Predictor role of heart rate variability in subarachnoid hemorrhage: A systematic review.

Background- Subarachnoid hemorrhage (SAH) is one of the most devastating diseases with a high rate of morbidity and mortality. The heart rate variability (HRV) is a non-invasive method of monitoring various components of the autonomic nervous system activity that can be utilized to delineate autonomic dysfunctions associated with various physiological and pathological conditions. The reliability of HRV as a predictor of clinical outcome in aneurysmal subarachnoid hemorrhage (aSAH) is not yet well investigated in literature. Methods- A systematic review and in depth analysis of 10 articles on early HRV changes in SAH patients was performed. Results- This systematic review demonstrates a correlation between early changes in HRV indices (time and frequency domain) and the development of neuro-cardiogenic complications and poor neurologic outcome in patients with SAH. Conclusions- A correlation between absolute values or changes of the LF/HF ratio and neurologic and cardiovascular complications was found in multiple studies. Because of significant limitations of included studies, a large prospective study with proper handling of confounders is needed to generate high-quality recommendations regarding HRV as a predictor of post SAH complications and poor neurologic outcome.

Effects of Anesthetic Agents on Blood Brain Barrier Integrity: A Systematic Review.

BACKGROUND: The blood brain barrier (BBB) is a highly selective permeable barrier that separates the blood and the central nervous system. Anesthesia is an integral part of surgery, and there is little known about the impact of anesthetics on the BBB. Therefore, it is imperative to explore reversible or modifiable variables such as anesthetic agents that influence BBB integrity. We aimed to synthesize the literature pertaining to the various effects of anesthetics on the BBB. METHODS: MEDLINE, Embase, and Cochrane were searched from inception up to September 2022. RESULTS: A total of 14 articles met inclusion into the review. The articles included nine randomized control studies (64.3%) and five quasi-experimental studies (35.7%). Twelve studies used volatile anesthetics, one study used fentanyl intravenously, and one study used pentobarbital or ketamine intraperitoneally. BBB structural deficits following the administration of an anesthetic agent included ultrastructural deficits, decreases in tight junctions, and decreases in BBB components. BBB functional deficits included permeability increases following exposure to volatile anesthetics. However, two studies found decreased permeability after fentanyl, pentobarbital, or ketamine exposure. Moreover, the impact of anesthetics on the BBB seems to be related to the duration of exposure. Notably, study findings also suggest that changes following anesthetic exposure demonstrate some reversibility over the short-term. CONCLUSION: Overall, our systematic review highlights interesting findings pertaining to the impact of anesthetic agents on BBB integrity in previously healthy models. These findings and mechanisms should inspire future work to aid practitioners and healthcare teams potentially better care for patients.

Anesthetic consideations for endovascular treatment of acute ischemic stroke.

PURPOSE: The purpose of this Continuing Professional Development module is to provide information pertaining to anesthetic considerations and management of endovascular thrombectomy (EVT) for patients with acute ischemic stroke. PRINCIPAL FINDINGS: Acute ischemic stroke is a devastating neurologic disorder and timely intervention is key to a good neurologic outcome. This article provides an overview of three important concepts: pathophysiology and disease characteristics of acute ischemic stroke, and the procedural and anesthetic aspects of EVT. Key considerations include recognition of stroke symptoms, timing and urgency of intervention, procedural considerations for anesthesiologists, risks and benefits of different anesthetic techniques, and a summary of recent guidelines. In particular, current recommendations for blood pressure management in this setting are reviewed. CONCLUSIONS: Timely intervention for patients with acute ischemic stroke is of utmost importance. Endovascular thrombectomy is a minimally invasive procedure that has evolved over recent decades and improves outcomes for selected patients with ischemic stroke. Anesthesiologists should have a good understanding of potential complications and anesthetic options. Recent randomized trials have shown that both general anesthesia and sedation are associated with good outcomes; the anesthetic approach should be individualized and may vary by institution. Careful monitoring and maintenance of hemodynamic goals are critical, as is effective communication with the multidisciplinary team.

