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The Do's and Don'ts of Autonomic (ANS) Testing

Autonomic Nervous System (ANS) testing is a strong diagnostic tool to uncover an array of clinical risks. Assessing conditions such as Autonomic Neuropathy, Vascular Dysfunction, Blood Pressure issues, and more requires the use of sensitive medical equipment with proper testing procedures and system maintenance. Also, like most things in life, there is a right way and a wrong way to perform ANS testing. Below are some tips to get the best results you can and keep your equipment functioning like new!

Patient Set-Up:

  • Don't: mix up the blood pressure and pulse oximeter ports on your ANS system box. The software assumes these are correctly placed, and using the wrong one will mix test data and skew results, making the test invalid

  • Do: correctly plug each cable into the designated port. The ports are labeled to correlate with the patient's upper and lower body. Anything with a “1” goes on the patient's UPPER body, anything with a “2” goes on the patient's LOWER body.

  1. NIBP 1: right arm - blood pressure cuff

  2. NIBP 2: Right ankle - blood pressure cuff

  3. PPG 1: left index finger - pulse oximeter

  4. PPG 2: right second toe - pulse oximeter

  • Don't: switch the blood pressure cuffs/ pulse oximeters between extremities (removing from the upper body and placing on the lower body) without also unplugging the wires from the ANS box and re-plugging them into the correct port. This may seem self-explanatory, but it can be easy to forget to do this! Otherwise, the data will be inaccurate!

  • Do: unplug and re-plug the entire cable if any component needs to be switched between extremities. This will ensure wires are correctly plugged into their "1" and "2" spots (see above). No matter what, always triple-check that they are correct before continuing with the test.

  • For example: If you put NIBP 2 on a patient's ankle but realize the cuff size would fit better on a patient's arm, remember to unplug the cable from NIBP 2 and re-plug it into NIBP 1 when switching between extremities. Don't just switch the cuffs!

  • Don't: sit the patient in a chair with wheels.

  • Do: use a stable chair that does not have wheels. The patient must stand and sit multiple times during a test. This can be hazardous, especially for patients who may feel lightheaded or dizzy.

  • Don't: place electrodes on patients without first connecting the wire to the sticker. We don't snap wires onto patients! This is uncomfortable and risks the gel diffusing from the center, reducing the reading accuracy and creating a ton of artifact.

  • Do: start by connecting the lead wire to the electrode sticker. Then place the stickers on the patient. Secure the electrodes by gently pressing around the edges of the circle. Remember to not press the center of the electrode where the lead is attached (pressing center = diffusing gel = bad data!)

  • Electrode placements:

  1. R= Right clavicle

  2. N= Left clavicle

  3. L= lower/ last left rib

Test Administration

  • Don't: let a patient talk or move a lot during the test.

  • Do: have a patient remain quiet and still while completing the testing phases. Otherwise, the data will not be accurate.

  • “We’d love to hear about your vacation! Let’s do the test first and then tell me all about it.”

  • Don't: have a patient struggle with the deep breathing tempo.

  • Do: remind the patient that it's harder to inhale for 5 seconds than it is to exhale for 5 seconds. Have them inhale slowly so they don't prematurely run out of lung capacity. Coaching the patient's breathing helps with timing.

  • It’s more important that the patient breathes in and out in 5-second increments than it is for the patient to breathe in when the system says, “breath in”. It’s ok if they’re off as long as it's a slow, deep inhale/exhale.

  • Don't: let a patient perform the Valsalva Maneuvers without an explanation AND demonstration. Also, don't have them do their first Valsalva alone. This breathing exercise is usually totally foreign to a patient, and they feel silly! As a result, patients usually under-exaggerate their first Valsalva.

  • Do: explain the Valsalva to the patient, perform an example, then do the first maneuver with them. Showing an example and doing the first Valsalva with the patient will clarify what they need to do, ensure proper intensity, and make them feel less embarrassed! This will produce better test results! *Just don’t hold your breath the whole time, since you, the test specialist, can’t risk passing out.

  • Have the patient take a huge breath in, and abruptly cut off their breath. A clear sound should be made during this, similar to a football player saying "hut, hut, HIKE!". Have the patient hold their breath and build as much intensity as they can, almost like trying to push out their breath without actually blowing any air out. Then, have the patient blow out as strongly as they can. Tell them to imagine 100 candles are placed across the room and they are trying to quickly and strongly blow them out in a single breath!

