Antonio Artigas
Critical Care Center
Sabadell Hospital
CIBER Enfermedades Respiratorias
Autonomos University of Barcelona
Spain
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 [email protected]