RéSUMé: OBJECTIF: L'objectif de ce module de développement professionnel continu est de fournir des informations sur les considérations anesthésiques et la prise en charge de la thrombectomie endovasculaire (TEV) chez les patients atteints d'AVC ischémique aigu. CONSTATATIONS PRINCIPALES: L'AVC ischémique aigu est un trouble neurologique dévastateur; une intervention rapide est la clé d'un bon devenir neurologique. Cet article donne un aperçu de plusieurs concepts importants : la physiopathologie et les caractéristiques pathologiques de l'AVC ischémique aigu, ainsi que les aspects procéduraux et anesthésiques de la TEV. Les principales considérations comprennent la reconnaissance des symptômes de l'AVC, le moment et l'urgence de l'intervention, les considérations procédurales pour les anesthésiologistes, les risques et les avantages des différentes techniques d'anesthésie, et un résumé des lignes directrices récentes. Plus spécifiquement, nous passerons en revue les recommandations actuelles pour la prise en charge de la pression artérielle dans un tel contexte. CONCLUSIONS: Une intervention rapide est essentielle pour les patients atteints d'AVC ischémique aigu. La thrombectomie endovasculaire est une procédure minimalement invasive qui a évolué au cours des dernières décennies et qui améliore les devenirs de certains patients atteints d'AVC ischémique. Les anesthésiologistes doivent avoir une bonne compréhension des complications potentielles et des options anesthésiques. Des études randomisées récentes ont montré que l'anesthésie générale et la sédation sont associées à de bons pronostics; l'approche anesthésique devrait être personnalisée et peut varier d'un établissement à l'autre. Un monitorage attentif et le maintien des cibles hémodynamiques sont essentiels, tout comme une communication efficace avec l'équipe multidisciplinaire.

Perioperative adverse cardiac events in maxillofacial surgery: A systematic review and meta-analysis.

Background and Aims: Maxillofacial surgeries, including procedures to the face, oral cavity, jaw, and head and neck, are common in adults. However, they impose a risk of adverse cardiac events (ACEs). While ACEs are well understood for other non-cardiac surgeries, there is a paucity of data about maxillofacial surgeries. This systematic review and meta-analysis report the incidence and presentation of perioperative ACEs during maxillofacial surgery. Methods: We included primary studies that reported on perioperative ACEs in adults. To standardise reporting, ACEs were categorised as 1. heart rate and rhythm disturbances, 2. blood pressure disturbances, 3. ischaemic heart disease and 4. heart failure and other complications. The primary outcome was ACE presentation and incidence during the perioperative period. Secondary outcomes included the surgical outcome according to the Clavien-Dindo classification and trigeminocardiac reflex involvement. STATA version 17.0 and MetaProp were used to delineate proportion as effect size with a 95% confidence interval (CI). Results: Twelve studies (34,227 patients) were included. The incidence of perioperative ACEs was 2.58% (95% CI 1.70, 3.45, I2 = 96.17%, P = 0.001). Heart rate and rhythm disturbances resulted in the greatest incidence at 3.84% among the four categories. Most commonly, these ACEs resulted in intensive care unit admission (i.e. Clavien-Dindo score of 4). Conclusion: Despite an incidence of 2.58%, ACEs can disproportionately impact surgical outcomes. Future research should include large-scale prospective studies that may provide a better understanding of the contributory factors and long-term effects of ACEs in patients during maxillofacial surgery.

Sumatriptan for Postcraniotomy Headache after Minimally Invasive Craniotomy for Clipping of Aneurysms: A Prospective Randomized Controlled Trial.