  • Don't: make a visibly lightheaded patient perform a second Valsalva at the same intensity.

  • Do: monitor the state of a patient after their first Valsalva and determine their capability for the second. Patients who "ace" the first Valsalva, especially older patients, may visibly look dizzy and lightheaded. To prevent the patient from potentially passing out if they perform a second Valsalva at the same intensity, instruct the patient to decrease the strength for their second motion. “This time, let’s just take a breath in and hold it, but maybe not bear down as much.”

  • More commonly, patients will need to increase their Valsalva intensity, rather than decrease it. As a rule of thumb, after your demonstration, evaluate their first Valsalva performance and adjust accordingly. Coach the patient the whole time! A better Valsalva will produce better results.

  • Don't: let a patient stand up without assistance. Some patients are at risk of fainting or collapsing upon standing.

  • Do: help a patient stand up when they are prompted to. With one hand, support the patient's upper back. With your other hand, grab the patient's shoulder. Guide them to a standing position every time the patient is instructed to stand. Do the same when the patient sits back down, helping them safely back to their chair. This is necessary every time a patient sits and stands, even if a patient appears stable.

  • After helping a patient stand after the Valsalva exercise, immediately ask if they feel dizzy or lightheaded. If they say they’re a little/kinda dizzy, ask if they are ok to remain standing. Valsalva can definitely make patients feel dizzy. The Valsalva creates changes in a patient's heart rate and blood pressure. Depending on the patient's ability to regulate they may feel extremely dizzy or lightheaded when standing. Always have a patient try standing up to collect data for possible orthostatic hypotension or syncope but evaluate a patient's safety and have them sit back down if necessary.

  • If a patient has to sit down after initially standing up, because of dizziness, always sit them down. Their safety is always most important. Also, at that point, the software has collected what it needs to in order to reflect the Blood Pressure.

  • Don't: let a patient move their hands and feet during sudomotor testing.

  • Do: have the patient firmly press their hands and feet on the plates. Although the sub-sensory signal can cause a patient to sweat, it is important that any sliding or movement is eliminated. Often times this happens without a patient noticing, so remind them to be aware of this and aim to remain still.

  • The best results come from patients who are standing, not seated, with the feet plate placed on the floor. This decreases the possibility of sliding feet, thus improving the accuracy of the test. The hands' plate should be placed on a table or system cart at a comfortable height.

System Cleaning

  • Don't: test a patient with dirty Sudomotor plates. This is unsanitary and the plates will be visibly dirty after each test. Patients do not want to touch mystery dirt, sweat, and grime from other people's hands, and especially not from other people's feet! Yuck!

  • Do: clean the Sudomotor plates after each test. Tell the patient the plates have been disinfected. You can even clean them in front of the patient.

  • Thoroughly wipe the plates with an antibacterial wipe, then immediately dry with a paper towel. Your plates will look brand new!

  • Don't: test a patient with dirty Sudo

  • Do: clean the Sudomotor plates after each test. Tell the patient the plates have been disinfected. You can even clean them in front of the patient.

  • Thoroughly wipe the plates with an antibacterial wipe, then immediately dry with a paper towel. Your plates will look brand new!

General System Maintenance:

  • Don't: continue to use the laptop without regularly checking for updates - Dell, Microsoft, Manufacturer. Oftentimes, updates don’t automatically run on their own. With any laptop-based equipment, Microsoft Updates can actually start compiling in the background, causing the computer to slow down. This ultimately affects the software's ability to communicate with the hardware!

  • Do: regularly check for Windows Updates. Most offices will check for Windows Updates every Friday after the last test.

  1. Click on the START / WINDOWS icon button on the bottom left corner of the Desktop.

  2. Click on the SETTINGS icon (the second on up from the bottom).

  3. Click on "Update & Security"

  4. No matter what the computer says, click "Check for updates".

  5. Update, restart when prompted, and repeat this till no updates are available.

  • Don't: run the software while offline.

  • Do: keep the laptop online and connected to Wi-Fi.

  • Don't: save your report PDFs on the laptop without an organization method

  • Do: develop a system to organize the reports you save to the laptop. This way you can easily find old patient records if needed.

  • Bonus: We recommend saving reports in folders correlating to the month of testing. At the end of the year, compile the monthly folders into a yearly folder, then repeat the process for every year. (Ex. 2019 Folder --> Jan 2019 Folder, Feb 2019 Folder, etc.)

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