Post-Operative Dexmedetomidine-Based Sedation After Uneventful Intracranial Surgery for Unruptured Cerebral Aneurysm: Comparison with Propofol-Based Sedation

Anesthetic management of unruptured intracranial aneurysms: a qualitative systematic review

Intracranial aneurysms (IA) occur in 3-5% of the general population and may require surgical or endovascular obliteration if the patient is symptomatic or has an increased risk of rupture. These procedures carry an inherent risk of neurological complications, and the outcome can be influenced by the physiological and pharmacological effects of the administered anesthetics. Despite the critical role of anesthetic agents, however, there are no current studies to systematically assess the intraoperative anesthetic risks, benefits, and outcome effects in this population. In this systematic review of the literature, we carefully examine the existing evidence on the risks and benefits of common anesthetic agents during IA obliteration, their physiological and clinical characteristics, and effects on neurological outcome. The initial search strategy captured a total of 287 published studies. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 28 studies were included in the final report. Our data showed that both volatile and intravenous anesthetics are commonly employed, without evidence that either is superior. Although no specific anesthetic regimens are promoted, their unique neurological, cardiovascular, and physiological properties may be critical to the outcome in vulnerable patients. In particular, patients at risk for perioperative ischemia may benefit from timely administration of anesthetic agents with neuroprotective properties and optimization of their physiological parameters. Further studies are warranted to examine if these anesthetic regimens can reduce the risk of neurological injury and improve the overall outcome in these patients.

Maternal and neonatal wellbeing during elective C-section induced with a combination of propofol and dexmedetomidine: How effective is the placental barrier in dogs?

Anaesthetics administered during C-section (CS) can cross the placenta and the foetal blood-brain barrier contributing to distress up to neonatal mortality. Therefore, to prevent neonatal risks, sedatives and analgesics are not commonly administered to the bitch until all pups are delivered. This study aims to evaluate the effect of a new anaesthetic and analgesic protocol for elective CS in dogs, focused on both maternal and neonatal wellbeing. General anaesthesia was induced by a combination of propofol (PPF) and dexmedetomidine (DEX) and maintained with isoflurane. DEX was added to PPF in order to provide analgesia and to reduce PPF dose. Propofol and DEX concentrations in maternal blood, amniotic fluid, and placenta were correlated to maternal and neonatal parameters. Maternal pain score was assessed with Glasgow Composite Measure Pain Scale short-form. Nine healthy purebred dogs scheduled for elective CS delivered 54 pups. The 77.8% of pups were vigorous at birth and assigned to the highest Apgar score (AS). The lowest AS was recorded in pups from mothers receiving additional doses of PPF (p < 0.001). Apgar scores improved with the increase in time between induction and pups' extraction, starting from 30 min after induction (p < 0.01). This study could contribute to clarify the controversy about the optimal extraction's time of pups after induction i.e. the best time between PPF administration and birth. No bitch showed post-operative pain or required additional analgesic doses based on their pain score. Maternal blood PPF and DEX, as well as placental PPF concentrations, decreased over time (p < 0.01). Conversely, placental DEX was fair uniformly detected in littermate pups. Both PPF and DEX were not detectable in amniotic fluid. Placenta resulted an effective barrier against foetal DEX exposure, making this protocol safe, analgesic and advisable for elective CS in dogs.

Safety and efficacy of applying sufficient analgesia combined with a minimal sedation program as an early antihypertensive treatment for spontaneous intracerebral hemorrhage: a randomized controlled trial

Background

Spontaneous intracerebral hemorrhage (ICH) is a serious threat to human health. Although early blood pressure (BP) elevation is closely associated with a poor prognosis, the optimal antihypertensive regimen for acute-phase ICH remains controversial. In ICH, pain, sleep deprivation, and stress are usually the main causes of dramatic BP increases. While traditional antihypertensive treatment resolves the increased BP, it does not address the root cause of the disease. Remifentanil relieves pain and, when combined with dexmedetomidine’s antisympathetic action, can restore elevated BP to normal levels. Here, we seek to validate the efficacy and safety of applying sufficient analgesia in combination with a minimal sedation program versus antihypertensive drug therapy for the early and rapid stabilization of BP in ICH patients.

Methods/design

We are conducting a multicenter, prospective, randomized controlled, single-blinded, superiority clinical trial across 15 hospitals. We will enroll 354 subjects in mainland China, and all subjects will be randomized into experimental and control groups in which they will be given remifentanil combined with dexmedetomidine or antihypertensive drugs (urapidil, nicardipine, and labetalol). The primary endpoint will be the systolic BP control rate within 1 h of treatment initiation, and the efficacy and safety of the antihypertensive regimens will be compared between the two groups. Secondary endpoints include the incidence rate of early hemorrhage growth, neurological function, duration of intensive care unit (ICU) stay, and staff satisfaction with the treatment process.

