1. Practical aspects of working in the operating room

2. Intraoperative neurophysiologic monitoring Electrophysiologic recordings in an electrical hostile environment Electrophysiologic recordings in an anesthetized patients The need to obtain interpretable records in a short time Interpretation of results must occur promptly What changes to report and what not to report? Communication with the surgeon Relation with the anesthesia team Relations with other members of the operating room team

3. Electrophysiologic recordings in an electrical hostile environment Survey an operating room that you not familiar with for sources of electrical interference –Best done the evening before an operation Always be in the operating room early enough to solve unexpected problems Always monitor the recorded potentials directly during an operation –EEG tells the signature of interference; averaged potentials do not

4. Find the source of interference

5. Electrophysiologic recordings in an anesthetized patient Advantages: –Can use needle electrodes freely –Can stimulate peripheral nerves supramaximal Disadvantages: –Can cause injury by too strong electrical stimulation of nerves or CNS

6. The need to obtain interpretable records in a short time Use optimal stimulus and recording parameters Reduce noise as much as possible at its source Use optimal placement of electrode wirings Plan your recordings ahead to avoid waste of time

7. Interpretation of results must occur promptly Prepare yourself ahead of time so you understand the recordings and their interpretation Understand the different kinds of changes that can occur and their meaning with regard to pathologies

8. What to report to the surgeon? INFORMATION THAT IS OF VALUE Changes in recorded potentials All unusual events In case of dramatic changes: –First assume a biologic cause and always notify surgeon immediately –Then check equipment etc.

9. What changes to report? Changes in the recorded potentials that are larger than the normal (small) variations

10. What not to report? Data without interpretation A stream of numbers without interpretation is of little value

11. Communication with the surgeon The surgeon is not a physiologist Therefore: Provide interpreted results, not raw data Place the observed changes in relationship to the ongoing operation You must know the basic steps in the operation you are monitoring

12. Interpretation of pathologic changes Which parameters are important? What to use as reference values? What is significant?

13. Change in relation to what? How to get a representative baseline

14. Which parameters are important? Latency Amplitude

15. Non-pathologic changes Change in anesthesia Change in body temperature

16. Artifacts Stimulus artifacts Movement artifacts Irrigation with cold saline may cause changes in recorded potentials

17. False positives False negatives Limited relevance for intraoperative monitoring

18. Relation with the anesthesia team Always discuss a case with the anesthesia team before an operation –What kind of anesthesia they want to use –How that will influence your work For that you must know the basics of modern anesthesia techniques

19. Relation with the anesthesia team Interchange of information –You can provide information of value for the anesthesia team –They can let you know of changes in vital signs and in anesthesia regimen

20. Relation with the anesthesia team Discuss each operation with the anesthesiologists in advance Ask to be informed about any changes in the anesthesia regimen that may occur during an operation Watch their displays and understand what they mean Treat the anesthesiologists as your friends and try to understand their situation and problems

21. Relations with other members of the operating room team Keep a good relationship with all nurses in the operating room (they control the environment) Do not be afraid of offering a helping hand Remember that they (and you) are all there for one single purpose, namely to provide the best possible care for the patient

22. Practical aspects of working in the operating room Should the person who is responsible for monitoring be present in the operating room? YES Can monitoring be done by watching a display of recorded potentials in an another room? NO