Introduction Postcraniotomy headaches are often underestimated and undertreaded. This study aimed to identify if postoperative administration of sumatriptan after minimally invasive craniotomy for clipping an unruptured aneurysm could reduce postcraniotomy headache and improve the quality of postoperative recovery. Settings and Design Tertiary care center, single-center randomized double-blind placebo-controlled trial. Materials and Methods Patients who complained of postoperative headaches after minimally invasive craniotomy for clipping of unruptured aneurysms were randomized to receive subcutaneous sumatriptan (6 mg) or placebo. The primary outcome was the quality of recovery measured 24 hours after surgery. Secondary outcomes were total opioid use and headache score at 24 hours after surgery. Data were analyzed using a Student's t -test or the chi-square test. Results Forty patients were randomized to receive sumatriptan ( n = 19) or placebo ( n = 21). Both groups had similar demographics, comorbidities, and anesthesia management. The Quality of Recovery 40 score was higher for patients receiving sumatriptan compared to placebo, however, not statistically significant (173 [156-196] vs. 148 [139-181], p = 0.055). Postoperative opioid use between sumatriptan and placebo was lower, but not significant (5.4 vs. 5.6 mg morphine equivalent, p = 0.71). The severity of headache was also not statistically different between the two groups (5 [4-5] vs. 4 [2-5], p = 0.155). Conclusion In patients undergoing minimally invasive craniotomies for aneurysm clipping, sumatriptan given postoperatively has a nonsignificant trend for a higher quality of recovery. Similarly, there was a nonsignificant trend toward lower postcraniotomy headache scores and opioid scores for the patient given sumatriptan.

The role of heart rate variability in predicting delirium: A systematic review and meta-analysis.

Brain and heart interact through multiple ways. Heart rate variability, a non-invasive measurement is studied extensively as a predicting model for various health conditions including subarachnoid hemorrhage, cancer, and diabetes. There is limited evidence to predict delirium, an acute fluctuating disorder of brain dysfunction, as it poses a significant challenge in the intensive care unit (ICU) and post-operative setting. In this systematic review of 9 articles, heart rate variability indices were used to investigate the occurrence of post-operative and ICU delirium. This systematic review and meta-analysis reveal evidence of a strong predilection between postoperative and intensive care unit delirium and alterations in the heart rate variability, measured by mean differences for standard deviation of NN-intervals. Other heart rate variability indices [root mean squares of successive differences, low-frequency (LF), high-frequency (HF), and LF:HF ratio] showed lack of or very weak association. A non-invasive tool of brain and heart interaction may refine diagnostic predictions for acute brain dysfunctions like delirium in such population and would be an important step in delirium research.

Variability of Resting Carbon Dioxide Tension in Patients with Intracranial Steno-occlusive Disease.

Introduction Controlling the partial pressure of carbon dioxide (PaCO 2 ) is an important consideration in patients with intracranial steno-occlusive disease to avoid reductions in critical perfusion from vasoconstriction due to hypocapnia, or reductions in blood flow due to steal physiology during hypercapnia. However, the normal range for resting PCO 2 in this patient population is not known. Therefore, we investigated the variability in resting end-tidal PCO 2 (P ET CO 2 ) in patients with intracranial steno-occlusive disease and the impact of revascularization on resting P ET CO 2 in these patients. Setting and Design Tertiary care center, retrospective chart review Materials and Methods We collected resting P ET CO 2 values in adult patients with intracranial steno-occlusive disease who presented to our institution between January 2010 and June 2021. We also explored postrevascularization changes in resting P ET CO 2 in a subset of patients. Results Two hundred and twenty-seven patients were included [moyamoya vasculopathy ( n = 98) and intracranial atherosclerotic disease ( n = 129)]. In the whole cohort, mean ± standard deviation resting P ET CO 2 was 37.8 ± 3.9 mm Hg (range: 26-47). In patients with moyamoya vasculopathy and intracranial atherosclerotic disease, resting P ET CO 2 was 38.4 ± 3.6 mm Hg (range: 28-47) and 37.4 ± 4.1 mm Hg (range: 26-46), respectively. A trend was identified suggesting increasing resting P ET CO 2 after revascularization in patients with low preoperative resting P ET CO 2 (<38 mm Hg) and decreasing resting P ET CO 2 after revascularization in patients with high preoperative resting P ET CO 2 (>38 mm Hg). Conclusion This study demonstrates that resting P ET CO 2 in patients with intracranial steno-occlusive disease is highly variable. In some patients, there was a change in resting P ET CO 2 after a revascularization procedure.

