Home » Research

Neuroanesthesia

Neuroanesthesia group members are conducting research in the following areas:

Computer simulation of cerebrovascular and cardiovascular systems

Our group has developed physiologic models of the cardiovascular and cerebrovascular system, which interface with pharmacodynamic-pharmacokinetic drug models. Intracranial hemodynamic simulation was used to examine the effects of various stimuli occurring during anesthesia on intracranial pressure and cerebral blood flow. We demonstrated that propofol is superior to etomidate and thiopental (commonly used induction agents) in preventing untoward intracranial pressure elevation associated with endotracheal intubation. However, if the therapeutic goal is preservation of cerebral blood flow, etomidate is a drug of choice.

The model of cerebrovascular circulation was also used to examine effect of various strategies in treating cerebral vasospasm following subarachnoid hemorrhage We demonstrated that both increases in MAP and vasodilation of the collateral circulation improves blood flow to an ischemic area distal to vasospasm. This result has significant clinical implications: the use of inodilators may successfully treat vasospasm at lower MAP, thus minimizing the complications related to HHH therapy.

We also have developed a model of the cardiovascular system to examine the effects of cardiotropic drugs on hemodynamic and myocardial energetics. Inotropic drugs may increase myocardial oxygen demand without a corresponding increase in supply. Our simulation demonstrates that although all the drugs studied improve cardiac function in simulated patients with severe heart failure, milrinone accomplishes this at a lower energy cost. The computer simulation developed can be used to assess the complex effect of cardiotropic drugs and possibly suggest optimal drug therapy.

Recovery of cognitive function after neurosurgical procedures

Postoperative confusion is a common and significant complication after neurosurgical procedures, especially in the elderly. Our results indicate that recently introduced intravenous anesthetic remifentanil shortens the recovery time compared to more traditional inhalational agents in geriatric patients undergoing laminectomy. At present time we are comparing emergence characteristics and recovery profile of patients after craniotomy anesthetized with different anesthetic techniques.

Postoperative pain control in neurosurgical patients

Relief of surgical pain with minimal side effects is one of the primary goals of postoperative patient care. Opioid analgesics are traditional first-line treatment of postoperative pain. Their use is associated, however, with side effects such as sedation, confusion, nausea, vomiting, respiratory depression, and constipation. All of these can lead to severe complications and unnecessary tests. The goal of our research is to develop new strategies to decrease postoperative pain and, thus, opioid requirement in neurosurgical patients. At present time we are conducting a double-blind evaluation of rofecoxib versus placebo in reducing postoperative pain and opioid requirement after lumbar disk surgery.

