Anesthesia in the patient for awake craniotomy

Epidemiology of Post-craniotomy Hypertension and Its Association With Adverse Outcome(s): A Systematic Review and Meta-analysis

After intracranial surgery, sympathetic overdrive and increased blood catecholamine levels can contribute to postoperative hypertension, a significant clinical problem. The objective of this review was to summarize, quantify, and assess the epidemiological perspective of post-craniotomy hypertension and its association with adverse outcomes. This PROSPERO-registered systematic review was conducted following PRISMA guidelines. We searched electronic databases for studies that investigated adult patients who had elective craniotomy for any indication and reported hypertension within 72 hours postoperatively. Study quality was assessed using the Newcastle-Ottawa scale. Twenty-one studies, including 2602 patients, were identified for inclusion in this review. Multiple thresholds and criteria for defining post-craniotomy hypertension were used across studies. The pooled incidence of post-craniotomy hypertension from 13 studies (2279 patients) was 30% [95% CI, 15%-50%]. Post-craniotomy hypertension was associated with a 2.6 times higher risk of having an intracerebral hemorrhage within 72 hours after surgery (pooled risk ratio, 2.63; 95% CI, 1.16-5.97). There were insufficient data to investigate the quantitative association of post-craniotomy hypertension with 30-day adverse events. In summary, 1 out of 3 patients exhibited hypertension post-craniotomy, and this was associated with a significantly higher risk of having intracranial hemorrhage within 72 hours post-procedure. A generally accepted and clinically relevant criteria for post-craniotomy hypertension should be defined.

Awake Craniotomy in Neurosurgery: A Bibliometric Analysis of the Top 100 Most-Cited Articles and Review of Technological Advancements

Awake craniotomy (AC) is a critical neurosurgical technique for maximizing tumor resection in eloquent brain regions while preserving essential neurological functions like speech and motor control. Despite its widespread adoption, no prior bibliometric analysis has evaluated the most influential research in this field. This study analyzed the top 100 most-cited articles on AC to identify key trends, influential works, and authorship demographics. A systematic search of the Web of Science Core Collection on September 17, 2024, yielded 718 publications, with the top 100 ranked by citation count. Analysis revealed a surge in AC research after 2013, peaking in 2021, with the Journal of Neurosurgery contributing significantly (49 articles; 2,611 citations). Themes included functional mapping, anesthetic techniques, and patient outcomes, with technological advancements such as intraoperative MRI and virtual reality enhancing surgical precision. Authorship analysis highlighted a gender disparity, with male authors occupying 77% of first authorship and 88% of senior roles. These findings underscore AC's evolution, foundational studies, and ongoing advancements while emphasizing the need for greater diversity and inclusion in the field.

Hypnosis-Assisted Awake Craniotomy for Eloquent Brain Tumors: Advantages and Pitfalls

BACKGROUND

Awake craniotomy (AC) is recommended for the resection of tumors in eloquent areas. It is traditionally performed under monitored anesthesia care (MAC), which relies on hypnotics and opioids. Hypnosis-assisted AC (HAAC) is an emerging technique that aims to provide psychological support while reducing the need for pharmacological sedation and analgesia. We aimed to compare the characteristics and outcomes of patients who underwent AC under HAAC or MAC.

METHODS

We retrospectively analyzed the clinical, anesthetic, surgical, and neuropsychological data of patients who underwent awake surgical resection of eloquent brain tumors under HAAC or MAC. We used Mann-Whitney U tests, Wilcoxon signed-rank tests, and repeated-measures analyses of variance to identify statistically significant differences at the 0.05 level.

RESULTS

A total of 22 patients were analyzed, 14 in the HAAC group and 8 in the MAC group. Demographic, radiological, and surgical characteristics as well as postoperative outcomes were similar. Patients in the HAAC group received less remifentanil (p = 0.047) and propofol (p = 0.002), but more dexmedetomidine (p = 0.025). None of them received ketamine as a rescue analgesic. Although patients in the HAAC group experienced higher levels of perioperative pain (p < 0.05), they reported decreasing stress levels (p = 0.04) and greater levels of satisfaction (p = 0.02).

CONCLUSION

HAAC is a safe alternative to MAC as it reduces perioperative stress and increases overall satisfaction. Further research is necessary to assess whether hypnosis is clinically beneficial.

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.