Early Cardiac Evaluation, Abnormal Test Results, and Associations with Outcomes in Patients with Acute Brain Injury Admitted to a Neurocritical Care Unit.

Background: to examine factors associated with cardiac evaluation and associations between cardiac test abnormalities and clinical outcomes in patients with acute brain injury (ABI) due to acute ischemic stroke (AIS), spontaneous subarachnoid hemorrhage (SAH), spontaneous intracerebral hemorrhage (sICH), and traumatic brain injury (TBI) requiring neurocritical care. Methods: In a cohort of patients ≥18 years, we examined the utilization of electrocardiography (ECG), beta-natriuretic peptide (BNP), cardiac troponin (cTnI), and transthoracic echocardiography (TTE). We investigated the association between cTnI, BNP, sex-adjusted prolonged QTc interval, low ejection fraction (EF < 40%), all-cause mortality, death by neurologic criteria (DNC), transition to comfort measures only (CMO), and hospital discharge to home using univariable and multivariable analysis (adjusted for age, sex, race/ethnicity, insurance carrier, pre-admission cardiac disorder, ABI type, admission Glasgow Coma Scale Score, mechanical ventilation, and intracranial pressure [ICP] monitoring). Results: The final sample comprised 11,822 patients: AIS (46.7%), sICH (18.5%), SAH (14.8%), and TBI (20.0%). A total of 63% (n = 7472) received cardiac workup, which increased over nine years (p < 0.001). A cardiac investigation was associated with increased age, male sex (aOR 1.16 [1.07, 1.27]), non-white ethnicity (aOR), non-commercial insurance (aOR 1.21 [1.09, 1.33]), pre-admission cardiac disorder (aOR 1.21 [1.09, 1.34]), mechanical ventilation (aOR1.78 [1.57, 2.02]) and ICP monitoring (aOR1.68 [1.49, 1.89]). Compared to AIS, sICH (aOR 0.25 [0.22, 0.29]), SAH (aOR 0.36 [0.30, 0.43]), and TBI (aOR 0.19 [0.17, 0.24]) patients were less likely to receive cardiac investigation. Patients with troponin 25th-50th quartile (aOR 1.65 [1.10-2.47]), troponin 50th-75th quartile (aOR 1.79 [1.22-2.63]), troponin >75th quartile (aOR 2.18 [1.49-3.17]), BNP 50th-75th quartile (aOR 2.86 [1.28-6.40]), BNP >75th quartile (aOR 4.54 [2.09-9.85]), prolonged QTc (aOR 3.41 [2.28; 5.30]), and EF < 40% (aOR 2.47 [1.07; 5.14]) were more likely to be DNC. Patients with troponin 50th-75th quartile (aOR 1.77 [1.14-2.73]), troponin >75th quartile (aOR 1.81 [1.18-2.78]), and prolonged QTc (aOR 1.71 [1.39; 2.12]) were more likely to be associated with a transition to CMO. Patients with prolonged QTc (aOR 0.66 [0.58; 0.76]) were less likely to be discharged home. Conclusions: This large, single-center study demonstrates low rates of cardiac evaluations in TBI, SAH, and sICH compared to AIS. However, there are strong associations between electrocardiography, biomarkers of cardiac injury and heart failure, and echocardiography findings on clinical outcomes in patients with ABI. Findings need validation in a multicenter cohort.

Perioperative considerations for neurosurgical procedures in the gravid patient: Continuing Professional Development.

