The Hemodynamic Puzzle
SVV
NIRS
O2ER Lactate
Oxygen Debt: To Pay or Not to Pay? Full Recovery Possible
Energy Metabolism (Oxygen Consumption) (Ml/min/m2)
Delayed Repayment of O2 Debt
Oxygen Deficit
Oxygen Deficit Oxygen Deficit
Time Excessive O2 Deficit Produces Lethal Cell Injury with Non-recovery Recovery Possible
The principle task of acute care is to avoid or correct oxygen debt by optimization of the oxygen supply and consumption.
Providing the right amount of fluid is vital in a critically ill patient, as both too little and too much can result in poor outcomes Under Resuscitation
Over Resuscitation
It is just as important to recognize that DO2 and tissue perfusion has normalized, therefore any further measures to increase DO2 may do harm by unnecessary over resuscitation
HR and BP as Resuscitation Endpoint SVV
Heart Rate
GEDV
SV
SvO2
NIRS OPSI
Urine Output Mental Status
Correlation Between Arterial Pressure And Oxygen Delivery 180
MAP mmHg
150
120
90
60
n= 1232
30 100
300
500
700
900
DO2 ml*m-2*min-1
1100
Correlation Between Heart Rate And Oxygen Delivery 180
HR b/min
150
120
90
60
n= 1236
30 100
300
500
700
DO2 ml*m-2*min-1
900
1100
CVP as a Resuscitation Endpoint SVV
Heart Rate
GEDV
SV
SvO2
NIRS OPSI
Urine Output Mental Status
Passive leg raising (PLR) Volume of blood transferred (usually 200-300 mL) to the heart during PLR is sufficient to increase the left cardiac preload and thus challenge the Frank-Starling curve. Maximal effect occurs at 30-90 seconds and assess for a 10% increase in stroke volume (cardiac output monitor) or using a surrogate such as pulse pressure (using an arterial line)
Diagnostic Accuracy of Passive Leg Raising for Prediction of Fluid Responsiveness in Adults: Systematic Review and Metaanalysis of Clinical Studies.
AUC= 0.96
• Meta-analysis 9 studies • PLR changes in CO predicts fluid responsiveness • Regardless of ventilation mode and cardiac rhythm • Difference in CO of 18% distinguished responder from NR
The pooled sensitivity and specificity of PLR-cCO were 89.4% (84.1-93.4%) and 91.4% (85.9-95.2%) respectively Cavallaro, F. et al. Intensive Care Med. 2010 Sep;36(9):1475-83
CVP as a Resuscitation Endpoint Heart Rate
CVP
SVV
GEDV
SV
SvO2
NIRS OPSI
Urine Output Mental Status
• European survey:
90%
More the of intensivist or anesthesiologists used the CVP to guide fluid management.
• Canadian survey:
90% of intensivists used the CVP to monitor fluid resuscitation in patients with septic shock.
Crit Care Med 2013; 41:1774–1781)
Paul E. Marik, MD, FCCP; Michael Baram, MD, FCCP; Bobbak Vahid, MD Chest. 2008;134(1):172-178.
The study demonstrates that cardiac filling pressures are poor predictors of fluid responsiveness in septic patients. Therefore, their use as targets for volume resuscitation must be discouraged, at least after the early phase of sepsis has concluded
Osman D1, Ridel C, Ray P, Monnet X, Anguel N, Richard C, Teboul JL. Crit Care Med. 2007 Jan;35(1):64-8.
There are no data to support the widespread practice of using central venous pressure to guide fluid therapy. This approach to fluid resuscitation should be abandoned.
Marik PE, Cavallazzi R . Crit Care Med. 2013 Jul;41(7):1774-81..
IVC Diameter and Collapsibility as End Point Heart Rate
CVP
SvO2
SVV
OPSI NIRS GEDV
Urine Output Mental Status
Simultaneous measurements of the central venous pressure (CVP) and IVC diameter at the end of expiration in 108 mechanically ventilated patients
Collapsibility Index =
𝑰𝑽𝑪𝒎𝒂𝒙 −𝑰𝑽𝑪𝒎𝒊𝒏 𝑰𝑽𝑪𝒎𝒂𝒙
>12% = responders (PPV 93% and NPV92%).
