Getting the most out of arterial blood pressure monitoring (M Pinsky)
Arterial pressure waveform – Systolic, mean, diastolic and pulse pressure
Systolic AP (which changes depending on where you measure it)
- LV SV
- Ejection velocity (contractility)
- Arterial elastance
Sepsis reverses the normal pulse pressure amplification down the arterial tree – therefore you would be underestimating the pressure in the aorta.
Diastolic pressure – determines coronary blood flow
- vascular tone
- arterial resistance
- heart rate
Large arteries are capacitor
Faster heart rate means that the diastolic pressure hasn’t had time to stabilise – it may actually be much lower (vasodilatation). Increased HR is the main physiological response to vasodilation to maintain diastolic pressure.
Perfusion pressure = input – output pressure
Personalizing blood pressure management in septic shock
Pulse pressure influenced by
- SV
- Central arterial elastance
- vascular stiffness, blood viscosity
The relationship between stroke volume and arterial pressure is determined by the elastance
Cardiac output monitoring: invasive or non-invasive? (T Scheeren)
Invasive monitors
- Thermodilution (pulmonary thermodilution is considered the gold standard)
- Pseudo randomised thermo signal (Vigilance)
Mini invasive
- pulse contour analysis e.g. Flotrac, Vigileo
- percentage error from 13 to 75%
- Noninvasive Cardiac Output Monitors: A State-of the-Art Review
- Minimally invasive cardiac output technologies in the ICU: putting it all together.
- Doppler techniques
Non-invasive
- Pulse contour analysis (without arterial line) e.g. Nexfin
- The accuracy of noninvasive cardiac output and pressure measurements with finger cuff: a concise review.
- CO2 rebreathing method
- Bioimpedence and bioreactance
- Pulse wave transit time
The Use of Pulmonary Artery Catheter in Sepsis Patients: A Literature Review
Perioperative cardiovascular monitoring of high-risk patients: a consensus of 12
Is CVP useful? PRO (S Magder)
CVP still the most used variable to guide fluid management in FENICE!
CVP does not
- indicate magnitude of blood volume
- does not predict response to fluid
CVP normally low, elevated CVP needs explanation. CVP single value is not helpful.
The clinical role of central venous pressure measurements.
Where is your reference/zero point???
What point of the wave are you recording your value?
CVP is best used with some measure of flow. Fall in CO with fall in CVC = return function (volume) problem. Fall in CO but rise in CVC = primarily pump problem
Most useful in response to therapy.
Fluids after cardiac surgery: a pilot study of the use of colloids versus crystalloids.
Is CVP useful? CON (P Marik)
CVP is useless (mostly) and harmful (almost always)
Iatrogenic salt water drowning and the hazards of a high central venous pressure
CVP > 8 predicts AKI – Association between systemic hemodynamics and septic acute kidney injury in critically ill patients: a retrospective observational study
Central venous pressure is a stopping rule, not a target of fluid resuscitation.