PURPOSE: The complexity of neurosurgical procedures and their interactions with maternal and fetal physiologies are key factors in determining the overall maternal and fetal outcome. The literature and guidelines provide only partial information regarding the standard of care in these cases. The purpose of this Continuing Professional Development module is to review the issues related to common neurosurgical conditions and their optimal anesthetic management. PRINCIPAL FINDINGS: The most common neurosurgical conditions found in pregnancy include brain tumours, cerebrovascular diseases, spinal pathologies, and neurotrauma. Though rare, these conditions and related procedures may affect maternal and fetal outcome. Maternal considerations should be given priority in cases of emergent surgeries irrespective of trimester. In the early first trimester, risk of fetal loss and congenital malformation are substantial; hence, proper counselling should be given to the mother with special emphasis on therapeutic abortion. When indicated, anticonvulsants should be started as early as possible and continued throughout pregnancy. Surgical procedures can be performed with relative safety during the second trimester and early third trimester. After 34 weeks, delivery seems to be the first choice, and the role of regional anesthesia in this situation should be carefully planned after proper review of neurosurgical pathology and maternal condition. During acute neurological deterioration, however, Cesarean delivery under general anesthesia should be anticipated. CONCLUSION: A multidisciplinary approach with good communication amongst all team members certainly plays a crucial role for successful management of such cases.

Perioperative variables contributing to the rupture of intracranial aneurysm: an update.

BACKGROUND: Perioperative aneurysm rupture (PAR) is one of the most dreaded complications of intracranial aneurysms, and approximately 80% of nontraumatic SAHs are related to such PAR aneurysms. The literature is currently scant and even controversial regarding the issues of various contributory factors on different phases of perioperative period. Thus this paper highlights the current understanding of various risk factors, variables, and outcomes in relation to PAR and try to summarize the current knowledge. METHOD: We have performed a PubMed search (1 January 1991-31 December 2012) using search terms including "cerebral aneurysm," "intracranial aneurysm," and "intraoperative/perioperative rupture." RESULTS: Various risk factors are summarized in relation to different phases of perioperative period and their relationship with outcome is also highlighted. There exist many well-known preoperative variables which are responsible for the highest percentage of PAR. The role of other variables in the intraoperative/postoperative period is not well known; however, these factors may have important contributory roles in aneurysm rupture. Preoperative variables mainly include natural course (age, gender, and familial history) as well as the pathophysiological factors (size, type, location, comorbidities, and procedure). Previously ruptured aneurysm is associated with rupture in all the phases of perioperative period. On the other hand intraoperative/postoperative variables usually depend upon anesthesia and surgery related factors. Intraoperative rupture during predissection phase is associated with poor outcome while intraoperative rupture at any step during embolization procedure imposes poor outcome. CONCLUSION: We have tried to create such an initial categorization but know that we cannot scale according to its clinical importance. Thorough understanding of various risk factors and other variables associated with PAR will assist in better clinical management as well as patient care in this group and will give insight into the development and prevention of such a catastrophic complication in these patients.

Role of colloids in traumatic brain injury: Use or not to be used?

Trauma is a leading cause of death worldwide and traumatic brain injury is one of the commonest injuries associated with it. The need for urgent resuscitation is warranted for prevention of secondary insult to brain. However, the choice of fluid in such cases is still a matter of conflict. The literature does not provide enough data pertaining to role of colloids in head injury patients. In this article, we have tried to explore the present role of colloid resuscitation in patient with head injury.

Predicting difficult laryngoscopy in acromegalic patients undergoing surgery for excision of pituitary tumors: A comparison of extended Mallampati score with modified Mallampati classification.