𝑰𝑽𝑪𝒎𝒂𝒙 −𝑰𝑽𝑪𝒎𝒊𝒏 Collapsibility Index = 𝑰𝑽𝑪𝒎𝒂𝒙
10%
Fluid Non-Responders
Fluid Responders
End-Diastolic Volume
29
Dynamic parameters should be used preferentially to static parameters to predict fluid responsiveness in ICU patients
Dynamic Changes in Arterial Waveform Derived Variables and Fluid Responsiveness in Mechanically Ventilated Patients: A Systematic Review of Literature
Sens. 0.89 Spec. 0.88 AUC= 0.94
Marik, PE et al. (2009). Citi Care Med. 37: 2642-2647
Lactic Acid as Endpoint Resuscitation Heart Rate
CVP
OPSI
SVV SV
GEDV
Urine Output Mental Status
Lactate
Oxygen consumption VO2 mls/min
Critical DO2
DO2 independent in normal patients
DO2 dependent in septic patients
Oxygen Debt
Lactate Oxygen delivery
300mls/min
DO2 mls/min
Prolonged lactate clearance is associated with increased mortality in the surgical intensive care unit
J. McNelis et al. The American Journal of Surgery 182 (2001) 481–485
Early lactate-guided therapy in intensive care unit patients: a multicenter, open-label, randomized controlled trial.
Jansen TC,van Bommel J, Schoonderbeek FJ,Sleeswijk Visser SJ, vander Klooster JM, Lima AP, et al. Am J Respir Crit Care Med (2010) 182:752– 61.doi:10.1164/rccm.200912-1918OC
Effects of Cardiac Output and Stroke Volume Guided Hemorrhage and Fluid Resuscitation CI-group
SVI-group
Tbsl
T0
tend
Tbsl
T0
Tend
Oxygen delivery (ml/min/m2)
335 ± 63
158 ± 62
284 ± 52
419 ± 62
272 ± 56
341 ± 62
VO2 (ml/min/m2)
44 ± 25
62 ± 38
76 ± 34
77 ± 26
96 ± 19
82 ± 27
Oxygen extraction (VO2/DO2)
0.13 ± 0.08
0.38 ± 0.19
0.32 ± 0.14
0.20 ± 0.07
0.36 ± 0.05
0.24 ± 0.09
Central venous oxygen saturation (%)
81 ± 8
58 ± 18
64 ± 15
78 ± 7
61 ± 5
73 ± 9
Venous to arterial carbon dioxide gap (mm Hg)
3.3 ± 3.1
8.9 ± 3.3
7.8 ± 4.8
5.3 ± 2
9.6 ± 2.3
5.1 ± 2.6
Lactate (mmol/L)
3.6 ± 1.1
5.0 ± 1.6
4.6 ± 2.0
1.62 ± 0.43
3.86 ± 1.49
3.54 ± 1.9
Hemoglobin (g/L)
9.0 ± 0.7
8.0 ± 2.7
6.9 ± 1.3
12.05 ± 1.37
11.22 ± 1.39
8.45 ± 1.1
Nemeth, M. et al. Acta Anaesthesiol Scand (2014). doi:10.1111/aas.12312
Oxygen Extraction-based Resuscitation Heart Rate
CVP
SVV
SvO2
SV
GEDV
Urine Output Mental Status
ScvO2
O2ER
Oxygen Extraction-based Resuscitation ScVO2
O2ER = 𝟏𝟎𝟎 𝐗 VO2 DO 2 VO2= CO x [CaO2-CvO2]
CaO2= [Hb X 1.34 x SaO2] + 0.003 x PaO2 DO2= CO x [CaO2]
Effects of Cardiac Output and Stroke Volume Guided Hemorrhage and Fluid Resuscitation CI-group
SVI-group
Tbsl
T0
tend
Tbsl
T0
Tend
Oxygen delivery (ml/min/m2)
335 ± 63
158 ± 62
284 ± 52
419 ± 62
272 ± 56
341 ± 62
VO2 (ml/min/m2)
44 ± 25
62 ± 38
76 ± 34
77 ± 26
96 ± 19
82 ± 27
Oxygen extraction (VO2/DO2)
0.13 ± 0.08
0.38 ± 0.19
0.32 ± 0.14
0.20 ± 0.07
0.36 ± 0.05
0.24 ± 0.09
Central venous oxygen saturation (%)
81 ± 8
58 ± 18
64 ± 15
78 ± 7
61 ± 5
73 ± 9
Venous to arterial carbon dioxide gap (mm Hg)
3.3 ± 3.1
8.9 ± 3.3
7.8 ± 4.8
5.3 ± 2
9.6 ± 2.3
5.1 ± 2.6
Lactate (mmol/L)
3.6 ± 1.1
5.0 ± 1.6
4.6 ± 2.0
1.62 ± 0.43
3.86 ± 1.49
3.54 ± 1.9
Hemoglobin (g/L)
9.0 ± 0.7
8.0 ± 2.7
6.9 ± 1.3
12.05 ± 1.37
11.22 ± 1.39
8.45 ± 1.1