Analgesic effects of dexmedetomidine and remifentanil on periprocedural pain during percutaneous ablation of renal carcinoma

Background: Percutaneous ablation of renal carcinoma is frequently a favourable treatment alternative, especially in elderly patients suffering from co-morbidities. Also, it is less resource-demanding than conventional surgery of renal carcinoma, and one may, therefore, assume that the incidence of this procedure may increase. Analgesia is necessary during this intervention. The aim of this study was to explore the possibility of analgosedation and its relation to patient comfort and safety during percutaneous ablation of renal carcinoma.Methods: Forty-six patients, sedated with dexmedetomidine and remifentanil, supplemented with infiltration anaesthesia (lidocaine 1%), underwent percutaneous (radiofrequency or microwave) ablation of renal carcinoma in this prospective study.Results: The patients expected pain intensity around the numerical rating score (NRS) 4.5 (interquartile range [IQR] 3.5-5.5), which was slightly lower than pain experienced during the procedure NRS 5 (IQR 2-7; p = 0.49). Eight percent of the patients needed supplementary morphine during the ablation procedure. Sedation score did not differ during ablation, at arrival to or discharge from the recovery ward. Median periprocedural treatment time was 12 minutes (IQR 12-16). Treatment time did not correlate with experienced pain (R²=0.000074, p = 0.96). The median length of stay in the recovery room was 120 minutes (IQR 84-154). There were seven serious adverse events.Conclusions: This proof-of-concept study has shown that analgosedation during percutaneous ablation of renal carcinoma can be performed with a generally tolerable degree of patient satisfaction. However, pain occurs and should be managed adequately. Patient safety must be a major concern for the anaesthetic care.

Supraglottic devices for airway management in awake craniotomy

Awake craniotomy is a unique technique utilized for mapping neuro and motor function during neurosurgical procedures close to eloquent brain tissue. Since active communication is required only during surgical manipulation of eloquent brain tissue and the patient is "sedated" during other parts of the procedure, different methods for anesthesia management have been explored. Furthermore, airway management ranges from spontaneous breathing to oro or nasotracheal intubation. Case reports have described the use of laryngeal masks (LMs) previously; however, its safety compared to tracheal intubation has not been assessed.We conducted a retrospective analysis of 30 patients that underwent awake craniotomy for tumor surgery to compare the feasibility and safety of different airway management strategies. Nasal fiberoptic intubation (FOI) was performed in 21 patients while 9 patients received LM for airway management. Ventilation, critical events, and perioperative complications were evaluated.Cannot intubate situation occurred in 4 cases reinserting the tube after awake phase, while no difficulties were described reinserting the LM (P < .0001). Furthermore, duration of mechanical ventilation after tumor removal was significantly lower in the LM group compared to FOI group (62 ± 24 vs. 339 ± 82 [min] mean ± sem, P < .0001). Postoperatively, 2 patients in each group were diagnosed with and treated for respiratory complications including pneumonia, without statistical significance between groups.In summary, LM is a feasible airway management method for patients undergoing awake craniotomy, resulting in reduced ventilation duration compared to FOI procedure.

The Stony Brook awake craniotomy protocol: A technical note

Most current awake craniotomy techniques utilize unnecessarily complicated airway management, and cause discomfort to the patients during the awake phase of the surgery. Our manuscript is written to discuss the neurosurgical and anesthetic techniques that we have developed to optimize awake craniotomy techniques at Stony Brook University Medical Center. We used the frameless Brainlab™ skull-mounted array for stereotactic navigation. Rigid fixation of the skull was avoided. General anesthesia with established airway was used during the "asleep" phase of the surgery. Following the removal of the bone flap and the opening of the dura, the patients were woken up, and the established airway was removed. Cortical mapping was performed to establish a safe entry zone for tumor removal. While the tumors were being removed, we continued motor examination and casual conversation with the patients to ensure safety. Patients were sedated during the remaining phase of the surgery until skin closure. No patient exhibited any neurological deficits or adverse anesthesia outcomes during the postoperative period. The protocol we developed avoids rigid skull fixation and emphasizes flexible intraoperative planning, thereby maximizing patient and physician comfort while allowing for successful tumor resection.

Dexmedetomidine: present and future directions

Dexmedetomidine is a potent, highly selective α-2 adrenoceptor agonist, with sedative, analgesic, anxiolytic, sympatholytic, and opioid-sparing properties. Dexmedetomidine induces a unique sedative response, which shows an easy transition from sleep to wakefulness, thus allowing a patient to be cooperative and communicative when stimulated. Dexmedetomidine may produce less delirium than other sedatives or even prevent delirium. The analgesic effect of dexmedetomidine is not strong; however, it can be administered as a useful analgesic adjuvant. As an anesthetic adjuvant, dexmedetomidine decreases the need for opioids, inhalational anesthetics, and intravenous anesthetics. The sympatholytic effect of dexmedetomidine may provide stable hemodynamics during the perioperative period. Dexmedetomidine-induced cooperative sedation with minimal respiratory depression provides safe and acceptable conditions during neurosurgical procedures in awake patients and awake fiberoptic intubation. Despite the lack of pediatric labelling, dexmedetomidine has been widely studied for pediatric use in various applications. Most adverse events associated with dexmedetomidine occur during or shortly after a loading infusion. There are some case reports of dexmedetomidine-related cardiac arrest following severe bradycardia. Some extended applications of dexmedetomidine discussed in this review are promising, but still limited, and further research is required. The pharmacological properties and possible adverse effects of dexmedetomidine should be well understood by the anesthesiologist prior to use. Moreover, it is necessary to select patients carefully and to determine the appropriate dosage of dexmedetomidine to ensure patient safety.

