mechanical support for acute cardiogenic shock mark j. russo, md, ms assistant professor of surgery...
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Mechanical Support for Acute Cardiogenic Shock
Mark J. Russo, MD, MSAssistant Professor of Surgery
Section of Cardiac and Thoracic SurgeryUniversity of Chicago
Disclosures
No relevant disclosures
Severe Acute Cardiogenic Shock
• Associated w excessive mortality
• If untreated will lead to imminent death
• Etiology: Post-cardiotomy, AMI, Myocarditis, Acute on chronic cardiomyopathy, Malignant arrhythmia
• Goals: Must rapidly stabilize and “rest” heart
• Treatment: Mechanical support + OMM
• Endpoint: Recovery• Definitive surgical therapy should not be offered in the acute setting
When and How to Initiate MCS
Simple Rules for Initiating MCS
• Pt continues to deteriorate despite increasing drugs
• Initiate before the patient absolutely needs it
• If you put an unsalvageable patient on MCS, they remain unsalvageable
• Its not the devices that are bad, it’s the patients who are sick
Hard Parameters for Initiating MCS• Already on inotropes and IABP
Increasing support level required
• Hemodynamics – must maintain– CI >2.0 – BP mean >60mmHg – SBP> 85 mmg– CVP <15 – PCWP <20– End organ function : renal, hepatic, pulmonary, cerebral
• Balance– Hemodynamics not attainable– Increasing inotrope requirements especially vasoconstrictors
MCS Options
• Partial Circulatory Support
• Full Circulatory Support
• Full Cardiopulmonary Support
Partial Circulatory Support
• IABP
• Impella/Abiomed
• Subclavain-IABP
Impella Abiomed
• Micro rotary pump– 2.5
• Cath lab, percutaneous insertion
– 5.0 (larger, more flow)• Graft or cutdown
• Advantages– Easy to insert– Active de-compression of LV
– Less invasive• Less support than rotary pumps
Impella Abiomed
Subclavian Intra-Aortic Balloon• Intra-aortic balloon pumps
(IABPs) are traditionally inserted through the femoral artery, limiting the patient’s mobility.
• Advantages of SC: • PVD less of an issue, • minimally invasive support, • ambulatory
• Limitations: • Time (40-1 hr), peri-stable, • Connective tissue disease
Subclavian Intra-Aortic Balloon• The graft is then tunneled into the
pocket.
• The guidewire is though the skin and then into the graft and then through the subclavian artery into the aorta.
• Under fluoroscopic guidance, the balloon wire is positioned in the descending thoracic aorta.
• The balloon is inserted and screened into an appropriate position.
• The wound over the Gore-Tex graft is closed in layers.
Operative Approach
Ambulating with IABP
Introduction
Methods
Results
Conclusions
• Mean duration of support : 21 days (range: 3 – 90)
• 19 patients (95%) were successfully bridged to transplant or LVAD.
• 2 patients (10%) required an emergent LVAD for worsening heart failure.
• All patients were extubated and ambulatory within 24 hours following the procedure
• No device-related complications while on support• 1 device exchanged at bedside
Outcomes (n=20)
Full Circulatory Support
• Extracorporeal VADs– LVADs– RVADs– BIVADs
• Implantable VADs – are not for acutely decompensating patients– Surgical trauma– Bridge to ?
Management options – what to support?
• LVAD– ECHO (function and MR)– High filling pressures with hypotension and low CO– PCWP >18 with mean BP <70mmHg and CI<1.8
• RVAD– ECHO (function and TR)– CVP > 15mmHg with mPA < 1.5 x CVP– Underfilled LV– mPA > 2x CVP relative exclusion (may need LVAD or ECMO)
Centrimag• Indications:
• Short-term support (<15 days) • Bridge-to-decision (recovery vs definitive
therapy)
• Device:• a single-use centrifugal pump, a motor,
and a primary drive console. • the motor magnetically levitates the
impeller, • achieving rotation with no friction or wear• rotates at 1500-5500 rpm • Flows: up to 9.9L/min
LVAD cannulation
• Surgical– Outflow from device
• Aorta, femoral artery
– Inflow to device• LA/PV• LV
Centrimag
• Off Pump
• Sternotomy
• Left Thoractomy
RVAD cannulation
• Surgical– Outflow from device
• PA - Do not push in too far• RVOT across PV
– Inflow to device• RA – careful positioning• RV
• Percutaneous– Outflow from device
• Via long cannula to PA
– Inflow to device• Femoral vein, IJ, subclavian
Advantages of Centrimag
• Relatively inexpensive• Reliable• High level of support• Allows for further esculation of care
– Implantable device– RVAD– ECMO
Case
• 65 year old male• S/P traumatic right BKA after MVA• Fully functional, employed as businessman• Crescendo chest pain for 2 weeks, neglected• Unrelenting angina for 24 hours before presenting to ER• LHC performed
Coronary angiogram
Patient course
• Emergency IABP placed• Transferred to tertiary care center• Hemodynamic data
– BP 70/50 augmented– PA 45/27– CVP 16– CI 1.2
• Labs: Cr 2.5; TB 4.0; AST/ALT >1,000• Support: IABP, dopamine 20 mg/kg/min, dobutamine 20
mg/kg/min, ventilator with paO2 70 on FIO2 80%
Patient course
• Anuric• Peripherally cold• Obtunded• ECHO:
– No AI– Severe MR– Moderate TR– LVEF <10%, without thrombus
Hospital course
• Centri-Mag LVAD placed off pump.• Reversed acidosis• Recovered renal and hepatic function• Pulmonary edema resolved• Total CT output <300cc• Anticoagulation started POD#1• Extubated POD#3• HeartMate II placed POD#5 to allow for rehabilitation
Full Cardiopulmonary Support
• Heart and pulmonary failure
• ECMO– Standard (Thoratec Centri-mag/Maquet Quadrox)– Portable (Maquet Cardiohelp)
Criteria
• With optimized ventilator settings– pO2 < 65mmHg– Sa02 < 90%– PEEP > 10
Standard ECMO: Centrimag + Quadrox
Centrimag Quadrox
In Situ
Centrimag
Quadrox
Advantages of Centrimag/Quadrox
• High level of support• Reliable• Relatively Inexpensive• Peripheral/Percutaneous/Central Access• Oxygenator can be cut-in to BIVAD/RVAD circuit at
the bedside
Disadvantages of ECMO
• It does not decompress the heart– unless LV vent placed
• Contraindicated in moderate to severe AI
• Oxygenator induced inflammatory response
• Need for anticoagulation– ACT 150-200
MCV00006533
CARDIOHELP – INSPIRING INNOVATIONS
• Acute Respiratory Distress Syndrome (ARDS)
• Septic Shock Syndrome• Multiple Organ System
Failure• Pulmonary Embolism
CRITICAL CARE MEDICINEPOSSIBLE APPLICATIONS
CARDIOHELP
• All in one heart-lung support system• 10 kg (22lbs)• 14 x 10 x 17 inches• Optional Sprinter Cart for in hospital
mobility
General Surgery
Neurosurgery
Cardiac Surgery
Vascular Surgery
Operating Room:
Cardiac Care
Neonatal Intensive Care
Critical CareUnit:
Options
Patient Transport:
Interventional
Cardiology Procedures
Hybrid OR / Cath Lab:
TRANSFER OPTIONS
• Transfer pt and initiate at accepting center
• Transferring center initiates ECMO– Convert to Cardiohelp
• Accepting initiates ECMO on site using Cardiohelp
In cardiovascular disease, we have a just say “YES” policy
Case
• 54yo M p/w CP to outside ED
• Troponin 20
• Taken to cath lab– Found to have RCA occlusion– Intervention unsuccessful– Worsening stability c high dose pressors– Intubated/IABP placed
• Transferred to UofC
Case
• Airlifted to UofC
• Directly to the OR
• Peripherally cool, MAPs 55, anuric, SaO2 85%
• Lactate: 7, pH 7.21, pO2 57
• ECHO: severe RV failure, LVEF=35%
Case
• Peripheral cannulation via femoral cutdown– RFA – arterial inflow– RFV – venous drainage– Antegrade to RFA via 12Fr cannula
Case• OR
– Flow: 6.0L, FiO2=100%– MAPs 70s, SaO2=100%
• HD#1– Weaning pressors– CVVHD– pH normalized, PaO2=300s
• HD#4– Off pressors and inotropy
Case• HD#6
– Weaned from ECMO after 2 day wean• Wean flows
– IABP, inotropy
• HD#10– Extubated
• HD#12– Off inotropy
• HD#19– Discharged to rehab
Support initiated – then what?• Maintenance:
– Anticoagulation• Initial – ECMO ACT 150 – 180, VAD none• After bleeding stops – 150 – 180 sec
– Minimize inotropic support– Evaluate cerebral and other end organ function– IABP for some pulsatility
• End goals:– Recovery and wean– Bridge to longer term solution
• Definitive surgical treatment is not appropriate in acute setting
Weaning / recovery
• Native ejections with decreasing support• Allow time to re-equilibrate• Continuous SG useful for LVAD (even for RVAD as it
give MVO2 saturation)• ECHO• Minimize anesthesia• Bad sign if escalating inotropes or requiring IABP
Outcomes
• Difficult to characterize given heterogeneity of patients• Recovery depends on ability to repair myocardium• Bridge to device depends on:
– Earlier initiation of mechanical therapy– Single vs bi-VAD support– Liver function marker for survival– Respiratory status– Neuro
• Reports vary from 30 – 80% success rates
Summary
• Paradigm shift– Initiate earlier–Better less inflammatory technology–Easier to initiate–Better Outcomes
Take Home Points
• MCS should be initiated early
• Temporary support, not implantable device
• Definitive therapy should only be offered after patient demonstrates measurable recovery