Back to Top

Research Grants

  • Assessment of therapeutic options in treating cerebral vasospasm. A computer simulation.
    Sponsor: Sanofi Pharmaceuticals Inc. $20,000
    Principal investigator: Alex Bekker, MD, Ph.D.
    Co-investigators: H Mass, Ph.D., M Ursino Ph.
  • Computer simulation of cardiovascular mechanics: Assessment of cardiotropic drug effects on myocardial oxygen balance.
    Sponsor: Sanofi Pharmaceuticals Inc. $ 25,000
    Principal investigator: Alex Bekker MD, Ph.D.
    Co-investigators: A. Ritter, Ph.D., S. Wolk, M.S.
  • Computer simulation of the closed loop control of cardiac output using milrinone.
    Sponsor: Sanofi Pharmaceuticals Inc (the same grant as 2)
    Principal investigator: Alex Bekker MD, Ph.D.
    Co-investigators: R Shah M.S, A. Reisman Ph.D., A.Ritter Ph.D.
  • Cognitive functional recovery in a geriatric population after spine surgery: comparison between remifentanil-nitrous oxide and isoflurane-nitrous oxide-fontanel anesthesia.
    Sponsor: GlaxoWellcome Inc: $15,000
    Principal Investigator: Alex Bekker MD, Ph.D.
    Co-investigators: P. Berklayd MD, I. Osborn MD, M. Bloom MD, Ph.D. H. Turndorf MD.
  • A double-blind evaluation of preincisional rofecoxib versus placebo in reducing postoperative pain and opioid requirement after lumbar disk surgery.
    Sponsor: Merck&Co: $ 36,250
    Principal investigator: Alex Bekker MD, Ph.D.
    Co-investigators: A. Pryadko MD
  • National Library of Medicine/Contract. Biomedical Applications of High Performance Computing and Communications Area 4: Collaborative Technology to Allow Several Healthcare Providers in Remote Locations to Provide Real Time-Treatment of Patients .
    Co-Investigator: with Yonas H, Principal Investigator: @ $2,160,235.00
  • National Institute of Health. Studies of the Pathophysiology of Hemifacial Spasm,
    Co-Investigator: Marc J Bloom MD, PhD  with Aage R Moller, Principal Investigator: @ Department of Neurological Surgery,
  • University of Pittsburgh, Pittsburgh, PA.
    Rehabilitation Research and Training Fellowship from Rehabilitation Services Administration of H.E.W. to study the quantitative evaluation of the vestibulo-ocular reflex using electro-oculography by on-line computer and programmed saccadic tracking task.
    Principal Investigator:Marc J Bloom MD, PhD   System is used to evaluate and possibly retrain stroke victims with reading disabilities.
  • Anesthesia Training Grant awarded from the National Institute of Health: Training in Anesthesia Research 5-T32-GM 07612,
    Principal Investigator: Marc J Bloom MD, PhD @  Dept of Anesthesia, University of Pennsylvania, Philadelphia, PA.
  • Teacher Investigator Award from the National Institute of Neurology and Communicative Disorders and Stroke: AMultineuronal Interaction in Auditory Cortical Columns,@ 1-RO7 NS00859-01 CDR
