IVC Collapse Physiology knowing the caveats &
Description: IVC Collapse Physiology knowing the caveats evidence Jon-Emile S. Kenny MD Senior contributor pulmccm.org Author of ICU Physiology in 1000 Word Series Creator heart-lung.org Cofounder Chief Medical Officer of Flosonics Medical Twitter
Related Topics
Download Presentation
"IVC Collapse Physiology knowing the caveats &" is the property of its rightful owner. Permission is granted to download and print the materials on this website for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Presentation Transcript
slide1. IVC Collapse Physiology knowing the caveats & evidence Jon-Emile S. Kenny MD
Senior contributor pulmccm.org
Author of ICU Physiology in 1000 Word Series
Creator heart-lung.org
Cofounder & Chief Medical Officer of Flosonics Medical
Twitter handle @heart_lung<br>
slide2. Conflicts of Interest Chief Medical Officer and Co-founder of
Flosonics Medical in Toronto, Canada<br>
slide3. The IVC acts as an un-stressed chamber Huh?<br>
slide4. Trans-mural pressure Vena cava pressure-volume relationship IVC volume [CVP – PAB] Spontaneous breathing without assistance<br>
slide5. Toronto Doppler Monster
RUQ Transverse plane
01/27/2015
MR: 29205<br>
slide6. Vena cava pressure-volume relationship IVC volume Trans-mural pressure [CVP – PAB]<br>
slide7. PRA [mm Hg] +5 Guyton Volume or Flow Pmsf Ppl Venous return curve doesn’t change with inspiration & Starling physiology occurs at atmospheric pressure Change in pleural pressure is standardized Cardiac function doesn’t change What are some basic assumptions here?<br>
slide8. PRA [mm Hg] +5 Specificity Venous return curve doesn’t change with inspiration & Starling physiology occurs at atmospheric pressure What are some basic assumptions here? Volume or Flow Pmsf Pcrit Cardiac function doesn’t change Ppl Clinical relevance? False positive = lower specificity<br>
slide9. 10 20 30 40 50 60 70 80 90 Specificity<br>
slide10. PRA [mm Hg] +5 Sensitivity What are some basic assumptions here? Volume or Flow Pmsf Ppl Clinical relevance? False negative = lower sensitivity Change in pleural pressure is standardized<br>
slide11. Based on the above, how could one improve specificity & sensitivity of IVC collapse for determining volume responsiveness? Exclude patients receiving ventilation assistance Ensure adequate inspiratory effort<br>
slide12. 10 20 30 40 50 60 70 80 90<br>
slide13. Thank you! www.heart-lung.org Stay hungry. Stay Foolish<br>
slide14. Advanced Doppler Theory for the intensivist Jon-Emile S. Kenny MD
Senior contributor pulmccm.org
Author of ICU Physiology in 1000 Word Series
Creator heart-lung.org
Cofounder & Chief Medical Officer of Flosonics Medical
Twitter handle @heart_lung<br>
slide15. Conflicts of Interest Chief Medical Officer and Co-founder of
Flosonics Medical in Toronto, Canada<br>
slide16. Background: Doppler & velocity<br>
slide17. Toronto Doppler Monster
Suprasternal Notch
01/27/2015
MR: 29205 20 40 60 80 cm/s<br>
slide18. Doppler Equation<br>
slide19. Velocity & Time At the Bedside So what?<br>
slide20. Velocity Time Integral = Distance So what?<br>
slide21. Continuous Wave & Pulsed Wave<br>
slide22. Velocity Error: intrinsic aspects<br>
slide23. ÆŸ Geometric Spectral Broadening Oh no! why?!<br>
slide24. Cosine Error Cosine Error<br>
slide25. Velocity Error: extrinsic aspects<br>
slide26. Velocity Time Integral = Distance What is the assumption here?<br>
slide27. Velocity Gradient Broadening<br>
slide28. Accounting for Velocity Gradient Broadening<br>
slide29. Uniform Insonation<br>
slide30. Area<br>
