Comparison of dexmedetomidine and propofol for conscious sedation in awake craniotomy: a prospective, double-blind, randomized, and controlled clinical trial

A Comparison of the Asleep-Awake Technique and Monitored Anesthesia Care During Awake Craniotomy: A 10-Year Analysis

Background Awake intracranial surgery with direct electrical stimulation (DES) is considered the gold standard for the resection of tumors affecting the eloquent areas of the brain. Awake craniotomy is a challenge for the anesthesiologist, as the patient's active cooperation is required throughout the operation. There are two frequent techniques, one is asleep-awake-asleep (AAA), and the other is called monitored anesthesia care (MAC). The AAA technique is the longer standing of the two and comprises general anesthesia followed by intraoperative awakening, which is necessary for neurological monitoring. In the present study, a comparison was made between the asleep-awake (AA) technique, a variation of the AAA anesthesia technique, and the MAC, which consists of a sedation that makes it possible to control pain and anxiety. Unlike the AA technique, the MAC does not involve the use of invasive airway devices. Objective The main objective was to contrast the two anesthetic management techniques for awake brain surgery used in our hospital. Methods A retrospective observational single-center study was performed consisting of a review of patient clinical records. The study sample comprised all patients above 18 years of age undergoing brain surgery through awake craniotomy between January 2013 and December 2022 at the Miguel Servet University Hospital (HUMS) in Zaragoza (Spain). Results Of the 79 patients included in the study, 39 were operated under AA anesthesia while the remaining 40 were operated under the MAC procedure. The main age of the participants was 52.8 years, the mean height was 169 cm, and the mean weight was 74.2 kg. No statistically significant differences were observed with respect to the patients' baseline characteristics, except for obesity which was more prevalent in the MAC group. In the MAC group, the airway was managed by means of nasal cannulas in all cases, with conversion to general anesthesia being required in only one instance. In the AA group, the laryngeal mask (LM) was used in 89.7% of the patients, and the endotracheal tube (ETT) in 10.3%. The surgical and anesthetic procedure duration was 15 and 20 minutes shorter in the MAC group, respectively. A reduction of almost 20 minutes in the anesthetic procedure and 15 minutes in the surgical one was observed. Tachycardia, desaturation, and airway complications were observed in four, five, and four patients respectively in the AA group but in none of the patients in the MAC group. The mean stay in the intensive care unit (ICU) and the mean postoperative hemoglobin levels between both groups were insignificant. Conclusions Both techniques analyzed in this study turned out to be equally safe and effective for brain tumor surgery in awake patients.

Awake Surgery for Lesional Epilepsy in Resource-Limited Settings: Case Report and Review of Literature

Epilepsy surgery is a well-established treatment for drug-resistant epilepsy, with awake craniotomy being used in certain cases to remove epileptogenic foci while preserving crucial brain functions. We are presenting the first reported case from Pakistan of a 19-year-old woman who underwent awake epilepsy surgery to treat cortical dysplasia. She had a history of generalized tonic-clonic seizures since her childhood and was referred to our clinic due to an increase in seizure frequency. EEG and MRI identified the epileptogenic focus in the right parieto-temporal region. The patient underwent a neuro-navigation guided awake craniotomy and an excision of the epileptogenic focus in the right parieto-temporal region. The procedure was carried out using a scalp block and dexmedetomidine for conscious sedation, enabling the patient to remain awake throughout the surgery. Intraoperative mapping and electrocorticography were used for complex multidisciplinary care. Post-resection corticography showed no spikes along the resected margins. The patient was discharged without any complications and remained free of symptoms a year after the surgery. Awake epilepsy surgery is a viable option for removing epileptogenic foci while preserving vital cognitive functions. However, it is seldom used in low- and middle-income countries such as Pakistan. The successful outcome of this case underscores the need for greater awareness and availability of epilepsy surgery in resource-limited settings. Cost-effective measures, such as using small subdural strips for intraoperative localization, can be implemented.

Risk Factors and Characteristics of Intraoperative Seizures During Awake Craniotomy: A Retrospective Cohort Study of 562 Consecutive Patients With a Space-occupying Brain Lesion

INTRODUCTION

Intraoperative seizures (IOSs) during awake craniotomy (AC) are associated with significant morbidity. The reported incidence of IOS is between 3% and 30%. The aim of this study was to identify risk factors for IOS during AC for elective resection or biopsy of a space-occupying brain lesion.

METHODS

In this retrospective study, we reviewed the records of all awake craniotomies performed by a single neurosurgeon at a single university hospital between July 2006 and December 2018. IOS was defined as a clinically apparent seizure that occurred in the operating room and was documented in the medical records. Explanatory variables were chosen based on previously published literature on risk factors for IOS.

RESULTS

Five hundred and sixty-two patients had a total of 607 AC procedures during the study period; 581 cases with complete anesthesia records were included in analysis. Twenty-nine (5.0%) IOS events were reported during 29 (5%) awake craniotomies. Most seizures (27/29; 93%) were focal in nature and did not limit planned intraoperative stimulation mapping. Variables associated with IOS at a univariate P -value <0.1 (frontal location of tumor, preoperative radiotherapy, preoperative use of antiepileptic drugs, intraoperative use of dexmedetomidine, and intraoperative stimulation mapping) were included in a multivariable logistic regression. Frontal location of tumor (adjusted odds ratio: 5.68, 95% confidence interval: 2.11-15.30) and intraoperative dexmedetomidine use (adjusted odds ratio: 2.724, 95% confidence interval: 1.24-6.00) were independently associated with IOS in the multivariable analysis.

