The Hemodynamic Puzzle SVV NIRS O 2 ER Lactate
Energy Metabolism (Oxygen Consumption) (Ml/min/m 2 ) Oxygen Debt: To Pay or Not to Pay? Full Recovery Possible Delayed Repayment of O 2 Debt Oxygen Deficit Oxygen Deficit Oxygen Deficit The principle task of acute care is to avoid or correct oxygen debt by optimization of the oxygen supply and consumption. Time Excessive O 2 Deficit Produces Lethal Cell Injury with Non-recovery Recovery Possible
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 Heart Rate SVV SvO 2 SV GEDV NIRS OPSI Urine Output Mental Status
MAP mmhg Correlation Between Arterial Pressure And Oxygen Delivery 180 150 120 90 60 30 n= 1232 100 300 500 700 900 1100 DO 2 ml*m -2 *min -1
HR b/min Correlation Between Heart Rate And Oxygen Delivery 180 150 120 90 60 30 n= 1236 100 300 500 700 900 1100 DO 2 ml*m -2 *min -1
CVP as a Resuscitation Endpoint Heart Rate SVV SvO 2 SV GEDV 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 Meta-analysis 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 SvO 2 SV GEDV NIRS OPSI Urine Output Mental Status
European survey: More the 90% 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 SVV SvO 2 OPSI GEDV NIRS 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 = IVC max IVCmin IVC max >12% = responders (PPV 93% and NPV92%).
Collapsibility Index = IVC max IVCmin IVC max <12% = non-responders (PPV 93% and NPV92%).
Total of 8 studies/235 Pts ΔIVC measured is of great value in predicting fluid responsiveness, particularly in patients on controlled mechanical ventilation Zhongheng Zhang, Xiao Xu, Sheng Ye, Lei Xu. Ultrasound in Medicine and Biology. Volume 40, Issue 5, Pages 845 853, May 2014
CO/SV as a Resuscitation Endpoint Heart Rate CVP SVV SvO 2 SV/CO GEDV NIRS OPSI Urine Output Mental Status
Effects of Cardiac Output and Stroke Volume Guided Hemorrhage and Fluid Resuscitation 21 animal subjects were bled until CI (n=9) or SVI (n=12) decreased by 50% then resuscitated during 60 minutes with LR till target is achieved CI-group SVI-group T bsl T 0 t end T bsl T 0 T end SVI (ml/m2) 33.6 ± 6.2 14.6 ± 10.1 23.4 ± 7.9 26.8 ± 4.7 13.4 ± 2.3 26.6 ± 4.1 CI (l/min/m2) 2.88 ± 0.42 1.79 ± 0.53 2.73 ± 0.35 2.6 ± 0.4 1.8 ± 0.3 2.9 ± 0.5 MAP (mmhg) 127 ± 13.07 75 ± 25 85 ± 22 112 ± 23 74 ± 18 91 ± 19 Heart rate (beats/min) 87 ± 16 140 ± 40 124 ± 37 95 ± 12 131 ± 27 107 ± 16 Central venous oxygen saturation (%) Venous to arterial carbon dioxide gap (mm Hg) 81 ± 8 58 ± 18 64 ± 15 78 ± 7 61 ± 5 73 ± 9 3.3 ± 3.1 8.9 ± 3.3 7.8 ± 4.8 5.3 ± 2 9.6 ± 2.3 5.1 ± 2.6 GEDV (ml/m2) 317 ± 36 198 ± 57 249 ± 46 309 ± 57 231 ± 61 287 ± 49 Stroke volume variation (%) 10.8 ± 5.5 17.3 ± 5.1 16.4 ± 8.2 13.6 ± 4.3 22.6 ± 5.6 12.2 ± 4.3 Nemeth, M. et al. Acta Anaesthesiol Scand (2014). doi:10.1111/aas.12312
SVV & PPV as End Point Heart Rate CVP SV GEDV SVV OPSI SvO 2 Urine Output Mental Status
Hemodynamics During Positive Pressure Ventilation: SVV and PPV
PVI to Help Clinicians Optimize Preload / Cardiac Output Stroke Volume 10 % Lower PVI = Less likely to respond to fluid administration 24 % Higher PVI = More likely to respond to fluid administration 0 0 Preload Frank-Starling Relationship