      Principal Investigator:Marc J Bloom MD, PhD 
      Dept of Anesthesia, University of Pennsylvania, Philadelphia, PA. $247,000
  • Pitt Summer Research Program: AInvestigation of the Relationship between the EEG Suppression Ration and the EEG Suppression Period as Parameters in Cerebroprotective Barbiturate Infusion
    Principal Investigator:Marc J Bloom MD, PhD  (Advisor to G. Bijak). $3,000.
  • National Science Foundation Undergraduate Research Grant: Burst Suppression of the Electroencephalogram (EEG) by Servo-controlled Thiopental Infusion During Cerebral Arterial Aneurysm Clipping.
    Principal Investigator: Marc J Bloom MD, PhD (Advisor to Stephen Badelt). @ $3,000
  • Identification of Reliable EEG Indicators of Brain Ischemia During Cardiac Surgery
    Principal Investigator: Marc J Bloom MD, PhD .
    ASPECT Medical Systems, Inc. @ $29,500.
  • Bispectral Analysis for Monitoring Hypnotic Drug Effects
    Principal Investigator: Marc J Bloom MD, PhD 
    ASPECT Medical Systems, Inc., $20,120.
  • Bispectral analysis for monitoring effects of intravenous hypnotic drugs
    Principal Investigator:Marc J Bloom MD, PhD 
    ASPECT Medical Systems, Inc., $22,880.
  • Desflurane Induced Changes in Somatosensory Evoked Potentials.
    Principal Investigator: Marc J Bloom MD, PhD 
  • Depth of Coma in Head Injury
    Co-Investigator:Marc J Bloom MD, PhD  
    PI: Joseph M. Darby, M.D
    ASPECT Medical Systems, Inc. . $8,200.
  • A Comparison of IV Ondansetron, Droperidol and Prochlorperazine for the Treatment of Post-Operative Nausea and Vomiting in Patients Undergoing a Retromastoid Craniotomy for Microvascular Decompression of the 7th or 8th Cranial Nerve
    PI: Moyses B. Mandel, M.D.
    Co-Investigator: Marc J Bloom MD, PhD 
    Glaxo Inc.,  $24,541.73
  • The determination of the Level of Neuromuscular Blockade with the Ability to Record Evoked and Spontaneous EMG.
    PI: Matthew Caldwell, M.D.
    Co-Investigator Marc J Bloom MD, PhD
    Seed grant -UPMC
  • Sedation in Neuro ICU Patients
    PI: W. Andrew Kofke, M.D. 
    Co-Investigator Marc J Bloom MD, PhD 
    ASPECT Medical Systems, Inc. $14,524.
  • Functional and Basal Brain Metabolism by PET in Monkeys
    PI: Edwin Nemoto, Ph.D.
    Co-Investigator Marc J Bloom MD, PhD 
    Dept of Neurological Surgery and Anesthesiology/CCM. 
  • Studies of the Pathophysiology of Hemifacial Spasm.
    PI: Aage R. Moller, Ph.D
    Co-Investigator fMarc J Bloom MD, PhD 
    National Institute of Health. . $420,888.
  • Multivariable Modeling and Control Methods for Intravenous Anesthetic Pharmacodynamics.
    PI: Carolyn L. Beck
    Co-Investigator Marc J Bloom MD, PhD 
    National Science Foundation. , $74,851.00

