UTILITY of ScvO 2 and LACTATE

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1 UTILITY of ScvO 2 and LACTATE Professor Jeffrey Lipman Department of Intensive Care Medicine Royal Brisbane Hospital University of Queensland

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3 THIS TRIP SPONSORED AND PAID FOR BY

4 STRUCTURE Physiology - Lactate - ScvO 2 How used - ScvO 2 - Lactate ScvO 2 vs Lactate (early goal directed therapy) Conclusions and Take home message

5 LACTATE Traditionally, the terms lactate and lactic acid are used interchangeably Lactic acid in human subjects exists predominantly in its ionized form even in severely low ph states Measurements are made of blood or plasma lactate, not lactic acid

6 LACTATE Glucose + 2ADP + 2NAD + 2Pyruvate + 2ATP + 2NADH Pyruvate + NADH + H + Lactate + NAD +

7 LACTATE The serum arterial lactate concentration reflects the balance between net lactate production and net lactate consumption/ clearance The daily production of lactate is about 1400 mmol, primarily from skeletal muscle (25%), skin (25%), brain (20%), intestine (10%), and red blood cells (20%).

8 LACTATE In the critically ill, lactate is produced in tissues outside the usual lactate producers, including the lungs, white blood cells, and splanchnic organs. Note: released in supraphysiologic amounts from the sites of infection and inflammation and is thought to be related to the augmented glycolysis in the recruited and activated leukocytes at the sites of infection

9 LACTATE Lactate is metabolized primarily in the liver (60%), kidneys (30%) and heart (10%). Elevated serum lactate levels are a product of some combination of excess production and reduced clearance.

10 LACTATE Okorie and Dellinger Crit Care Clinics 2011;27:

11 Venous Oxygen Saturation

12 CaO 2 (ml O 2 /dl) = (Hb x 1.38 x SaO 2 ) + (PaO 2 x 0.003) 12

13 CvO 2 = CaO 2 -VO 2 /Q DO 2 = Cardiac output (Q) x Arterial oxygen content (CaO 2 ) Q = DO 2 /CaO 2 VO 2 = Q x (CaO 2 -CvO 2 ) CvO 2 = CaO 2 -VO 2 /Q 13

14 Venous Oxygen Saturation CvO 2 = CaO 2 -VO 2 /Q Reflects the extraction of oxygen from the tissue A surrogate marker of adequacy of circulation/perfusion Basis of Rivers work 14

15 Venous Oxygen Saturation CvO 2 = CaO 2 -VO 2 /Q If low (particularly in yng fit trauma pts) will indicate under-resuscitation 15

16 Central and Mixed Venous Oxygen Saturations SvO 2 = pulmonary artery catheter ScvO 2 = central venous catheter 16

17 CHEST 2004;126:1891 6

18 Resuscitation 2009;80:811 8 Conclusions: Management of ANZ patients presenting to ED with sepsis does not routinely include protocolised, ScvO2-directed resuscitation. Inhospital mortality compares favourably with reported mortality in international sepsis trials.

19 EARLY GOAL DIRECTED THERAPY As described by Rivers Addresses 3 sequential physiological targets: 1 IV fluids to achieve a CVP (originally 8-12mmHg) 2 Pressors to achieve a MAP at least 65mmHg 3 Dobutamine or red blood cell transfusions to restore tissue oxygen delivery, as assessed by ScvO 2 of at least 70%. CvO 2 = CaO 2 -VO 2 /Q

20 300 pts Pts randomly assigned Jones et al JAMA 2010;303: a) ScvO2 group resuscitated to normalize CVP, MAP, and ScvO2 of at least 70% b) lactate clearance group was resuscitated to normalize CVP, MAP, and lactate clearance of at least 10% The study protocol was continued until all goals were achieved or for up to 6 hours. Clinicians who subsequently assumed the care of the patients were blinded to the treatment assignment.