CONCLUSIONS

This study identified a low incidence (5%) of IOS during AC. The association between dexmedetomidine and IOS should be further studied in randomized trials as this is a modifiable risk factor.

Comparison of dexmedetomidine and propofol for sedation in awake craniotomy: A meta-analysis

BACKGROUND

Awake craniotomy (AC) is the preferred option for the resection of tumors adjacent to eloquent cortical areas and in cases of intractable epilepsy. It is mostly used to maintain the integrity of the brain during intracranial neurosurgical procedures. Awake craniotomy requires the use of ideal anesthetics, hypnotics, and analgesics to balance sedation, prompt the reversal of sedation, and prevent respiratory depression while maintaining communication between patient and medical team. Although a wide variety of anesthetics and hypnotics have been used for awake craniotomy over the past several decades, the optimal drug for the procedure has yet to be determined. The purpose of this meta-analysis was to compare dexmedetomidine and propofol in terms of intraoperative adverse events (i.e., hypertension, hypotension, nausea, vomiting, respiratory depression), patient and surgeon satisfaction, and procedure duration.

METHODS

We searched PubMed, Google Scholar, and the Cochrane Library for relevant articles published between the inception of these databases and April of 2022. The systematic search yielded 781 articles. After screening, we excluded 778 articles. The remaining three articles reporting 138 patients were selected for meta-analysis.

RESULTS

This meta-analysis showed no statistically significant difference between propofol and dexmedetomidine related to intraoperative adverse events, patient satisfaction, or procedure duration. The only statistically significant result was surgeon satisfaction, which appeared to be higher in the dexmedetomidine group.

CONCLUSIONS

Further high-quality randomized and controlled trials are needed to find a preferred agent for intraoperative sedation in awake craniotomy.

Neurosurgical Anesthesia: Optimizing Outcomes with Agent Selection

Anesthesia in neurosurgery embodies a vital element in the development of neurosurgical intervention. This undisputed interest has offered surgeons and anesthesiologists an array of anesthetic selections to utilize, though with this allowance comes the equally essential requirement of implementing a maximally appropriate agent. To date, there remains a lack of consensus and official guidance on optimizing anesthetic choice based on operating priorities including hemodynamic parameters (e.g., CPP, ICP, MAP) in addition to the route of procedure and pathology. In this review, the authors detail the development of neuroanesthesia, summarize the advantages and drawbacks of various anesthetic classes and agents, while lastly cohesively organizing the current literature of randomized trials on neuroanesthesia across various procedures.

Predictors for time to awake in patients undergoing awake craniotomies

OBJECTIVE

Awake craniotomies are often characterized by alternating asleep-awake-asleep periods. Preceding the awake phase, patients are weaned from anesthesia and mechanical ventilation. Although clinicians aim to minimize the time to awake for patient safety and operating room efficiency, in some patients, the time to awake exceeds 20 minutes. The goal of this study was to determine the average time to awake and the factors associated with prolonged time to awake (> 20 minutes) in patients undergoing awake craniotomy.

METHODS

Records of patients who underwent awake craniotomy between 2003 and 2020 were evaluated. Time to awake was defined as the time between discontinuation of propofol and remifentanil infusion and the time of extubation. Patient and perioperative characteristics were explored as predictors for time to awake using logistic regression analyses.

RESULTS

Data of 307 patients were analyzed. The median (IQR) time to awake was 13 (10-20) minutes and exceeded 20 minutes in 17% (95% CI 13%-21%) of the patients. In both univariate and multivariable analyses, increased age, nonsmoker status, and American Society of Anesthesiologists (ASA) class III versus II were associated with a time to awake exceeding 20 minutes. BMI, as well as the use of alcohol, drugs, dexamethasone, or antiepileptic agents, was not significantly associated with the time to awake.

CONCLUSIONS

While most patients undergoing awake craniotomy are awake within a reasonable time frame after discontinuation of propofol and remifentanil infusion, time to awake exceeded 20 minutes in 17% of the patients. Increasing age, nonsmoker status, and higher ASA classification were found to be associated with a prolonged time to awake.

Monitored Anesthetic Care Combined with Scalp Nerve Block in Awake Craniotomy: An Effective Attempt at Enhanced Recovery After Neurosurgery

BACKGROUND

Enhanced recovery after surgery has been attempted in neurosurgery at a greater rate. However, concern exists regarding the feasibility of using enhanced recovery after neurosurgery (ERANS). How to manage available resources to safely perform ERANS and improve clinical outcomes has been the subject of much debate and discussion.

METHODS

Owing to the paucity of data available on the use of ERANS protocols, we performed the present feasibility study. We studied the outcomes of the protocols used within a tertiary referral neurosurgery center. Data from patients who had undergone awake craniotomy within an ERANS protocol were prospectively recorded in our institution from September 2017 to December 2018. We also evaluated the safety and effectiveness of the novel ERANS protocol.

