Neuromonitoring Identifies Occlusion of Femoral Artery in STA-MCA Bypass Procedure: A Case Report.

Intraoperative neurophysiological monitoring (IONM) is a technique used to assess the somatosensory and gross motor systems during surgery. While it is primarily used to detect and prevent surgically induced nervous system trauma, it can also detect and prevent injury to the nervous system that is the result of other causes such as trauma or ischemia that occur outside of the operative field as a result of malpositioning or other problematic physiologic states. We present a case study where a neuromonitoring alert altered the surgical procedure, though the alert was not correlated to the site of surgery. A 69-year-old male with a history of bilateral moyamoya disease and a left middle cerebral artery infarct underwent a right-sided STA-MCA bypass and encephaloduroarteriosynangiosis (EDAS) with multimodal IONM. During the procedure, the patient experienced a loss of motor evoked potential (MEP) recordings in the right lower extremity. Blood pressure was elevated, which temporarily restored the potentials, but they were lost again after the angiography team attempted to place an arterial line in the right femoral artery. The operation was truncated out of concern for left hemispheric ischemia, and it was later discovered that the patient had an acute right external iliac artery occlusion caused by a fresh thrombus in the common femoral artery causing complete paralysis of the limb. This case highlights the importance of heeding IONM alerts and evaluating for systemic causes if the alert is not thought to be of surgical etiology. IONM can detect adverse systemic neurological sequelae that is not necessarily surgically induced.

Increasing rates of general anesthesia use in lumpectomy procedures: A 15-year trends analysis.

BACKGROUND: Anesthesia methods in oncologic breast surgery have evolved with less invasive practices. The aims of this study were primarily to examine trends in anesthesia type used during lumpectomy. METHODS: We analyzed lumpectomy procedures from 2005 to 2019 using the NSQIP database. Upon defining the nadir in general anesthesia (GA) and peak in monitored anesthesia care (MAC) use as 2007, we compared patient characteristics and complications in the 2007 versus 2019 GA and MAC cohorts. Multivariable logistic regression was used to examine associations with receipt of GA. RESULTS: Of 253 545 lumpectomy patients, 191 773 (75.6%) received GA and 61 772 (24.4%) received MAC. From 2005 to 2019, GA rates increased from 66.7% to 82.5%, while MAC rates decreased from 33.3% to 17.5%. More GA patients were obese and American Society of Anesthesiologists class 3. Over time, age and body mass index (BMI) increased in both GA and MAC cohorts. Odds of receiving GA increased over time, and predictors included concurrent axillary lymph node dissection (p < 0.0001) or sentinel lymph node biopsy (p < 0.0001). CONCLUSIONS: We demonstrate increasing use of GA over time for lumpectomy, which may be related to aging lumpectomy patient population with higher BMIs. We also find a strong association between use of GA and concurrent lymph node procedures.

Evolution of flash visual evoked potentials to monitor visual pathway integrity during tumor resection: illustrative cases and literature review.

Flash visual evoked potentials (fVEPs) provide a means to interrogate visual system functioning intraoperatively during tumor resection in which the optic pathway is at risk for injury. Due to technical limitations, fVEPs have remained underutilized in the armamentarium of intraoperative neurophysiological monitoring (IONM) techniques. Here we review the evolution of fVEPs as an IONM technique with emphasis on the enabling technological and intraoperative improvements. A combined approach with electroretinography (ERG) has enhanced feasibility of fVEP neuromonitoring as a practical application to increase safety and reduce error during tumor resection near the prechiasmal optic pathway. The major advance has been towards differentiating true cases of damage from false findings. We use two illustrative neurosurgical cases in which fVEPs were monitored with and without ERG to discuss limitations and demonstrate how ERG data can clarify false-positive findings in the operating room. Standardization measures have focused on uniformity of photostimulation parameters for fVEP recordings between neurosurgical groups.

Enhanced Recovery After Surgery (ERAS) for Cranial Tumor Resection: A Review.

Enhanced Recovery After Surgery (ERAS) protocols describe a standardized method of preoperative, perioperative, and postoperative care to enhance outcomes and minimize complication risks surrounding elective surgical intervention. A growing body of evidence is being generated as we learn to apply principles of ERAS standardization to neurosurgical patients. First applied in spinal surgery, ERAS protocols have been extended to cranial neuro-oncologic procedures. This review synthesizes recent findings to generate evidence-based guidelines to manage neurosurgical oncology patients with standardized systems and assess ability of these systems to coordinate multidisciplinary, patient-centric care efforts. Furthermore, we highlight the potential usefulness of multimedia, app-based communication platforms to facilitate patient education, autonomy, and team communication within each of the 3 settings.

Roadmap for Conducting Neuroscience Research in the COVID-19 Era and Beyond: Recommendations From the SNACC Research Committee.

