Cerebral Monitoring after Asphyxia: Tissue Oxygenation and Cerebral Blood Flow - PowerPoint PPT Presentation

Loading...

PPT – Cerebral Monitoring after Asphyxia: Tissue Oxygenation and Cerebral Blood Flow PowerPoint presentation | free to view - id: 19ff26-YjQ2M



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Cerebral Monitoring after Asphyxia: Tissue Oxygenation and Cerebral Blood Flow

Description:

Measure brain tissue oxygen tension in cortex and thalamus in our model of cardiac arrest ... Oxygen Titration. in the Post Cardiac Arrest Period. Cortical PbO2 ... – PowerPoint PPT presentation

Number of Views:327
Avg rating:3.0/5.0
Slides: 27
Provided by: OEM5147
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Cerebral Monitoring after Asphyxia: Tissue Oxygenation and Cerebral Blood Flow


1
Cerebral Monitoring after AsphyxiaTissue
Oxygenation and Cerebral Blood Flow
  • Mioara D. Manole
  • University of Pittsburgh
  • Safar Center for Resuscitation Research
  • Carnegie Mellon University, NMR Center for
    Biomedical Research

2
Aims for MNTP course
  • To learn a variety of new methods for cerebral
    monitoring
  • Cerebral oxygenation (Tissue sensors)
  • White matter tracts post injury (DTI)
  • Water content of the brain (DWI)
  • Cerebral microvasculature (two photon microscopy)

3
Cerebral blood flow after pediatric asphyxial
CAASL-MRI
4
Regional CBF After Asphyxial CA in Immature 17
Day Old Rats
Manole et al, JCBFM 2009
5
Aim 1Assess brain tissue oxygenation in cortex
and thalamus
  • Polarographic oxygen sensor
  • Assess the sampling volume of the oxygen sensor
  • Measure brain tissue oxygen tension in cortex and
    thalamus in our model of cardiac arrest

6
Oxygen sensor
  • 10-50 µm tip
  • can sample at cellular or vascular level

7
  • 30 µm increments
  • record pO2

Air
Nitrogen in water
8
Sampling volume for oxygen sensor
  • Time constant
  • Sampling volume
  • Time constant 0.23 s
  • Sampling volume 124 µm

9
PbO2 during Cardiac Arrest
0.21
0.5
Asphyxia
10
PbO2 after ROSC Cortex
Twofold increase in PbO2 in the cortex Decrease
to values of 20 mm Hg after 30 min
11
PbO2 after ROSCThalamus
Fivefold increase in PbO2 in the thalamus

12
Aim 2Explore other imaging modalities
  • DTI
  • Two photon microscopy

13
DTI
  • DTI studio
  • Explore DTI

14
Two photon microscopy
  • Cortical vascular system
  • Fluorescein Dextran injection
  • Excitation 860 nm/ emission 500-500 nm

15
Carnegie Mellon University Pittsburgh NMR
Center Lesley Foley Kevin Hitchens Chien Ho
Safar Center for Resuscitation Research Robert
Clark Patrick Kochanek Hülya Bayir Keri
Feldman Robert Hickey
Pittsburgh Center for Free Radical and
Antioxidant Health Valerian Kagan Hülya Bayir
MNTP program Seong Gi Kim Alberto Vasquez Hiro
Fukuta Justin Crawley Kwan-Jin Jung
University of Pennsylvania William Armstead
Synzyme Technologies Li Ma Carleton Hsia
Support NIH K08HD058798 (MM), T32NS07485-02
(PMK), HD045968 (RSBC), P41EB-001977 (CH),
Laerdal Foundation (MM)
16
  • Oxygen sensor
  • diffusion of oxygen through a silicone membrane
  • oxygen reducing cathode which is polarized
    against an internal Ag/AgCl anode

Ag Cl- AgCl e- (anode) O2 2H2O 4e- 4
OH- (cathode)
17
  • Oxygen sensor
  • The flow of electrons from the anode to the
    oxygen reducing cathode reflects linearly the
    oxygen partial pressure around the sensor tip
  • The current is measured by a high
    quality picoammeter.

18
Oxygen sensorresponse time and sampling
  • Response time is influenced by
  • Electrode diameter
  • Membrane thickness
  • Membrane diffusion coefficient
  • Sampling distance 2-4 times tip diameter

19
Sampling from Cortex and Thalamus
  • Cortex coordinates
  • 2 mm lateral
  • 1.5 mm deep
  • 3.14 mm posterior
  • Thalamus coordinates
  • 2.5 mm lateral
  • 6 mm deep
  • 3.14 mm posterior



20
(No Transcript)
21
(No Transcript)
22
PbO2 during resuscitation
CPR
ROSC
22 s
23
PbO2 after ROSC Cortex
Twofold increase in PbO2 in the cortex Decrease
to values of 20 mm Hg after 30 min
24
PbO2 after ROSCThalamus
Fivefold increase in PbO2 in the thalamus

25
Oxygen Titration in the Post Cardiac Arrest
PeriodThalamic PbO2
O2 sat 80 Hb saturation- Rate limiting
factor for oxygen delivery?

26
Oxygen Titration in the Post Cardiac Arrest
PeriodCortical PbO2
About PowerShow.com