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OBJECTIVE: To evaluate whether elevated intraoperative blood glucose concentrations are associated with an increased risk of long-term neurologic dysfunction in patients at risk for ischemic brain injury. PATIENTS AND METHODS: Data from 1000 patients were retrieved from the Intraoperative Hypothermia for Aneurysm Surgery Trial database. All patients were recruited between February 2000 and April 2003, and underwent surgery for aneurysm clipping within 14 days of subarachnoid hemorrhage. Gross neurologic and neuropsychological function was evaluated at 3 months after surgery using certified observers and standardized assessment instruments. Intraoperative blood glucose concentrations, measured once when the aneurysm clip was placed, were correlated with neurologic outcome using both univariable and multivariable logistic regression analyses. RESULTS: Blood glucose concentrations at the time of aneurysm clipping ranged from 59 to 331 mg/dL. At 3 months after surgery, those with blood glucose concentrations of 129 mg/dL or more (upper 2 quartiles) were more likely to have impaired cognition (P=.03). Those with glucose concentrations of 152 mg/dL or more (upper quartile) were more likely to experience deficits in gross neurologic function assessed by the National Institutes of Health Stroke Scale (P<.05), but not other scoring scales. Length of stay in intensive care units was longer in those with glucose concentrations of 129 mg/dL or more, but there was no difference among glucose groups in the duration of overall hospital stay or the fraction of patients discharged to home. CONCLUSION: In patients at high risk for ischemic brain injury, intraoperative hyperglycemia, of a magnitude commonly encountered clinically, was associated with long-term changes in cognition and gross neurologic function. [ABSTRACT FROM AUTHOR]

Further study is needed to determine the safest mode of delivery and anesthetic management for parturients with ventriculoperitoneal shunts (VP). Prior recommendation for delivery in women with ventriculoperitoneal shunts was cesarean delivery. However, both vaginal delivery and neuraxial anesthesia have been shown to be safe in women with appropriately functioning VP shunts. We present a case series of parturients with VP shunt. Parturients with VP shunts were identified and VP shunt placement indications, neurologic symptoms during pregnancy, delivery mode, anesthetic type, and postpartum complications were reviewed. Forty patients were identified, and fifteen women with twenty deliveries were included. Two women experienced neurological symptoms during pregnancy and one required postpartum shunt revision for blurry vision and ataxia. There were ten cesarean deliveries and ten vaginal deliveries (eight normal spontaneous, one vacuum assisted, and one forceps assisted). Assisted vaginal deliveries were performed to decrease Valsalva including the patient with neurological symptoms related to shunt malfunction. Of the vaginal deliveries, six (60%) had epidural analgesia. Anesthesia for cesarean delivery included neuraxial anesthesia (n = 5) and general anesthesia (n = 5). In our cohort, women with VP shunt received neuraxial blockade without complication. Neuraxial techniques should be offered to women with appropriately functioning VP shunt., (© 2024. The Author(s) under exclusive licence to Japanese Society of Anesthesiologists.)

Background and Objectives: Venous air embolism (VAE) can cause significant morbidity and mortality. Prevention and management of VAE include cessation of air entrainment, positioning changes, and hemodynamic support. The degree to which position change and cardiac output (CO) moderate resolution of intracardiac air has not been rigorously studied using contemporary transesophageal echocardiography (TEE)., Methods: This observational cohort-type study aimed to identify the effect of supine vs sitting positioning on the movement and resolution of intracardiac air. In 20 patients undergoing seated neurosurgery, central venous air aspiration catheters were placed through the median basilic vein. TEE was used to estimate the time required for clearance of agitated microbubbles from the right atrium and ventricle in both the supine and sitting position. Estimates of CO were also obtained echocardiographically in each position., Results: Average clearance time was faster in the sitting vs the supine position with no significant difference in CO. A negative correlation between CO and right atrial clearance time across all patients was demonstrated with a Pearson coefficient of -0.4 (95% CI -0.07, -0.65) with P = .02., Conclusion: During VAE, both patient position and CO can significantly affect how bubbles move through intracardiac chambers. However, augmenting CO during VAE may be clinically more feasible, efficient, and productive than changing positioning-especially during crises unless the changing in position is intended to halt the entrainment of air. Further TEE studies of intravascular air movement affected by other position changes (lateral, reverse Trendelenburg) and vasopressors should be considered., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Motor-evoked potential (MEP) monitoring is an electrophysiologic technique useful for testing peripheral motor nerve integrity during cryoablation cases with risk of nerve injury. Previously, neuromonitoring within the magnetic resonance imaging (MRI) suite for cryoablation has not been performed as magnetic needles are used which could cause magnetic field interactions with neuromonitoring leads. We present the first report of a patient who underwent MEP monitoring during MRI-guided cryoablation of a vascular malformation adjacent to the brachial plexus. We demonstrate that MEPs may be safely and accurately performed by interleaving MRI and MEPs during treatment, reducing the risk of postprocedural complications., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 International Anesthesia Research Society.)