    Back to Top

    Bibliography (1990-2000)

    Peer Reviewed Articles:

    • Bekker A, Wolk S, Rim J, Turndorf H, Ritter A. Comparison of cardiotropic drug effects on hemodynamic and myocardial energetics in patients with heart failure. A computer simulation. J Med Eng & Techn; In Press
    • Baumann, SB, Welch, WC and Bloom MJ. Intraoperative SSEP detection of ulnar nerve compression or ischemia in an obese patient: a unique complication associated with a specialized spinal retraction system. Arch. Phys. Med. Rehabil., 81:130-2, 2000.
    • Bekker A, Berklayd P, Osborn I, Bloom M, Yarmush J, Turndorf H. Recovery of cognitive function after remifentanil - N 2O anesthesia is faster than after isoflurane - N 2O - fentanyl combination in the elderly. Anesthesia & Analgesia 2000; 91:117-22
    • Bekker A, Mistry A, Ritter A, Wolk S, Turndorf H. Computer simulation of intracranial pressure changes during induction of anesthesia: comparison of thiopental, propofol, and etomidate. J Neurosurgical Anesthesia 1999; 11: 69-80
    • Brauer P, Kochs E, Werner C, Bloom M, Policare R, Pentheny S, Yonas H, Kofke WA, Schulte am Esch J: Correlation of transcranial Doppler sonography mean flow velocity with cerebral blood flow in patients with intracranial pathology. J Neurosurg Anesthesiol 10:80?5, 1998.
    • Glass PS, Bloom M, Kearse L, Rosow C, Sebel P, Manberg P: Bispectral analysis measures sedation and memory effects of propofol, midazolam, isoflurane, and alfentanil in healthy volunteers. Anesthesiology 86:836?47, 1997.
    • Kofke WA, Bloom MJ, Van Cott A, Brenner RP: Electrographic tachyphylaxis to etomidate and ketamine used for refractory status epilepticus controlled with isoflurane. J Neurosurg Anesthesiol 9:269?72, 1997.
    • Bekker A, Wolk S, Turndorf H, Kristol, Ritter A. Computer simulation of cerebrovascular circulation: assessment of intracranial hemodynamics during induction of anesthesia. J Clin Monit 1996; 12:433-444
    • Bloom MJ, Kofke WA, Nemoto E, Whitehurst S: Monitoring for cerebrovascular surgery. Int Anesthesiol Clin 34(3):137?47, 1996.
    • Bekker A, Baker K, Baker C, Young W. Anesthetic consideration for management of cerebrovascular aneurysm surgery. Amer J Anesth 1995; 22:248-258
    • Kofke WA, Dong ML, Bloom M, Policare R, Janosky J, Sekhar L: Transcranial Doppler ultrasonography with induction of anesthesia for neurosurgery. J Neurosurg Anesthesiol 6:89-97, 1994.
    • Young ML, Hanson CW 3rd, Bloom MJ, Savino JS, Muravchick S: Localized hypothermia influences assessment of recovery from vecuronium neuromuscular blockade. Can J Anaesth 41:1172?7, 1994.
    • Bloom MJ: Techniques to identify clinical contexts during automated data analysis. Int J Clin Monit Comput 10:17-22, 1993.
    • Sekhar LN, Iwai Y, Wright DC, Bloom M: Vein graft replacement of the middle cerebral artery after unsuccessful embolectomy: case report. Neurosurgery 33:723-6; discussion 726-7, 1993.
    • Bekker A, Von Hagen S, Yarmush J. A Macintosh HyperCard stack to simulate the pharmacokinetics of intravenous opioid infusions (NarSim). Comp Appl in Biosciences 1991; 7:531-532
    • Aggarwal S, Bloom M, Kang Y, Kramer D, Martin M, De Wolf AM: EEG and AVDO2 monitoring: adjuncts in the management of acute hepatic encephalopathy during liver transplantation. Transplant Proc 23:1992?3, 1991.
    • Isley MR, Kafer ER, Bloom MJ: Intraoperative cerebral monitoring during cardiac surgery using computer-processed EEG. Med Electronics 122:82-94, 1990.
    • Paul J, Bekker A, Duran W. Calcium entry blockade prevents leakage of macromolecules induced by ischemia-reperfusion in skeletal muscle. Circulation Research 1990; 66:1636-1642
    • Bekker A, Ritter A, Duran W. Analysis of microvascular permeability to macromolecules by video-image digital processing. Microvascular Research 1989; 38:200-216
    • Bekker A, Dillon P, Paul J, Duran W. Dose-response relationship between platelets activating factor and permeability-surface area product of FITC-Dextran 150 in the hamster cheek pouch. Microcir. Endoth. Lymph. 1988; 4:433-446
    • Young ML. Smith DL. Bagshaw RJ. Bloom MJ. Is metocurine better?. Anesthesiology. 68(1):168-9, 1988 Jan.
    • Bekker A, Ritter A, Duran W. Reduction of pressure in post-capillary venules induced by epifluorescent illumination of FITC-Dextran. Microcirc. Endoth. Lymph. 1987; 3:411- 423
    • Bloom MJ, Dong ML, Kofke WA, Swedlow P, Policare R: The effects on cerebral blood flow velocity of succinylcholine with and without oreservative. J Neurosurg Anesth.

