mercury sphygmomanometer (circa 1905) · pdf filemercury sphygmomanometer (circa 1905)...

Antonio Artigas

Critical Care Center

Sabadell Hospital

CIBER Enfermedades Respiratorias

Autonomos University of Barcelona

Spain

aartigas@tauli.cat

EVOLUCIÓN DE LA MONITORIZACIÓN

CARDIOVASCULAR EN LA UCI

MERCURY SPHYGMOMANOMETER (Circa 1905)

FORSSMANN’S PLACEMENT OF A CATHETER INTO HIS RIGHT ATRIUM (Nobel Prize 1956)

SHOCK UNIT. Los Angeles County General Hospital (1967)

What Do I Want to Know

Adequacy of Tissue Perfusion

CardiovascularPerformance

What to use.....

Part

Resistance

Pvein

Central V. pressures estimate ‘preload’ of Rt. and Lt.

circulation

Art. BP is the most accessible surrogate of organ blood flow

Intravascular pressures are easily acquired and exceedingly accurate!

....Pressures!?!??

The venous reservoir- mean systemic pressure (MSP): 6- 12 mmHg

The heart: RA pressure (CVP): 0 - 6 mmHg

Venous Return = (MSP - CVP) / Rveins

The Determinants of the CVP:1. Venous Return- a Pressure Gradient

Q

Pra

� Ejection of blood from the RV depends on preload (venous return) and contractile state

� The relationship between venous return and contractile state determines the CVP

The Determinants Cardiac Output:2. The Contractile State

Assumption:Pressures Reflect Volumes

CVP ≅ RVEDV, PAOP ≅ LVEDV

It Rarely Works Like That…

� PA-line vs. no PA- line: 1,000 pts. with ALI, ARDS, randomized to:

� CVP, monitoring phys. exam, UO & BP� PA- line: all the above, and PAP, PAOP, CO

� No difference in outcome� No difference in complications� ‘PAC is not for routine management of ALI’

Q

Pra

� A single value of pressure (CVP, PAOP) does not adequately assess cardiocirculatory status

� Add a measure of flow (cardiac output or surrogates)� Perturbate the system

Dynamic Evaluation:Fluid Responsiveness

Other Hemodynamic Monitors� Transthoracic thermodilution: CCO, SV, SVV,

volumetric cardiopulmonary indices

� Arterial pressure- based CO: CCO, SV, SVV, SVR

� Partial CO2 rebreathing

� Ultrasonic Esophageal Doppler

� Finger pulse plethysmography

� Thoracic bioimpedance

� ECHO Kaplan & Mayo, Chest ‘09

Minimally-Invasive Estimates of Cardiac Output

• Alternative to PAC thermodilution CO• Use the arterial pulse pressure to estimate flow• Based on the principal that the primary determinant of

changes in pulse pressure are changes in stroke volume– PiCCO, BMEYE: Wessling algorithm– LiDCO: power transfer– FloTrac: modified version of power transfer

• Electrical resistance of the thorax– BioZ and NICOM

Pulse Contour Analysis:Bottom Line

• Reports mean cardiac output, PPV and SVV well– PiCCOplus, LiDCOplus, FloTrac (?SVV)

• Can be used in protocolized care to improve outcome– LiDCOplus, FloTrac

• Can be used to assess dynamic step changes in flow (passive leg raising)– LiDCOplus, LiDCOrapid, PiCCOplus, FloTrac

• Does not require external calibration– FloTrac, LiDCOrapid

• Not clear if abilities and clinical benefit reported with one device can be extrapolated to the others

Non-invasive Methods to Measure Cardiac Output

• Finger pulse plethysmography• Finepres

• CO2 rebreathing• NICO

• Thoracic Electrical Induction• BioZ (bioempedence)• NICOM (bioreactance)

EKG

X(t)DX

DV

DX’

dX/dtVET

dX/dt max

SV = DV’

Global Blood volume

NICOM BioReactance

Time

NICOM vs. Transonic Flowprobe

0

2

4

6

8

10

12

1 3 5 7 9 11 13 15 17 19 21

CO in L/min.

Transonic pulmonary artery doppler NICOM

Keren et al. Am J Physiol 293:H583-9, 2007

Comparisons of Various Methods of Estimating Cardiac Output

PAC vs. LiDCO®

y = 0.96 x + 0.52

r2 = 0.89 p<0.001

Bias = -0.32 ± 0.56 L/min2 4 6 8 10 12

1.0

0.5

0.0

-0.5

-1.0

-1.5

-2.0

PAC

CO

-L

IDC

O C

O

Mean-0.32

-1.96 SD-1.42

+1.96 SD0.78

3 4 5 6 7 8 9 10 11

11109876543

PAC CO

LID

CO

CO

Bias = -0.16 ± 0.61 L/min

PAC vs. PiCCO®

y = 0.92 x + 0.64

r2 = 0.87 p<0.001

2 4 6 8 10 12 14

6

4

2

0

-2

-4

-6

PAC

CO

–PI

CC

O C

O

Mean0.1

-1.96 SD-3.8

+1.96 SD3.9

3 4 5 6 7 8 9 10 11

11

10

9

8

7

6

5

4

PAC CO

PIC

CO

CO

PAC vs. NICOM®

Bias = 0.24 ± 1.39 L/min

y = 0.48 x + 2.54

r2 = 0.50 p<0.05

2 4 6 8 10 12

5

4

3

2

1

0

-1

-2

-3

PAC

CO

-N

ICO

M C

OMean

0.2

-1.96 SD-2.5

+1.96 SD3.0

2 4 6 8 10 12

8

7

6

5

4

3

2

PAC CO

NIC

OM

CO

PAC vs. Vigileo®

Bias = -0.33 ± 1.25 L/min

y = 0.58 x + 2.66

r2 = 0.46 p<0.05

2 4 6 8 10 12

4

3

2

1

0

-1

-2

-3

-4

PAC

CO

-V

IGIL

EO

CO

Mean-0.3

-1.96 SD-2.8

+1.96 SD2.1

2 4 6 8 10 12

10

9

8

7

6

5

4

3

PAC CO

VIG

ILE

O C

O

Lamia et al. Am J Respir Crit Care Med 177: A631, 2008

Minimally invasive estimates of Cardiac Output

Bottom Line• All FDA-approved to assess cardiac output• PiCCO, LiDCO and FloTrac are report CO accurately but

may not trend similarly• Bioreactance probably as accurate • Consider the type of monitoring relative to the clinical

setting– OR and ICU with arterial catheter: LiDCO, FloTrac– OR and ICU with femoral arterial catheter: PiCCO– ED and acute triage elsewhere: NICOM

SUPRA-STERNAL DOPPLER

94 ICU patients, 250 measurements USCOM1A vs. PA catheter

Percentage of error ~ 100%

102 fluid challenges in 89 patients USCOM for performing a PLR test

Since corss-sectional aortic area is expected to be fixed.

Short-term changes in VTI should reflect short-term changes in SV

Crit Care 2009;13:R11

SDF

Proportion of perfused vessels Functional capillary density

early

Whichever the monitor, a dynamic assessment of the circulation (fluid challenge, respiratory- induced BP variations) is vastly superior than relying upon isolated values

ECHO is coming

NIRS may be coming

Conclusions

Thank youaartigas@tauli.cat