different types of anaesthesia for endovascular interventions in people with acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Specialised Register of Trials on 5 July 2022, and CENTRAL, MEDLINE, and seven other databases on 21 March 2022. We performed searches of reference lists of included trials, grey literature sources, and other systematic reviews.  SELECTION CRITERIA: We included all randomised controlled trials with a parallel design that compared general anaesthesia versus local anaesthesia, conscious sedation anaesthesia, or monitored care anaesthesia for mechanical thrombectomy in acute ischaemic stroke. We also included studies reported as full-text, those published as abstract only, and unpublished data. We excluded quasi-randomised trials, studies without a comparator group, and studies with a retrospective design.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, extracted data, and assessed the risk of bias and the certainty of the evidence using the GRADE approach. The outcomes were assessed at different time periods, ranging from the onset of the stroke symptoms to 90 days after the start of the intervention. The main outcomes were functional outcome, neurological impairment, stroke-related mortality, all intracranial haemorrhage, target artery revascularisation status, time to revascularisation, adverse events, and quality of life. All included studies reported data for early (up to 30 days) and long-term (above 30 days) time points.

MAIN RESULTS

We included seven trials with 982 participants, which investigated the type of anaesthesia for endovascular treatment in large vessel occlusion in the intracranial circulation. The outcomes were assessed at different time periods, ranging from the onset of stroke symptoms to 90 days after the procedure. Therefore, all included studies reported data for early (up to 30 days) and long-term (above 30 up to 90 days) time points. General anaesthesia versus non-general anaesthesia(early) We are uncertain about the effect of general anaesthesia on functional outcomes compared to non-general anaesthesia (mean difference (MD) 0, 95% confidence interval (CI) -0.31 to 0.31; P = 1.0; 1 study, 90 participants; very low-certainty evidence) and in time to revascularisation from groin puncture until the arterial reperfusion (MD 2.91 minutes, 95% CI -5.11 to 10.92; P = 0.48; I² = 48%; 5 studies, 498 participants; very low-certainty evidence). General anaesthesia may lead to no difference in neurological impairment up to 48 hours after the procedure (MD -0.29, 95% CI -1.18 to 0.59; P = 0.52; I² = 0%; 7 studies, 982 participants; low-certainty evidence), and in stroke-related mortality (risk ratio (RR) 0.98, 95% CI 0.52 to 1.84; P = 0.94; I² = 0%; 3 studies, 330 participants; low-certainty evidence), all intracranial haemorrhages (RR 0.92, 95% CI 0.65 to 1.29; P = 0.63; I² = 0%; 5 studies, 693 participants; low-certainty evidence) compared to non-general anaesthesia. General anaesthesia may improve adverse events (haemodynamic instability) compared to non-general anaesthesia (RR 0.21, 95% CI 0.05 to 0.79; P = 0.02; I² = 71%; 2 studies, 229 participants; low-certainty evidence). General anaesthesia improves target artery revascularisation compared to non-general anaesthesia (RR 1.10, 95% CI 1.02 to 1.18; P = 0.02; I² = 29%; 7 studies, 982 participants; moderate-certainty evidence). There were no available data for quality of life. General anaesthesia versus non-general anaesthesia (long-term) There is no difference in general anaesthesia compared to non-general anaesthesia for dichotomous and continuous functional outcomes (dichotomous: RR 1.21, 95% CI 0.93 to 1.58; P = 0.16; I² = 29%; 4 studies, 625 participants; low-certainty evidence; continuous: MD -0.14, 95% CI -0.34 to 0.06; P = 0.17; I² = 0%; 7 studies, 978 participants; low-certainty evidence). General anaesthesia showed no changes in stroke-related mortality compared to non-general anaesthesia (RR 0.88, 95% CI 0.64 to 1.22; P = 0.44; I² = 12%; 6 studies, 843 participants; low-certainty evidence). There were no available data for neurological impairment, all intracranial haemorrhages, target artery revascularisation status, time to revascularisation from groin puncture until the arterial reperfusion, adverse events (haemodynamic instability), or quality of life. Ongoing studies We identified eight ongoing studies. Five studies compared general anaesthesia versus conscious sedation anaesthesia, one study compared general anaesthesia versus conscious sedation anaesthesia plus local anaesthesia, and two studies compared general anaesthesia versus local anaesthesia. Of these studies, seven plan to report data on functional outcomes using the modified Rankin Scale, five studies on neurological impairment, six studies on stroke-related mortality, two studies on all intracranial haemorrhage, five studies on target artery revascularisation status, four studies on time to revascularisation, and four studies on adverse events. One ongoing study plans to report data on quality of life. One study did not plan to report any outcome of interest for this review.

AUTHORS' CONCLUSIONS

In early outcomes, general anaesthesia improves target artery revascularisation compared to non-general anaesthesia with moderate-certainty evidence. General anaesthesia may improve adverse events (haemodynamic instability) compared to non-general anaesthesia with low-certainty evidence. We found no evidence of a difference in neurological impairment, stroke-related mortality, all intracranial haemorrhage and haemodynamic instability adverse events between groups with low-certainty evidence. We are uncertain whether general anaesthesia improves functional outcomes and time to revascularisation because the certainty of the evidence is very low. However, regarding long-term outcomes, general anaesthesia makes no difference to functional outcomes compared to non-general anaesthesia with low-certainty evidence. General anaesthesia did not change stroke-related mortality when compared to non-general anaesthesia with low-certainty evidence. There were no reported data for other outcomes. In view of the limited evidence of effect, more randomised controlled trials with a large number of participants and good protocol design with a low risk of bias should be performed to reduce our uncertainty and to aid decision-making in the choice of anaesthesia.

