An article titled “Advanced Neurological Monitoring” was published in 2016 in the Oxford Journal discusses the advantages of using intensive neurological monitoring in conjunction with conventional monitoring to promote better outcomes in patients who have suffered traumatic brain injuries (TBI) and/or subarachnoid hemorrhage (SAH). The monitoring modalities included in the discussion involve the following: pressure monitoring, cerebral perfusion pressure monitoring, jugular bulb oximetry, transcranial doppler ultrasongraphy, brain tissue oximetry, near infrared cerebral spectroscopy, cerebral microdialysis, cerebral imaging, and continous EGG. This article suggests that using a combination of the above listed monitoring strategies will improve outcomes through early detection and intervention secondary to advanced monitoring. Furthermore, it is suggested that “An integrated approach to measuring intracranial pressure alongside cerebral oxygenation and metabolites may therefore be useful in predicting patients at risk of deterioration.” Through use of a variety of measurements nurses and physicians are able to gain a more clear understanding of the cellular and pressure changes occurring in the brain of a patient who has sustained a TBI or SAH. Below is a summary of the purpose of the above mentioned monitoring strategies:
Pressure Monitoring: the intraventricular catheter is considered the most accurate way of monitoring and draining CSF
Cerebral Perfusion Pressure: is equal to the MAP- ICP. CPP below 50mmHg is directly related to blood flow and means ischemia may occur in the brain injured patient and leads to poorer outcomes. Target CPP should be between 50-70 mmHg
Jugular Bulb Oximetry: catheter that is inserted into internal jugular vein. normal oximetry for such a catheter is between 55%-85%, if less than 55% the patient has a deficit of cerebral oxygen delivery. The most common reason for jugular bulb desaturation is reduced CPP secondary to increased ICP. “Acute hyperventilation is a life saving ICP-reducing maneuver that can be titrated to SjO2 lmiting hypocapnia-induced vasoconstriction and ischemia”. ( Ralph & Singh, 2016, p. 95)
Transcranial Doppler Ultrasonography: non-invasive tool used to help approximate cerebral blood flow. This monitoring tool is most commonly used to assess for vasospasm, cerebrovascular autoregulation, emboli detection and, cerebral perfusion (Ralph & Singh, 2016).
Brain Tissue Oximetry: this is used to assess oxygen tension within brain tissues extracellular fluids. It is thought that balancing oxygen delivery through this type of monitoring improves patient outcomes.
Near Infrared Cerebral Spectroscopy: non-invasive method to assess cerebral oxygen concentrations. Mostly used in pediatrics but has proven helpful in TBI and SAH patients as well
Cerebral Microdialysis: used to assess and quantify the extracellular fluid makeup inside the brain itself. It filters small molecules through diffusion and allows for sample testing of the fluid drained to assess for chemicals, drugs and byproducts of metabolism
Cerebral Imaging: produces very detailed photographs of the metabolic and hemodynamic status of the brain (Ralph & Singh, 2016)
Continuous EEG: allows for the early recognition and rapid intervention of a patient experiencing seizure activity which often occurs after TBI and SAH.