Cerebral Oximetry : Current data to support its use

1. Cerebral Oximetry: Current data to support its use William Dedo, MD Lafayette, Louisiana Professional Anesthesia Services

2. NIRS/ Technology improving • Where CBF monitoring has been • What is currently available • What to expect • Where we are going

3. Casual observation Yep….he IS asleep!!! Curious about his brain?

4. Brain mapping circa late 1800’s

5. We have a desire to increase our ability to quantify all the details

6. Different perspectives to measure: Function Blood flow Metabolism

7. Functional assessment: EEG (electroencephalogram) Evoked potentials EMG (electromyography)

8. Blood flow: Jugular venous bulb sampling Brain oxygen probes Trans Cerebral doppler

9. Metabolism Microdialysis (neurochemical research tool) Biomarker levels (glu, lactate, ammonia metabolites)

10. All have drawbacks Ease of use Invasiveness Utility of information Adjustment in therapy

11. Cumbersome can be an issue:

12. Sep 18, 2011 00:00 in article by Nick Owens UK Mirror about Baby lab

13. Additional holes in the skull:

14. Other modalities studied • Transcranial Doppler (TCD) • Intraop EEG • IntraopRadiolnuclide CBF measuring with Xenon-133 • Intraop cerebral arteriograms Friedman, JA, Anderson, RE, Neurosurg Focus 2000; 9(5)

16. Gold Standard for a monitoring modality: Pulse oximetry

17. Pulse Oximeter: • Totally non-invasive • Ease of use • Exceedingly reliable • Can verify measurements with other modalities/techs • Not only provides SaO2, but also heart rate and ability to audibly provide data with changing tonality of pulse

18. Related technology • Continuous Cardiac Output SVO2 catheter (Edwards Lifesciences) • Cerebral Oxygen Saturation monitors

19. Picture of SG with red light at fiberoptic tip

20. Fiberoptic strands transmit finely tuned frequencies to the tip

21. Edwards Lifesciences Monitor

22. Three main Cerebral Oximeter monitors avail: CASMED – FORE-SIGHT rSO2 system COVIDIEN – INVOS rSO2 system NONIN MEDICAL – SenSmart Universal Oximetry System

23. CASMED – FORE-SIGHT

24. COVIDIEN - INVOS

25. NONIN Medical’s EQUANOX

26. Nonin’s many channels:

27. Nonin’s clean display:

28. NO RELATIONSHIP TO REPORT • For the record: I have no allegiance to any of these companies • imperative to make this declaration, since there really only appears to be one device that is relevant • Not just my opinion, but supported by several articles and our experience • May simply be a function of which one is newest and has the latest technology • We are using them at The Heart Hosp, Lafayette (OLOL)

29. NONIN Medical’s unit: • Smaller/lighter than the other models • 2 lbs vs 14 lbs (0.9 kg vs 6.9kg) • Relevant when you keep adding monitors on top of monitors

30. Out of control stack of monitors:

31. Our workstation

32. NONIN’s other attributes • EMR-capable with wireless connectivity possible • Double the emitters of the other two units • Longer battery life ( if you need to run it unplugged) • Can monitor SpO2 as well • Warranty is 36 months vs 12 months

33. Nonin’s cost/value: • 8004CA, 20 Units of sensors: $1400 • Calculates to: $70/sensor (x2 = $140) • Down from $130/unit with prior product (x2 = $260) • Annualized savings: $48,000 +

34. Survey of the sensors:

35. Newest generation and benefiting from tech improvements as they become available Better stick-on device for forehead Less trouble with ambient light Signal starts without calibration issue

36. Elements of the Technology • NIRS operates in 700-900 nm wavelength spectrum • Generated pulsed light source • Multiple wavelenghts to discern between oygenatedvs de-oxygenated chromophores assoc with Hemoglobin • Reflectance of signal hampers interpretation • No gold standard to validate the measured values

37. Full Details of Patent description

39. Hgb molecule

40. Drawbacks still remain!

41. “RNG” features “What is THIS?!,“ you may ask

42. R RandomN NumberG Generator

43. Extracranial Contamination • Davie et al from Winnipeg, Canada in a study from April 2012 in Anesthesiology, demonstrated with all three monitors, significant change of signal occurs when a circumferential headcuff is inflated in a headband-fashion • All three monitors experienced drop-off of their signal • NOT “seeing” just the brain’s blood oxygen characteristics Davie, SN, Anesthesiology 2012; 116:834-40

44. Cerebral Tourniquet Davie, SN, Anesthesiology 2012; 116:834-40

45. Investigational study sequence: Davie, SN, Anesthesiology 2012; 116:834-40

46. Oximetry results from Davie et al: Davie, SN, Anesthesiology 2012; 116:834-40

47. More monitors coming: Gadget Jan 2014

48. Current investigation: • In an abstract presented at the Society for Technology in Anesthesia 2014 Annual Meeting in Orlando, Fla., Dr. Daniel Redford from the University of Arizona evaluated cerebral oxygen saturation on 23 subjects and 202 paired measurements of rSO2 from their probe and reference arterial and venous blood samples • Est good correlation with JVB sampling • for use in subjects larger than 40 kg (88 lbs) and has not yet received FDA 510(k) clearance (News Release Masimo Jan 2014)

49. Jugular Venous Bulb Physio:

50. Another study in Ohio