The case for why it matters Fluid balance a common concern Patients - PDF document

5/9/2015 Goal-Directed Fluid Resuscitation Goal-Directed Fluid Resuscitation Christopher G. Choukalas, MD, MS Christopher G. Choukalas, MD, MS Department of Anesthesia and Perioperative Care Department of Anesthesia and Perioperative Care University of California, San Francisco University of California, San Francisco The case for why it matters • Fluid balance a common concern • Patients with Sepsis who developed ALI • Sepsis • 4 groups: • ALI/ARDS – Adequate initial + Conservative late fluids – Adequate initial only • Sepsis PLUS ARDS! – Conservative late only – Neither 1

5/9/2015 It matters • And it’s hard… • … and we’re really bad at it! Murphry, CV, et al. 2009. Chest. 136(1) It matters • Retrospective, 8000 cases, • And it’s hard… uncomplicated, elective • So how do we do it? • mL/kg/hr by center, case type, provider – 6.7 vs 8.2 – Huge inter-provider differences • 700 vs 5.4 • Exceeded differences due to blood loss, hemodynamic factors, case type 2

5/9/2015 I would posit two factors: Hemodynamic Goals • Hemodynamic: • Blood pressure – Is the circulation adequate? • CVP • Metabolic • Dynamic respiratory indices: – Are oxygen delivery and utilization adequate? – Pulse pressure/systolic pressure/perfusion • Both have their own goals. index variation Hemodynamic Goals Blood pressure • Blood pressure • A proxy for flow, end organ perfusion • CVP • Flow = pressure/resistance • Dynamic respiratory indices: • Do we ever really KNOW resistance? – Pulse pressure/systolic pressure/perfusion index variation 3

5/9/2015 Wax, et al. • Non-cardiac cases with both ABP and NIBP. • Compared SBP, DBP, and MAP btwn technologies: – A-line alone vs A-line + cuff Randomized trials • This used to be the 2 nd joke of the talk 4

5/9/2015 Interesting review • Reviewed 2 trials and 1 meta-analysis (13 studies) – Target BP – Actual BP • Dissociation – BPs invariably higher than goal – Higher goal ranges permitted higher actual ranges:  pressors The NEJM study • Randomized to MAP 65 vs 85 (800 total) • Norepinephrine • Mortality • AKI/RRT, stratified by HTN 5

5/9/2015 Blood pressure • Necessary but not sufficient • Goals are nebulous • We’re really bad at following them • Supra-normal levels common, not helpful Hemodynamic Concept: assumptions • Blood pressure Normal CVP • CVP • Dynamic respiratory indices: Optimal actin-myosin match – Pulse pressure/systolic pressure/perfusion index variation Adequate contractility Adequate DO 2 6

5/9/2015 Sepsis +  CVP = Death The data • Critical target in EGDT for sepsis • Retrospective analysis of VASST trial – 778 pts w/ septic shock on NE • Incorporated into SSC guidelines • CVP at 12 hrs did predict 28-d mortality in patients: HR CVP < 8 0.61 CVP 8-12 0.76 CVP >12 1 Boyd, JH, et al. 2011. CCM. 39(2) Fluid responsiveness and total blood volume • Volume responsiveness • Cardiac output before and after fluid challenge • 19 evaluated CVP and volume responsiveness Marik, PE, et al. 2008. Chest. 134(1) 7

5/9/2015 Fluid responsiveness Volume responsiveness • Calculated a Receiver Operating Characteristic curve • Likelihood that at any given point (CVP level, score, etc) the true positives will exceed false positives. • Higher = better discrimination Marik, PE, et al. 2008. Chest. 134(1) Deja vu CVP • 43 studies, half ICU • Necessary? • Same design • Certainly not sufficient – AUC btwn CVP and ΔSV • Potentially misleading • Same pooled AUC – 0.56 • Same aggressive conclusion 8

