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BackgroundThis study aims to explore factors that affect venous sinus pressures and associated gradients while awake and under general anesthesia (GA) both before and after venous sinus stenting (VSS) in patients with idiopathic intracranial hypertension (IIH).MethodsA retrospective analysis was performed examining pressures and gradients in patients with IIH having undergone awake venography followed by VSS under GA.Results174 patients were included. Compared with awake, GA superior sagittal sinus (SSS) pressures were 2.6 mmHg lower (p=0.01) resulting in a total cranial gradient reduction of 2.5 mmHg (p=0.002). The transverse-sigmoid gradient, the most commonly stented segment, did not differ under the two conditions (p=0.30). Regression analyses demonstrated that body mass index, gender, blood pressure, and end-tidal carbon dioxide content significantly affected venous pressures (all pConclusionsThis study is the largest series to date to report on cerebral venous pressure measurements and gradients recorded while awake and under GA both before and after VSS for IIH. In a well-controlled cardiorespiratory and anesthetic setting, GA venography may provide information that is not substantially inequivalent to that obtained while awake.

Background In-training examinations (ITEs) are commonly used by residency programs to measure competency in their respective fields. It has been demonstrated that success on the ITE is correlated to First Time Pass Rate (FTPR) on the boards. Therefore, it is important to motivate residents to perform well on these exams. Previous studies indicate positive incentivization may contribute to improvement on examinations. The objective of our study was to determine whether introduction of a positive incentive could improve resident performance on the ITE and/or FTPR on the advanced certifying exam. Methods A positive incentive was introduced in 2017 (certificate of commendation, curriculum vitae honor, public recognition, and $500 in their books/travel allowance) to residents who achieved the target score on the ITE (80th percentile). A survey was then provided to these residents to determine which incentives contributed most to their motivation. Results Before the incentivization, 21 (15.1%) of the previous 149 senior residents reached the target score on the annual ITE. After incentivization, this improved to 28 (30.9%) of 81 (P = .0056). The FTPR on the advanced certifying exam was 90% before incentivization and 97.6% after (P = .14). The survey found that the primary motivators were extra funding, honor on their curriculum vitae, and public recognition. Conclusions We found that our residents had significant improvements on the annual ITE after the introduction of positive incentives. This incentivization may be easily implemented by program directors in their respective medical residencies to increase examination performance.

Background In the diagnosis of venous stenosis associated with idiopathic intracranial hypertension, previous studies have identified significant differences when venous pressures are measured under conscious sedation versus general anesthesia. No previous reports have investigated the effect that respiratory parameters may have on cerebral venous sinus pressure and the associated trans-stenosis pressure gradient. Case Description Two patients with idiopathic intracranial hypertension were retrospectively identified from a prospective database wherein venous manometry was performed as part of a venous stenting procedure with waveform recording during changes in end-tidal carbon dioxide level (EtCO2). Upon microcatheterization of the superior sagittal sinus after induction of general anesthesia, both patients were noted to have an EtCO2 of 29 mm Hg. After EtCO2 was corrected to 40 mm Hg, repeat venous manometry was conducted, which demonstrated increased SSS venous pressures from 12.6 to 21.1 mm Hg and 18.4 to 30.3 mm Hg in patients 1 and 2, respectively. In addition, the waveform amplitude increased in both patients after EtCO2 correction. Conclusions This series demonstrates that EtCO2 changes have an immediate and pronounced effect on venous sinus pressure measurements with waveform changes that may correlate to increased intracranial pressure. These findings underscore the need to perform measurements of venous sinus pressure gradients under normal awake conditions.

IntroductionVenous outflow obstruction is recognized as a contributing factor in a subset of patients with idiopathic intracranial hypertension (IIH). Little is known about venous sinus waveform morphology or how it changes after stenting.MethodsFifteen patients with IIH underwent waveform recording during catheter venography and manometry. Ten patients (Group A) with venous sinus stenosis and pressure gradient ≥7 mm Hg underwent waveform recording during awake venography and during stenting under general anesthesia. Five control IIH patients (Group B) without a gradient underwent awake recording only.ResultsGroup A patients underwent successful stenting with reduction of their gradient from 15.1±6.19 mm Hg to 1.2±0.60 mm Hg. This resulted in an amplitude reduction from 8.3 mm Hg to 2.8 mm Hg (P=0.02). Qualitative evaluation of the waveform yielded a number of novel findings. In Group A before stenting, the observed waveform progressed from an intracranial pressure (ICP)-dominated to central venous pressure (CVP)-dominated waveform. Stenting abolished the high amplitude waveform and smoothed the transition from the intracranial to central venous measurement points. Group B displayed primarily CVP-influenced waveforms distal and proximal to the transverse-sigmoid junction along with respiratory variability of the waveform, absent in 8/10 Group A patients. General anesthesia appeared to blunt the waveform in 5/10 Group A patients.ConclusionThe cerebral venous waveform appears to be influenced by both the ICP and CVP waveforms. As measurement moves proximally, the waveform progressively changes to mirror the CVP waveform. Venous sinus stenosis results in a high amplitude waveform which improves with treatment of the stenosis.