Anaesthetic management for awake craniotomy in brain glioma resection: initial experience in Military Hospital Mohamed V of Rabat

The awake brain surgery is an innovative approach in the treatment of tumors in the functional areas of the brain. There are various anesthetic techniques for awake craniotomy (AC), including asleep-awake-asleep technique, monitored anesthesia care, and the recent introduced awake-awake-awake method. We describe our first experience with anesthetic management for awake craniotomy, which was a combination of these techniques with scalp nerve block, and propofol/rémifentanil target controlled infusion. A 28-year-oldmale underwent an awake craniotomy for brain glioma resection. The scalp nerve block was performed and a low sedative state was maintained until removal of bone flap. During brain glioma resection, the patient awake state was maintained without any complications. Once, the tumorectomy was completed, the level of anesthesia was deepened and a laryngeal mask airway was inserted. A well psychological preparation, a reasonable choice of anesthetic techniques and agents, and continuous team communication were some of the key challenges for successful outcome in our patient.

Awake Craniotomy Anesthesia: A Comparison of the Monitored Anesthesia Care and Asleep-Awake-Asleep Techniques

BACKGROUND

Commonly used sedation techniques for an awake craniotomy include monitored anesthesia care (MAC), using an unprotected airway, and the asleep-awake-asleep (AAA) technique, using a partially or totally protected airway. We present a comparative analysis of the MAC and AAA techniques, evaluating anesthetic management, perioperative outcomes, and complications in a consecutive series of patients undergoing the removal of an eloquent brain lesion.

METHODS

Eighty-one patients underwent awake craniotomy for an intracranial lesion over a 9-year period performed by a single-surgeon and a team of anesthesiologists. Fifty patients were treated using the MAC technique, and 31 were treated using the AAA technique. A retrospective analysis evaluated anesthetic management, intraoperative complications, postoperative outcomes, pain management, and complications.

RESULTS

The MAC and AAA groups had similar preoperative patient and tumor characteristics. Mean operative time was shorter in the MAC group (283.5 minutes vs. 313.3 minutes; P = 0.038). Hypertension was the most common intraoperative complication seen (8% in the MAC group vs. 9.7% in the AAA group; P = 0.794). Intraoperative seizure occurred at a rate of 4% in the MAC group and 3.2% in the AAA group (P = 0.858). Awake cases were converted to general anesthesia in no patients in the MAC group and in 1 patient (3.2%) in the AAA group (P = 0.201). No cases were aborted in either group. The mean hospital length of stay was 3.98 days in the MAC group and 3.84 days in the AAA group (P = 0.833).

CONCLUSIONS

Both the MAC and AAA sedation techniques provide an efficacious and safe method for managing awake craniotomy cases and produce similar perioperative outcomes, with the MAC technique associated with shorter operative time.

Awake craniotomy: improving the patient's experience

PURPOSE OF REVIEW

Awake craniotomy patients are exposed to various stressful stimuli while their attention and vigilance is important for the success of the surgery. We describe several recent findings on the perception of awake craniotomy patients and address nonpharmacological perioperative factors that enhance the experience of awake craniotomy patients. These factors could also be applicable to other surgical patients.

RECENT FINDINGS

Proper preoperative counseling gives higher patient satisfaction and should be individually tailored to the patient. Furthermore, there is a substantial proportion of patients who have significant pain or fear during an awake craniotomy procedure. There is a possibility that this could induce post-traumatic stress disorder or related symptoms.

SUMMARY

Preoperative preparation is of utmost importance in awake craniotomy patients, and a solid doctor-patient relationship is an important condition. Nonpharmacological intraoperative management should focus on reduction of fear and pain by adaptation of the environment and careful and well considered communication.

Comparison of propofol pharmacokinetic and pharmacodynamic models for awake craniotomy: A prospective observational study

BACKGROUND

Anaesthesia for awake craniotomy aims for an unconscious patient at the beginning and end of surgery but a rapidly awakening and responsive patient during the awake period. Therefore, an accurate pharmacokinetic/pharmacodynamic (PK/PD) model for propofol is required to tailor depth of anaesthesia.

OBJECTIVE

To compare the predictive performances of the Marsh and the Schnider PK/PD models during awake craniotomy.

DESIGN

A prospective observational study.