slide32. In Review … Inherent variability at high angles of insonation Inherent variability with linear array transducers Velocity profiles pose sampling problems with PW Small errors in measurement leads to large error in flow Assumes constant circular shape Small errors in diameter may be due to inherent ultrasound characteristics<br>
slide33. Thank you! www.heart-lung.org Stay hungry. Stay Foolish<br>
Senior contributor pulmccm.org
Author of ICU Physiology in 1000 Word Series
Creator heart-lung.org
Cofounder & Chief Medical Officer of Flosonics Medical
Twitter handle @heart_lung<br>
slide2. Conflicts of Interest Chief Medical Officer and Co-founder of
Flosonics Medical in Toronto, Canada<br>
slide3. The IVC acts as an un-stressed chamber Huh?<br>
slide4. Trans-mural pressure Vena cava pressure-volume relationship IVC volume [CVP – PAB] Spontaneous breathing without assistance<br>
slide5. Toronto Doppler Monster
RUQ Transverse plane
01/27/2015
MR: 29205<br>
slide6. Vena cava pressure-volume relationship IVC volume Trans-mural pressure [CVP – PAB]<br>
slide7. PRA [mm Hg] +5 Guyton Volume or Flow Pmsf Ppl Venous return curve doesn’t change with inspiration & Starling physiology occurs at atmospheric pressure Change in pleural pressure is standardized Cardiac function doesn’t change What are some basic assumptions here?<br>
slide8. PRA [mm Hg] +5 Specificity Venous return curve doesn’t change with inspiration & Starling physiology occurs at atmospheric pressure What are some basic assumptions here? Volume or Flow Pmsf Pcrit Cardiac function doesn’t change Ppl Clinical relevance? False positive = lower specificity<br>
slide9. 10 20 30 40 50 60 70 80 90 Specificity<br>
slide10. PRA [mm Hg] +5 Sensitivity What are some basic assumptions here? Volume or Flow Pmsf Ppl Clinical relevance? False negative = lower sensitivity Change in pleural pressure is standardized<br>
slide11. Based on the above, how could one improve specificity & sensitivity of IVC collapse for determining volume responsiveness? Exclude patients receiving ventilation assistance Ensure adequate inspiratory effort<br>
slide12. 10 20 30 40 50 60 70 80 90<br>
slide13. Thank you! www.heart-lung.org Stay hungry. Stay Foolish<br>
slide14. Advanced Doppler Theory for the intensivist Jon-Emile S. Kenny MD
Senior contributor pulmccm.org
Author of ICU Physiology in 1000 Word Series
Creator heart-lung.org
Cofounder & Chief Medical Officer of Flosonics Medical
Twitter handle @heart_lung<br>
slide15. Conflicts of Interest Chief Medical Officer and Co-founder of
Flosonics Medical in Toronto, Canada<br>
slide16. Background: Doppler & velocity<br>
slide17. Toronto Doppler Monster
Suprasternal Notch
01/27/2015
MR: 29205 20 40 60 80 cm/s<br>
slide18. Doppler Equation<br>
slide19. Velocity & Time At the Bedside So what?<br>
slide20. Velocity Time Integral = Distance So what?<br>
slide21. Continuous Wave & Pulsed Wave<br>
slide22. Velocity Error: intrinsic aspects<br>
slide23. ÆŸ Geometric Spectral Broadening Oh no! why?!<br>
slide24. Cosine Error Cosine Error<br>
slide25. Velocity Error: extrinsic aspects<br>
slide26. Velocity Time Integral = Distance What is the assumption here?<br>
slide27. Velocity Gradient Broadening<br>
slide28. Accounting for Velocity Gradient Broadening<br>
slide29. Uniform Insonation<br>
slide30. Area<br>
slide32. In Review … Inherent variability at high angles of insonation Inherent variability with linear array transducers Velocity profiles pose sampling problems with PW Small errors in measurement leads to large error in flow Assumes constant circular shape Small errors in diameter may be due to inherent ultrasound characteristics<br>
slide33. Thank you! www.heart-lung.org Stay hungry. Stay Foolish<br>