In the US alone, traumatic brain injuries (TBI) affect 2 million people on a yearly basis. TBI makes up 40% of trauma cases and is responsible for a significant rates of morbidity and mortality worldwide . One of the leading causes for morbidity and mortality is ischemic brain injury, which occurs when the brain is deprived of the necessary oxygen to meet metabolic demand . Jugular venous oximetry (SjvO2) is a measurement used to estimate the balance between the delivery and consumption of global cerebral oxygen. SjvO2 measurements are used to determine cerebral ischemia by detecting events of desaturation (SjvO2 drops below 50% for 10 minutes or longer) . Events of desaturation are strongly associated with poor neurological outcomes . Monitoring SjvO2 allows early identification of desaturation, thereby allowing physicians to make timely decisions in order to lower the risk of secondary brain injuries, improve the patient’s wellbeing, and reduce long term neurological outcomes.
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Interpreting Changes in SjvO2 1-4
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Currently SjvO2 monitoring is done invasively with the use of fiber optic catheters and co-oximetry laboratory blood analysis. This timely and complex method requires the retrograde insertion of a catheter through the jugular vein by a highly trained healthcare professional . As well, fiber optic catheters are susceptible to erroneous readings due to, the rate that the blood is withdrawn, patient head positioning, and correct tip placement . The current precision for commonly used fiber optic catheters, is ±4.41% . Due to the problems associated with fiber optic catheters they are limited in use to only a few clinical applications.
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Our solution to improve TBI management
The Mespere VO 100 Jugular Venous Oximetry is a noninvasive and continuous jugular venous oximetry monitoring system that uses near infrared spectroscopy to measure venous hemodynamics without the need for invasive catheterization. The VO 100 can be applied to the patient in a matter of minutes by any healthcare professional. The VO100 works by simply attaching a low cost adhesive to the reusable sensor and adhering it over the patient’s jugular vein. Once the sensor is applied to the patient, the VO100 continuously monitors jugular venous oximetry (SjvO2) and jugular vein distention (BVI). The VO 100 is not susceptible to the same sensitivity and clinical risks as the traditional invasive catheter method, since: it is 100% non-invasive, it does not rely on blood samples, and it does not require placement/insertion of a catheter. Additionally, the VO 100 has an accuracy of ±2%, which is more precise than current invasive fiber optic SjvO2 monitoring methods.
Parameters monitored using the VO 100
SjvO2 - Venous oxygen saturation as an indication of oxygen consumption
BVI - Regional blood to tissue volume ratio as an indication of jugular vein distention
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Advantages of using the VO 100 versus traditional invasive catheters
Low Risk - 100% non-invasive using near infrared spectroscopy
Efficient measurement times - measurements achieved in minutes versus hours
Easy to Use - any healthcare professional can place the sensor on the patient's jugular vein
Low Cost - single-use adhesives adhere a reusable sensor probe to the patient's skin
High accuracy - validated accuracy of ±2%
Continuous monitoring of venous oxygenation has been proven to be a valuable measurement tool for clinicians, especially for treating TBI. It allows them to monitor the balance between oxygen delivery and consumption. The Mespere VO 100 is a non-invasive continuous jugular venous oximetry monitoring system that is accurate, can be placed by any healthcare professional in a matter of minutes, and has far fewer risks than fiber optic catheters. The VO 100 Jugular Venous Oximetry is ideal for monitoring SjvO2 for TBI in the emergency department, intensive care units and anesthesia settings.
References​
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Sharf M, El-Gebali M. Correlation between Glasgow coma scale and jugular venous oxygen saturation in severe traumatic brain injury, Egyptian Journal of Anaesthesia, 2011:29:3, 267-272, DOI:10.1016/j.egja.2013.02.008
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Chan M, Ng S, Lam J, Poon W, Gin T. Re-defining the ischemic threshold for jugular venous oxygen saturation – a microdialysis study in patients with severe head injury. Acta Neurochir, 2005:95:63-66
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Gopinath S, Robertson C, Contant C, Hayes C, Feldman Z, Narayan R, Grossman R. Jugular venous desaturation and outcome after head injury, J Neurol Neurosurg Pshychiatry 1994;57:717-23.
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Cormio M, Valadka A, Roberston C.(1999) Elevated jugular venous oxygen saturation after severe head injury, J Neurosurg, 90:9-15
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Vavilala M, Soriano S. Anesthesia for neurosurgery. In Peter J, Franklyn P, Etsuro K, eds. Smith’s Anesthesia for Infants and Children. Elsevier, Amsterdam, The Netherland, 2011:713-44
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Holly CG, Matta BF, Lam AM, Mayberg TS. Accuracy of continuous jugular bulb venous oximetry during intracranial surgery. J Neurosurgical Anesthesiology 1995:7(3):174-7
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Mahajan A, et al. An experiment and clinical evaluation of a novel central venous catheter with integrated oximetry for pediatric patients undergoing cardiac surgery. International Anesthesia Research Society 2006;16:1257-63