SETTING

Single university hospital from February 2009 to May 2010.

PATIENTS

Twelve patients undergoing elective awake craniotomy for resection of brain tumour or epileptogenic areas.

INTERVENTION

Arterial blood samples were drawn at intervals and the propofol plasma concentration was determined.

MAIN OUTCOME MEASURES

The prediction error, bias [median prediction error (MDPE)] and inaccuracy [median absolute prediction error (MDAPE)] of the Marsh and the Schnider models were calculated. The secondary endpoint was the prediction probability PK, by which changes in the propofol effect-site concentration (as derived from simultaneous PK/PD modelling) predicted changes in anaesthetic depth (measured by the bispectral index).

RESULTS

The Marsh model was associated with a significantly (P = 0.05) higher inaccuracy (MDAPE 28.9 ± 12.0%) than the Schnider model (MDAPE 21.5 ± 7.7%) and tended to reach a higher bias (MDPE Marsh -11.7 ± 14.3%, MDPE Schnider -5.4 ± 20.7%, P = 0.09). MDAPE was outside of accepted limits in six (Marsh model) and two (Schnider model) of 12 patients. The prediction probability was comparable between the Marsh (PK 0.798 ± 0.056) and the Schnider model (PK 0.787 ± 0.055), but after adjusting the models to each individual patient, the Schnider model achieved significantly higher prediction probabilities (PK 0.807 ± 0.056, P = 0.05).

CONCLUSION

When using the 'asleep-awake-asleep' anaesthetic technique during awake craniotomy, we advocate using the PK/PD model proposed by Schnider. Due to considerable interindividual variation, additional monitoring of anaesthetic depth is recommended.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT 01128465.

Conscious sedation and local anesthesia for patients undergoing neurotologic and complex otologic procedures

OBJECTIVE

Is conscious sedation an effective, safe, and efficient anesthetic choice in patients undergoing select neurotologic and otologic procedures?

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Six patients underwent eight neurotologic procedures including cerebrospinal fluid leak and encephalocele repair, and primary and revision cochlear implant surgery. Patients were deemed poor candidates for general anesthesia secondary to medical comorbidities. These were compared to 11 control patients who underwent same procedures under general anesthesia with intubation.

INTERVENTION

Dexmedetomidine infusion was utilized as the primary agent for conscious sedation in this high-risk patient population because, unlike other commonly used sedatives, it preserves normal respirations while providing adequate analgesia.

MAIN OUTCOME MEASURES

Preoperative Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (P-POSSUM) scores were calculated for the study group. We measured total anesthesia, and perioperative and recovery times. Cost of anesthetic agents was considered and any adverse effects were noted. Patient satisfaction with the operative experience was assessed with telephone surveys.

RESULTS

P-POSSUM scores were high for the study group. Postoperative anesthesia was shorter for the study patients undergoing conscious sedation. Difference in cost of anesthetic agents was negligible. The adverse effects were few and as expected for the type of procedure. Patients reported satisfaction and comfort with their operative experience.

CONCLUSION

Select neurotologic and otologic procedures can be safely, effectively, and efficiently performed under conscious sedation with dexmedetomidine infusion as the primary anesthetic choice for patients who are deemed poor medical candidates for general endotracheal anesthesia.

Awake craniotomy: A qualitative review and future challenges

Neurosurgery in awake patients incorporates newer technologies that require the anesthesiologists to update their skills and evolve their methodologies. They need effective communication skills and knowledge of selecting the right anesthetic drugs to ensure adequate analgesia, akinesia, along with patient satisfaction with the anesthetic conduct throughout the procedure. The challenge of providing adequate anesthetic care to an awake patient for intracranial surgery requires more than routine vigilance about anesthetic management.

Anesthesia for awake craniotomy: case report

BACKGROUND AND OBJECTIVES

Some intracranial procedures are achievable with patients awake, however, there are challenges ranging from patient compliance to homeostasis. The aim of this study is to present a case of intracranial surgery for removal of a tumor in the left parietal lobe with the patient awake during the procedure.

CASE REPORT

After patient selection and psychological preparation, the proposed excision of the left parietal lobe lesion in the waking state was clarified and accepted. Continuous infusion of propofol and remifentanil was administered to maintain a Ramsay score of 2-3. The bilateral scalp blockade was performed with ropivacaine. The Mayfield head fixation device was installed and drapes adjusted to maintain the airway and eyes accessible for mapping with electrical stimulation and tumor excision. For dura mater incision, a pad with 2% lidocaine was applied for 3 minutes. The surgery was uneventful. The patient was discharged on the seventh day of hospitalization without presenting complication.

