Comparison of parenchymal and ventricular intracranial pressure readings utilizing a novel multi-parameter intracranial access system

Abstract

IntroductionBoth ventricular and parenchymal devices are available for measurement of intracranial pressure (ICP). The Hummingbird® Synergy Ventricular System is a novel device allowing multi-parametric neurological monitoring, including both ventricular and parenchymal ICP. The purpose of this study is to compare the congruence of the device’s ventricular and parenchymal ICP readings.MethodsThis single-center, quantitative, interventional study compared parenchymal and ventricular ICP readings from 35 patients with the Hummingbird® System. If a difference of > ± 3 mmHg existed between an individual patient’s parenchymal and ventricular values, progressive intervention strategies were applied to correct identified issues.ResultsFrom a total of 2,259 observations, statistical analysis revealed congruence (within ±0-3 mmHg) of 93% of readings comparing parenchymal and ventricular ICP. Of the observations requiring intervention, 58% involved the parenchymal component, 30% involved the ventricular component, and 12% involved both components. Following prescribed interventions, 98% of readings became congruent (within ±0-3 mmHg). The adjusted mean difference between the two methods was -0.95 (95% CI: -0.97,-0.93) mmHg and all mean ICP readings fell between -2 and 2 mmHg.ConclusionThe Hummingbird® Synergy Ventricular System demonstrates congruence between ventricular and parenchymal ICP measurements within accepted parameters. Interventions required to realign parenchymal and ventricular readings serve as reminders to clinicians to be vigilant with catheter/cable connections and to maintain appropriate positioning of the ventricular drainage system. The results of this study support the recommendation to use the parenchymal ICP component for routine ICP monitoring, allowing dedication of the ventricular catheter to drainage of cerebrospinal fluid (CSF).

Evaluation of a New Catheter for Simultaneous Intracranial Pressure Monitoring and Cerebral Spinal Fluid Drainage: A Pilot Study

“…Several studies compared the ICP measurements from IPM and EVD, and their conclusions vary. Some studies suggest ICP data from the two devices are not interchangeable [30,31], while others show good agreement between ICP readings from IPM and EVD [21,32]. A system that can serve the needs of ICP monitoring and CSF drainage simultaneously is highly desirable, such as Integra ® Camino ® FLEX Ventricular Catheter used in this study.…”

“…The mean difference of 1.69 mmHg between ICP e and ICP f in our study is within the 2 mmHg tolerance level required by the ANSI/AAMI standard and can be considered as a surrogate of conventional EVD for ICP monitoring. Besides mean value, ICP waveform morphology should be considered when assessing reliability of ICP monitors [21,34]. The ICP pulse waveforms, characterized by three notches (P 1 , P 2 , P 3 ), also contain pathological information.…”

“…Both approaches are not desirable. The first approach introduces additional risk of having a second invasive probe, and the second approach introduces additional burden on health care providers and may miss important information due to intermittent nature of the measurement [21].…”

Evaluation of a novel noninvasive ICP monitoring device in patients undergoing invasive ICP monitoring: preliminary results

“…The EVD system allows therapeutic CSF drainage and clearance of intraventricular blood. 2,14,27 More importantly, an elevated ICP is considered a medical emergency and can be managed medically via placement of an EVD system. The fundamental indication for management of elevated ICP is to prevent secondary ischemia due to the decrease in cerebral perfusion, which may lead to brain herniation.…”

“…However, EVD devices are considered the most accurate, reliable, and cost-effective ICP monitoring methodology today, 2,15 with functional accuracy of 87%. 14 To overcome these obstacles, a variety of NI-ICP monitoring modalities have been explored in recent years, but according to several comparative analyses, none are as accurate as the invasive modalities.…”