RESULTS

A total of 20 patients (mean age, 49.5 ± 17.8 years) were included in the present study. Intraoperative hypertension, hypotension, and bradycardia were present in 4 (20%), 1 (5%), and 1 (5%) patient, respectively. The postoperative morbidities included epilepsy in 1 (5%), pain in 3 (15%), and nausea or vomiting in 2 (10%). No significant changes had occurred in the mean arterial pressure, heart rate, blood glucose, or lactic acid level throughout the procedure. The median length of intensive care unit stay and postoperative hospital stay were 1 and 9.5 days, respectively. No 30-day readmissions or reoperations occurred during the present study.

CONCLUSIONS

Applying an ERANS protocol was feasible, associated with a low incidence of complications, and acceptable intensive care unit and postoperative hospital lengths of stay. The findings from the present study might provide a new approach for the further research of ERANS.

Comparison of clinical efficacy and safety between dexmedetomidine and propofol among patients undergoing gastrointestinal endoscopy: a meta-analysis

OBJECTIVE

To compare the clinical efficacy and safety of dexmedetomidine and propofol in patients who underwent gastrointestinal endoscopy.

METHODS

Relevant studies comparing dexmedetomidine and propofol among patients who underwent gastrointestinal endoscopy were retrieved from databases such as PubMed, Embase, and Cochrane Library.

RESULTS

Seven relevant studies (dexmedetomidine group, n = 238; propofol group, n = 239) met the inclusion criteria. There were no significant differences in the induction time (weighted mean difference [WMD] = 3.46, 95% confidence interval [CI] = -0.95-7.88, I2 = 99%) and recovery time (WMD = 2.74, 95% CI = -2.72-8.19, I2 = 98%). Subgroup analysis revealed no significant differences in the risks of hypotension (risk ratio [RR] = 0.56, 95% CI = 0.25-1.22) and nausea and vomiting (RR = 1.00, 95% CI = 0.46-2.22) between the drugs, whereas dexmedetomidine carried a lower risk of hypoxia (RR = 0.26, 95% CI = 0.11-0.63) and higher risk of bradycardia (RR = 3.01, 95% CI = 1.38-6.54).

CONCLUSIONS

Dexmedetomidine had similar efficacy and safety profiles as propofol in patients undergoing gastrointestinal endoscopy.

Intraoperative Neuromonitoring During Resection of Gliomas Involving Eloquent Areas

In the case of resection of gliomas involving eloquent areas, equal consideration should be given to maintain maximal extent of resection (EOR) and neurological protection, for which the intraoperative neuromonitoring (IONM) proves an effective and admirable approach. IONM techniques applied in clinical practice currently consist of somatosensory evoked potential (SSEP), direct electrical stimulation (DES), motor evoked potential (MEP), electromyography (EMG), and electrocorticography (ECoG). The combined use of DES and ECoG has been adopted widely. With the development of technology, more effective IONM tactics and programs would be proposed. The ultimate goal would be strengthening the localization of eloquent areas and epilepsy foci, reducing the incidence of postoperative dysfunction and epilepsy improving the life quality of patients.

Neurocognitive Impairment After Propofol With Relevance for Neurosurgical Patients and Awake Craniotomies-A Prospective Observational Study

Background: Short-acting anesthetics are used for rapid recovery, especially for neurological testing during awake craniotomy. Extent and duration of neurocognitive impairment are ambiguous.

Methods: Prospective evaluation of patients undergoing craniotomy for tumor resection during general anesthesia with propofol (N of craniotomies = 35). Lexical word fluency, digit span and trail making were tested preoperatively and up to 24 h after extubation. Results were stratified for age, tumor localization and hemisphere of surgery. Results in digit span test were compared to 21 patients during awake craniotomies.

Results: Word fluency was reduced to 30, 33, 47, and 87% of preoperative values 10, 30, 60 min and 24 h after extubation, respectively. Digit span was decreased to 41, 47, 55, and 86%. Performances were still significantly impaired 24 h after extubation, especially in elderly. Results of digit span test were not worse in patients with left hemisphere surgery. Significance of difference to baseline remained, when patients with left or frontal lesions, i.e., brain areas essential for these tests, were excluded from analysis. Time for trail making was increased by 87% at 1 h after extubation, and recovered within 24 h. In 21 patients undergoing awake craniotomies without pharmacological sedation, digit span was unaffected during intraoperative testing.

Conclusion: Selected aspects of higher cognitive functions are compromised for up to 24 h after propofol anesthesia for craniotomy. Propofol and the direct effects of surgical resection on brain networks may be two major factors contributing (possibly jointly) to the observed deficits. Neurocognitive testing was unimpaired in patients undergoing awake craniotomies without sedation.

Experience with awake throughout craniotomy in tumour surgery: technique and outcomes of a prospective, consecutive case series with patient perception data

BACKGROUND

Awake craniotomy is the standard of care in surgery of tumours located in eloquent parts of the brain. However, high variability is recorded in multiple parameters, including anaesthetic techniques, mapping paradigms and technology adjuncts. The current study is focused primarily on patients' level of consciousness, surgical technique, and experience based on a cohort of 50 consecutive cases undergoing awake throughout craniotomy (ATC).