CONCLUSION

Although the maintenance of analgesia and hemodynamic stability was a challenge with the patient awake, the target-controlled infusion of propofol provided the desired level of consciousness, remifentanil titrated analgesia and sedation without drug accumulation, and the blockade with ropivacaine provided satisfactory analgesia. We conclude that the anesthetic technique was satisfactory for our patient.

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

BACKGROUND

It has been reported that dexmedetomidine (DEX) can be used for conscious sedation in awake craniotomy, but few data exist to compare DEX versus propofol (PRO).

OBJECTIVE

To compare the efficacy and safety of DEX versus PRO for conscious sedation in awake craniotomy.

METHODS

Thirty patients of American Society of Anesthesiologists grade I-II scheduled for awake craniotomy, were randomized into 2 groups each containing 15 subjects. Group D received DEX and group P received PRO. Two minutes after tracheal intubation (T1), PRO (target plasma concentration) was titrated down to 1 to 4 µg/mL in group P. In group D, PRO was discontinued and DEX was administered 1.0 µg/kg followed by a maintenance dose of 0.2 to 0.7 µg/kg/h. The surgeon preset the anticipated awake point-in-time (T0) preoperatively. Ten minutes before T0 (T3), DEX was titrated down to 0.2 µg/kg/h in group D, PRO was discontinued and normal saline (placebo) 5 mL/h was infused in group P. Arousal time, quality of revival and adverse events during the awake period, degree of satisfaction from surgeons and patients were recorded.

RESULTS

Arousal time was significantly shorter in group D than in group P (P < .001). The quality of revival during the awake period in group D was similar to that of group P (P = .68). The degree of satisfaction of surgeons was significantly higher in group D than in group P (P < .001), but no difference was found between the 2 groups with respect to patient satisfaction (P = .80). There was no difference between the 2 groups in the incidence of adverse events during the awake period (P > .05).

CONCLUSIONS

Either DEX or PRO can be effectively and safely used for conscious sedation in awake craniotomy. Comparing the two, DEX produced a shorter arousal time and a higher degree of surgeon satisfaction.

Awake surgery between art and science. Part I: clinical and operative settings

Awake surgery requires coordinated teamwork and communication between the surgeon and the anesthesiologist, as he monitors the patient, the neuroradiologist as he interprets the images for intraoperative confirmation, and the neuropsychologist and neurophysiologist as they evaluate in real-time the patient's responses to commands and questions. To improve comparison across published studies on clinical assessment and operative settings in awake surgery, we reviewed the literature, focusing on methodological differences and aims. In complex, interdisciplinary medical care, such differences can affect the outcome and the cost-benefit ratio of the treatment. Standardization of intraoperative mapping and related controversies will be discussed in Part II.

Dexmedetomidine: an adjuvant making large inroads into clinical practice

The introduction of newer more selective α(-2) adrenergic agonist, dexmedetomidine has made a revolution in the field of anesthesia owing to its varied application. The aim of the current review is to highlight the various clinical and pharmacological aspects of dexmedetomidine in daily routine practice of anesthesiology and intensive care besides its potential role in other clinical specialties. This review of dexmedetomidine was carried out after searching the medical literature in Pubmed, Science direct, Scopus, Google scholar and various text books and journal articles using keywords anesthesia, dexmedetomidine, neurosurgery, pediatric surgery, regional dexmedetomidine, anesthesia, regional, neurosurgery, and pediatric surgery. Dexmedetomidine has made its application from a novel sedating agent in the intensive care unit to its use as an adjuvant in various regional anesthetic techniques because of its "cooperative sedation" without any respiratory depression. It has a favorable pharmacokinetic profile suitable to be used in the perioperative period to reduce the requirements of opioids and anesthetic drugs. There are few side-effects of dexmedetomidine, which should always be kept in mind before choosing the patients for its use. The various side-effects associated with dexmedetomidine include, but are not limited to hypotension, bradycardia, worsening of heart block, dry mouth, and nausea. However, large scale randomized controlled trials are still needed to establish various effects of dexmedetomidine and to clearly define its safety profile.

Training anesthesiology residents in providing anesthesia for awake craniotomy: learning curves and estimate of needed case load

STUDY OBJECTIVE

To measure the learning curves of residents in anesthesiology in providing anesthesia for awake craniotomy, and to estimate the case load needed to achieve a "good-excellent" level of competence.

DESIGN

Prospective study.

SETTING

Operating room of a university hospital.

SUBJECTS

7 volunteer residents in anesthesiology.

MEASUREMENTS

Residents underwent a dedicated training program of clinical characteristics of anesthesia for awake craniotomy. The program was divided into three tasks: local anesthesia, sedation-analgesia, and intraoperative hemodynamic management. The learning curve for each resident for each task was recorded over 10 procedures. Quantitative assessment of the individual's ability was based on the resident's self-assessment score and the attending anesthesiologist's judgment, and rated by modified 12 mm Likert scale, reported ability score visual analog scale (VAS). This ability VAS score ranged from 1 to 12 (ie, very poor, mild, moderate, sufficient, good, excellent). The number of requests for advice also was recorded (ie, resident requests for practical help and theoretical notions to accomplish the procedures).

