The cientificWorldJOURNAL Clinical Study Signal Persistence of Bispectral Index and State Entropy during Surgical Procedure under Sedation

Introduction. Bispectral index (BIS) and state entropy (SE) are prone to artifacts, especially due to electrocautery (EC). We compared the incidence of artifacts in BIS and SE during surgery under local anesthesia and sedation. Methods. 28 females undergoing breast surgery under local anesthesia and sedation were studied. Simultaneous BIS and SE measurements were recorded every 10 seconds. Artifact was defined as a failure of the device to display a numerical value while the electrodes remained appropriately attached to the patient's forehead. Ratio of artifact to good signal was compared between BIS and SE in the presence or absence of EC use. Results. 7679 data points were collected from 28 patients. Overall, artifact incidence was similar in BIS and SE (6.2% and 6.3%, resp.). In the presence of EC (1370 data points), BIS had significantly more artifact compared to SE (18.6% versus 6.4%, P < 0.0001). Without EC (6309 data points), BIS had significantly less artifact compared to SE (4.1% versus 7.3%, P < 0.0001). Discussion. BIS and SE were comparable for incidence of artifacts in patients under sedation. Use of EC lead to more artifact in BIS than SE. Conversely, BIS had fewer artifacts than SE when there was no EC use

Assessment of anesthesia practice patterns for endovascular therapy for acute ischemic stroke: A Society for Neuroscience in Anesthesiology and Critical Care (SNACC) member survey

Background: The choice of general anesthesia (GA) or conscious sedation (CS) may impact neurological outcomes of patients undergoing endovascular therapy (EVT) for acute ischemic stroke (AIS). The aim of this survey was to describe the practice patterns of members of the Society for Neuroscience in Anesthesiology and Critical Care (SNACC) for anesthetic management of AIS. Methods: Following institutional review board approval, a 16-question online survey assessing anesthetic management of patients with AIS undergoing EVT was circulated to members of SNACC. Results: A total of 76 SNACC members from 52 institutions and 11 countries completed the survey (12.5% response rate). Overall, 33% of institutions reported dedicated neuroanesthesia teams for EVT. Patients treated with GA ranged from 5% to 100% between centers. In total 51% and 49% of centers in the United States reported preferentially providing GA and CS, respectively, compared with 34% and 66%, respectively, in European centers. Reported anesthetic induction agents are propofol (64%), etomidate (4%) and either medication (33%). For maintenance of GA, volatile anesthetic is used more often (54%) than propofol (16%). There was wide variation in medications used for CS. Arterial catheter placement was reported by 75% and 43% of respondents for patients undergoing GA and CS, respectively. Systolic blood pressure \u3e140 mm Hg was targeted by 35.7% of respondents, with others targeting mean arterial pressure within 10%, 20% or 30% of baseline values. Phenylephrine and norepinephrine were the most commonly used vasopressors. Conclusions: There is wide variation in anesthesia technique and hemodynamic management during EVT for AIS, and no consensus on the choice of, or preferred medications for, GA or CS, or target blood pressure and management of hypotension during the procedure

Anesthesia care in the interventional neuroradiology suite: an update.

PURPOSE OF REVIEW The scope of procedures conducted by neurointerventionalists is expanding quickly, with lacking consensus over the best anesthesia modality. Although the procedures involve all age groups, the interventions may be complex and lengthy and may be provided in hospitals currently not yet familiar with the field. Here we review current literature addressing elective outpatient neurointerventional procedures and aim to provide an update on the management of intervention-specific crises, address special patient populations, and provide key learning points for everyday use in the neurointerventional radiology suite. RECENT FINDINGS Various studies have compared the use of different anesthesia modalities and preinterventional and postinterventional care. Monitored anesthesia care is generally recommended for elderly patients, whereas children are preferably treated with general anesthesia. Additional local anesthesia is beneficial for procedures, such as percutaneous kyphoplasty and vascular access. SUMMARY Combining different anesthetic modalities is a valuable approach in the neurointerventional radiology suite. More interventional and patient population-specific studies are needed to improve evidence-based perioperative management

Effect of age on brain oxygenation regulation during changes in position.

IntroductionReports indicate that brain regulation of oxygenation is inhibited in patients with low baseline oxyhemoglobin concentrations and that brain oxyhemoglobin concentrations are decreased with aging. The purpose of this study was to determine if regulation of brain oxygenation to changes in blood pressure is inhibited by normal aging.MethodsBrain oxyhemoglobin (OHb) and deoxyhemoglobin (HHb) concentrations were determined from the forehead using a frequency domain near infrared spectroscopy in 27 healthy volunteers. Subjects were separated into two groups by age (20-39, n=16; 40-60, n=11). Brain hemoglobin and non-invasive blood pressure were measured in (1) supine, (2) sitting, (3) supine and (4) sitting positions with 10-min equilibration intervals between each determination. Statistical differences were determined by two way repeated measures analysis of variance.ResultsYoung subjects were 28+/-5 years (mean+/-S.D.) and older subjects were 48+/-6 years. In supine position, OHb and HHb were 28.4+/-8.3 and 15.4+/-2.4micromol/L, respectively, in young; 22.4+/-5.7 and 13.4+/-2.9micromol/L, respectively, in older subjects, both P<0.05 between groups. Changing position from supine to sitting decreased OHb 5% and increased HHb 5% with no difference between groups.ConclusionsThere was a small but significant decrease in OHb and an increase in HHb from supine to sitting position, and this effect was similar between young and older subjects. Regulation of brain oxygenation during modest decreases in blood pressure did not change in normal aging to 60 years compared to young adults

Subarachnoid hemorrhage in C57BL/6J mice increases motor stereotypies and compulsive-like behaviors

Objective: Long-term behavioral, mood, and cognitive deficits affect over 30% of patients with subarachnoid hemorrhage (SAH). The aim of the present study was to examine the neurobehavioral outcomes following endovascular perforation induced SAH in mice. Methods: C57BL/6 J (B6) mice were exposed to endovascular perforation induced SAH or control surgery. Three weeks later, mice received a series of behavioral tests, e.g. motor function, stereotypy, learning, memory, behavioral flexibility, depression and anxiety. The immunohistologic experiment examined neuronalloss in the cortex following SAH. Results: SAH mice exhibited increased marble burying and nestlet shredding compared to that of control mice. Although SAH did not affect memory, learning or reversal learning,mice displayed greater overall object exploration in the novel object recognition test, as well as elevated perseveration during probabilistic reversal learning.In the forced swim and open field tests, SAH mice performed comparably to that of control mice. However, SAH mice exhibited an increased frequency in \u27jumping\u27 behavior in the open field test. Histological analyses revealed reduced neuron density in the parietal-entorhinal cortices of SAH mice on the injured side compared to that of control mice. Discussion: The findings suggest that parietal-entorhinal damage from SAH increases stereotyped motor behaviors and \u27compulsive-like\u27 behaviors without affecting cognition (learning and memory) or mood (anxiety and depression). This model can be used to better understand the neuropathophysiology following SAH that contributes to behavioral impairments in survivors with no gross sensory-motor deficits