METHODS

Data was collected prospectively for 46 patients undergoing 50 operations over 14-month period, by the senior author, including demographics, extent of resection (EOR), adverse intraoperative events, surgical morbidity, surgery duration, levels of O₂ saturation and brain oedema. A prospective, patient experience questionnaire was delivered to 38 patients.

RESULTS

The ATC technique was well tolerated in all patients. Once TCI stopped, all patients were immediately assessable for mapping. Despite > 75% of cases being considered inoperable/high risk, gross total resection (GTR) was achieved in 68% patients and subtotal resection in 20%. The average duration of surgery was 220 min with no episodes of hypoxia. Early and late severe deficits recorded in 12% and 2%, respectively. No stimulation-induced seizures or failed ATCs were recorded. Patient-recorded data showed absent/minimal pain during (1) clamp placement in 95.6% of patients; (2) drilling in 94.7% of patients; (3) surgery in 78.9% of patients. Post-operatively, 92.3% of patients reported willingness to repeat the ATC, if necessary.

CONCLUSIONS

The current ATC paradigm allows immediate brain mapping, maximising patient comfort during self-positioning. Despite the cohort of challenging tumour location, satisfactory EOR was achieved with acceptable morbidity and no adverse intraoperative events.

[Sensations of patients and their satisfaction during awake craniotomy]

Awake craniotomy (AC) has gained fantastic popularity over the past years. This approach is no longer the destiny of only highly specialized neurosurgical centers. Technical features of AC are completely developed. However, certain aspects of patients' sensations and their satisfaction are still unclear. The review is devoted to these issues. It was shown that AC is positively evaluated by the vast majority of patients. Many patients would choose this technique for redo surgery. However, there are certain important details that can adversely affect satisfaction of patients. Thus, these features should be considered in AC.

Assessment of wakefulness during awake craniotomy to predict intraoperative language performance

OBJECTIVE

Maximal safe tumor resection in language areas of the brain relies on a patient's ability to perform intraoperative language tasks. Assessing the performance of these tasks during awake craniotomies allows the neurosurgeon to identify and preserve brain regions that are critical for language processing. However, receiving sedation and analgesia just prior to experiencing an awake craniotomy may reduce a patient's wakefulness, leading to transient language and/or cognitive impairments that do not completely subside before language testing begins. At present, the degree to which wakefulness influences intraoperative language task performance is unclear. Therefore, the authors sought to determine whether any of 5 brief measures of wakefulness predicts such performance during awake craniotomies for glioma resection.

METHODS

The authors recruited 21 patients with dominant hemisphere low- and high-grade gliomas. Each patient performed baseline wakefulness measures in addition to picture-naming and text-reading language tasks 24 hours before undergoing an awake craniotomy. The patients performed these same tasks again in the operating room following the cessation of anesthesia medications. The authors then conducted statistical analyses to investigate potential relationships between wakefulness measures and language task performance.

RESULTS

Relative to baseline, performance on 3 of the 4 objective wakefulness measures (rapid counting, button pressing, and vigilance) declined in the operating room. Moreover, these declines appeared in the complete absence of self-reported changes in arousal. Performance on language tasks similarly declined in the intraoperative setting, with patients experiencing greater declines in picture naming than in text reading. Finally, performance declines on rapid counting and vigilance wakefulness tasks predicted performance declines on the picture-naming task.

CONCLUSIONS

Current subjective methods for assessing wakefulness during awake craniotomies may be insufficient. The administration of objective measures of wakefulness just prior to language task administration may help to ensure that patients are ready for testing. It may also allow neurosurgeons to identify patients who are at risk for poor intraoperative performance.

Psychomotor recovery of dexmedetomidine compared with propofol after sedation during spinal anesthesia: A randomized control trial

Background and Aims:

Early psychomotor recovery is an essential part of day care surgery which depends on brain integration of motor and sensory co-ordination. Even though dexmedetomidine is commonly used for day care procedures, the recovery profile was not studied. Hence, this study was designed to evaluate the psychomotor recovery of sedation with dexmedetomidine during spinal anesthesia.

Material and Methods:

Sixty-six patients were included. Group D received dexmedetomidine 0.5 μg/kg (loading dose) followed by 0.2–1 μg/kg/hour. Group P received propofol infusion of 25–100 μg/kg/minute. Psychomotor recovery was assessed by finger-tapping, manual dexterity, visual spatial memory capacity, and pen and paper tests. Psychomotor tasks were given to the patients postoperatively at every 30 minutes for 2 hours followed by every hour up to 4 hours after surgery. Distribution of patients, age, weight, duration of surgery, and the level of sensory blockade was compared using independent t-test. Student's t-test has been used to find the significance of parameters such as heart rate, mean arterial pressure, oxygen saturation (SpO₂), psychomotor recovery between two groups. P < 0.05 was considered as significant.

Results:

The motor recovery using finger tapping test was faster in Group D than Group P (73.94 ± 42.13 vs 101.21 ± 37.98 minutes, P–value = 0.007). Motor recovery using peg board test was faster in Group P than Group D (82.12 ± 40.37 vs 99.39 ± 43.08 minutes, P–value = 0.098). Visual spatial capacity memory test and pen and paper test were unaffected.

