Dr Peter Sherren

Optimal monitoring of critically ill patient is an important part of haemodynamic management.

Not everything that counts can be counted and not everything that can be counted counts!

CVP and PAOP involve large assumptions to equate to LVEDV.

Liver transplants involve problems with bleeding and reduced SVR post graft reperfusion.

Therefore, not only is it important to have an idea of various static cardiac indices but more importantly dynamic response to fluid loads and pharmacological interventions.

Waveform of a finger artery without invasive calibration before use.

Type of pulse contour analysis, but not using calibration with dye/thermodilution instead using a computer algorithm .

Measures SV, SVV, CO and ScvO2 if appropriate catheters in situ. FloTrac/Vigileo™, Edwards Lifesciences

• individual demographic data • calibration is not required• Uses radial artery cannula• Aortic pulse pressure is proportional to SV and is inversely related to

aortic compliance

Earlier software versions: 4 earlier study• Not recommend routine use

The new software version• Estimating vascular tone from 10 min to 60 s • Reduction of pulsewave detection noise.• More on Friday.

To assess whether SVV obtained with this new technology can predict fluid responsiveness in patients undergoing liver transplantation and to compare its predictive value to the commonly measured haemodynamic variables.

Secondly, to compare CO obtained with Vigileo device and CO obtained from TTE and PAC.

Design: Single centre (University Hospital, France), prospective observational study.

Intervention: 40 consecutive patients in the post-operative period of liver transplantation on the ICU, for whom the decision to give fluid was taken by the physician. The volume expansion used was 20ml x BMI of 4% albumin over 20 min. Patients were all sedated with Propofol/Sufentanil. VCV, Tv 10ml/kg, PEEP 3cmH20, I:E 1:2, PaO2 >90mmHg, PaCO2 35-40mmHg.

Exclusion criteria• Hypoxaemia PaO2/FiO2 <100mmHg• Blood volume overload PAOP >18mmHg• Pulmonary Oedema on Cxr• Patient less then 18 years old• Arrythmias• BMI >40-<15 kg m-2

• Significant Aortic/Mitral Valve disease• Intracardiac shunts• Spontaneous breathing activity• Unsatifactory cardiac echogenicity

All patients had• 7.5F Pac LSCV• 3F vygon Lt radial aterial line and Flotrac/Vigileo monitor set up• TTE performed by same operator, S obtained via product of VTI

and Aortic valve area, averaged over 5 cycles. LVEF measure using Simpsons Biplane measurement.

Two measurements were performed before and immediately after VE.

CO via Flotrac/PPV/TTE/PAC were simultaneously measured.

A rise in CO of >15% was used to distinguish between a Responder and a Non Responder.

5 patients excluded VE given for

• Tachycardia (8)• Mottling (7)• Low UO (14)• Acid-base derangement (6)

17 Responders, 18 Non responders Before VE: SVV and PPV were significantly higher and CVP/CO/PAOP

were significantly lower in Rs than NRs. Post VE: all parameters showed significant changes in Rs and NRs. No correlation between CVP/PAOP and % change in CO-TTE post

VE. However, SVV/PPV correlated significantly and closely with change in CO-TTE ( p< 0.0001).

10% SVV threshold discriminated between Rs and NRs with sensitivity of 94% (95% CI) and specificity 94% (95% CI).

Following VE, the % change in CO-vigileo correlated with % change in CO-TTE (p< 0.0001) and CO-PAC (p< 0.0001)

R and NR classification was similar. 34 patients were well classified using CO-vigileo (97%). Only one patient in vigileo group was classified as NR and as a R in TTE/PAC group.

Demonstrated that uncalibrated SVV measurement by arterial waveform analysis can be used to predict the effects of VE in mechanically ventilated patients after liver transplantation.

CO-vigileo correlated well with CO-TTE/PAC.

Threshold of 10% SVV discriminated well between Rs and NRs. Correlated well with Hofer et al 9.6%, Berkenstadt et al 9.5%.

Failure of CVP/PAOP to correlate fluid responsiveness goes with the mounting evidence that static preload indictators not suited for functional haemodynamic monitoring.

Using CO-TTE to define Rs and NRs. Some CO changes of 15.4-17.6%, ?guarantee these were all Rs.

Small patient number.

Real world limitations (Spontaneous breathing, arrythmias, LVEF >50%)

Norephinephrine infusions, known to effect accuracy.

High TV 8-10 ml/kg, realistic for modern ICU? SVV known to be effected by depth of respiration.

As above

No declared conflict of interest.

Limitations to note

Interesting monitoring device for select patients. ?Suitability for MOF, shock, poor tissue perfusion, high dose NA etc.

Await further large number, validation studies.

More on Friday.