21 300 pts Jones et al JAMA 2010;303: Thirty-four patients (23%) in the ScvO2 group died while in the hospital (95% confidence interval [CI], 17%-30%) compared with 25 (17%; 95% CI, 11%-24%) in the lactate clearance group. This observed difference between mortality rates did not reach the predefined 10% threshold.

22 Jones et al JAMA 2010;303: Overall, Jones et al observed a mortality of 23% among patients receiving ScvO 2 guided treatment and a mortality of 17% among those receiving lactate-guided treatment.

23 Lewis RJ. Editorial JAMA 2010;303:777-9 How should physicians proceed in the initial management of the adult patient with severe sepsis or septic shock? There are really 2 questions to be considered: first, should early goaldirected therapy be used whenever possible, and, second, if so, what should the resuscitation targets be? Lewis RJ Editorial JAMA 2010;303:777-9

24 Lewis RJ. Editorial JAMA 2010;303:777-9 Thus, uncertainty remains about the true benefit of early goal-directed therapy. Without new trials. clinicians should use the original central venous pressure target of between 8 and 12 mm Hg (unventilated) and a mean arterial pressure target of at least 65 mm Hg I AGREE Lewis RJ Editorial JAMA 2010;303:777-9

25 Hence ProCESS ARISE ProMISe (USA) (ANZICS) (UK)

26 Same parameters but including ScvO 2 Am J Respir Crit Care Med 2010;182:752 61

27 Am J Respir Crit Care Med 2010;182: pts: hospital mortality: 43.5% (77/177) vs 33.9% (58/171) in the lactate group (P=0.067)

28 166 patients Logical/reasonable algorithm

29 166 patients Logical/reasonable algorithm Lactate clearance >10% over the first 6 h

30 Arnold et al Shock 2009;32:35-9

31 LACTATE CLEARANCE Okorie and Dellinger Crit Care Clinics 2011;27:

32 LACTATE Okorie and Dellinger Crit Care Clinics 2011;27:

33 LACTATE Okorie and Dellinger Crit Care Clinics 2011;27:

34 LACTATE Okorie and Dellinger Crit Care Clinics 2011;27:

35 INTENSIVE CARE MED 2008;34: patients, 139 received A and 138 N. Median time to resolution of acute circulatory failure was 35.3 hours with A vs 40.0 with N. There was no difference on MAP or development of organ failure. In severe sepsis, the time to resolution of acute circulatory failure was 35.6 hours with A (n=76) and 50.5 hours with N (n=82). A was associated with significant tachycardia, lactic acidosis and hyperglycaemia in the first 4 hours that resolved after 24 hours of infusion.

36 INTENSIVE CARE MED 2008;34: MAP TARGETS

37 INTENSIVE CARE MED 2008;34:

38 CONCLUSION INTENSIVE CARE MED 2008;34: Despite the development of transient metabolic effects associated with adrenaline, there was no difference between infusions of adrenaline and noradrenaline for the resolution of acute circulatory failure in ICU patients.

39 INTENSIVE CARE MED 2008;34: NO DIFFERENCE IN OUTCOME

40 MAY Anaesth Intensive Care 2011;39: Hypothesis a lactate stress test may reflect underlying metabolic reserve. Ratio of the change in whole blood lactate concentration to the increase in adrenaline dosage LI=(LAC2 LAC1)/(ADR2 ADR1)=ΔLAC/ΔADR

41 MAY Anaesth Intensive Care 2011;39:

42 UTILITY of ScvO 2 and LACTATE I hardly use ScvO2 only useful, at best, if low I use lactate EVERYDAY if its normal pt may not be, but if high pt has a problem

43 UTILITY of ScvO 2 and LACTATE I hardly use ScvO2 only useful, at best, if low I use lactate EVERYDAY if its normal pt may not be, but if high pt has a problem

44 TAKE HOME MESSAGE ScvO 2 or LACTATE

45 TAKE HOME MESSAGE LACTATE