    Back to Top

    Book Chapters, Abstracts

    • Bekker A, O'Neill, Rambissoon G. Basic principles of total intravenous anesthesia. Current Reviews in Anesthesiology. 20 (20):241-253, 2000
    • Bloom, MJ, Electroencephalography and Monitoring of Anesthetic Depth. In: Clinical Monitoring, Lake, Hines, and Blitt, W.B. Saunders, Philadelphia, 2000, pp 92-102.
    • Shah R, Bekker A, Reismann S. Development and testing of a simulated closed loop drug delivery system for congestive heart failure patients under milrinone administration. Proceedings of the IEEE 26 th Annual Northeast Bioengineering Conference, pp 49-50, 2000
    • Bekker A. Myocardial ischemia during embolization of brain AVM. 1999 Problem-Based Learning Discussions. American Society of Anesthesiologists, 1999
    • Bekker A. Keywords definitions - physiology and pharmacology. Anesthesia defined keywords 1998. MedText Medical Publishing Co., Redondo Beach, CA
    • Bekker A. Neurophysiology; Clinical Neuroanesthesia; Anesthesia for the patient with psychiatric disease. Big Cram before Exam. Anesthesia Board Essentials 1999. MedText Medical Publishing Co., Redondo Beach, CA
    • Bekker A, Berklayd P, Osborn I, Sharma S, Turndorf H. Remifentanil-N2O anesthesia shortens recovery time of cognitive function compared to isoflurane-fentanyl-N2O anesthesia in elderly patients. Anesthesiology (Supplement) 1999; Abstracts of Scientific Papers, ASA Annual Meeting.
    • Bekker A, Rim J, Ritter A, Turndorf H. Comparative effects of cardiotropic drugs on hemodynamics and myocardial energetics. A computer simulation. Anesthesiology (Supplement) 1999; Abstracts of Scientific Papers, ASA Annual Meeting.
    • Bekker A, Rim J, Wolk, Turndorf H. A PC-based graphical simulator for comparison of hemodynamic effects and myocardial energetics of cardiotropic drugs. J Clin Monit 1999; In press
    • Bekker A, Mistry A, Wolk S, Turndorf H, Kristol D, Osborn I, Ritter A. Computer simulation of cerebrovascular responses during induction of anesthesia: comparison of thiopental, propofol, and etomidate. J Clin Monit. 1998; 14: 511
    • Bekker A, Turndorf H, Wolk S, Ritter A: Computer analysis of cerebrovascular hemodynamics during induction of anesthesia. In: L. Henson and A. Lee, eds. Simulators in Anesthesiology Education. New York: Plenum Publishing Corp. 1998; pp: 121-122
    • Bekker A, Osborn I, Turndorf H. Computer simulation of intracranial hemodynamics during induction of anesthesia. J Neurosurg Anesthesiology 1998; 10: 265
    • Shalago J, Wolk S, Kristol D, Turndorf H, Bekker A. Cerebral blood flow and intracranial pressure during induced hypotension. Computer simulation. Proc. 8th Annual Uni-Tech Conference on Science and Technology, Newark, NJ 1998; p. 7
    • Bekker A, Kim J, Sharma S, O Neill D, Osborn I. The arterial to end-tidal carbon dioxide difference in neurosurgical patients ventilated with the laryngeal mask. Anesthesia 2000 1998; 1:78
    • Bloom MJ: EEG monitoring: intraoperative application. Anesthesiol Clin N Am 15(3):551-71, 1997
    • Bloom MJ, Whitehurst S, Mandel M, Policare R: Sedation by methohexital is best controlled by bispectral index of EEG (BIS). Anesthesiology 87:A1997.
    • Osborn I, Choudhary R, Ekstein M, Bekker A, Miller S. The laryngeal mask for stereotactic biopsy. J Neurosurg Anesthesia 1997; 9: 389
    • Bloom MJ, Greenwald S, Day R: Analgesics decrease arousal response to stimulation as measured by changes in bispectral index (BIS). Anesthesiology 85:A481, 1996.
    • Bloom MJ, Kofke WA, Whitehurst SL, Nemoto EM: Monitoring for Cerebrovascular Surgery. International Anesthesiology Clinics 34(3):137-147, Little Brown and Co., Boston, 1996.
    • Bloom MJ, Whitehurst SL, Mandel MD, Policare R: Bispectral index as an EEG measure of sedation with methohexital. Anesthesiology 85:A461, 1996.
