Invasive multimodal monitoring in TBI

Critical Care Canada Forum 2019

Donald Griesdale MD MPHAssociate Professor

Department of Anesthesiology, Pharmacology & Therapeutics

Divisions of Critical Care Medicine & Neurology

University of British Columbia

@dgriesdale donald.griesdale@ubc.ca

Speaker Disclosures

PhysicalExamination

ICP

Microdialysis

PbtO2

CBF

Auto-regulation

Jugular bulb

EEG

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

http://braintrauma.org

Monitoring guidelines (ICP)

• Salvageable patients with severe TBI

(GCS 3 – 8 post resuscitation)

AND

• Abnormal CT Head

CPP Thresholds:

• Recommended CPP between

60 – 70 mmHg.

Treat ICP:

• Treating ICP above 22 mmHg is

recommended

GCS≤8 + abnormal CT: 53 – 63% had increased ICP

GCS≤8 + normal CT: 13 % had increased ICP

Patients >40 years, SBP < 90 mmHg or posturing had similar rates of increased ICP as group with abnormal CT head

Important events of

1982

Collaboration with ICU

and Neurosurgery

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

ICM+

Autoregulation indices with PRx

PbtO2

ICP

Microdialysis

Bowman (CBF)

Neuromonitoring

Platform

PbtO2

ICP

ICM+

Intravascular

coolingMicrodialysis

PbO2 is a measure of CBF under normoxia

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

22 yo male with DAI + Fat Embolism Syndrome

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

CPP

PbO2

90

60

20

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

PbrO2

PRx

CPP ~ 50

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

PbrO2

PRx

CPP ~ 85

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

Crit Care Med. 2019 Jul;47:960

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

CCM 2017;45:1907

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

sTBI who required ICP monitoring

ICP onlyn=62

ICP + PbtO2n=57

Outcomes• Degree of brain tissue hypoxia (PbtO2 <20 mmHg)• Safety & Feasibility• Clinical Outcomes

CCM 2017;45:1907

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

sTBI who required ICP monitoring

ICP onlyn=62

ICP + PbtO2n=57

CCM 2017;45:1907

Proportion of time with PbtO2 <20mmHg

ICP only44%

ICP + PbtO215%

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

sTBI who required ICP monitoring

ICP onlyn=62

ICP + PbtO2n=57

CCM 2017;45:1907

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

CCM 2017;45:1907

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

CCM 2017;45:1907

What PbtO2 threshold do you use?

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

glutamate

Increased Lactate / Pyruvate Ratio

IschemiaMitochondrial

dysfunction

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

17 year old female

Sudden onset headache and became unresponsive

Vomited and urinary incontinence

EHS arrives, GCS 3, pupils reactive and hemodynamically stable

Transferred to VGH through a regional hospital Large left frontal ICH from AVM rupture

Left pupil 5 mm and fixed

Right pupil 3 mm and reactive

Take to OR for immediate FTP craniectomy, evacuation of ICH, and resection of AVM

Placement of EVD

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

CPP

PbtO2

• ICP 8 – 14 via EVD

• Temperature 36C

• Sedated on midazolam 20mg/hr & fentanyl 100mcg/hr

• Serum Na 148 mEq/L

• EEG: burst suppression

CBF CBV MTT

Evolving L MCA and bilateral ACA infarcts

CPP

PbtO2

• Oligemia

• Diffusion hypoxia

• Infarct

• Increased CMRO2

Why PbtO2 persistently low?

Increased MAP

Increased PaO2

Nothing to do

Hypothermia

LP ratio = 31

CPP

PbtO2

Temp

LP ratioLP ratio = 320

Invasive multimodal neuromonitoring helps individualize therapy

Impact on neurologic outcomes remains unclear

Introduction

Our platform

PbtO2 monitoring

Microdialysis

Case example

Conclusion

Thank you!