Conclusions:

We conclude that patients who received dexmedetomidine showed earlier recovery with finger tapping test. Hence, we suggest to use dexmedetomidine for complete psychomotor recovery and fast-track discharging of the patient after spinal anesthesia.

Conscious sedation with dexmedetomidine compared with asleep-awake-asleep craniotomies in glioma surgery: an analysis of 180 patients

OBJECTIVEAwake craniotomies have become a feasible tool over time to treat brain tumors located in eloquent regions. Different techniques have been applied in neurooncology centers. Both "asleep-awake-asleep" (asleep) and "conscious sedation" were used subsequently at the authors' neurosurgical department. Since 2013, the authors have only performed conscious sedation surgeries, predominantly using the α2-receptor agonist dexmedetomidine as the anesthetic drug. The aim of this study was to compare both mentioned techniques and evaluate the clinical use of dexmedetomidine in the setting of awake craniotomies for glioma surgery.METHODSThe authors retrospectively analyzed patients who underwent operations either under the asleep condition using propofol-remifentanil or under conscious sedation conditions using dexmedetomidine infusions. In the asleep group patients were intubated with a laryngeal mask and extubated for the assessment period. Adverse events, as well as applied drugs with doses and frequency of usage, were recorded.RESULTSFrom 224 awake surgeries between 2009 and 2015, 180 were performed for the resection of gliomas and included in the study. In the conscious sedation group (n = 75) significantly fewer opiates (p < 0.001) and vasoactive (p < 0.001) and antihypertensive (p < 0.001) drugs were used in comparison with the asleep group (n = 105). Furthermore, the postoperative length of stay (p < 0.001) and the surgical duration (p < 0.001) were significantly lower in the conscious sedation group.CONCLUSIONSUse of dexmedetomidine creates excellent conditions for awake surgeries. It sedates moderately and acts as an anxiolytic. Thus, after ceasing infusion it enables quick and reliable clinical neurological assessment of patients. This might lead to reducing the amount of administered antihypertensive and vasoactive drugs as well as the length of hospitalization, while likely ensuring more rapid surgery.

Awake craniotomy without sedation in treatment of patients with lesional epilepsy

BACKGROUND

The use of awake craniotomy for surgical treatment of epilepsy was applied in surgery of convexital tumors, arteriovenous malformations, some superficial aneurysms, and stereotactic neurosurgery. The aim of this study was to show the advantages of awake craniotomy without sedation, accompanied by intraoperative neurophysiological monitoring in patients with symptomatic epilepsy.

METHODS

This article describes the results of surgical treatment in 41 patients with various pathologies; 31 among them suffered from epilepsy.

RESULTS

Most frequently, the pathological foci were located in frontal and parietal lobes nearby eloquent brain areas. Irrespective of damage location, simple partial and complex partial seizures were seen almost with the same frequency. Intraoperative mapping of eloquent cortical areas and subcortical tracts without sedation resulted in total resection of pathological area in 75% of cases with low rate of permanent neurological deficit (two patients). Minor perioperative complications, including the decrease in blood pressure in six patients and intraoperative convulsions in two patients, were handled and did not led to operation termination or anesthesia conversion. Excellent seizures control (Engel 1) was achieved in 80% of patients with available catamnesis.

CONCLUSION

Thus, the proposed method allows eliminating the complications associated with sedation and provides radical resection of pathological epileptogenic foci with low complication rate.

Novel Technique for Insertion of Cervical Spinal Cord Stimulator Percutaneous Leads: Technical Note and Institutional Experience

OBJECTIVE

Cervical spinal cord stimulation is a safe and effective treatment for chronic axial neck pain and upper limb neuropathic pain. We report our novel institutional experience with performing cervical spinal cord stimulation trials with patients placed in an upright sitting position. This allows easy access to the cervical epidural space and has the added benefit of unobstructed access to the airway.

METHODS

We retrospectively reviewed data for patients who had undergone cervical spinal cord stimulation trial procedures in an upright, sitting position at the Vanderbilt University Medical Center. Demographic information including age, gender, preoperative diagnosis, progression to permanent implant after a successful trial, and operative time in minutes was collected.

RESULTS

A detailed description of the technique for implantation of cervical spinal cord stimulator trial leads in an upright sitting position is described. A total of 29 patients were implanted; 16 (55%) were female. Mean operative time was 78 minutes from incision to closing. The majority of patients (25/29; 86%) had successful trials and proceeded to permanent implant. No complications occurred, and the procedure was well tolerated by all patients.

CONCLUSIONS

Cervical spinal cord stimulation trials performed in an upright, sitting position allow for easy epidural access and an unobstructed airway with reasonable setup time.

Xenon anesthesia for awake craniotomy: safety and efficacy

BACKGROUND

The asleep-awake-asleep (AAA) craniotomy is a technique that offers the opportunity of having a patient fully cooperative during the awake phase, and minimizes the possible discomfort, due to the asleep phase. The aim of this prospective observational study was to test the use of xenon in the first asleep phase of an AAA craniotomy, in patients undergoing craniotomy for brain tumor resection.