Comparing the Effect of Dexmedetomidine and Midazolam in Patients with Brain Injury

BACKGROUND

Studies have shown that dexmedetomidine improves neurological function. Whether dexmedetomidine reduces mortality or improves quantitative electroencephalography (qEEG) among patients post-craniotomy remains unclear.

METHODS

This single-center randomized study was conducted prospectively from 1 January 2019 to 31 December 2020. Patients who were transferred to the ICU after craniotomy within 24 h were included. The analgesic was titrated to a Critical care Pain Observation Tool (CPOT) score ≤2, and the sedative was titrated to a Richmond Agitation-Sedation Scale (RASS) score ≤-3 for at least 24 h. The qEEG signals were collected by four electrodes (F3, T3, F4, and T4 according to the international 10/20 EEG electrode practice). The primary outcome was 28-day mortality and qEEG results on day 1 and day 3 after sedation.

RESULTS

One hundred and fifty-one patients were enrolled in this study, of whom 77 were in the dexmedetomidine group and 74 in the midazolam group. No significant difference was found between the two groups in mortality at 28 days (14.3% vs. 24.3%; p = 0.117) as well as in the theta/beta ratio (TBR), the delta/alpha ratio (DAR), and the (delta + theta)/(alpha + beta) ratio (DTABR) between the two groups on day 1 or day 3. However, both the TBR and the DTABR were significantly increased in the dexmedetomidine group. The DTABR in the midazolam group was significantly increased. The DAR was significantly increased on the right side in the dexmedetomidine group (20.4 (11.6-43.3) vs. 35.1 (16.7-65.0), p = 0.006) as well as on both sides in the midazolam group (Left: 19.5 (10.1-35.8) vs. 37.3 (19.3-75.7), p = 0.006; Right: 18.9 (10.1-52.3) vs. 39.8 (17.5-99.9), p = 0.002).

CONCLUSION

Compared with midazolam, dexmedetomidine did not lead to a lower 28-day mortality or better qEEG results in brain injury patients after a craniotomy.

Comparison of Anesthetic Agents Dexmedetomidine and Midazolam During Mechanical Thrombectomy

OBJECTIVES

The ideal anesthetic for mechanical thrombectomy (MT) is a subject of debate. Recent studies have supported the use of monitored anesthesia care (MAC), but few have attempted to compare MAC neuroanesthetics. Our study directly compares midazolam and dexmedetomidine (DEX) on blood pressure control during thrombectomy and functional outcomes at discharge.

MATERIALS AND METHODS

We performed a retrospective review of an MT database, which consisted of 612 patients admitted between 2010-2019 to our tertiary stroke center. 193 patients who received either midazolam or DEX for MAC induction were identified. Primary and secondary outcomes were >20% maximum decrease in mean arterial pressure during MT and functional independence respectively.

RESULTS

146 patients were administered midazolam, while 47 were administered DEX. Decrease in blood pressure (BP) during MT was associated with lower rates of functional independence at last follow-up (p=0.034). When compared to midazolam, DEX had significantly higher rates of intraprocedural decrease in MAP at the following cut-offs: >20% (p<0.001), >30% (p=0.001), and >40% (p=0.006). On multivariate analysis, DEX was an independent predictor of >20% MAP decrease (OR 7.042, p<0.001). At time of discharge, NIHSS scores and functional independence (mRS 0-2) were statistically similar between DEX and midazolam. Functional independence at last known follow-up was statistically similar between DEX and midazolam (p = 0.643).

CONCLUSIONS

Use of DEX during MT appears to be associated with increased blood pressure volatility when compared to midazolam. Further investigation is needed to determine the impact of MAC agents on functional independence.

DEXmedetomidine compared to PROpofol in NEurocritical Care [DEXPRONE]: A multicenter retrospective evaluation of clinical utility and safety

PURPOSE

Although guidelines recommend dexmedetomidine (DEX) or propofol (PRO) as preferred sedatives in critically ill adults, comparisons in neurocritical care (NCC) are limited. We aimed to evaluate the clinical utility and safety of DEX compared with PRO in NCC setting.

MATERIALS AND METHODS

This retrospective, multicenter, observational cohort study conducted at three tertiary academic hospitals with Level 1 Trauma Center and Comprehensive Stroke Center designations, compared the clinical indication and safety of DEX vs PRO in patients in NCC setting.

RESULTS

179 patients were included (94 DEX and 85 PRO), median age of 58, 49% were male (DEX) and 58% were male (PRO). PRO was more commonly used to manage agitation. DEX was more commonly used for facilitating extubation, alcohol withdrawal, and sedation during frequent neurologic assessments. Mean Glasgow Coma Scale scores were higher in DEX group (11 vs. 9; p = .04). The duration of either infusions, mechanical ventilation, and lengths of stay were similar. No difference was observed in hypotension or bradycardia rates. Death was significantly higher with PRO (DEX 10% vs. PRO 22%; p = .02).

CONCLUSIONS

DEX and PRO were used for distinct indications in our cohort. Adverse effect profiles and clinical outcome, in the cohorts are largely similar.