Department of Anesthesiology/Critical Care Medicine
Johns Hopkins University School of Medicine
600 North Wolfe Street, Blalock 904
Baltimore, MD 21287
E-Mail Address: firstname.lastname@example.org
Dr. Brady and his colleagues are studying new methods of continuously monitoring pressure autoregulation in the cerebral vasculature. By performing continuous cross-correlation functions of arterial blood pressure and cerebral blood flow surrogate waveforms, the team uses spontaneous fluctuations in blood pressure to quantify the activity of the pressure-autoregulation mechanism in the brain and determine the range of cerebral perfusion pressure that is supportive of autoregulation. This method was first applied in 1996 at Cambridge University using transcranial Doppler as a surrogate of cerebral blood flow. The clinical implications of this approach are obvious: with this method, safe boundaries of blood pressure can be defined in real time at the bedside.
An array of methods has been developed to perform this analysis, with divergent neuromonitors as surrogates of either cerebral blood flow or cerebral blood volume. For instance, Dr. Brady has used the signal from a commercial near-infrared cerebral oximeter, with the assumption that cerebral metabolism is constant over the brief period of each analysis epoch. To validate the different modalities, a piglet model is used. Cerebral blood flow is measured with both laser-Doppler techniques and microsphere injections. Controlled cortical-impact injuries are produced for a more detailed validation of the role of autoregulation monitoring in traumatic brain injury.
The autoregulation monitor has been used in various forms on patients with traumatic brain injury, on patients with congenital cardiac anomalies requiring cardiac surgery, and on patients receiving extracorporeal membrane oxygenation. These data collections are the first descriptions of the limits of autoregulation in pediatric patients.
- Society for Pediatric Anesthesia
- American Society of Anesthesiologists
- American Academy of Pediatrics
- Heart Care International
- Brady KM, Shaffner DH. Management of cerebral perfusion pressure after head injury: Increase mean arterial pressure or decrease intracranial pressure? A debate for intensivists. Contemp Criti Care (4):1–12, 2006.
- Brady KM, Texel SJ, Kishimoto K, Koehler RC, Sapirstein A. Cytosolic phospholipase A2 alpha modulates NMDA neurotoxicity in mouse hippocampal cultures. Eur J Neurosci 24(12):3381–6, 2006.
- Mester R, Easley RB, Brady KM, Groeper K, Tobias JD. Monitored anesthesia care with a combination of ketamine and dexmedetomidine during cardiac catheterization. Am J Therapeutics 15(1):24–30, 2008.
- Brady KM, Lee, JK, Kibler K, Smielewski P, Czosnyka M, Easley RB, Koehler RC, Shaffner DH. Continuous time-domain analysis of cerebrovascular autoregulation using near-infrared spectroscopy. Stroke (38):2818–2825, 2007.
- Brady KM, Koehler RC, Vricella LA, Jallo GI, Thompson WR, Guerguerian AM, Shaffner DH, Easley RB. A dynamic association between cavopulmonary shunt pressure and cerebrovascular autoregulation in an infant with congenital heart disease and intracranial hemorrhage. J Cardiothorac Vasc Anesth 2008 (in press).
- Brady KM, Lee JK, Kibler KK, Easley RB, Koehler RC, Shaffner DH. Continuous measurement of autoregulation by spontaneous fluctuations in cerebral perfusion pressure: a comparison of 3 methods. Stoke 39(9):2531–7, 2008.
Laboratory Members/Key Associates
Kathy Kibler, BS
Erin Carter, BA
Jennifer Mytar, BS
Jennifer Lee, MD
Raymond C. Koehler, PhD
- I.L. Chaikoff Award, University of California Berkeley, Department of Neurobiology (1993)
- Dean’s Summer Research Fellowship (1994)
- American Academy of Pediatrics, California Chapter 3
- Resident Award for “Outstanding Medical Care to and Advocacy for Patients” (1997)
- Resident Teacher of the Year Award
- University of California San Diego, Department of Internal Medicine (2001)
- Resident Teacher of the Year Award
- University of California San Diego, Dept of Pediatrics (2001)
- Research Fellow Award, Foundation for Anesthesia Education and Research (2004)
- Departmental NIH T32 training grant
- The Johns Hopkins University, Department of Anesthesia/Critical Care Medicine (2006)
- Innovator of the Year, The Maryland Daily Record
- For development of the Cerebral Oximetry Index (2007)
- Young Investigator Award, Society for Pediatric Anesthesia (2008)