METHODS

The data have been collected from 40 awake craniotomy procedures, performed in patients with cerebral tumor, treated with the AAA technique. Patients were treated with xenon during the asleep phase, and quality of mapping, complications and qualitative judgment of the experience given by the patients were recorded.

RESULTS

The mapping was carried out as planned in 37 out of 40 cases. The doses of xenon administered during the first asleep phase of the anesthesia was 13±2 L. Time for awakening after xenon was switched off was 5±1 minute. A combination of xenon and regional anesthesia (with no need for additional systemic anesthetics) was adequate to accomplish craniotomy in 27/40 patients (67.5%). On the day after the operation, 37 patients recalled the testing procedure for mapping during the awake period, none had recollection of local anesthetic injections for regional anesthesia or sound associated with the neurosurgical drill. Five patients (12.5%) reported mild pain during tumor removal (VAS Score less than three).

CONCLUSIONS

In this case series, xenon anesthesia was successfully used for the sedative phase of an awake craniotomy accomplished with an AAA approach.

Synergistic Interaction Between Dexmedetomidine and Ulinastatin Against Vincristine-Induced Neuropathic Pain in Rats

Antimicrotubulin chemotherapeutic agents such as vincristine (VCR), often induce peripheral neuropathic pain. It is usually permanent and seriously harmful to cancer patients' quality of life and can result in the hampering of clinical treatments. Currently, there is no definitive therapy, and many of the drugs approved for the treatment of other neuropathic pain have shown little or no analgesic effect. It is therefore vital to find new and novel therapeutic strategies for patients suffering from chemotherapeutic agent-induced neuropathic pain to improve patients' quality of life. This study shows that intrathecal injections of dexmedetomidine (DEX), or intraperitoneally administered ulinastatin (UTI) significantly reduces Sprague Dawley rats' mechanical allodynia induced by VCR via upregulation of interleukin-10 expression and activating the α2-adrenergic receptor in dorsal root ganglion (DRG). Moreover, when combined there is a synergistic interaction between DEX and UTI, which acts against VCR-induced neuropathic pain. This synergistic interaction between DEX and UTI may be partly attributed to a common analgesic pathway in which the upregulation of interleukin -10 plays an important role via activating α2-adrenergic receptor in rat dorsal root ganglion. The combined use of DEX and UTI does not affect the rat's blood pressure, heart rate, sedation, motor score, spatial learning, or memory function. All of these show that the combined use of DEX and UTI is an effective method in relieving VCR-induced neuropathic pain in rats.

PERSPECTIVE

This article documents the synergistic interaction between 2 widely used drugs, DEX and UTI, against VCR-induced neuropathic pain. The results provide a potential target and novel drug administrated method for the clinical treatment of chemotherapy-induced peripheral neuropathic pain.

Awake craniotomy anesthetic management using dexmedetomidine, propofol, and remifentanil

INTRODUCTION

Awake craniotomy allows continuous monitoring of patients' neurological functions during open surgery. Anesthesiologists have to sedate patients in a way so that they are compliant throughout the whole surgical procedure, nevertheless maintaining adequate analgesia and anxiolysis. Currently, the use of α2-receptor agonist dexmedetomidine as the primary hypnotic-sedative medication is increasing.

METHODS

Nine patients undergoing awake craniotomy were treated with refined monitored anesthesia care (MAC) protocol consisting of a combination of local anesthesia without scalp block, low-dose infusion of dexmedetomidine, propofol, and remifentanil, without the need of airways management.

RESULTS

The anesthetic protocol applied in our study has the advantage of decreasing the dose of each drug and thus reducing the occurrence of side effects. All patients had smooth and rapid awakenings. The brain remained relaxed during the entire procedure.

CONCLUSION

In our experience, this protocol is safe and effective during awake brain surgery. Nevertheless, prospective randomized trials are necessary to confirm the optimal anesthetic technique to be used.

Dexmedetomidine as an Anesthetic Adjuvant in Intracranial Surgery

BACKGROUND

The basic principle of neuroanesthesia is to provide hemodynamic stability, provision of optimal operative conditions, maintenance of cerebral perfusion pressure, and cerebral oxygenation.

AIM

This study was undertaken to see the effect of dexmedetomidine infusion on hemodynamics and its ability to act as an anesthetic adjuvant in patients undergoing supratentorial tumor surgery.

SETTING AND DESIGN

Prospective randomized control double blind study.

SUBJECTS AND METHODS

In this study, we compared two groups with 25 patients in each group. Group C patients received saline infusion during surgery and 4 μg/kg of fentanyl intravenously (i.v.) at the induction and at pin head application. Group D patients received dexmedetomidine infusion during surgery at the rate of 0.4 μg/kg/h and 2 μg/kg of fentanyl i.v. at the induction and at pin head application.

STATISTICAL ANALYSES USED

Parametric data were analyzed using Student's t-test. The categorical data were studied using Chi-squared test or Fisher's test as appropriate.

RESULTS

The vitals remained within 20% of baseline in both groups during the study period except at the time of extubation where the rise in heart rate was more than 20% in control group. The requirement of thiopentone for induction was significantly less in dexmedetomidine group. In dexmedetomidine group, less number of patients required intraoperative fentanyl (P < 0.05), and the time to rescue analgesic was also more in Group D (P < 0.05).