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have emerged as an increasingly popular class of medications commonly used for glycemic control in patients with type 2 diabetes mellitus and for weight loss. GLP-1 RAs also have potential benefits in patients with various neurological diseases independent of their glucose-modulating effect. In this focused review, we explore animal and clinical evidence evaluating the impact of GLP-1 RAs in common neurological diseases. Our aim is to provide a basis for hypothesis generation for future studies to assess the role that GLP-1 RAs may have on the nervous system, including implications for the perioperative period., Competing Interests: J.F.P.: Associate editor for the Journal of Neurosurgical Anesthesiology. The remaining authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Remimazolam is a novel ultrashort-acting benzodiazepine that produces sedation by acting as a positive allosteric modulator of the gamma-amino butyric acid-A receptor. Its high water solubility and metabolism via tissue esterases allow for a rapid onset of sedation/anesthesia and prompt arousal despite prolonged use. In addition, the effects of remimazolam can be reversed with flumazenil. This narrative review discusses the role of remimazolam in patients undergoing neurosurgical and neuroradiological procedures, specifically its role during awake craniotomies and compatibility with neuromonitoring. Considerations for remimazolam use in patients with neurological diseases are also highlighted. In addition, the impact of remimazolam on postoperative excitation, risk for postoperative delirium, and delayed neurocognitive recovery are discussed. Although there seems to be a clinical promise for remimazolam based on limited case studies and our own institutional experience of its use, further clinical investigation is warranted to understand the potential impact of remimazolam on surgical and neurological outcomes., Competing Interests: J.J.P. is an Associate Editor of the Journal of Neurosurgical Anesthesiology and Neuroanesthesia Section Editor of Up-To-Date. A.S.A. is a JNA Editorial Board member. The remaining authors have no conflicts of interest to declare., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Patients with recent concussion experience disruption in neurocellular and neurometabolic function that may persist beyond symptom resolution. Patients may require anesthesia to facilitate diagnostic or surgical procedures following concussion; these procedures may or may not be related to the injury that caused the patient to sustain a concussion. As our knowledge about concussion continues to advance, it is imperative that anesthesiologists remain up to date with current principles. This Focused Review will update readers on the latest concussion literature, discuss the potential impact of concussion on perianesthetic care, and identify knowledge gaps in our understanding of concussion., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Positive-pressure myelogram (PPM) is an emerging radiologic study used to localize spinal dural defects. During PPM, cerebrospinal fluid pressure (CSFp) is increased by injecting saline with contrast into the cerebrospinal fluid. This has the potential to increase intracranial pressure and compromise cerebral perfusion., Methods: We performed a retrospective chart review and analysis of 11 patients. The aim was to describe the periprocedural anesthetic management of patients undergoing PPM., Results: All patients underwent PPM with general anesthesia and intra-arterial blood pressure and near-infrared spectroscopy monitoring of regional cerebral tissue oxygen saturation. Mean±SD maximum lumbar CSFp was 58±12 mm Hg. Upon intrathecal injection, mean systolic blood pressure increased from 115±21 to 142±32 mm Hg (P<0.001), diastolic blood pressure from 68±12 to 80±20 mm Hg (P≤0.001), and mean blood pressure from 87±10 to 98±14 mm Hg (P=0.02). Ten of 11 patients received blood pressure augmentation with phenylephrine to minimize the risk of reduced cerebral perfusion secondary to increased CSFp after intrathecal injection. The mean heart rate before and following injection was similar (68±15 vs. 70±15 bpm, respectively; P=0.16). There was a decrease in regional cerebral oxygen saturation after positioning from supine to prone position (79±10% to 74±9%, P=0.02) and a further decrease upon intrathecal injection (75±10% to 69±9%, P≤0.01)., Conclusions: Systemic blood pressure increased following intrathecal injection during PPM, possibly due to a physiologic response to intracranial hypertension/reduced cerebral perfusion or administration of phenylephrine. Regional cerebral oxygen saturation decreased with the change to prone position and further decreased upon intrathecal injection. Cerebral near-infrared spectroscopy has a potential role to monitor the adequacy of cerebral perfusion and guide adjustment of systemic blood pressure during PPM., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Physiological alterations during the perianesthetic period may contribute to secondary neurocognitive injury after a concussion., Methods: Patients exposed to concussion and who received an anesthetic within 90 days were matched to unexposed patients without concussion. Intraoperative and postoperative events were compared. Subgroup analyses assessed relationships among patients with a concussion in the prior 30, 31 to 60, and 61 to 90 days and their respective unexposed matches. To facilitate identification of potential targets for further investigation, statistical comparisons are reported before, as well as after, correction for multiple comparisons., Results: Sixty concussion patients were matched to 176 unexposed patients. Before correction, 28.3% postconcussion versus 14.8% unexposed patients reported postanesthesia care unit pain score≥7 (P=0.02); 16.7% concussion versus 6.5% unexposed patients reported headache within 90 days of anesthesia (P=0.02) and 23.5% of patients who received surgery and anesthesia within 30 days of concussion experienced headache within 90 days of anesthesia compared with 7.1% in the unexposed group (P=0.01). Patients who experienced concussion and had anesthesia between 31 and 60 days after injury had a postanesthesia care unit Richmond Agitation and Sedation Scale score of -1.61±1.29 versus a score of -0.2±0.45 in unexposed patients (P=0.002). After adjusting the P-value threshold for multiple comparisons, the P-value for significance was instead 0.0016 for the overall cohort. Our study revealed no significant associations with application of adjusted significance thresholds., Conclusions: There were no differences in intraoperative and postoperative outcomes in patients with recent concussion compared with unexposed patients. Before correction for multiple comparisons, several potential targets for further investigation are identified. Well-powered studies are warranted., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Despite advances in perioperative neuroscience, there is low interest among anesthesiology trainees to pursue subspecialty training in neuroanesthesiology. We conducted a pilot survey to assess attitudes about neuroanesthesiology fellowship training., Materials and Methods: A confidential survey was distributed to an international cohort of anesthesiology attendings and trainees between January 15, 2017 and February 26, 2017., Results: A total of 463 responses were received. Overall, 309 (67%), 30 (6%), 116 (25%), and 8 (2%) of respondents identified themselves as attendings, fellows, residents, and "other," respectively. In total, 390 (84%) of respondents were from the United States. Individuals typically pursue anesthesiology fellowship training because of interest in the subspecialty, acquisition of a special skill set, and the role of fellowship training in career planning and advancement. Overall, 64% of attendings, 56% of fellows, and 55% of residents favored accreditation of neuroanesthesiology fellowships, although opinion was divided regarding the role of accreditation in increasing interest in the specialty. Respondents believe that increased opportunities for research and greater exposure to neurocritical care and neurological monitoring methods would increase interest in neuroanesthesiology fellowship training. Perceived barriers to neuroanesthesiology fellowship training were perceptions that residency provides adequate training in neuroanesthesiology, that a unique skill set is not acquired, and that there are limited job opportunities available to those with neuroanesthesiology fellowship training., Conclusions: In this pilot survey, we identified several factors that trainees consider when deciding to undertake subspecialty training and barriers that might limit interest in pursuing neuroanesthesiology subspecialty training. Our findings may be used to guide curricular development and identify factors that might increase interest among trainees in pursuing neuroanesthesiology fellowship training., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: To provide an overview of acute and chronic repeated concussion. We address epidemiology, pathophysiology, anesthetic utilization, and provide some broad-based care recommendations., Recent Findings: Acute concussion is associated with altered cerebral hemodynamics. These aberrations can persist despite resolution of signs and symptoms. Multiple repeated concussions can cause chronic traumatic encephalopathy, a disorder associated with pathologic findings similar to some organic dementias. Anesthetic utilization is common following concussion, especially soon after injury, a time when the brain may be most vulnerable to secondary injury., Summary: Brain physiology may be abnormal following concussion and these abnormalities may persist despite resolutions of clinical manifestations. Those with recent concussion or chronic repeated concussion may be susceptible to secondary injury in the perioperative period. Clinicians should suspect concussion in any patient with recent trauma and strive to maintain cerebral homeostasis in the perianesthetic period.

