Complications of ECLS Rajasekhar Malyala, MD Assistant Professor, Surgery University of Kentucky
Faculty Disclosure No financial Disclosures
Education Need/Practice Gap Recommendations and guidelines regarding complications in ECLS are difficult to find. Providers need to be aware of the possible risks of ECLS.
Objectives Upon completion of this educational activity, you will be able to: 1. Indicate common complications of ECLS. 2. Recognize, intervene early, and alter management based on the complication
Expected Outcomes The desired change/result in practice is to be aware of the major complications or injuries that can occur with ECLS.
Overview Immediate Complications with Cannulation and Initiation Delayed Bleeding and Thrombotic Complications Delayed Organ System Failure: Renal failure Other complications: Air Embolism
Major Vascular Complications Difficulty with this topic is it is under reported in the literature Publication Bias Perforation of Major vessel, or dissection of an artery are known complications Incidence of these complications is fortunately low. However, it is usually fatal and since ECLS was never initiated not reported in the ELSO Registry! One frequently has to go to international journals to find literature.
Venous Injury During Insertion 1. Perforation of the left Iliac Vein 2. Right Internal Jugular vein at the thoracic inlet 3. Right Subclavian Vein: would not use for ECLS! 4. One paper reported traumatic rupture of the IVC with death of the patient 5. Another instance of implantation of the arterial cannula into the femoral vein.
Arterial Injury Most frequent serious problem is dissection A localized dissection can often be managed An extensive dissection is frequently fatal One may note poor flows on ECMO or high pressures on the circuit No blood return from the arterial cannula may also be noted Fortunately major injuries are rare, while localized dissections are not uncommon
Underlying Cause of Vascular Injuries Failure to use Modified Seldinger Kinked guide wire Atherosclerosis or tortuosity Emergent circumstances leading to rushing
General Principle of Management Buy Time Leave cannula in place, and secure it, and clamp it Alternative access for ECMO and stabilize patient Then consult Interventional, Vascular Surgery If time permits, imaging study (Fluoroscopy, TEE, or CT)
Lower Extremity Ischemia Pulseless/Cold Leg Compartment Syndrome
Distal Perfusion Catheter
Compartment Syndrome Often noted after reperfusion of the leg with restoration of pulses However, compartment pressures above 20 mm Hg require urgent fasciotomy Compartment syndrome is due to venous obstruction due to swelling and will result in irreversible neurologic injury and muscle necrosis if it is not treated promptly
Normal Pulses in Compartment Syndrome
Tight Calf Compartment
Compartment Pressure Above 20
Biochemical Evidence of Ischemia Increasing Lactate Increased CPKs (frequently well above 10,000) Finally leading to rhabdomyolysis, myoglobinuria, renal failure, hyperkalemia
Bleeding Complications Can occur anywhere from Cannula insertion sites, surgical incisions, lung, gi tract, nose, mouth, thorax, abdomen, and brain. Causes: Heparin effect, overdose, coagulopathy, thrombocytopenia, platelet dysfunction, acquired VWS, Hyperfibrinolysis.
Intracranial Bleeding Wide range with a frequency between 1.8% to 21%. Higher incidence occurs with routine CT scans Increase is associated with prolonged duration, antithrombotic therapy, altered intrinsic coagulation, renal failure, need of blood products. In the H1N1 pandemic in Australia and Newzealand, ICH was the most common cause of death among ECMO treated patients. In large series, relative risk of death is 1.48 to 2.91. However, modality of ECMO does not seem to make a difference
Reducing ICH Unproven: 1. Lowering ACT goals, prophylactic correction of coagulation factor deficiencies, possible use of Enoxaparin exclusively, low dose anticoagulation 2. There is evidence in pediatric and neonatal patients that certain biomarkers may be elevated prior to imaging detection of ICH (S100B, NSE, GFAP and others). 3. One Swedish study found that pre admission antithrombotic therapy and low plt count were independently associated with a high mortality with ICH
G.I. Bleeding Kiefer et al from Maryland found a 13.6% incidence of GI bleeding Duration of ECLS (12 days vs 7 days) was a factor Higher inhospital mortality (83% vs 44%). Odds ratio of 5.91 for in hospital mortality Most frequent diagnosis was stress gastritis. Cause thought to be coagulopathy, systemic inflammation, non pulsatile blood flow In a Canadian paper by Cook et al., regarding stress ulcer prophylaxis, studying 2252 critically ill patients, patients with respiratory failure (odds ratio of 15.6) and coagulopathy (odds ratio of 4.3) were most likely to encounter gi bleeding. ECMO patients seems to be thus the highest risk population for gi bleeding
Acquired VW Syndrome in ECLS Patients AVWS associated with loss of HMW multimers of VWF, leading to impaired binding of VWF to platelets This was studied in 32 patients with ECLS and 19 without. Ratios of ristocetin cofactor activity and collagen binding capacity to VWF antigen and multimeric analysis were performed 31/32 ECLS patients presented with AVWS, but none of the patients without it.
Thrombotic Complications High fibrinogen, Factor VIII levels, heparin resistance, and platelet activation LV thrombus may occur in cases of VA ECMO if there is minimal ejection Interaction between PVWF and PfHb may explain thrombosis Circuit Clots
Renal Failure Incidence is 30-40% In a review of multiple studies, OR for mortality of ECMO and CRRT was about 6.
Survival with Kidney Injury C. Delmas et al. / Journal of Critical Care 44 (2018) 63 71 Patients' outcome at 30 days and 3 months (M3) according to groups 1 and 2. Group 1: No AKI, AKI KDIGO stages 1 and 2 patients (n = 31); group 2: AKI KDIGO stage 3 patients (n = 29) * and α p b 0.05.
Uncommon Complications Massive Air Embolism Can Occur even during routine care of the central line Air can enter the venous system, and then the oxygenator, and the arterial line, resulting in immediate shut down of the circuit, and air embolism to the arterial side Can also result from a PFO or a Bubble Study
Air Embolism from a Central Line
Conclusions 1. ECLS is a modality with high morbidity and mortality 2. Complications occur from insertion, to mechanical problems, to bleeding and thrombotic events remote from cannulation 3. When they occur, they often require specialized personnel to manage them 4. A team approach to monitoring and early intervention is necessary to mitigate complications and their morbidity