CONCLUSION

Dexmedetomidine infusion started before surgery maintains hemodynamic stability intraoperatively and is effective in attenuating the cardiovascular responses to intubation, skull pin application, and extubation. It decreases the requirement of other anesthetic agents as well.

The Opioid-Sparing Effect of Perioperative Dexmedetomidine Plus Sufentanil Infusion during Neurosurgery: A Retrospective Study

Background: Approximately 60% of patients experience moderate-to-severe pain after neurosurgery, which primarily occurs in the first 24–72 h. Despite this, improved postoperative analgesia solutions after neurosurgery have not yet been devised. This retrospective study was conducted to evaluate the effect of intra- and post-operative infusions of dexmedetomidine (DEX) plus sufentanil on the quality of postoperative analgesia in patients undergoing neurosurgery.

Methods: One hundred and sixty-three post-neurosurgery patients were divided into two groups: Group D (DEX infusion at 0.5 μg·kg⁻¹ for 10 min, then adjusted to 0.3 μg·kg⁻¹·h⁻¹ until incision suturing) and Group ND (no DEX infusion during surgery). Patient-controlled analgesia was administered for 72 h after surgery (Group D: sufentanil 0.02 μg·kg⁻¹·h⁻¹ plus DEX 0.02 μg·kg⁻¹·h⁻¹, Group ND: sufentanil 0.02 μg·kg⁻¹·h⁻¹) in this retrospective study. The primary outcome measure was postoperative sufentanil consumption. Hemodynamics, requirement of narcotic, and vasoactive drugs, recovery time and the incidence of concerning adverse effects were recorded. Pain intensity [Visual Analogue Scale (VAS)], Ramsay sedation scale (RSS) and Bruggemann comfort scale (BCS) were also evaluated at 1, 4, 8, 12, 24, 48, and 72 h after surgery.

Results: Postoperative sufentanil consumption was significantly lower in Group D during the first 72 h after surgery (P < 0.05). Compared with Group ND, heart rate (HR) in Group D was significantly decreased from intubation to 20 min after arriving at post anesthesia care unit (PACU), while mean arterial pressure (MAP) in Group D was significantly decreased from intubation to 5 min after arriving at PACU (P < 0.05). The intraoperative requirements for sevoflurane, remifentanil, and fentanyl were approximately 35% less in Group D compared with Group ND. VAS at rest at 1, 4, and 8 h and with cough at 12, 24, 48, and 72 h after surgery were significantly lower in Group D (P < 0.05). Compared with Group ND, patients in Group D showed lower levels of overall incidence of tachycardia, hypertension, nausea, and vomiting (P < 0.05). There were no significant differences between the two groups in terms of baseline clinical characteristics, recovery time, RSS, and BCS (P > 0.05).

Conclusions: DEX (0.02 μg·kg⁻¹·h⁻¹) plus sufentanil (0.02 μg·kg⁻¹·h⁻¹) could reduce postoperative opioid consumption and concerning adverse adverse effects, while improving pain scores. However, it did not influence RSS and BCS during the first 72 h after neurosurgery.

The Opioid-sparing Effect of Intraoperative Dexmedetomidine Infusion After Craniotomy

BACKGROUND

We conducted a randomized trial to evaluate the opioid-sparing effect of an intraoperative infusion of dexmedetomidine (DEX) after craniotomy.

METHODS

Sixty adult patients scheduled for craniotomy were divided randomly into group A (DEX infusion at 0.5 μg/kg/h for 10 min and then adjusted to 0.2 to 0.5 μg/kg/h from tracheal intubation to incision suturing) and group B (0.9% saline infusion). Additional intravenous injections and patient-controlled analgesia with morphine were used to control postoperative pain for verbal Numerical Rating Scale scores >4. Cumulative morphine consumption, Numerical Rating Scale pain score, and the Ramsay Sedation Scale score were evaluated at 1, 2, 4, 6, 8, 12, and 24 hours; the incidence of postoperative nausea and vomiting, agitation, and respiratory depression were recorded at 24 hours after surgery.

RESULTS

Postoperative pain scores within 12 hours and Ramsay Sedation Scale scores within 6 hours of surgery were both significantly lower in group A than in group B (P<0.001). Patients in group A required 54.4%, 43.3%, and 31.4% less cumulative morphine consumption during the first 4, 12, and 24 hours, respectively. No patient in group A and 5 patients in group B presented agitation within 1 hour after surgery. Three patients in group A and 9 patients in group B showed pruritus (P<0.001).

CONCLUSIONS

An intraoperative infusion of DEX reduced cumulative morphine consumption and adverse effects after craniotomy.

Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis

BACKGROUND

Awake craniotomy (AC) renders an expanded role in functional neurosurgery. Yet, evidence for optimal anaesthesia management remains limited. We aimed to summarise the latest clinical evidence of AC anaesthesia management and explore the relationship of AC failures on the used anaesthesia techniques.