Purpose: Compare functional outcomes of acute ischemic stroke patients undergoing embolectomy with either local anesthesia or conscious sedation. Secondarily, identify differences in hemodynamic parameters and complication rates between groups., Materials and Methods: Single institution, retrospective review of all acute ischemic stroke patients undergoing embolectomy between January 2014 and July 2018 ( n  = 185). Patients receiving general anesthesia ( n  = 27) were excluded. One-hundred and eleven of 158 (70.3%) composed the local anesthesia group, and 47 (29.7%) composed the conscious sedation group. Median age was 71 years (interquartile range 59-79). Seventy-eight (49.4%) were male. The median National Institute of Health stroke scale score was 17.5 (interquartile range 11-21). Hemodynamic, medication, complication, and functional outcome data were collected from the anesthesia protocol and medical records. Good functional outcome was defined as a three-month modified Rankin Scale < 2. A multivariate analysis was performed to estimate the association of anesthesia type on three-month modified Rankin Scale score., Results: Three-month modified Rankin Scale score <2 was similar between groups ( p  = 0.5). Patients receiving conscious sedation were on average younger than patients receiving local anesthesia ( p  = 0.01). Conscious sedation patients were more likely to receive intravenous thrombolytic prior to embolectomy ( p  = 0.025). The complication rate and hemodynamic parameters were similar between groups., Conclusion: Functional outcome of acute ischemic stroke patients undergoing embolectomy appears to be similar for patients receiving local anesthesia and conscious sedation. This similarity may be beneficial to a future study comparing general anesthesia to local anesthesia and conscious sedation. The use of local anesthesia or conscious sedation does not significantly impact hemodynamic status.