MAIN RESULTS

Each task had a specific learning rate; the number of procedures necessary to achieve "good-excellent" ability with confidence, as determined by the recorded results, were 10 procedures for local anesthesia, 15 to 25 procedures for sedation-analgesia, and 20 to 30 procedures for intraoperative hemodynamic management.

CONCLUSIONS

Awake craniotomy is an approach used increasingly in neuroanesthesia. A dedicated training program based on learning specific tasks and building confidence with essential features provides "good-excellent" ability.

Awake craniotomies without any sedation: the awake-awake-awake technique

BACKGROUND

Temporary anaesthesia or analgosedation used for awake craniotomies carry substantial risks like hemodynamic instabilities, airway obstruction, hypoventilation, nausea and vomiting, agitation, and interference with test performances. We tested the actual need for sedatives and opioids in 50 patients undergoing awake craniotomy for brain tumour resection in eloquent or motoric brain areas when cranial nerve blocks, permanent presence of a contact person, and therapeutic communication are provided.

METHODS

Therapeutic communication was based on the assumption that patients in such an extreme medical situation enter a natural trance-like state with elevated suggestibility. The anaesthesiologist acted as a continuous guide, using a strong rapport, nonverbal communication, hypnotic suggestions, such as dissociation to a "safe place", and the reframing of disturbing noises, while simultaneously avoiding negative suggestions. Analgesics or sedatives were at hand according to the principle "as much as necessary, but not more than needed".

RESULTS

No sedation was necessary for any of the patients besides for the treatment of seizures. Only two-thirds of the patients requested remifentanil, with a mean dosage of 96 μg before the end of tumour resection and a total of 156 μg. Hemodynamic reactions indicative of stress were mainly seen during nerve blockades and neurological testing. Postoperative vigilance tests showed equal or higher scores than preoperative tests.

CONCLUSIONS

The main challenges for patients undergoing awake craniotomies include anxiety and fears, terrifying noises and surroundings, immobility, loss of control, and the feeling of helplessness and being left alone. In such situations, psychological support might be more helpful than the pharmacological approach. With adequate therapeutic communication, patients do not require any sedation and no or only low-dose opioid treatment during awake craniotomies, leaving patients fully awake and competent during the entire surgical procedure without stress. This approach can be termed "awake-awake-awake-technique".

Awake craniotomy for tumor resection

Surgical treatment of brain tumors, especially those located in the eloquent areas such as anterior temporal, frontal lobes, language, memory areas, and near the motor cortex causes high risk of eloquent impairment. Awake craniotomy displays major rule for maximum resection of the tumor with minimum functional impairment of the Central Nervous System. These case reports discuss the use of awake craniotomy during the brain surgery in Alzahra Hospital, Isfahan, Iran. A 56-year-old woman with left-sided body hypoesthesia since last 3 months and a 25-year-old with severe headache of 1 month duration were operated under craniotomy for brain tumors resection. An awake craniotomy was planned to allow maximum tumor intraoperative testing for resection and neurologic morbidity avoidance. The method of anesthesia should offer sufficient analgesia, hemodynamic stability, sedation, respiratory function, and also awake and cooperative patient for different neurological test. Airway management is the most important part of anesthesia during awake craniotomy. Tumor surgery with awake craniotomy is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit.

Dexmedetomidine: current role in anesthesia and intensive care

BACKGROUND AND OBJECTIVES

To update and review the application of dexmedetomidine in anesthesia and intensive care. This study is a comprehensive review of clinical uses, pharmacology, pharmacokinetics, mechanism of action and adverse effects of dexmedetomidine.

CONTENT

The effective use of sedative-hypnotic agents and analgesics is an integral part of comfort and safety of patients. Dexmedetomidine is a potent and highly selective α-2 adrenoceptor agonist with sympatholytic, sedative, amnestic, and analgesic properties, which has been described as a useful and safe adjunct in many clinical applications. It provides a unique "conscious sedation", analgesia, without respiratory depression. The current reviewed uses include sedation at Intensive Care Unit-ICU (both adult and pediatric), emergency department, regional and general anesthesia, neurosurgery, sedation for pediatric procedures, awake fiber-optic intubation, cardiac surgery and bariatric surgery.

CONCLUSIONS

Dexmedetomidine offers a unique ability of providing both sedation and analgesia without respiratory depression. It is a new agent with a wide safety margin, excellent sedative capacity and moderate analgesic properties. Although its wide use is currently in patients of surgical and non-surgical intensive care units, dexmedetomidine seems to have promising future applications in neuroprotection, cardioprotection and renoprotection. More detailed studies are required to define its role as sedative in critical, neurosurgical and pediatric patients, as anesthesia adjunct and sedative during procedures.