Discussion

We hypothesize that applying sufficient analgesia in combination with minimal sedation will act as an effective and safe antihypertensive strategy in ICH and that this treatment strategy could, therefore, be widely used as an ICH acute-phase therapy.

Trial registration

ClinicalTrials.gov, ID: NCT03207100. Registered on 22 July 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2943-6) contains supplementary material, which is available to authorized users.

Role of Dexmedetomidine for Sedation in Neurocritical Care Patients: A Qualitative Systematic Review and Meta-analysis of Current Evidence

INTRODUCTION

This systematic review appraises the clinical evidence on efficacy and safety of dexmedetomidine (DEX), as a sole sedative or as sedative adjunct in adult neurocritical care (NCC) patients.

MATERIALS AND METHODS

A database search was conducted to identify randomized clinical trials and observational studies reporting the use of DEX alone or as adjunct for sedation in NCC setting. The primary outcome was the occurrence of hemodynamic changes, whereas the secondary outcomes were sedative and analgesic efficacy, quality and time to awakening, and development of adverse events.

RESULTS

Eight trials including 3 randomized controlled trials and 5 observational studies, enrolling 650 patients, were selected. All the retrieved studies had a high risk of bias and a low to moderate quality. Dexmedetomidine provided a better sedation score and reduced analgesic requirements when compared to propofol or midazolam sedation. No statistically significant difference in the combined hemodynamic effect (hypotension or bradycardia) between DEX and controls (risk ratio, 1.50; 95% confidence interval, 0.65-3.48; P = 0.34; I = 56%) was identified. Adverse events were not consistently reported.

CONCLUSIONS

Available clinical literature supporting the efficacy and safety of DEX use in adult NCC setting is of limited quantity and quality. However, from the current evidence on the use of DEX in NCC, as sole sedative agent or as an adjunct, seems to be both efficient and safe.

Effects of dexmedetomidine on outcomes following craniocerebral operation - a meta-analysis

OBJECTIVE

To evaluate the effect of dexmedetomidine on outcomes following craniocerebral operation and provide evidence for individualized medication.

METHODS

We searched the Cochrane Library, PubMed, Springer, CNKI, Wanfang Data Resource and other Chinese and foreign databases with electronic retrieval, within the period 1990-2013, for records relating to dexmedetomidine, brain pharmacokinetics and clinical randomized controlled studies. Records were assessed using the Cochrane system evaluation method for assessing the quality of research, using Revman 5.1 Meta-analysis software.

RESULTS

After screening and removal of duplicate documents there were 22 English and 44 Chinese articles, among which there were eight describing clinical trials, with a total of 412 cases. Meta-analysis showed that dexmedetomidine on rate during craniocerebral operation (standardized mean difference=-8.32, 95% confidence interval [CI] -10.38 to 6.26, P<0.00001), and blood pressure (standardized mean difference=-3.37, 95% CI -5.36 to 1.38, P<0.00001). The study had good heterogeneity using random effects model analysis, and there was no publication bias.

CONCLUSION

Dexmedetomidine can reduce the hemodynamic response and play a role in brain protection.

Research studies that have influenced practice of neuroanesthesiology in recent years: A literature review

Through evolving research, recent years have witnessed remarkable achievements in neuromonitoring and neuroanesthetic techniques, with a huge body of literature consisting of excellent studies in neuroanaesthesiology. However, little of this work appears to be directly important to clinical practice. Many controversies still exist in care of patients with neurologic injury. This review discusses studies of great clinical importance carried out in the last five years, which have the potential of influencing our current clinical practice and also attempts to define areas in need of further research. Relevant literature was obtained through multiple sources that included professional websites, medical journals and textbooks using key words “neuroanaesthesiology,” “traumatic brain injury,” “aneurysmal subarachnoid haemorrhage,” “carotid artery disease,” “brain protection,” “glycemic management” and “neurocritical care.” In head injured patients, administration of colloid and pre-hospital hypertonic saline resuscitation have not been found beneficial while use of multimodality monitoring, individualized optimal cerebral perfusion pressure therapy, tranexamic acid and decompressive craniectomy needs further evaluation. Studies are underway for establishing cerebroprotective potential of therapeutic hypothermia. Local anaesthesia provides better neurocognitive outcome in patients undergoing carotid endarterectomy compared with general anaesthesia. In patients with aneurysmal subarachnoid haemorrhage, induced hypertension alone is currently recommended for treating suspected cerebral vasospasm in place of triple H therapy. Till date, nimodipine is the only drug with proven efficacy in preventing cerebral vasospasm. In neurocritically ill patients, intensive insulin therapy results in substantial increase in hypoglycemic episodes and mortality rate, with current emphasis on minimizing glucose variability. Results of ongoing multicentric trials are likely to further improvise our practice.