BACKGROUND: There are numerous reports of difficult laryngoscopy and intubation in patients with acromegaly. To date, no study has assessed the application of extended Mallampati score (EMS) for predicting difficult intubation in acromegalics. The primary aim of this study was to compare EMS with modified Mallampati classification (MMP) in predicting difficult laryngoscopy in acromegalic patients. We hypothesized that since EMS has been reported to be more specific and better predictor than MMP, it may be superior to the MMP to predict difficult laryngoscopy in acromegalic patients. MATERIALS AND METHODS: For this prospective cohort study with matched controls, acromegalic patients scheduled to undergo pituitary surgery over a period of 3 years (January 2008-December 2010) were enrolled. Preoperative airway assessment was performed by experienced anesthesiologists and involved a MMP and the EMS. Under anesthesia, laryngoscopic view was assessed using Cormack-Lehane (CL) grading. MMP and CL grades of I and II were defined "easy" and III and IV as "difficult". EMS grade of I and II were defined "easy" and III as "difficult". Data were used to determine the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MMP and EMS in predicting difficult laryngoscopy. RESULTS: Seventy eight patients participated in the study (39 patients in each group). Both MMP and EMS failed to detect difficult laryngoscopy in seven patients. Only one laryngoscopy was predicted to be difficult by both tests which was in fact, difficult. CONCLUSION: We found that addition of neck extension did not improve the predictive value of MMP.

Feasibility of intraoperative MRI for endovascular coiling of intracranial aneurysms: A single centre experience.

BACKGROUND: Intraoperative magnetic resonance imaging system (iMRIS) surgical theatre is a highly integrated operating room with an intraoperative magnetic resonance imaging (iMRI) designed originally for brain tumour surgery. Its use in neurointerventional procedures, particularly in the setting of endovascular coiling of intracranial aneurysms, has not been discussed in the literature to date. We present our initial experience about the safety and feasibility of iMRI to assess post operative complications and provide baseline imaging post coiling of intracranial aneurysms. METHODS: Consecutive patients who underwent iMRI between 2015 and 2018 were included in the study. Demographic, clinical details, endovascular technique and surgical outcomes were collected. Details of anesthesia during the procedure were also collected. RESULTS: Fifteen patients underwent iMRI with MRA to assess post coiling status of their elective endovascular coiling of intracranial aneurysms. The mean age in this cohort was 61 years and 46.7% were male. No immediate complications were seen either from the endovascular procedures or from the iMRI. All iMRI scans were performed as planned with no aborted or truncated scans. The image quality of the iMRI/MRA was adequate to detect the residual aneurysm, if present. There was no residual aneurysm on the angiogram that were not detected on the iMRIs. Of the 15 patients, 10 were safely discharged the following day and other 5 were discharged 2 days after their surgery. CONCLUSIONS: The iMRI is an advantageous tool which can be integrated into neurointerventional workflow resulting in early post peri-procedural feedback and potentially reduced post-operative hospital stay.

Postoperative cognitive recovery and prevention of postoperative cognitive complications in the elderly patient.

Elderly patients undergoing surgery are at higher risk of life-altering and costly complications. This challenge is increasingly recognized with the growing geriatric surgical population. Advanced age and comorbid conditions, such as disability and frailty that often develop with age, are all independent risk factors of postoperative morbidity and mortality. A common factor in this age group is cognitive impairment, which poses a challenge for the patient and clinician in the perioperative setting. It affects the capacity for informed consent and limits optimization before surgery; furthermore, an existing impairment may progress in severity during the perioperative period, and new onset of signs of delirium or postoperative cognitive dysfunction may arise during postoperative recovery. In this article, we aim to review the current literature examining the latest definitions, diagnostic criteria, and preventive strategies that may ameliorate postoperative cognitive complications.

The elderly in the post-anesthesia care unit.

It is increasingly conceivable that elderly patients will be treated in perioperative settings as the world's population shifts toward an older age distribution. They are more prone to a variety of unfavorable outcomes as a consequence of the physiological changes that accompany aging and the coexistence of multiple medical conditions. Postoperative complications in elderly patients are linked to a large increase in morbidity and mortality and the burden placed on the healthcare system. Our goal is to determine how elderly patients' recovery after anesthesia differs from that of younger patients. In addition, we will discuss the main postoperative complications experienced by elderly patients and the measures that are utilized to limit the risk of these complications developing.