Nemeth, M. et al. Acta Anaesthesiol Scand (2014). doi:10.1111/aas.12312
Mixed Venous Saturation in Critically Ill Patient Oxygen Supply: DO2
Oxygen Demand: VO2 SvO2/ScvO2
Low
High
↓DO2
↑VO2
↑DO2
↓VO2
Anemia Bleeding Hypovolemia Hypoxia Heart faliure
Pain Agitation Shivering Seizure Fever
Hg Oxygen Fluids Inotropics
Sedation Analgesia Hypothermia Sepsis
10.0
DO2/ VO2
8.2
6.4
4.6 r= 0.906 y= -9.58 + 0.19*x n= 1149
2.8
1.0 25
40
55
70
SvO2 %
85
100
100 Shock
% SsvO2
80
r= 0.73
60
Normal
r= 0.88 40
20
0 Lee J et al. (1972) Anaesthesiology 36: 472
20
40
60
% SvO2
80
100
SvO2 closely correlates with ScvO2 Mixed venous Central venous
80
Normoxia
Bleeding
Volume Therapy (HAES)
Hyperoxia
20
Normoxia
40
Hypoxia
% Sat
60
Bleeding
0 0
30
60
90
120
Time (min) Reinhart K et al, Chest, 1989; 95:1216-1221
150
180
210
240
ScvO2 of < 70%,
Pope, J et al. Ann Emerg Med. 55:40-46
ScvO2 of > 90%,
Oxygen Parameters as Endpoint Heart Rate
CVP
SVV
SvO2
SV
GEDV
Urine Output Mental Status
P(cv-a)CO2
ScvO2
O2ER
P(cv-a)CO2 ∆PCO2= K X
𝑽𝑪𝑶𝟐 𝑪𝒂𝒓𝒅𝒊𝒂𝒄 𝑶𝒖𝒕𝒑𝒖𝒕
Normal is 2-5 mmHg. Is not a marker of tissue hypoxia but it is a marker of the adequacy of cardiac output
Persistently high venous-to-arterial carbon dioxide differences during early resuscitation are associated with poor outcomes in septic shock The persistence of high Pv-aCO2 during the early resuscitation of septic shock was associated with more severe multi-organ dysfunction and worse outcomes at day-28 H-H, mixed venous-to-arterial carbon dioxide difference (PvaCO2) high at Time 0 (T0) and 6 hours later (T6); L-H, PvaCO2 normal at T0 and high at T6; H-L, Pv-aCO2 high at T0 and normal at T6; and L-L, Pv-aCO2 normal at T0 and T6
Ospina-Tascón GA et al., Crit Care. 2013; 17(6)
Central Venous-to-Arterial Gap Is a Useful Parameter in Monitoring Hypovolemia-Caused Altered Oxygen Balance: Animal Study
ScvO2 < 73% and CO2 gap >6 mmHg can be complementary tools in detecting hypovolemia-caused imbalance of oxygen extraction.
Kocsi S et al, Crit Care Res Pract. 2013; 583-598.
The Hemodynamic Puzzle Heart Rate
CVP
SVV
SvO2
SV
ScvO2
GEDV
Urine Output Mental Status
P(cv-a)CO2
OPSI
NIRS
O2ER
Near-infrared spectroscopy (NIRS)
NIRS StO2 (at 20 mm, skeletal muscle) is an index of profusion that tracks DO2 during active resuscitation
Crit Care. 2009; 13(Suppl 5): S10.
Orthogonal Polarization Spectral Imaging (OPS): Sublingual capillaroscopy. Orthogonal polarization spectral (OPS) imaging is an optical imaging technique that uses a handheld microscope and green polarized light to visualize the red blood cells in the microcirculation of organ surfaces
Orthogonal Polarization Spectral Imaging (OPS): Sublingual capillaroscopy.
Red blood cells are visualised as black-grey points flowing along the vessels. Up-right and up-left: normal findings; bottomleft: septic shock; bottom-right: after cardiac arrest under therapeutic hypothermia
The Hemodynamic Puzzle Heart Rate
CVP
SVV
SvO2
SV
ScvO2
GEDV
Urine Output Mental Status
P(cv-a)CO2
OPSI
O2ER
NIRS Lactate