The coronavirus disease 2019 (COVID-19) pandemic has impacted many aspects of neuroscience research. At the 2020 Society of Neuroscience in Anesthesiology and Critical Care (SNACC) Annual Meeting, the SNACC Research Committee met virtually to discuss research challenges encountered during the COVID-19 pandemic along with possible strategies for facilitating research activities. These challenges and recommendations are included in this Consensus Statement. The objectives are to: (1) provide an overview of the disruptions and challenges to neuroscience research caused by the COVID-19 pandemic, and; (2) put forth a set of consensus recommendations for strengthening research sustainability during and beyond the current pandemic. Specific recommendations are highlighted for adapting laboratory and human subject study activities to optimize safety. Complementary research activities are also outlined for both laboratory and clinical researchers if specific investigations are impossible because of regulatory or societal changes. The role of virtual platforms is discussed with respect to fostering new collaborations, scheduling research meetings, and holding conferences such that scientific collaboration and exchange of ideas can continue. Our hope is for these recommendations to serve as a valuable resource for investigators in the neurosciences and other research disciplines for current and future research disruptions.

Anesthesia for Carotid Endarterectomy, Angioplasty, and Stent.

Anesthetic management of carotid artery disease requiring carotid endarterectomy or carotid stenting is complex and varies widely, but relies on excellent communication between the anesthesia and surgical team throughout the procedure to ensure appropriate cerebral perfusion. With a systematic approach to vascular access and hemodynamic and neurologic monitoring, anesthesia can be applied to maximize cerebral perfusion while minimizing the risk of postoperative hemorrhage or hyperperfusion.

Perioperative Serotonin Syndrome Manifesting as Gastrocnemius Myofasciculations: A Case Report.

In perioperative settings where a patient under general anesthesia, presentation of serotonin syndrome might be far from the "classical" description of this potentially fatal condition. A patient who manifested signs of serotonin toxicity during an intravenous anesthetic, remifentanil, is presented. At the time of surgery, the patient was being treated with tramadol for pain management. The patient displayed myofasciculations on both gastrocnemius muscles confirmed electromyographically. All other conventional signs of serotonin syndrome were absent except hypotension and nystagmus. A presumptive diagnosis of serotonin syndrome was made intraoperatively. The symptoms resolved once remifentanil infusion was discontinued in the operating room without incident. Mild-to-moderate perioperative serotonin syndrome may manifest with myofasciculations in gastrocnemius muscles in the settings of no neuromuscular blockade. In spinal surgeries involving intraoperative EMG monitoring, the neuromonitoring team should be aware of this presentation and include serotonin syndrome in the differential diagnosis of unexplained EMG activity.

Intraoperative vasopressors and thrombotic complications in free flap breast reconstruction.

OBJECTIVE: The purpose of this study was to critically examine intraoperative vasopressor usage as it relates to free flap perfusion and its effect on perioperative complications in autologous breast reconstruction. METHODS: A retrospective cohort study was performed involving all free autologous breast reconstructions at a single institution over a 5 year period. Data collection focused on perioperative care, specifically fluid administration, urine output (UOP), use of vasopressors, and case duration. Outcomes included major intraoperative and postoperative complications. Patients who received intraoperative vasopressors were compared to all patients who did not. The use, type, and timing of the vasopressor agent were assessed with standard statistical analyses and regression modelling. RESULTS: Six hundred and eighty-two patients reconstructed with 1039 flaps were included. Of these, 475 (69.6%) patients received vasopressors. The vasopressor cohort was older (p = 0.001), with higher rates of hypertension (p = 0.02). They had a greater number of hypotensive episodes (2.3 vs 0.8, p < 0.0001) and received a greater volume of fluid (4653.0 vs 4291.7 ml, p = 0.004). Examining complications, no increase in intraoperative thrombotic events (arterial or venous) or flap loss was noted with vasopressor administration. A higher rate of minor complications was, however, noted (53.1% vs 43.0%, p = 0.016). CONCLUSIONS: This study demonstrates that the use of intraoperative vasopressor agents in the anaesthetic care of free flap breast reconstruction patients is common, but likely does not impact thrombotic events or flap loss. Minor complications may, however, be more common in these patients.

Intraoperative perfusion management impacts postoperative outcomes: an analysis of 682 autologous breast reconstruction patients.