METHODS

Two authors performed independently a systematic search of English articles in PubMed and EMBASE database 1/2007-12/2015. Search included randomised controlled trials (RCTs), observational trials, and case reports (n>4 cases), which reported anaesthetic approach for AC and at least one of our pre-specified outcomes: intraoperative seizures, hypoxia, arterial hypertension, nausea and vomiting, neurological dysfunction, conversion into general anaesthesia and failure of AC. Random effects meta-analysis was used to estimate event rates for four outcomes. Relationship with anaesthesia technique was explored using logistic meta-regression, calculating the odds ratios (OR) and 95% confidence intervals [95%CI].

RESULTS

We have included forty-seven studies. Eighteen reported asleep-awake-asleep technique (SAS), twenty-seven monitored anaesthesia care (MAC), one reported both and one used the awake-awake-awake technique (AAA). Proportions of AC failures, intraoperative seizures, new neurological dysfunction and conversion into general anaesthesia (GA) were 2% [95%CI:1-3], 8% [95%CI:6-11], 17% [95%CI:12-23] and 2% [95%CI:2-3], respectively. Meta-regression of SAS and MAC technique did not reveal any relevant differences between outcomes explained by the technique, except for conversion into GA. Estimated OR comparing SAS to MAC for AC failures was 0.98 [95%CI:0.36-2.69], 1.01 [95%CI:0.52-1.88] for seizures, 1.66 [95%CI:1.35-3.70] for new neurological dysfunction and 2.17 [95%CI:1.22-3.85] for conversion into GA. The latter result has to be interpreted cautiously. It is based on one retrospective high-risk of bias study and significance was abolished in a sensitivity analysis of only prospectively conducted studies.

CONCLUSION

SAS and MAC techniques were feasible and safe, whereas data for AAA technique are limited. Large RCTs are required to prove superiority of one anaesthetic regime for AC.

The efficacy, safety and cost-effectiveness of intra-operative cell salvage in high-bleeding-risk cardiac surgery with cardiopulmonary bypass: a prospective randomized and controlled trial

OBJECTIVE

Intra-operative cell salvage (CS) was reported to be ineffective, safe and not cost-effective in low-bleeding-risk cardiac surgery with cardiopulmonary bypass (CPB), but studies in high-bleeding-risk cardiac surgery are limited. The objective of this study is to evaluate the efficacy, safety and cost-effectiveness of intra-operative CS in high-bleeding-risk cardiac surgery with CPB.

METHODS

One hundred and fifty patients were randomly assigned to either with intra-operative CS group (Group CS) or without intra-operative CS group (Group C). Study endpoints were defined as perioperative allogeneic red blood cell (RBC) transfusion, perioperative impairment of blood coagulative function, postoperative adverse events and costs of transfusion-related.

RESULTS

Both the proportion and quantity of perioperative allogeneic RBC transfusion were significantly lower in Group CS than that in Group C (p=0.0002, <0.0001, respectively). The incidence of residual heparin and total impairment of blood coagulative function in the 24 hours after surgery, the incidence of postoperative excessive bleeding, were significantly higher in Group CS than that in Group C (p=0.018, 0.042, 0.034, respectively). Cost of both allogeneic RBC transfusion and total allogeneic blood transfusion were significantly lower in Group CS than that in Group C (p<0.001, =0.002, respectively). Cost of total blood transfusion was significantly higher in Group CS than that in Group C (p =0.001).

CONCLUSION

Intra-operative CS in high-bleeding-risk cardiac surgery with CPB is effective, generally safe, and cost-effective in developed countries but not in China.

Awake craniotomy for brain tumor: indications, technique and benefits

Increasing interest in the quality of life of patients after treatment of brain tumors has led to the exploration of methods that can improve intraoperative assessment of neurological status to avoid neurological deficits. The only method that can provide assessment of all eloquent areas of cerebral cortex and white matter is brain mapping during awake craniotomy. This method helps ensure that the quality of life and the neuro-oncological result of treatment are not compromised. Apart from the medical aspects of awake surgery, its economic issues are also favorable. Here, we review the main aspects of awake brain tumor surgery. Neurosurgical, neuropsychological, neurophysiological and anesthetic issues are briefly discussed.

Awake Craniotomy with Intraoperative MRI: Description of a Sedation Technique Using Remifentanil and Dexmedetomidine

We describe the anaesthetic management of a patient requiring intra-operative MRI and awake neurological testing during neurosurgical resection of a frontal tumour. This tumour involved her motor and speech areas. The anaesthetic drugs administered during awake craniotomy should be safe and allow appropriate changes in the level of sedation, so that the patient is adequately sedated during periods of intense surgical stimulus, yet awake, comfortable and cooperative during functional testing and tumour resection. We report the novel and successful use of a sedative — dexmedetomidine in combination with a narcotic, remifentanil. There has not been much experience with this combination locally. Dexmedetomidine, a selective alpha-2 agonist with sedative, analgesic and anaesthetic-sparing effect does not suppress ventilation. Patients are sedated, but can be easily roused verbally. Remifentanil is a useful choice in this surgery as it can be rapidly titrated according to level of surgical intensity and has a reliable context sensitive half life. Potential problems associated with awake craniotomy such as impaired ventilation during sedation, nausea, vomiting and seizures are discussed. These anaesthetic challenges are compounded by the challenges posed by the iMRI environment. Emphasis is placed on patient selection and preparation peri-operatively. This is crucial to the success of the operation.