Background: We evaluated the hypothesis that the rate of postoperative decline in global cognition is greater in older adults exposed to general anesthesia with nitrous oxide (N2O) compared to general anesthesia without N2O., Methods: Longitudinal measures of cognitive function were analyzed in nondemented adults, 70-91 years of age, enrolled in the Mayo Clinic Study of Aging. Linear mixed-effects models with time-varying covariates assessed the relationship between exposure to surgery with general anesthesia (surgery/GA) with or without N2O and the rate of long-term cognitive changes. Global cognition and domain-specific cognitive outcomes were defined using z scores, which measure how far an observation is, in standard deviations, from the unimpaired population mean., Results: The analysis included 1819 participants: 280 exposed to GA without N2O following enrollment and before censoring during follow-up (median [interquartile range {IQR}] follow-up of 5.4 [3.9-7.9] years); 256 exposed to GA with N2O (follow-up 5.6 [4.0-7.9] years); and 1283 not exposed to surgery/GA (follow-up 4.1 [2.5-6.4] years). The slope of the global cognitive z score was significantly more negative following exposure to surgery/GA after enrollment (change in slope of -0.062 [95% confidence interval {CI}, -0.085 to -0.039] for GA without N2O, and -0.058 [95% CI, -0.080 to -0.035] for GA with N2O, both P < .001). The change in slope following exposure to surgery/GA did not differ between those exposed to anesthesia without versus with N2O (estimated difference -0.004 [95% CI, -0.035 to 0.026], P = .783)., Conclusions: Exposure to surgery/GA is associated with a small, but statistically significant decline in cognitive z scores. Cognitive decline did not differ between anesthetics with and without N2O. This finding provides evidence that the use of N2O in older adults does not need to be avoided because of concerns related to decline in cognition.

Purpose: To determine safety and efficacy of retrograde pyeloperfusion for ureteral protection during cryoablation of adjacent renal tumors., Materials and Methods: Retrospective review of 155 patients treated with renal cryoablation, including adjunctive retrograde pyeloperfusion, from 2005 to 2019 was performed. Ice contacted the ureter in 67 of the 155 patients who represented the study cohort. Median patient age was 68 years old (interquartile range [61, 74]), 52 patients (78%) were male, and 37 tumors (55%) were clear cell histology. Mean tumor size was 3.4 ± 1.3 cm, and 42 tumors (63%) were located at the lower pole. Treatment-related complication and oncologic outcomes were recorded based on a review of post-procedural images and chart review., Results: Technical success of cryoablation was attained in 67 cases (100%), and technical success of pyeloperfusion was attained in 66 cases (99%). A total of 13 patients (19.4%) experienced SIR major C or D complications related to the procedure, including hemorrhage (n = 4), urine leak (n = 3), transient urinary obstruction (n = 2), pulmonary embolism (n = 1), hypertensive urgency (n = 1), acute respiratory failure (n = 1), and ureteropelvic junction (UPJ) stricture (n = 1). No complications were attributable to pyeloperfusion. Three of 45 patients with biopsy-proven renal cell carcinoma experienced local recurrence resulting in local recurrence-free survival of 92% (95% confidence interval, 81.5%-100%) 3 years after ablation., Conclusions: Retrograde pyeloperfusion of the renal collecting system is a relatively safe and efficacious option for ureteral protection during renal tumor cryoablation. This adjunctive procedure should be considered for patients in whom cryoablation of a renal mass could potentially involve the ureter., (Copyright © 2019 SIR. Published by Elsevier Inc. All rights reserved.)

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

Background: Venous air embolism (VAE) is a well-described complication of neurosurgical procedures performed in the seated position. Although most often clinically insignificant, VAE may result in hemodynamic or neurological compromise resulting in urgent change to a level position. The incidence, intraoperative course, and outcome in such patients are provided in this large retrospective study., Methods: Patients undergoing a neurosurgical procedure in the seated position at a single institution between January 2000 and October 2013 were identified. Corresponding medical records, neurosurgical operative reports, and computerized anesthetic records were searched for intraoperative VAE diagnosis. Extreme VAE was defined as a case in which urgent seated to level position change was performed for patient safety. Detailed examples of extreme VAE cases are described, including their intraoperative course, VAE management, and postoperative outcomes., Results: There were 8 extreme VAE (0.47% incidence), 6 during suboccipital craniotomy (1.5%) and 2 during deep brain stimulator implantation (0.6%). VAE-associated end-expired CO2 and mean arterial pressure reductions rapidly normalized following position change. No new neurological deficits or cardiac events associated with extreme VAE were observed. In 5 of 8, surgery was completed. Central venous catheter placement and aspiration during VAE played no demonstrable role in patient outcome., Conclusions: Extreme VAE during seated intracranial neurosurgical procedures is infrequent. Extreme VAE-associated CO2 exchange and hemodynamic consequences from VAE were transient, recovering quickly back to baseline without significant neurological or cardiopulmonary morbidity.

