Jagid, Jonathan

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Jagid, Jonathan

  1. 1. ICP Management<br />Jonathan R. Jagid, M.D.<br />Associate Professor of Neurological Surgery<br />University of Miami<br />
  2. 2.
  3. 3. 2o Mechanisms<br />
  4. 4. Cerebral Ischemia: What Happens?<br />activation of protein <br />kinase enzymes<br />electrical <br />depolarization<br />cytoskeleton<br />breakdown<br />Ischemic Event <br />Triggers <br />Chemical Cascade<br />blood/brain<br />barrier breakdown<br />oxygen radicals<br />production<br />release of<br />neurotransmitters<br />
  5. 5. All strategies targeted towards attenuation of ischemia<br />
  6. 6. Facts about High ICP…<br />Commonest cause of death, in Traumatic Brain Injury(80%), severe occlusive stroke, SAH,ICH,Cardiac arrest.<br />Commonest mechanism of brain death.<br />UNDERSTAND THE PATHOMECHANISMS!!<br />
  7. 7.
  8. 8. Indications for ICP Monitoring <br />No Level I evidence for ICP Monitoring<br />Level II Evidence<br />Should monitor all salvageable patients with severe (GCS 3-8) TBI and abnormal CT scan<br />60% have high ICP<br />Level III Evidence<br />Also indicated in patients with severe TBI and negative CT Scan if 2 or more criteria met:<br />Age ≥ 40 years, unilateral/bilateral posturing, SBP < 90 mmHg<br />60% high ICP<br />
  9. 9. Intracranial Pressure Monitoring Technology<br />I. <br />In the current state of technology the ventricular catheter connected to an external strain gauge is the most accurate, low cost, and reliable method of monitoring intracranial pressure (ICP). It also can be recalibrated in situ. ICP transduction via fiberoptic or micro strain gauge devices placed in ventricular catheters provide similar benefits, but at a higher cost.<br />Parenchymal ICP monitors cannot be recalibrated during monitoring. Comparison to zero drift after removal for current parenchymal micro strain gauge transduced ICP monitors is negligible at levels > +/-5 mmHg. The measurement drift is independent of duration of monitoring. <br />Subarachnoid, subdural, and epidural monitors (fluid coupled or pneumatic) are less accurate.<br />$$<br />X<br />Subarachnoid, subdural, epidural<br />
  10. 10. When should treatment be initiated?<br />ICP > 20-25<br />Ratanalert et al. 2004, Prospective trial of 27 patients<br />Grouped into ICP treatment thresholds of 20 or <br />25mmHg. Treatment protocols were similar between <br />Groups with CPP kept as > 70 and SjO2 at > 54%<br />No difference in outcome.<br />
  11. 11. Marmarou et al, 1991<br />Prospectively collected database of 1,030 severe TBI patients<br />428 met ICU monitoring criteria<br />Analyzed for monitoring parameters that determined outcome and their threshold values<br />Results<br />Threshold value of 20mm Hg found to be best correlate with outcome<br />
  12. 12. Cerebral Perfusion Pressure<br /> B. Level 2<br />Aggressive attempts to maintain cerebral perfusion pressure (CPP) above 70 mm Hg with fluids and pressors should be avoided because of the risk of adult respiratory distress syndrome (ARDS). <br /> C. Level 3<br /> CPP < 50 mm Hg should be avoided.<br /> The CPP value to target lies within the range of 50 – 70 mm Hg. Patients with intact pressure autoregulation tolerate higher CPP values.<br />Ancillary monitoring of cerebral blood flow, cerebral oxygenation, cerebral oxygen extraction or lactate production, and cerebral metabolism can facilitate CPP management<br />X<br />>70<br />X<br /><50<br />50-70<br />
  13. 13. ICP Monitoring to “titrate” therapy <br />To severity<br />
  14. 14. Effect of Guidelines-Based Protocols<br />Consistent application of an acute care protocol based on the Guidelines for the management of severe traumatic brain injury improves outcome<br />Class 2 study<br />Two groups of patients were studied. Group I, the pre-TBI guidelines group consisting of 37 patients admitted between January 1994 and June 1997, was managed with an emphasis on ICP reduction. Group II, the post-TBI guidelines group consisting of 56 patients admitted between June 1997 and December 1999, was managed with an emphasis on concurrent ICP reduction, CPP enhancement, and maximization of cerebral oxygenation<br /> Palmer, S. J Mission Regional Medical Center, Mission Viejo California J Trauma 2001;50: 657-664<br />