Determine success of fluid by the response in stroke volume/index and SvO2 Stroke Volume D 0% D < 10% D > 10% Fluid Non-Responders Fluid Responders End-Diastolic Volume 30
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 SVV OPSI SV GEDV Urine Output Mental Status Lactate
Oxygen consumption VO 2 mls/min Critical DO 2 DO2 dependent in septic patients DO2 independent in normal patients Oxygen Debt Lactate Oxygen delivery 300mls/min DO 2 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 Oxygen delivery (ml/min/m 2 ) T bsl T 0 t end T bsl T 0 T end 335 ± 63 158 ± 62 284 ± 52 419 ± 62 272 ± 56 341 ± 62 VO2 (ml/min/m 2 ) 44 ± 25 62 ± 38 76 ± 34 77 ± 26 96 ± 19 82 ± 27 Oxygen extraction (VO 2 /DO 2 ) Central venous oxygen saturation (%) Venous to arterial carbon dioxide gap (mm Hg) 0.13 ± 0.08 0.38 ± 0.19 0.32 ± 0.14 0.20 ± 0.07 0.36 ± 0.05 0.24 ± 0.09 81 ± 8 58 ± 18 64 ± 15 78 ± 7 61 ± 5 73 ± 9 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 SvO 2 SV GEDV ScvO 2 O 2 ER Urine Output Mental Status
Oxygen Extraction-based Resuscitation ScVO2 O 2 ER = 100 X VO 2 DO 2 CaO 2 = [Hb X 1.34 x SaO 2 ] + 0.003 x PaO 2 VO 2 = CO x [CaO 2 -CvO 2 ] DO 2 = CO x [CaO 2 ]
Effects of Cardiac Output and Stroke Volume Guided Hemorrhage and Fluid Resuscitation CI-group SVI-group Oxygen delivery (ml/min/m 2 ) T bsl T 0 t end T bsl T 0 T end 335 ± 63 158 ± 62 284 ± 52 419 ± 62 272 ± 56 341 ± 62 VO2 (ml/min/m 2 ) 44 ± 25 62 ± 38 76 ± 34 77 ± 26 96 ± 19 82 ± 27 Oxygen extraction (VO 2 /DO 2 ) Central venous oxygen saturation (%) Venous to arterial carbon dioxide gap (mm Hg) 0.13 ± 0.08 0.38 ± 0.19 0.32 ± 0.14 0.20 ± 0.07 0.36 ± 0.05 0.24 ± 0.09 81 ± 8 58 ± 18 64 ± 15 78 ± 7 61 ± 5 73 ± 9 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: DO 2 Oxygen Demand: VO 2 SvO 2 /ScvO 2 Low DO 2 VO 2 High DO 2 VO 2 Anemia Bleeding Hypovolemia Hypoxia Heart faliure Pain Agitation Shivering Seizure Fever Hg Oxygen Fluids Inotropics Sedation Analgesia Hypothermia Sepsis
10.0 8.2 DO 2 / VO 2 6.4 4.6 2.8 r= 0.906 y= -9.58 + 0.19*x n= 1149 1.0 25 40 55 70 85 100 SvO 2 %
100 80 Shock r= 0.73 % SsvO 2 60 40 Normal r= 0.88 20 0 20 40 60 80 100 Lee J et al. (1972) Anaesthesiology 36: 472 % SvO 2
Hypoxia Normoxia Hyperoxia % Sat SvO 2 closely correlates with ScvO 2 80 Mixed venous Central venous 60 40 20 Normoxia Bleeding Volume Therapy (HAES) Bleeding 0 0 30 60 90 120 150 180 210 240 Reinhart K et al, Chest, 1989; 95:1216-1221 Time (min)
ScvO2 of < 70%, ScvO2 of > 90%, Pope, J et al. Ann Emerg Med. 55:40-46
Oxygen Parameters as Endpoint Heart Rate CVP SVV SvO 2 SV GEDV ScvO 2 O 2 ER Urine Output Mental Status P (cv-a) CO2
P(cv-a)CO2 PCO 2 = K X VCO 2 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-aCO 2 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 (PvaCO 2 ) high at Time 0 (T0) and 6 hours later (T6); L-H, PvaCO 2 normal at T0 and high at T6; H-L, Pv-aCO 2 high at T0 and normal at T6; and L-L, Pv-aCO 2 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 SvO 2 SV GEDV ScvO 2 O 2 ER Urine Output Mental Status P (cv-a) CO2 OPSI NIRS
Near-infrared spectroscopy (NIRS)
NIRS StO 2 (at 20 mm, skeletal muscle) is an index of profusion that tracks DO 2 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 SvO 2 SV GEDV ScvO 2 O 2 ER Urine Output Mental Status P (cv-a) CO2 OPSI NIRS Lactate