Role of midazolam on cancer progression/survival - An updated systematic review.

Background and Aims: Cancer is a leading cause of mortality worldwide. Despite advancements in cancer management, cancer progression remains a challenge, requiring the development of novel therapies. Midazolam is a commonly used adjunct to anaesthesia care for various surgeries, including cancer. Recently, there has been a growing interest in exploring the potential role of midazolam as an anticancer agent; however, the exact mechanism of this linkage is yet to be investigated thoroughly. Methods: Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, this systematic review presented aggregated evidence (till November 2022) of the effects of midazolam on cancer progression and survival. All primary research article types where midazolam was administered in vivo or in vitro on subjects with cancers were included. No restrictions were applied on routes of administration or the type of cancer under investigation. Narrative synthesis depicted qualitative findings, whereas frequencies and percentages presented numerical data. Results: Of 1720 citations, 19 studies were included in this review. All articles were preclinical studies conducted either in vitro (58%, 11/19) or both in vivo and in vitro (42%, 8/19). The most studied cancer was lung carcinoma (21%, 4/19). There are two main findings in this review. First, midazolam delays cancer progression (89%, 17/19). Second, midazolam reduces cancer cell survival (63%, 12/19). The two major mechanisms of these properties can be explained via inducing apoptosis (63%, 12/19) and inhibiting cancer cell proliferation (53%, 10/19). In addition, midazolam demonstrated antimetastatic properties via inhibition of cancer invasion (21%, 4/19), migration (26%, 5/19), or epithelial-mesenchymal transition (5%, 1/19). These anticancer properties of midazolam were demonstrated through different pathways when midazolam was used alone or in combination with traditional cancer chemotherapeutic agents. Conclusion: This systematic review highlights that midazolam has the potential to impede cancer progression and decrease cancer cell survival. Extrapolation of these results into human cancer necessitates further investigation.

Emergence Patterns from General Anesthesia after Epilepsy Surgery: An Observational Pilot Study.

Objective Emergence from anesthesia starts from the limbic structures and then spreads outwards to brainstem, reticular activating systems, and then to the cortex. Epilepsy surgery often involves resection of limbic structures and hence may disrupt the pattern of emergence. The aim of this study was to explore the pattern of emergence from anesthesia following epilepsy surgery and to determine associated variables affecting the emergence pattern. Setting and Design Tertiary care center, prospective observational study. Materials and Methods We conducted a prospective observation pilot study on adult patients undergoing anterior temporal lobectomy and amygdalohippocampectomy for epilepsy. Anesthesia management was standardized in all patients, and they were allowed to wake up with "no touch" technique. Primary outcome of the study was the pattern of emergence (normal emergence, agitated emergence, or slow emergence) from anesthesia. Secondary outcomes were to explore the differences in preoperative neuropsychological profile and limbic structure volumes between the different patterns of emergence. Quantitative variables were analyzed using Student's t -test. Qualitative variables were analyzed using chi-square test. Results Twenty-nine patients completed the study: 9 patients (31%) had agitated emergence, and 20 patients had normal emergence. Among the agitated emergence, 2 patients had Riker scale of 7 indicating violent emergence. Patient demographics, anesthetic used, neuropsychological profile, and limbic structure volumes were similar between normal emergence and agitated emergence groups. However, two patients who had severe agitation (Riker scale of 7) had the lowest intelligence quotient. Conclusion Our pilot study showed that emergence agitation is not uncommon in patients undergoing epilepsy surgery. However, due to smaller sample size, the role of preoperative neuropsychologic profile and hippocampal volumes in predicting the pattern of emergence is inconclusive.

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.