This review provides a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, traumatic brain injury, neuromonitoring, neurotoxicity, and perioperative disorders of cognitive function.

Background and Objectives: Practice guidelines for preoperative fasting have not clearly established the fasting time needed after oral administration of water-soluble contrast media. The aim of this study was to determine the time required for the gastric emptying during the water-soluble contrast media in patients with acute abdominal pain., Methods: This prospective longitudinal study included sixty-eight patients older than 18 years of age with acute abdominal pain, who required a water-soluble contrast media enhanced abdominal computed tomography study. Plain radiographs were obtained hourly until complete the gastric emptying. Patients with probable bowel obstruction were not included in the study., Results: A total of 31 (45,6%), 54 (79,4%), and 64 (94,1%) patients achieved a complete gastric clearance of barium in 1, 2 and 3 hours, respectively. All patients achieved complete emptying of water-soluble contrast media within 6 hours. Gastric emptying time was not associated with gender (P=0,44), body mass index (P=.35), fasting time prior to water-soluble contrast media intake (P=0,12), administration of opioids in the emergency room (P=0,7), and the presence of comorbidities (P=0,36)., Conclusion: Ninety-four percent of the patients with acute abdominal pain achieved complete gastric emptying within 3hours after the administration of water-soluble contrast media. All of them achieved complete gastric emptying within 6hours. The results suggested 6hours after oral intake of the contrast media is enough to complete transit of water-soluble contrast media through the stomach and avoid unnecessary risks., (Copyright © 2018 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.)

Study Objective: Determine if changes in expired carbon dioxide tension correlate with the severity of venous air embolism (VAE) associated hemodynamic changes in humans., Design: Retrospective case series., Setting: A single academic medical center with high-volume neurosurgical practice., Patients: One hundred forty seven adult patients having neurosurgical procedures performed with general anesthesia in the sitting position who experienced venous air embolism., Interventions: Identification of documentation of venous air embolism by either precordial Doppler sonography or transesophageal echocardiography., Measurement: Retrospective determination of changes in end-expired carbon dioxide (EECO 2 ) changes associated with venous air embolism., Main Results: Greater absolute and relative decreases in end-expired carbon dioxide tension were associated with greater hemodynamic manifestations of venous air embolism. However, based on receiver operating characteristic curve analysis, the absolute and relative changes in EECO 2 have moderate utility for predicting the severity of hemodynamic consequences of venous air embolism as area under the curve for absolute and relative carbon dioxide tensions were 0.7654 and 0.7263, respectively., Conclusions: Greater magnitude of decreases in EECO 2 is associated with hemodynamically-significant VAE in mechanically-ventilated patients. However, the magnitude of changes may have limited utility to diagnose VAE or exclude the diagnosis of VAE in patients with unexplained intraoperative hypotension., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Selective dorsal rhizotomy is a surgical spine procedure used to reduce spasticity in patients with upper motor neuron dysfunction caused by conditions such as cerebral palsy. The optimal anesthetic approach for obstetric patients who have undergone a selective dorsal rhizotomy is unknown. The use and efficacy of neuraxial anesthesia in these patients has not been described. We describe the use of neuraxial anesthesia in two patients with prior selective dorsal rhizotomy. Unless contraindicated for other reasons, a neuraxial anesthetic approach appears to be an effective option in patients with a history of a selective dorsal rhizotomy., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Endoscopic neurosurgical procedures involving the upper cervical vertebrae are challenging due to a narrow operating field and close proximity to vital anatomical structures. Historically, transoropharyngeal (transoral) endoscopy has been the preferred approach. More recently, however, an endoscopic transnasal approach was developed as an alternative method in hopes to reduce postoperative dysphagia, a common complication following transoral neurosurgery., Methods: Twenty-two endoscopic neurosurgical cases involving the odontoid or C1 vertebra were reviewed between January 1, 2005 and December 31, 2015 (17 and 5 through transoral and transnasal approaches, respectively). Patient demographics, anesthetic technique, intraoperative course, and postoperative outcomes such as were recorded., Results: Patients who underwent transnasal odontoidectomy had a shorter length of stay and lower rates of tracheostomy compared with those having similar surgery via the transoral route. In those having transoral surgery, no patient presented to the operating room with a preexisting tracheostomy. In 16 of 17 patients within the transoral group, a tracheostomy was performed. In those having transnasal surgery, 2 of 5 patients had a preexisting tracheostomy. In the remaining 3 of 5 patients, orotracheal intubation was performed and patients were extubated after the procedure., Conclusions: The transnasal odontoid resection technique may become a more popular surgical approach without increasing rates of complications compared with those having transoral surgery. Ultimately, a larger, study is needed to further clarify these relationships.