  15. 15. What Else is occuring?<br />Autoregulatory dysfunction<br />Compliance issue<br />Are these variables equal for all injuries?<br />
  16. 16. PROBABLY NOT!<br />
  17. 17. Intracranial Pressure Wave Form<br />
  18. 18. Analysis<br />ICP Waveform has 3 components<br />Pulse waveform<br />Respiratory waveform<br />Slow waves or Lundberg B waves<br />Pulse waveform can be divided into several harmonic components<br />Most prominent has frequency equal to heart rate<br />
  19. 19. Amplitude of this component is called AMP<br />A correlation coefficient can be obtained between AMP and mean ICP<br />This correlation coefficient represents cerebral compliance (RAP)<br />
  20. 20.
  21. 21. Cerebrovascular Pressure Reactivity (PRx)<br />Indication of autoregulatory state<br />Ability of vascular smooth muscle to respond to changes in transmural pressure<br />Response of ICP to changes in MAP<br />Normal response is vasoconstriction to increased MAP<br />increase in MAP, decrease in ICP<br />
  22. 22. How to measure?<br />Do not want to manipulate MAP in head injured patients<br />Takes advantage of slow waves in MAP due to mechanical ventilation<br />These minor fluctuations are compared to ICP and define PRx or cerebrovascular pressure reactivity index<br />
  23. 23. Negative values correlate with intact autoregulatory response<br />Validated with PET CBF and CMRO2<br />Zweifel, et al., Neurosurg Focus 25 (10):E2, 2008<br />
  24. 24. Zweifel, et al., Neurosurg Focus 25 (10):E2, 2008<br />
  25. 25. Zweifel, et al., Neurosurg Focus 25 (10):E2, 2008<br />
  26. 26. Zweifel, et al., Neurosurg Focus 25 (10):E2, 2008<br />
  27. 27. Zweifel, et al., Neurosurg Focus 25 (10):E2, 2008<br />
  28. 28. Surgical Decompression <br />If other options fail, entertain hemicraniectomy, holocraniectomy, lobectomies, etc.<br />Results controversial<br />
  29. 29. Massive decompressive craniectomy and duroplasty- the most effective current therapy, for high ICP…..??<br />
  30. 30. Miami Experience<br />2003-2009<br />47 patients<br />Ages 15-54<br />Follow up range 6 mos to 5 years<br />6 unilateral, 41 bifrontal<br />
  31. 31. Pre vs. Post Operative ICP’s<br />
  32. 32. Time of Surgery<br />87%<br />60%<br />49%<br />
  33. 33. Severity vs. Timing<br />
  34. 34. GCS vs. Timing<br />
  35. 35. Timing of Surgery vs. GOS <br />61%<br />22%<br />50%<br />17%<br />80%<br />60%<br />30%<br />100%<br />20%<br />10%<br />20%<br />20%<br />100%<br />10%<br />
  36. 36. Age vs. Outcome<br /># of <br />Patients<br />Age<br />
  37. 37. GCS 3-8 vs. GOS<br />64%<br />37%<br />27%<br />44%<br />66%<br />100%<br />13%<br />100%<br />67%<br />9%<br />17%<br />17%<br />33%<br />6%<br />
  38. 38. Chibbaro, et al., World Neuros., 75 (3/4):558-562, Mar/Apr 2011.<br />Chibbaro, et al., World Neurosurgery, 75 (3/4): 558-562<br />
  39. 39. Chibbaro, et al., World Neuros., 75 (3/4):558-562, Mar/Apr 2011.<br />Chibbaro, et al., World Neurosurgery, 75 (3/4): 558-562<br />
  40. 40. Timofeev, et al., J. Neurosurg, vol 108, Jan 2008<br />
  41. 41.
  42. 42.
  43. 43. Hypothermia lowers Intracranial Hypertension<br />
  44. 44.
  45. 45. Intravascular Cooling<br />
  46. 46. NABIS:H Mortality<br />N=199<br />N=193<br />
  47. 47. NABIS:H Outcome<br />57%<br />57%<br />N=199<br />N=193<br />
  48. 48. Subgroup (Age≤45, Hypo on admission)<br />76%<br />52%<br />
  49. 49. NABIS:H II<br />
  50. 50.
  51. 51. ICP<br />
  52. 52. Zweifel, et al., Neurosurg. Focus, Vol 25, 2008<br />Zweifel, et al, Neurosurg Focus 25 (10):E2, 2008<br />
  53. 53. Future Targets <br />Aquaporins<br />AQP4<br />MMPs<br />Vasoactive Agents<br />Complex Processes which are time dependent<br />Upregulation of AQP4 reduces Vasogenic edema<br />Downregulation improves cytotoxic edema<br />
  54. 54. Conclusion<br />Head injury is variable from patient to patient<br />ICP control critical<br />Craniectomy improves most bedside paramaters<br />Does it improve outcome<br />Hypothermia improves ICP, Neuoprotection?<br />

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