Development of a safe and pragmatic awake craniotomy program at Maine Medical Center

BACKGROUND

Awake craniotomy offers an excellent means of performing intraoperative mapping and optimizing surgical resection of brain tumors. Awake craniotomy relies on a strong collaboration between anesthesiologists, neurosurgeons, and operating room staff. The authors recently introduced awake craniotomy for tumor resection at the Maine Medical Center and propose that it can be performed safely, effectively, and efficiently in a high-volume community hospital.

METHODS

We describe a practical approach to performing awake craniotomy involving streamlined anesthetic protocols and simplified intraoperative testing parameters in a carefully selected group of patients. Our first 25 patients are retrospectively reviewed with particular attention to the anesthetic protocol, the extent of resection, the operative time, post-operative complications, the length of hospitalization, and their functional status at follow-up.

RESULTS

The authors established an anesthetic protocol based primarily on midazolam, fentanyl, propofol, and local anesthetic. The authors note that all but one patient was able to tolerate the awake procedure. Gross total resection was achieved in nearly 80% of patients with a glial tumor. Operative time was short, averaging 159 minutes of entire anesthesia care. Length of stay averaged 3.7 days. Persistent new post-operative deficits were noted in 2 of 25 patients. There was no substantial difference in total hospital charges for patients undergoing awake craniotomy when compared to a matched historical control.

CONCLUSIONS

With attention focused on patient selection and a streamlined anesthetic protocol, the authors were able to successfully implement an awake craniotomy protocol in a community setting with satisfying results, including low operative morbidity, short operative times, low anesthetic complications, and excellent patient tolerance.

Language testing during awake "anesthesia" in a bilingual patient with brain lesion adjacent to Wernicke's area

Awake "anesthesia" is the preferable anesthetic approach for neurosurgical procedures that require intraoperative localization of eloquent brain areas. We describe intraoperative inducible selective English aphasia in a bilingual (English and Italian) patient undergoing awake anesthesia for excision of a brain lesion adjacent to Wernicke's area with no postoperative neurological sequelae. We discuss the importance of intraoperative brain mapping and intraoperative language testing in bilingual patients to prevent iatrogenic-related morbidity.

Propofol decreases neuronal population spiking activity in the subthalamic nucleus of Parkinsonian patients

BACKGROUND

Implantation of deep brain stimulation (DBS) electrodes in the subthalamic nucleus (STN) for the treatment of Parkinson disease is often performed using microelectrode recording (MER) of STN population spike activity. The extent to which sedative drugs interfere with MER is unknown. We recorded the population activity of STN neurons during propofol sedation and examined its effect on neuronal activity.

METHODS

The procedure was performed during DBS surgery for Parkinson disease. We administered propofol (50 μg/kg/min) at a constant electrode location in the STN until stable sedation was achieved. We recorded the electrical activity, and calculated its root mean square (RMS) before, during, and after the propofol infusions.

RESULTS

The activity of 24 electrode trajectories was recorded in 16 patients. The RMS of STN activity decreased significantly after propofol administration in 18 of the 24 trajectories. The average normalized RMS decreased by 23.2%± 9.1% (mean ± SD) during propofol administration (P < 0.001), and returned to baseline 9.3 ± 4.0 minutes after it was stopped.

CONCLUSIONS

Propofol administration leads to a significant decrease of STN neuronal activity. Thus, it may interfere with MER identification of the STN borders. However, activity returns to baseline shortly after administration stops. Therefore, propofol can be safely used until shortly before MER for DBS.

A randomized, controlled trial on dexmedetomidine for providing adequate sedation and hemodynamic control for awake, diagnostic transesophageal echocardiography

OBJECTIVE

Transesophageal echocardiography (TEE) has become established as a sensitive and accurate diagnostic method for the rapid assessment of myocardial function. It was theorized that dexmedetomidine (Precedex; Hospira, Inc, Lake Forest, IL) might prove to be useful for sedating patients while undergoing TEE.

DESIGN

A prospective, randomized trial was designed comparing dexmedetomidine versus standard therapy (eg, midazolam and opioids) for sedation.

SETTING

This trial was performed in a tertiary care, single-institution university hospital.

PARTICIPANTS

Males and females, American Society of Anesthesiologists I to IV, ages 18 to 65 years, requiring diagnostic TEE. Patients were excluded if pregnant, if they had taken benzodiazepines or opioids within 24 hours, or if they were deemed to be too unstable to receive any kind of sedation.