We provide a synopsis of innovative research, recurring themes, and novel experimental findings pertinent to the care of neurosurgical patients and critically ill patients with neurological diseases. We cover the following broad topics: general neurosurgery, spine surgery, stroke, traumatic brain injury, monitoring, and anesthetic neurotoxicity.

Background: Thyroid-stimulating hormone (TSH)-secreting pituitary adenomas are a rare cause of secondary hyperthyroidism. Anesthetic management of these patients has not been formally described in the literature., Materials and Methods: Patients who underwent resection of a TSH-secreting pituitary adenoma during 1987 to 2012 at a single institution were identified. Preoperative thyroid hormone state, anesthetic management, and outcome were recorded. Hemodynamic associations with intraoperative events were compared between those who were hyperthyroid and euthyroid at the time of surgery., Results: Of 2268 patients having transsphenoidal resection of a pituitary tumor, 19 (0.84%) had resection of a TSH-secreting adenoma. At the time of surgery, 6 (32%) were hyperthyroid, 11 (58%) were euthyroid, and 2 (10%) were hypothyroid based on serum thyroxine concentration. General anesthesia was maintained with a potent inhaled anesthetic in all patients, and included nitrous oxide in 18 of 19 (95%). Seventeen (90%) had an arterial catheter placed for surgery. Only 1 patient (5%) required an intraoperative blood transfusion. There were no significant differences in heart rate or blood pressure at induction of anesthesia, upon intranasal injection of local anesthetic containing epinephrine, or upon emergence from anesthesia, between patients who were chemically hyperthyroid or euthyroid. Twelve of 19 (63%) had tumor extension beyond the sella turcica. Common complications were nausea and vomiting (42%), diabetes insipidus (32%), and temporary or permanent hypopituitarism (42%)., Conclusions: Patients having resection of TSH-secreting pituitary adenomas can present in any thyroid state. An awareness of risks and potential complications in patients with TSH-secreting adenomas can help tailor perioperative care.

Objective: To describe the epidemiology of surgical and anesthetic procedures in patients recently diagnosed as having a concussion due to mild traumatic brain injury., Patients and Methods: Study patients presented to a tertiary care center after a concussion due to mild traumatic brain injury from July 1, 2005, through June 30, 2015, and underwent a surgical procedure and anesthesia support under the direct or indirect care of a physician anesthesiologist., Results: During the study period, 1038 patients met all the study inclusion criteria and subsequently received 1820 anesthetics. In this population of anesthetized patients, rates of diagnosed concussions due to sports injuries, falls, and assaults, but not motor vehicle accidents, increased during 2010-2011. Concussions were diagnosed in 965 patients (93%) within 1 week after injury. In the 552 patients who had surgery within 1 week after concussive injury, 29 (5%) had anesthesia and surgical procedures unrelated to their concussion-producing traumatic injury. The highest use of surgery occurred early after injury and most frequently required general anesthesia. Orthopedic and general surgical procedures accounted for 57% of procedures. Nine patients received 29 anesthetics before a concussion diagnosis, and all of these patients had been involved in motor vehicle accidents and received at least 1 anesthetic within 1 week of injury., Conclusion: Surgical and anesthesia use are common in patients after concussion. Clinicians should have increased awareness for concussion in patients who sustain a trauma and may need to take measures to avoid potentially injury-augmenting cerebral physiology in these patients., (Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

We reviewed manuscripts published in 2016 that are related to the care of neurosurgical patients or the perioperative care of patients with neurological diseases. We address the broad categories of general neurosurgery and neuroanesthesiology, anesthetic neurotoxicity and neuroprotection, stroke, traumatic brain injury, and nervous system monitoring.

