Our question is trying to answer whether PoCUS can be used as a bedside screening tool to aid in the diagnosis and management of acute neurological dysfunction. Recent advancements in robotic transcranial ultrasound technology focusing on its utility in neuromonitoring enhance our ability to monitor neurological functions in real time, providing more precise and reliable data for our studies. Our protocol offers a simplified step-by-step PoCUS approach for bedside screening of neurological dysfunction.
It provides a quicker, more accessible assessment, compared to other techniques, and enables timely diagnosis and intervention in critical situations. To begin, select the phased array probe for the TCCD scan to provide the smallest footprint for the insonation of the transtemporal window. Set the ultrasound machine to the transcranial preset to position the indicator to the right of the screen.
Now, set the initial mode to B-mode and adjust the depth to 13 to 16 centimeters. Position the machine so that the ultrasound screen is directly in line with the ultrasound probe for optimal scanning ergonomics. Then, place the patient in a supine position with the head of the bed elevated to 30 degrees.
Now, apply ultrasound gel to the phased array probe. Place the probe on the transtemporal window, parallel to the ground with the index mark aimed toward the patient's anterior. Use a sliding motion to scan through the nearby brain tissue until the relevant intracranial structures are identified.
These structures serve as starting points to identify the landmarks needed for PoCUS TCCD. Identify the ipsilateral temporal bone, typically seen at a depth of around one centimeter. Then, identify the contralateral temporal bone observed at a depth of 14 to 16 centimeters.
Next, locate the third ventricle, which appears as two hyperechoic lines with a thin hypoechoic structure in between, representing cerebrospinal fluid. Begin with the view obtained from the previous steps. Reduce the depth so that the far field is set to 10 centimeters.
Then, locate the large color flow sampling box on the left side of the top half of the ultrasound screen. Initiate pulse-wave Doppler and center the box over the red color flow signal of the MCA. To obtain a spectral Doppler waveform, trace its contour to measure the velocity time integral for one cardiac cycle.
Ensure that the mean flow velocity, time average velocity, time-adjusted peak velocity, or time average maximum velocity is displayed. Also, verify that the pulsatility index is shown. Finally, review the acquired images in Doppler spectra to ensure they meet diagnostic quality standards.
Ensure that all images in Doppler data are properly saved and labeled for future reference and analysis. Inform the patient about any follow-up steps or additional tests, if required.
