Draft

155  Guyton Asthma Pp

155.1 Summary

  • Does PP tell influence the likelihood of preload responsiveness?
  • Pressure in Right Atrium (mmHg)
  • Considerations in Tamponade and Asthma
  • Cardiac Output (L/min)
  • Mean systemic filling pressure
  • Venous return does not increase further due to venous collapse
  •  Actual CO and RApressure that results
  • Right Ventricle Starling Curve

155.2 Slide outline

155.2.1 Slide 1

  • Does PP tell influence the likelihood of preload responsiveness?
  • Considerations in Tamponade and Asthma ### Slide 2
  • Pressure in Right Atrium (mmHg)
  • Cardiac Output (L/min)
  • Mean systemic filling pressure
  • Venous return does not increase further due to venous collapse
  •  Actual CO and RApressure that results
  • Right Ventricle Starling Curve ### Slide 3
  • Pressure in Right Atrium (mmHg)
  • Cardiac Output (L/min)
  • Mean systemic filling pressure
  • Venous collapse happens at higher RA pressure due to elevated Ppericardium
  • Right Ventricle Starling Curve
  • Pulsus Paradoxus in Tamponade
  • Fluids increase mean systemic filling pressure, and thereby increase CO where venous return plateaus
  • Large change in CO ### Slide 4
  • Pressure in Right Atrium (mmHg)
  • Cardiac Output (L/min)
  • Mean systemic filling pressure
  • Venous return already elevated due to below atmospheric intra-thoracic pressure from respiratory efforts (up to -30 cmH2O)
  • Fluids only move RApressure and CO operating point further onto flattened portion of RV starling curve
  • Right Ventricle Starling Curve – flattened due to increased afterload/PVR due to elevated lung volumes
  • Pulsus Paradoxus in Asthma
  • Small (if any – depending where exactly Starling curve flattens) change in CO
  • Limitation: Guyton curves use gauge pressure, whereas relevant pressure in Asthma are transmural pressures because intrathoracic pressure is negative during inspiration, may be positive on expiration if air trapping

155.3 Learning objectives

  • Does PP tell influence the likelihood of preload responsiveness?
  • Pressure in Right Atrium (mmHg)
  • Considerations in Tamponade and Asthma
  • Cardiac Output (L/min)
  • Mean systemic filling pressure

155.4 Bottom line / summary

  • Does PP tell influence the likelihood of preload responsiveness?
  • Pressure in Right Atrium (mmHg)
  • Considerations in Tamponade and Asthma
  • Cardiac Output (L/min)
  • Mean systemic filling pressure

155.5 Approach

  1. TODO: Outline the initial assessment or decision point.
  2. TODO: Outline the next diagnostic or management step.
  3. TODO: Outline follow-up or escalation criteria.

155.6 Red flags / when to escalate

  • TODO: List red flags that require urgent escalation.

155.7 Common pitfalls

  • TODO: Capture common errors or missed steps.

155.8 References

TODO: Add landmark references or guideline citations.

155.9 Slides and assets

155.10 Source materials