Background: Induced hypotension (IH) had been used for decades in neurosurgery to reduce the risk for intraoperative blood loss and decrease blood replacement. More recently, this method fell out of favor because of concerns for cerebral and other end-organ ischemia and worse treatment outcomes. Other contributing factors to the decline in its popularity include improvements in microsurgical technique, widespread use of endovascular procedures, and advances in blood conservation and transfusion protocols. Permissive hypotension (PH) is still being used occasionally in neurosurgery; however, its role in current anesthesia practice remains unclear. Our objective was to describe contemporary utilization of IH and PH (collectively called PH) in clinical practice among members of the Society for Neuroscience in Anesthesiology and Critical Care (SNACC)., Methods: A questionnaire was developed and distributed among SNACC members that addressed practice patterns related to the use of PH. The responses were analyzed based on the number of individuals who responded to each specific question., Results: Of 72 respondents, 67.6% reported over 10 years of clinical experience, while 15.5% reported 5-10 years of post-training experience. The respondents admitted to providing anesthesia for 300 (median) neurosurgical cases per year. PH was applied most commonly during open interventions on cerebral aneurysms (50.8%) and arteriovenous malformations (46%). Seventy-three percent of respondents were not aware of any complications in their practice attributable to PH., Conclusion: PH is still being used in neuroanesthesia practice by some providers. Further research is justified to clarify the risks and benefits of PH in modern neuroanesthesia practice.

Background and Purpose: Many studies have suggested a relationship between the type of anesthesia provided during intra-arterial therapy for acute ischemic stroke and patient outcomes. Variability in blood pressure and hypotension have previously been identified as possible reasons for worse outcomes in acute stroke. Our aim was to investigate hemodynamic parameters and neurological outcomes of patients receiving either general anesthesia or conscious sedation for intra-arterial therapy of acute stroke., Methods: We performed a retrospective review of patients undergoing intra-arterial therapy from December 2008 to March 2015. Demographic data, baseline National Institutes of Health Stroke Scale score, preoperative physiological variables, procedural details, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate, and modified Rankin Scale scores were recorded., Results: 99 patients were included in the study, with 38 receiving general anesthesia and 61 receiving conscious sedation. Patients who received general anesthesia had a lower maximum SBP (p=0.02), minimum SBP (p<0.0001), minimum DBP (p<0.0001), and minimum MAP (p<0.0001). On multivariate analysis, general anesthesia was associated with lower minimum SBP (p=0.04), DBP (p=0.02), and MAP (p=0.007). Conscious sedation was associated with more favorable neurological outcomes (p=0.02). Patients with favorable neurological outcomes had a lower maximum variability in SBP (p=0.01) and MAP (p=0.03), as well as a higher minimum DBP (p=0.03)., Conclusions: Patients with acute ischemic stroke undergoing intra-arterial therapy with general anesthesia had lower minimum SBP, DBP, and MAP, greater fluctuations in blood pressure, and less favorable outcomes. More studies are needed to examine the implications of variable and reduced blood pressures and neurological outcomes., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: Carcinoid tumors are derived from enterochromaffin cells and may release physiologically active compounds into the systemic circulation, leading to the development of carcinoid syndrome. Occasionally, these tumors metastasize to the brain, warranting biopsy or resection. In these surgical patients, the perioperative implications for anesthetic management are not heretofore defined in the indexed literature., Methods: Patients who had craniotomy for biopsy or resection of intracranial carcinoid tumors were retrospectively identified at a single medical center. Patient demographics, perioperative anesthetic management, adverse events, and outcome were summarized in this case series., Results: Eleven patients were identified; median age was 60 years (range = 42-78 years), and 45% were male. Immediately before surgery, 4 patients (36%) were receiving a somatostatin analog drug, and no patient had unchecked carcinoid syndrome. All patients received general anesthesia that included inhaled isoflurane and nitrous oxide, and all had invasive arterial blood pressure monitoring. One patient developed sustained hypotension after induction of anesthesia, likely related to hypovolemia and anesthetic drugs, but the possibility of carcinoid mediator release cannot be excluded. There were no other signs or symptoms of carcinoid syndrome in this or any other patient. Of all 11 patients, 10 (91%) experienced either significant disease progression (n = 2; 18%) or death (n = 8; 73%) from carcinoid disease, its sequelae, or an undetermined cause within 3 years after surgery. Of note, 3 of the deaths occurred shortly after surgery, on postoperative days 3, 7, and 8., Conclusions: In our experience, carcinoid tumor metastasis to the brain-whether because of tumor makeup or prior treatment-is unlikely to produce symptoms of new-onset carcinoid syndrome intraoperatively; however, the risk cannot be completely excluded. Postsurgical prognosis was poor, both within the hospital and after hospital discharge., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We provide a synopsis of innovative research, recurring themes, and novel experimental findings pertinent to the care of neurosurgical patients and critically ill patients with neurological diseases. The following broad topics are covered: general neurosurgery, spine surgery, stroke, traumatic brain injury, anesthetic neurotoxicity, perioperative cognitive dysfunction, and monitoring.