INTRODUCTION: Anesthetic management remains an understudied aspect of free autologous breast reconstruction. This study aims to critically examine intraoperative anesthetic management as it relates to free flap perfusion and its effect on major complications. METHODS: A retrospective cohort study was performed examining all abdominally based free autologous breast reconstructions from 2005 to 2011 at a single institution. Analysis focused on perioperative care and specifically fluid administration, urine output (UOP), vasopressor administration, and case duration. Outcomes included major intraoperative and postoperative complications. A post-hoc analysis was performed to determine anesthetic factors associated with thrombotic events. RESULTS: Overall, 682 patients (1033 flaps) were included. Patients with low UOP had lower rates of intraoperative fluid infusion rates/kg (p=0.0001), Estimated Blood Loss (EBL) (p=0.006) and pressor administration (p=0.03), but no significant differences were noted in intraoperative thrombotic events according to UOP. However, the below normal UOP cohort demonstrated a significant increased rate of delayed postoperative thromboses (p=0.03). A post hoc analysis of postoperative thrombotic events revealed that low rates of fluid resuscitation (OR=3.01, p=0.04) and low intraoperative UOP (OR=3.67, p=0.04) were independently associated with delayed thrombosis. A sub-analysis demonstrated that patients with ≥2 comorbidities and below normal UOP were at particular risk (any delayed thrombotic event OR=4.3, p=0.03; any delayed venous thrombosis OR=9.1, p=0.03). CONCLUSIONS: This study demonstrates that intraoperative fluid under-resuscitation may place patients at increased risk for postoperative flap thrombosis, and low UOP is an important metric whereby intraoperative resuscitation should be gauged. Patients with comorbid conditions and below normal intraoperative UOP should be monitored particularly closely for delayed thrombotic events. LEVEL OF EVIDENCE: Prognostic/risk category, level II.

Malignant hyperthermia in children: an analysis of the North American malignant hyperthermia registry.

BACKGROUND: Clinical characteristics of malignant hyperthermia (MH) in pediatric patients have not been elucidated. In this study, we used the North American Malignant Hyperthermia Registry to determine differences in clinical characteristics of acute MH across pediatric age groups. We hypothesized that there are differences in clinical presentation, clinical course, and outcomes, which correlate with age. A secondary aim was to determine the types of preexisting medical conditions associated with pediatric MH. METHODS: We performed a retrospective review of the North American Malignant Hyperthermia Registry to identify pediatric subjects (up to and including 18 years) with an MH clinical grading score at or above 35 indicating "very likely" or "almost certain" MH. Preoperative patient characteristics, perianesthetic factors, and outcome data were compared for 3 cohorts based on age: 0 to 24 months, 25 months to 12 years, and 13 to 18 years. We used statistical analysis to determine differences among the groups. RESULTS: We analyzed 264 records: 35 in the youngest age group, 163 in the middle age group, and 66 in the oldest group. There was no indication of any predisposing risk factors for MH based on family history or physical examination. Sinus tachycardia, hypercarbia, and rapid temperature increase were the most common signs of acute MH (observed in 73.1%, 68.6%, and 48.5%, respectively) and were more common in the oldest age cohort. Higher maximum temperatures and higher peak potassium values were seen in the oldest age cohort. Masseter spasm was more common in the middle age cohort. The youngest age cohort was more likely to develop skin mottling and was approximately half as likely to develop muscle rigidity. The youngest age group also demonstrated significantly higher peak lactic acid levels and lower peak creatine kinase values. Treatments were similar across age cohorts. There were 10 MH-associated deaths, 6 in the middle age group and 4 in the oldest age group. Recrudescence of symptoms after initial treatment occurred in 14.4% of subjects, with no difference across age cohorts. Two of these subjects, 1 in the middle age group and 1 in the oldest age group, died after the recrudescence event. CONCLUSIONS: There are differences in clinical characteristics of acute MH among different age cohorts in childhood. Older subjects demonstrated higher body temperatures and higher potassium levels, and the youngest subjects had greater levels of metabolic acidosis. Most children in each age group were phenotypically normal before developing MH.

Chronic pain following abdominal free flap breast reconstruction: a prospective pilot analysis.

BACKGROUND: Chronic pain after breast reconstruction is an ill-defined process which can generate significant patient morbidity and disability. The purpose of this study was to examine chronic, persistent pain in a prospective study of free flap breast reconstruction patients, in an effort to identify possible points of intervention and counseling. METHODS: We performed a prospective study evaluating function, quality of life, and satisfaction in patients undergoing abdominally based autologous reconstruction between 2006 and 2010. Using the short form 36, we examined the presence of chronic body pain (>4 months) as well as overall mental and physical health. Patients with debilitating pain were compared to those without in a post hoc analysis. RESULTS: Overall, 399 women underwent reconstruction during the study period, with 149 enrolling and having long-term follow-up in this portion of the prospective study. Twenty-six (17%) of 149 patients experienced chronic body pain that was moderately debilitating after autologous reconstruction, making it one of the most common complications experienced in this cohort. No differences were noted in demographics, medical history, procedure type, history of axillary surgery, radiation treatment, surgical outcomes, or follow-up time between the cohorts. However, patients with chronic pain were found to have higher preoperative pain scores (P < 0.0001) and lower physical, mental, and overall health scores across time points. All scores significantly worsened with time in comparison to the cohort without pain, who, in contrast showed score improvement across all areas. Although pain issues trended toward being noted in postoperative visits more frequently in the chronic pain cohort (37% vs 19%, P = 0.051), only 1 (4.2%) patient was referred for pain service consultation. Additionally, satisfaction with reconstruction was significantly lower in patients who demonstrated chronic pain (P = 0.03). CONCLUSIONS: Factors contributing to chronic pain continue to be elusive and understudied. Our data demonstrate the importance of screening for chronic pain, as we determined that preoperative pain is linked to increased, moderately debilitating postoperative chronic pain. Persistent chronic pain, in turn, is associated with significant morbidity, disability, and dissatisfaction. Such patients with pain issues may benefit from additional preoperative counseling and early involvement of the pain service.