INTERVENTIONS

Patients were randomized to standard therapy or dexmedetomidine infusion groups. Sedation was assessed at 6 time points. Pulse oximetry, electrocardiogram, heart rate, noninvasive blood pressure, and respiratory rate were monitored. Additional variables measured were the amount of each drug given, the time of the TEE procedure, and the time to recovery.

MEASUREMENTS AND MAIN RESULTS

A survey about the quality of sedation, the level of comfort, and whether or not they would accept this type of sedation again was administered after recovery from sedation. Demographic data and patient questionnaire responses were reported as means and standard errors or percents and were analyzed with the t test and chi-square test. Twenty-two patients were enrolled. Hemodynamics were statistically different between the two groups at several time points. Both systolic and diastolic blood pressures (BP) were elevated in the standard therapy group, whereas the dexmedetomidine group had a lower BP. Heart rate was elevated significantly in the standard therapy group compared with the dexmedetomidine group. There was no statistical or clinical difference between the groups in terms of oxygenation or respiratory rate.

CONCLUSIONS

The authors concluded that dexmedetomidine appears equivalent in achieving adequate levels of sedation without increasing the rate of respiratory depression or decreasing oxygen saturation compared with standard therapy, and it may be better in achieving desired hemodynamic results.

'Anesthesia' for awake neurosurgery

PURPOSE OF REVIEW

In this review we focus on recent findings in the anesthetic management of patients undergoing craniotomy while awake, and propose a structured approach to the clinical practice of 'anesthesia' for awake neurosurgery.

RECENT FINDINGS

The increasing use of functional neurosurgery and recent evidence favoring resection of tumor involving eloquent cortex has expanded the indications for awake craniotomy, a procedure needing a fully cooperative patient and expert intraoperative anesthetic management. Despite the shorter hospital stay, the more recently published studies have highlighted perioperative anesthetic complications and have proposed ways to improve anesthesia techniques for awake procedures in adults and children.

SUMMARY

Although anesthesia for awake craniotomy is usually a well tolerated procedure it requires an extensive knowledge of the principles underlying neuroanesthesia and of specific technical strategies including local anesthesia for scalp blockade, advanced airway management, dedicated sedation protocols, and skillful management of hemodynamics.

[Scalp blocks. A useful technique for neurosurgery, dermatology, plastic surgery and pain therapy]

Safe and effective cranial analgesia can be achieved by blocking the sensitive nerves of that region. These include the supraorbital nerve, the supratrochlear nerve, the zygomaticotemporal nerve, the auriculotemporal nerve and the greater and lesser occipital nerves which are accessible at typical and most proximal points. Preferably long acting local anesthetics such as ropivacaine 0.75% or levobupivacaine 0.5% are used supplemented with 5 microg/ml epinephrine to reduce systemic resorption and to elongate the duration. Scalp blocks are useful for intraoperative neurologic testing of the patient during awake craniotomy or for supplementation of general anesthesia for other forms of craniotomy. Other applications are minimally invasive and stereotactic neurosurgery including deep brain stimulation, photodynamic therapy of actinic ceratosis, cranial plastic surgery and pain therapy.

Awake craniotomy

Awake craniotomy has become an increasingly frequent procedure. In this paper, the principles of its anaesthetic management are reviewed. The means allowing achievement of anaesthetic objectives are described, with emphasis on points that determine success of the procedure. A careful and adequate selection and preparation of patients are mandatory, and the intervening team must be a skilled team. Choosing an awake technique or general anaesthesia depends on several factors, including the risk of obstructive apnoea, seizures, nausea and vomiting, patient's ability to cooperate, and localization of lesions. The main challenge of intraoperative anaesthetic management relies on the ability of rapidly adjusting the level of sedation and analgesia according to the sequence of surgical events, while ensuring haemodynamic stability, adequate ventilation, and minimal interference with eventual electrophysiological recordings. Throughout the procedure, complications must be anticipated and managed according to predefined guidelines. More prospective randomized clinical trials are still needed to improve safety and efficacy of awake craniotomies, as well as to validate this technique in comparison with more conventional anaesthetic management.

Inflammatory profile of awake function-controlled craniotomy and craniotomy under general anesthesia

Background. Surgical stress triggers an inflammatory response and releases mediators into human plasma such as interleukins (ILs). Awake craniotomy and craniotomy performed under general anesthesia may be associated with different levels of stress. Our aim was to investigate whether those procedures cause different inflammatory responses. Methods. Twenty patients undergoing craniotomy under general anesthesia and 20 patients undergoing awake function-controlled craniotomy were included in this prospective, observational, two-armed study. Circulating levels of IL-6, IL-8, and IL-10 were determined pre-, peri-, and postoperatively in both patient groups. VAS scores for pain, anxiety, and stress were taken at four moments pre- and postoperatively to evaluate physical pain and mental duress. Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups. Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia.