BASIC CRITICAL CARE OF THE PATIENT. Hannelisa Callisen PA C February 2017

BASIC CRITICAL CARE OF THE PATIENT Hannelisa Callisen PA C February 2017

Disclosures Industry: None ECMO is off label

Objectives ECMO initiation selection, cannulation Physiology : Review of DO2 on ECMO Monitoring on ECMO Bedside management of the ECMO patient Complications 2 ICU patients

FIRST.. WHAT IS ECMO? Image credit: S. Conrad

42F to ED w/ SOB PMH: Obesity, Pre diabetes Admitted last night for acute hypoxic respiratory failure Intubated, paralyzed On low dose pressors BAL: +H1N1 PIP 40 Vt 210 PEEP 14 RR 32 ABG ph 7.15 paco2 66 pao2 52 SaO2 76 HCO3 19

To Cannulate? CURRENT SITUATION: ARDS w/ significant hypercapnia & hypoxia affecting DO2 and end organ function, on maximal vent settings Does she meet criteria? When is the right time to cannulate? What is the likelihood of recovery? PIP 40 Vt 210 PEEP 12 RR 32 ABG ph 7.15 paco2 66 pao2 52 SaO2 76 HCO3 19

To Cannulate? SELECTION CRITERIA

To Cannulate? SELECTION CRITERIA? Are these specific gas exchange parameters useful?why 7 days of aggressive ventilation?how definite are these contraindications Brodie NEJM 2011

To Cannulate? INDICATIONS? Are these specific gas exchange parameters useful GENERAL CRITERIA: Reversible (or transplantable) disease Refractory to maximal conventional therapy High risk of mortality

To Cannulate? TIMING TO ECMO?Why 7 days of aggressive ventilation Timing to cannulation / transfer is difficult to discern Trajectory of illness is most important factor Ferguson ND ICM 2012 Rescue therapies for ARDS Moerer. Curr Opin 2016

To Cannulate? TIMING TO ECMO?Why 7 days of aggressive ventilation Domico M, Ped Crit Care Med 2012 Nance, J of Ped Surg 2009

To Cannulate? CONTRAINDICATIONS?How definite are these contraindications ECMO IS A BRIDGE THERAPY Goal: Buy time for disease process to resolve Avoid injury from other therapies Consider end point & ability to recover and overcome potential complications of ECMO therapy (early) ELSO Guidelines for acute resp failure

To Cannulate? PRE ECMO PREDICTORS RESP Score ECMOnet Score Pre ECMO SOFA Score?helpful

Rationale for VV ECMO ARDS continues to have high mortality VILI may develop and worsen lung disease ECMO: Puts less dependence on ventilator, reduces transpulmonary pressures Allows DO2 and VO2 to be better controlled and manipulated (even if SaO2 NOT improved) May improve hemodynamics & CO

RATIONALE FOR ECMO Improve Cellular Oxygenation DO2 normally 4 5 times that of VO2 Resting VO2: 3 5mL/kg/min for adults DO2 (ml/min) = CO (L/min) x CaO2 (ml O2 / L blood) [1.34 Hgb SaO2] + [0.003 PaO2] OER = VO2 / DO2 [Normal~25%] CO (L/min) x CaO2 CvO2 (ml O2 / L blood) = VO2 (ml/min) Cells determined by tissue metabolic rate

RATIONALE FOR ECMO Improve Cellular Oxygenation DO2 normally 4 5 times that of VO2 Resting VO2: 3 5mL/kg/min for adults OER = VO2 / DO2 [Normal~25%] If DO2:VO2 is < 2:1 Anaerobic Metabolism ILLNESS SvO2 < 50 60% DO2crit ~4mL/kg/min Monitoring DO2 in the crit ill Huang. Chest 2005 O2 delivery and consumption, macrocirc perpective Nichols. Crit Care Clin 2010

VV ECMO NO cardiac support NO in pulmonary blood flow Configura on Usually PARTIAL pulmonary support Based on ECBF : CO Ratio ECMO flow Venous Admixture Outlet / Return Native Lung Function Recirculation Patient Cardiac Output VV perfusate mixes with mixed venous blood return, bypassed by ECMO Venous Admixture Inlet / Drainage Venous Return mixed Cells Bypassed Venous Flow

VV ECMO Cannulation SINGLE SITE CANNULATION DUAL SITE CANNULATION ECMO in CP disease in adults Abrams. JACC 2014

ECMO CIRCUIT Cannula Biggest, shortest cannula = least resistance to flow Appropriate cannula selection is critical! ECMO for adult resp failure Turner. Resp Care 2013

ECMO CIRCUIT Tubing PVC TUBING Neonates: 1/4 inch Peds: 3/8 inch Adults: 3/8 1/2 inch TUBING SIZE SV (ml/rpm) PRIME VOLUME MAX ART FLOW MAX VEN FLOW 1/4 inch 13ml 9.65ml/ft 3 LPM 1.3 LPM 3/8 inch 27ml 21.71ml/ft 8 LPM 4 :PM Biocompatible surface coating

ECMO CIRCUIT Pump CENTRIFUGAL PUMP Non occlusive pump Pre load sensitive Afterload dependent (must overcome positive resistance) Flow RPM Impeller design Magnetically coupled to motor NO Direct relationship between RPM and Flow Flowmeter is necessary

ECMO CIRCUIT Oxygenator MICROPOUROUS HOLLOW FIBER Polymethylpentene Gas inside fibers, blood on outside Low pressure drop across membrane Very small nano pore size Rare plasma leakage High gas permeability Rated flow Maquet.com

ECMO CIRCUIT Heat Exchanger Integrated in hollow fiber membrane lungs External water bath warms blood Bath temp usually set 1 1.5 C above 37 C

ECMO CIRCUIT Gas Blender Connected to oxygenator Mixes air and oxygen O2 Dial for FiO2 (0 100%) Connects to 30 70PSI inlet Air Gas flow = Sweep 2 dials 0 10 LPM

Cannulated for VV ECMO using fem fem approach Sedated, paralyzed 42F w/ ARDS on VV ECMO ABG BP: 78/50 (60) on Norepinephrine HR: 100 CVP: 16 SWEEP FiO2 ph 7.29 paco2 42 pao2 59 SaO2 88 HCO3 17 Lactate 4.1 FLOW: RPM:

42F w/ ARDS on VV ECMO What is most concerning? What are we missing here? What do we address first? vent?? ABG BP: 78/50 (60) on Norepinephrine HR: 100 CVP: 16 SWEEP FiO2 ph 7.29 paco2 42 pao2 58 SaO2 87 HCO3 17 Lactate 4.1 FLOW: RPM:

42F w/ ARDS on VV ECMO

PATIENT A B C Vitals / Pressures / Waveforms SpO2 RR HR BP CVP Physical Exam IMAGING MEDS LABS CO VO2 CANNULAS TUBING FLOWS PRESSURES OXYGEN ATOR PUMP CaO2 ECMO VENTILATOR INTERACTION GAS EXCHANGE FiO 2 PEEP RR V T PIP

Oxygen Delivery ON VV ECMO DO2 = CaO2 CO native cardiac function

VV Air/O2 Blender MO V A Motor Pump S inlet O2 MO FiO2 MO Dynamics Blood Flow Rate membrane oxygenated blood For Best Ratio: Effec ve ECBF Recircula on CO true S V O2 Lung Function Ventilator Settings lung oxygenated blood

Blood Viscosity Blender / O2 Blood Flow : CO Ratio?OK OK MO Dynamics Membrane thickness Membrane Surface Area Diffusion capacity OK OK Lung Function MINIMAL, but that is OK! True SvO2 LOW: due to shock, VO2 Recirculation Fraction HIGH: Due to PTX Cells Oxygen Delivery Adequate CO NO: Obstructive shock due to PTX & high PIP Hemoglobin?OK NEEDS CHEST TUBE!

Mechanical Ventilation ON VV ECMO

38M w/ NIMCP Code Blue PEA ARREST Admitted 1 day ago w/ decompensated HF Hx of dilated CMP (non ischemic, previous viral) CPR ROSC Ends up on high dose inotropes Hypoxic & Acidemic ABG ph 7.20 paco2 36 pao2 50 SaO2 86 HCO3 12 Lactate 11? VA ECMO

38M w/ NIMCP Code Blue? VA ECMO INDICATIONS CONTRAINDICATIONS CONSIDERATIONS

38M w/ NIMCP Code Blue ECMO in CP disease in adults Abrams. JACC 2014

Outcomes FOR VA ECMO

VA ECMO Configura on Inlet / Drainage in pulmonary blood flow ECMO flow Outlet / Return Cardiac bypass support (partial to sub total) Total CO = Native CO + ECBF Native Lung Function Native Cardiac Output Arterial oxygenation: Dependent on sample location (in relation to mixing cloud) Mixture of ECLS perfusate and natively oxygenated blood in aorta Venous Return mixed Mixing Cloud Cells

VA ECMO Peripheral Cannulation ECMO in CP disease in adults Abrams. JACC 2014

DO2 = C Nat O2 CO Nat + C ECMO O2 ECBF VA V A S V O2 Lung Function Ventilator Settings lung oxygenated blood Ratio Native CO : ECBF membrane oxygenated blood S V O2 MO FiO2 MO Dynamics Native CO + ECBF

38M w/ Card Shock on VA ECMO What to do with inotropes? How to approach hypoxia? What is an acceptable SaO2? How to manage ventilator?

38M w/ Card Shock on VA ECMO With most inotropes off:

LV Distention ON PERIPHERAL VA ECMO Risk of LV thrombosis Pulmonary Edema LV Failure

CHEST TUBE now in place 42F w/ ARDS on VV ECMO BP: 110/50(70) HR: 120 CVP: 11 SaO2: 83% What SaO2 is acceptable? If DO2 inadequate, how can it be improved?

Lung Function Oxygen Delivery Adequate CO Blood Flow : CO Ratio Hemoglobin Blood Viscosity Blender / O2 MO Dynamics Membrane thickness Membrane Surface Area Diffusion capacity True SvO2 Recirculation Fraction Cells

VV ECBF DETERMINANTS AND LIMITATIONS Effective

Recirculation CAUSES 1. RPM 2. Cannula Positioning 3. Venous Chamber Compliance 4. Low CO

38M w/ Card Shock on VA ECMO Inotropes increased to arterial pulsatility (native CO) Ventilator Settings decreased (FiO2 50%, PEEP 5) BP: 72/60 (64) SaO2: 80%

Differential Hypoxia ON PERIPHERAL VA ECMO C. Lotz Circulation 2014

VV & VA side by side IN SERIES Cells Cells IN PARALLEL

Complications, Considerations Bleeding, Hemolysis, Thrombosis Renal Failure Pharmacy Neurocognitive Limb perfusion Nursing care Team Cost

Complications, Considerations Lim ECLS physiological concepts and clinical outcomes. J of Card Failure 2016

Final Thoughts ECMO: Physiology is complex! Needs meticulous consideration of risks, potential for recovery (or transplant), & co morbidities Is resource intensive & costly Best practiced at experienced, high volume centers w/ well trained team members (that means everyone involved)

PATIENT A B C Vitals / Pressures / Waveforms SpO2 RR HR BP CVP Physical Exam IMAGING MEDS LABS CO VO2 CANNULAS TUBING FLOWS PRESSURES OXYGEN ATOR PUMP CaO2 ECMO VENTILATOR INTERACTION GAS EXCHANGE FiO 2 PEEP RR V T PIP

THANK YOU callisen.hannelisa@mayo.edu