An alternative position for the BIS-Vista montage in frontal approach neurosurgical cases.

BACKGROUND: Appropriate placement of the bispectral index (BIS)-vista montage for frontal approach neurosurgical procedures is a neuromonitoring challenge. The standard bifrontal application interferes with the operative field; yet to date, no other placements have demonstrated good agreement. The purpose of our study was to compare the standard BIS montage with an alternate BIS montage across the nasal dorsum for neuromonitoring. MATERIALS AND METHODS: The authors performed a prospective study, enrolling patients and performing neuromonitoring using both the standard and the alternative montage on each patient. Data from the 2 placements were compared and analyzed using a Bland-Altman analysis, a Scatter plot analysis, and a matched-pair analysis. RESULTS: Overall, 2567 minutes of data from each montage was collected on 28 subjects. Comparing the overall difference in score, the alternate BIS montage score was, on average, 2.0 (6.2) greater than the standard BIS montage score (P<0.0001). The Bland-Altman analysis revealed a difference in score of -2.0 (95% confidence interval, -14.1, 10.1), with 108/2567 (4.2%) of the values lying outside of the limit of agreement. The scatter plot analysis overall produced a trend line with the equation y=0.94x+0.82, with an R coefficient of 0.82. CONCLUSIONS: We determined that the nasal montage produces values that have slightly more variability compared with that ideally desired, but the variability is not clinically significant. In cases where the standard BIS-vista montage would interfere with the operative field, an alternative positioning of the BIS montage across the nasal bridge and under the eye can be used.

The ethnic divide in breast reconstruction: a review of the current literature and directions for future research.

Ethnic disparities exist in many areas of breast cancer treatment. When a mastectomy is necessary, the next discussion in the overall surgical management often focuses on breast reconstruction. This review will examine breast reconstruction trends within different ethnic groups and will briefly discuss underlying factors influencing current disparities. The literature available on differences in breast reconstruction loosely fits into two general categories: (1) the decision making process for reconstruction and (2) the receipt, timing and type of breast reconstruction. This review will seek to highlight several areas for possible intervention as well as areas where further research is needed.

Fetal responses to induced maternal relaxation during pregnancy.

Fetal responses to induced maternal relaxation during the 32nd week of pregnancy were recorded in 100 maternal-fetal pairs using a digitized data collection system. The 18-min guided imagery relaxation manipulation generated significant changes in maternal heart rate, skin conductance, respiration period, and respiratory sinus arrhythmia. Significant alterations in fetal neurobehavior were observed, including decreased fetal heart rate (FHR), increased FHR variability, suppression of fetal motor activity (FM), and increased FM-FHR coupling. Attribution of the two fetal cardiac responses to the guided imagery procedure itself, as opposed to simple rest or recumbency, is tempered by the observed pattern of response. Evaluation of correspondence between changes within individual maternal-fetal pairs revealed significant associations between maternal autonomic measures and fetal cardiac patterns, lower umbilical and uterine artery resistance and increased FHR variability, and declining salivary cortisol and FM activity. Potential mechanisms that may mediate the observed results are discussed.

The relationship between hiccups and heart rate in the fetus.

OBJECTIVE: The purpose of this study was to determine the effect of fetal hiccups on fetal heart rate from 20 weeks of gestation onward. METHODS: One thousand four hundred and fifty-six collected fetal heart rate tracings from three cohorts that participated in longitudinal studies of fetal neurobehavioral development were reviewed retrospectively for fetal hiccups. Tracings were recorded at four-week intervals from 20 weeks. A hiccup-free period before or after the episode of hiccups was used as the control fetal heart rate; thus each fetus was used as its own control. The paired t-test was used for statistical analysis. RESULTS: From 28 weeks onward, the mean fetal heart rate increased with hiccups reaching statistical significance at 32 weeks. Fetal heart rate variability was unaffected by hiccups until 36 weeks, at which time it decreased during hiccup periods. CONCLUSION: This change in response to fetal hiccups may represent another neurodevelopment milestone for the fetus.