5/9/2015 Hemodynamic The Principles • Blood pressure • CVP • Dynamic respiratory indices: – Pulse pressure/systolic pressure/perfusion index variation  LV Preload  LV SV Decreased RV SV  RV Preload  RV Afterload Variations on a theme… Applies to lots of measures • Systolic pressure variation • A waveform… • Pulse pressure variation • A peak and trough… • Plethysmogram variation • And a proprietary algorithm: • Outcome is “fluid responsiveness” 9

5/9/2015 The data • Small studies • 29 studies, 685 patients – 9 ICU • Mostly OR – 20 OR (15 in cardiac surgery) • All included correlation/ROC between SPV, PPV, or SVV and ΔSVI/CI after a fluid challenge. SVV, Vigileo PVI, Masimo 40% MORE fluid 1/3 LESS fluid Lower lactate Lower lactate Fewer “complications” Now, keep in mind… • Regular HR • Sedated, mechanically ventilated Measure r AUC for ROC Threshold • Vt = 8 mL/kg PPV 0.78 0.94 12.5% SVV 0.72 0.84 15.3% SPV 0.72 0.86 CVP 0.56 10

5/9/2015 Non-invasive CO toys Hemodynamic goals • Numerous • State of the art: Dynamic indices – PPV – SPV – PVI – VTI and esophageal doppler • Necessary but not sufficient Metabolic Metabolic • Mental status, urine output • Mental status, urine output • Lactate • Lactate • S(c)vO2 • S(c)vO2 11

5/9/2015 Metabolic Lactate • Mental status, urine output • The product of anaerobic respiration • Lactate • Presence implies inadequate oxygen utilization, shock • S(c)vO2 • Easily, quickly measured in arterial blood Lactate: the data Two trials: • JAMA: 300 patients, EGDT vs lactate clearance – Non-inferiority • AJRCCM: 348 patients, EGDT vs lactate clearance – Improved mortality (multivariate) – Less time on vent, in ICU 12

5/9/2015 The underpinnings… How did they do it? Jones, et al (JAMA) Jansen et al (AJRCCM) Monitoring interval 2 2 Goal 10% clearance 20% clearance Fluid totals (L) Control: 4.3 Control: 2.2 Intervention: 4.5 ns Intervention: 2.7 * Outcome Non-inferiority to EGDT Decreased time on vent, in ICU Metabolic • Mental status, urine output • Lactate • S(c)vO2 13

5/9/2015 How it’s used: DOGS  ScvO 2 attributed to:  Supply (cardiac output)  Demand (hypermetabolism) Changes in SvO2 and ScvO2 • In either case, treat by increasing DO 2 Humans w/ shock – Volume, inotropes, RBCs • But does it work? Humans w/ sepsis But does it work? Metabolic goals • Rivers, et al. • Lactate • ScvO 2 • Physiological rationale meets objective data. 14

5/9/2015 Does any of this… Single point design • Save lives? • Close to the patient • Save money? • “does this surrogate metric predict optimal filling/SV/some outcome” • Actually work? • These seem to work 15

5/9/2015 Subgroup Mortality Complications Jadad high --- +++ Jadad low +++ +++ 1980s-1990s +++ +++ 2000s --- +++ Similar goals (SVV), similar Taking a step back… protocols… 16

5/9/2015 …different outcomes So is GDT no good, or… • Fewer post-op complications • Basically shows the NICOM doesn’t work? • Left the ICU and hospital a full day sooner • Complication rate much lower than • No difference in fluid totals, RBCs, UOP expected (underpowered?) »VS • GDT group bolused starch and gelatin • No difference on any clinical measure (twice the control group) • Indictment of GDT? Does the PROCESS of GDT aRISE to the Does the PROCESS of GDT aRISE to the challenge? challenge? Will GDT SURVIVE? 17

5/9/2015 Putting it all together: The end • Volume isn’t easy The End • Volume is important • Common conditions; competing goals • Stepwise plan – Hemodynamic – Metabolic • It seems to work 18