Introduction/purpose Idiopathic intracranial hypertension (IIH), otherwise known as pseudotumor cerebri or benign intracranial hypertension, is a syndrome defined by a severe headache in the setting of increased intracranial pressure (ICP) in the absence of an intracranial mass. The pathophysiology of IIH remains poorly understood. However, venous outflow obstruction detected by cerebral venous manometry at the transverse sinus has been recognized as a contributing factor in a subset of patients with IIH, and stent placement in this subset of patients is associated with good clinical outcomes. Surgeons often determine candidacy for stent placement based on the magnitude of the venous pressure gradient across the site of stenosis. Furthermore, there is little known about venous sinus pressure waveform morphology in patients with this condition or how it changes after stenting. The purpose of this study was to prospectively analyze patients’ venous sinus waveforms, their component peaks, and the influence of stenosis or anesthesia on waveform morphology with a goal of ultimately providing insight into the waveform and pathological morphologic changes seen with venous sinus stenosis. Materials and methods Fifteen patients with IIH were enrolled prospectively and underwent waveform recording during catheter venography and manometry. Ten patients (Group A) with venous sinus stenosis and pressure gradient >8 mmHg underwent waveform recording during awake venography and then pre- and post-stent manometry while under general anesthesia. Five control IIH patients (Group B) without a trans-stenosis gradient underwent awake recording only. Results All Group A patients underwent successful stenting with reduction of their gradient from 15.1 (+6.19) mmHg to 1.2 (+0.60) mmHg. This resulted in statistically significant reduction of the transverse sinus amplitude from 8.3 mmHg to 2.8 mmHg (p Conclusion In conclusion, the cerebral venous waveform morphology appears to be influenced by both the intracranial pressure (ICP) waveform and the central venous pressure (CVP) waveform. Additionally, venous sinus stenosis with significant venous outflow obstruction results in morphologic changes to the waveforms. After performing stenting in patients with stenosis, waveforms return to match the control group. Future studies should expand on the qualitative patterns described in this study and place a significant amount of consideration in determining the clinical and hemodynamic ramifications of these findings. Disclosures J. West: None. R. Garner: None. G. Greeneway: None. J. Traunero: None. C. Aschenbrenner: None. J. Singh: None. S. Wolfe: None. K. Fargen: None.

Volatile anesthetic agents comprise a substantial portion of every hospital's pharmacy budget. Challenged with an initiative to lower anesthetic drug expenditures, we developed an education-based intervention focused on reducing volatile anesthetic costs while preserving access to all available volatile anesthetics. When postintervention evaluation demonstrated a dramatic year-over-year reduction in volatile agent acquisition costs, we undertook a retrospective analysis of volatile anesthetic purchasing data using time series analysis to determine the impact of our educational initiative.We obtained detailed volatile anesthetic purchasing data from the Central Supply of Wake Forest Baptist Health from 2007 to 2014 and integrated these data with the time course of our educational intervention.Aggregate volatile anesthetic purchasing data were analyzed for 7 consecutive fiscal years.The educational initiative emphasized tissue partition coefficients of volatile anesthetics in adipose tissue and muscle and their impact on case management.We used an interrupted time series analysis of monthly cost per unit data using autoregressive integrated moving average modeling, with the monthly cost per unit being the amount spent per bottle of anesthetic agent per month.The cost per unit decreased significantly after the intervention (t=-6.73, P.001). The autoregressive integrated moving average model predicted that the average cost per unit decreased $48 after the intervention, with 95% confidence interval of $34 to $62. As evident from the data, the purchasing of desflurane and sevoflurane decreased, whereas that of isoflurane increased.An educational initiative focused solely on the selection of volatile anesthetic agent per case significantly reduced volatile anesthetic expense at a tertiary medical center. This approach appears promising for application in other hospitals in the rapidly evolving, value-added health care environment. We were able to accomplish this with instruction on tissue partition coefficients and each agent's individual cost per MAC-hour delivered.