    • Bekker A, Wolk S, Turndorf H. Mathematical model of intracranial hemodynamics: clinical applications. Proc. 2nd Annual Conference on Simulation in Anesthesia Education, Rochester, NY 1996; p. 4
    • Nemoto EM, Klemantatavicius, Bloom MJ, Yonas H: Resistance of the EEG to hypothermia. J Neurosurg Anesthesiol 8:341, 1996.
    • Bloom MJ, Kearse L, Rosow C, Sebel P, Glass p, Devlin P, Greenwald S: Bispectral index measures EEG changes due to response to stimulus. Anesthesiology 83:A516, 1995.
    • Kearse L, Rosow C, Sebel P, Bloom MJ, Glass P, Howell S, Greenwald S: The bispectral index correlates with sedation/hypnosis and recall: Comparison using multiple agents. Anesthesiology 83:A507, 1995.
    • Bloom MJ, Whitehurst S, Mandel M, Policare R: Bispectral Index as an EEG measure of the sedative effect of isoflurane. Anesthesiology 83:A195, 1995.
    • Bekker A, Wolk S, Ritter A, Kristol D. Computer simulation of cerebrovascular circulation. Assessment of intracranial hemodynamics during induction of anesthesia. Proc. 15th International symposium on Computing in Anesthesia and Intensive Care. Philadelphia, PA 1995; p. 5
    • Bloom MJ, Whitehurst S, Mandel M, Policare R: Bispectral Index as an EEG measure of the sedative effect of isoflurane. J Neurosurg Anesthesiol 7:312, 1995.
    • Wolk S, Bekker A, Ritter A, Kristol D. Mathematical model of cerebrovascular hemodynamics. Proc. IEEE 21 st Northeast Bioengineering Conference, Univ of Maine, Orono, ME 1995; 21: 34
    • Glass P, Gan TJ, Sebel PS, Rosow C, Kearse L, Bloom MJ, Manberg P: Comparison of the bispectral index (BIS) and measured drug concentrations for the monitoring effects of propofol, midazolam, alfentanil, and isoflurane. Anesthesiology 83:A507, 1995.
    • Gasior T,, Quinlan J, Kormos R, Bloom MJ, Arseniev S, Kiselev M: Intelligent data analysis to predict right ventricular support with left ventricular assist. Anesthesiology 83:A119, 1995.
    • Caldwell MW, Bloom MJ, royal MA, Donaldson W, Kang J, Bowles S, O'Hara J: Postoperative airway complications in patients undergoing anterior cervical corpectomy with graft placement:A review of the Pittsburgh Experience. Anesth Analg 80:S64, 1995.
    • Bekker A, Sundaran G, Ritter A, Kristol D. Computer simulation of cerebrovascular responses during induction of anesthesia. Proc. 3rd Annual North American Anesthesia Resident Research Conference, Philadelphia, PA, 1995; p. 4
    • Caldwell MW, Bloom MJ, Royal MA, Donaldson W, Kang J, Bowles S, O'Hara J: Postoperative airway complications in patients undergoing anterior cervical corpectomy with graft placement: A review of the Pittsburgh Experience. J Neurosurg Anesthesiol 6:311, 1994.
    • Royal MA, Bloom MJ, Maloney MJ. Rose RD: Desflurane-induced deterioration of somatosensory evoked potentials. J Neurosurg Anesthesiol 6:332, 1994.
    • Bloom MJ: The use of processed EEG in the operating room.In: Central Nervous System Monitoring in Anesthesia and Intensive Care. Schulte am Esch J, Kochs E (eds). Springer?Verlag, New York, 1994, pp 56-68.
    • Bloom MJ, Firestone LL, Sclabassi R, Policare RS: EEG Changes associated with the start of cardiopulmonary bypass (CB). Anesth Analg 76:S21, 1993.
    • Kofke WA, Dong ML, Bloom MJ, Policare R, Janosky J, Sekhar L. Transcranial doppler ultrasonography with induction of anesthesia for neurosurgery. Anesthesiology 79:A181, 1993.
    • Ritter A, Sundaram G, Kristol D, Bekker A. Simulation of intracranial hemodynamics. Proc. 19 th IEEE Northeast Bioengineering Conference 1993; 19:27-30
    • Puranic B, Bekker A, Kristol D, Ritter A. Assessment of myocardial oxygen supply and demand using a dynamic model of the cardiovascular system. Proc. IEEE 18 th Annual Northeast Bioengineering Conference. Univ of Rhode Island 1992; 18: 67
    • Gerstein C, Aertsen A, Bloom MJ,, Espinosa I, Evanczuk S, Turner M: Multineuron experiments: observation of state in neural nets. In: Synergetics, edited by H Haken, Springer, 1986. 

    Back to Top