Background and Objectives: In March 2012, the American Society of Regional Anesthesia and Pain Medicine convened its second Practice Advisory on Neurological Complications in Regional Anesthesia and Pain Medicine. This update is based on the proceedings of that conference and relevant information published since its conclusion. This article updates previously described information on the pathophysiology of spinal cord injury and adds new material on spinal stenosis, blood pressure control during neuraxial blockade, neuraxial injury subsequent to transforaminal procedures, cauda equina syndrome/local anesthetic neurotoxicity/arachnoiditis, and performing regional anesthetic or pain medicine procedures in patients concomitantly receiving general anesthesia or deep sedation., Methods: Recommendations are based on extensive review of research on humans or employing animal models, case reports, pathophysiology research, and expert opinion., Results: The pathophysiology of spinal cord injury associated with regional anesthetic techniques is reviewed in depth, including that related to mechanical trauma from direct needle/catheter injury or mass lesions, spinal cord ischemia or vascular injury from direct needle/catheter trauma, and neurotoxicity from local anesthetics, adjuvants, or antiseptics. Specific recommendations are offered that may reduce the likelihood of spinal cord injury associated with regional anesthetic or interventional pain medicine techniques., Conclusions: The practice advisory's recommendations may, in select cases, reduce the likelihood of injury. However, many of the described injuries are neither predictable nor preventable based on our current state of knowledge., What's New: Since publication of initial recommendations in 2008, new information has enhanced our understanding of 5 specific entities: spinal stenosis, blood pressure control during neuraxial anesthesia, neuraxial injury subsequent to transforaminal techniques, cauda equina syndrome/local anesthetic neurotoxicity/arachnoiditis, and performing regional anesthetic or pain procedures in patients concomitantly receiving general anesthesia or deep sedation.

We describe the use of dexmedetomidine for an awake neurosurgical procedure in a pregnant patient and quantify the effect of mannitol on intrauterine volume. A 27-year-old woman underwent a craniotomy, with intraprocedural motor and speech mapping, at 20 weeks of gestation. Sedation was maintained with dexmedetomidine. Mannitol at 0.25 g/kg IV was administered to control brain volume during surgery. Internal uterine volume was estimated at 1092 cm before surgery and decreased to 770 and 953 cm at 9 and 48 hours, respectively, after baseline assessment. No adverse maternal or fetal effects were noted during the intraoperative period or up to 48 hours postoperatively.

This survey provides a synopsis of new findings, recurring themes, and data that may initiate practice changes in the perioperative care of neurosurgical patients and critically ill patients with neurological diseases.

With improvements in management and rehabilitation, more women with spinal cord injury are conceiving children. Physiologic manifestations of spinal cord injury can complicate anesthetic management during labor and delivery. Patients who delivered at Mayo Clinic, Rochester, Minnesota between January 1, 2001 and May 31, 2012 with a history of traumatic spinal cord injury were identified via electronic record search of all parturients. Eight patients undergoing nine deliveries were identified. Six deliveries (67%) among five patients (63%) involved a trial of labor. Among these deliveries, three (50%) occurred vaginally, all with successful epidural analgesia. Trial of labor failed in the remaining three patients, and required cesarean delivery facilitated via epidural (n=1), spinal (n=1) and general anesthesia (n=1). Three patients (33%) underwent scheduled cesarean delivery via epidural (n=1), spinal (n=1), and general anesthesia (n=1). Four patients having five deliveries had a history of autonomic hyperreflexia before pregnancy. One patient had symptoms during pregnancy, two patients had episodes during labor and delivery, and three patients described symptoms in the immediate postpartum period. These symptoms were not reported by any patient without a history of autonomic hyperreflexia. Neuraxial labor analgesia may have a higher failure rate in patients with spinal cord injury, possibly related to the presence of Harrington rods. Postpartum exacerbations of autonomic hyperreflexia are common in patients with a history of the disorder., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: Past research has explored patients' expectations about the informed consent process. However, it is currently unknown if the complexity of the surgical procedure influences the type of anesthesia-related risks that patients wish disclosed. This study explored fears of anesthesia-related complications and whether these changed based on severity of surgery classification., Methods: Patients presenting to our pre-operative evaluation clinic from February 2013 to May 2013 were asked to participate in a survey-based study meant to evaluate their perception of five possible anesthetic risks (peripheral nerve injury, death, nausea and vomiting, heart attack and stroke) when confronted with differing levels of surgical severity., Results: One thousand surveys were administered, and 894 were returned for an overall response rate of 89%. Fear of death was the greatest concern as compared to the other risk factors independent of the severity of surgery. The level of fear for all risk factors, with the exception of stroke and heart attack, were dependent on the severity of surgery. Fear of death decreased as the severity of surgery decreased (major 46%, moderate 38%, minor 25%). For major surgery, the fear of perioperative death differed significantly with age (P < 0.001); specifically, with increasing age came a lessened fear of death., Conclusion: Awareness by anesthesia providers of those fears that patients report may allow for a more personalized approach to providing information that may better allay anxiety. Further, these results may better tailor the informed consent process to one that meets particular patient concerns., (© 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)