Extracorporeal cardiopulmonary resuscitation for post-operative cardiac arrest: indications, techniques, controversies, and early results--what is known (and unknown)

State of the Art: Extracorporeal Cardiopulmonary Resuscitation for In-Hospital Arrest

Extracorporeal membrane oxygenation has been used since the 1970s and recently has seen increased use for in-hospital arrest requiring extracorporeal cardiopulmonary resuscitation (ECPR). This paper provides an updated review of the ECPR literature and practical recommendations for implementation of an ECPR program.

Extracorporeal Cardiopulmonary Resuscitation in the Pediatric Cardiac Population: In Search of a Standard of Care

OBJECTIVES

Although clinical and pharmacologic guidelines exist for the practice of cardiopulmonary resuscitation in children (Pediatric Advanced Life Support), the practice of extracorporeal cardiopulmonary resuscitation in pediatric cardiac patients remains without universally accepted standards. We aim to explore variation in extracorporeal cardiopulmonary resuscitation procedures by surveying clinicians who care for this high-risk patient population.

DESIGN

A 28-item cross-sectional survey was distributed via a web-based platform to clinicians focusing on cardiopulmonary resuscitation practices and extracorporeal membrane oxygenation team dynamics immediately prior to extracorporeal membrane oxygenation cannulation.

SETTINGS

Pediatric hospitals providing extracorporeal mechanical support services to patients with congenital and/or acquired heart disease.

SUBJECTS

Critical care/cardiology specialist physicians, cardiothoracic surgeons, advanced practice nurse practitioners, respiratory therapists, and extracorporeal membrane oxygenation specialists.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Survey web links were distributed over a 2-month period with critical care and/or cardiology physicians comprising the majority of respondents (75%). Nearly all respondents practice at academic/teaching institutions (97%), 89% were from U.S./Canadian institutions and 56% reported less than 10 years of clinical experience. During extracorporeal cardiopulmonary resuscitation, a majority of respondents reported adherence to guideline recommendations for epinephrine bolus dosing (64%). Conversely, 19% reported using only one to three epinephrine bolus doses regardless of extracorporeal cardiopulmonary resuscitation duration. Inotropic support is held after extracorporeal membrane oxygenation cannulation "most of the time" by 58% of respondents and 94% report using afterload reducing/antihypertensive agents "some" to "most of the time" after achieving full extracorporeal membrane oxygenation support. Interruptions in chest compressions are common during active cannulation according to 77% of respondents.

CONCLUSIONS

The results of this survey identify wide variability in resuscitative practices during extracorporeal cardiopulmonary resuscitation in the pediatric cardiac population. The deviations from established Pediatric Advanced Life Support CPR guidelines support a call for further inquiry into the pharmacologic and logistical care surrounding extracorporeal cardiopulmonary resuscitation.

Practical Implementation of Failure Mode and Effects Analysis for Extracorporeal Membrane Oxygenation Activation

Extracorporeal membrane oxygenation (ECMO) is used to treat severe hypoxemic respiratory failure and as a rescue therapy for patients with cardiopulmonary arrest within a narrow window of time. A failure modes and effects analysis (FMEA) was conducted to analyze the clinical and operational processes leading to delays in initiating ECMO. FMEA determined these highest-risk failure modes that were contributing to process failure: (1) ECMO candidacy not determined in time, (2) no or incomplete evaluation for ECMO prior to consult or arrest, (3) ECMO team not immediately available, and (4) cannulation not completed in time. When implemented collectively, a total of 4 interventions addressed more than 95% of the system failures. These interventions were (1) ECMO response pager held by a team required for decision, (2) distribution of institutionally defined inclusion/exclusion criteria, (3) educational training for clinicians consulting the ECMO team, and (4) establishment of a mobile ECMO insertion cart.

The Use of Extracorporeal Membrane Oxygenation-Cardiopulmonary Resuscitation in Prolonged Cardiac Arrest in Pediatric Patients: Is it Time to Expand It?

Extracorporeal membrane oxygenation was instituted as an aid to in-hospital cardiopulmonary resuscitation (E-CPR) nearly 23 years ago, this led to remarkable improvement in survival considering the mortality rate associated with conventional cardiopulmonary resuscitation (CPR). Given this success, one begins to wonder whether the time has come for expanding the use of E-CPR to outside hospital cardiac arrests especially in the light of development of newer extracorporeal life support devices that are small, mobile, and easy to assemble. This editorial will review recent studies on this subject and address some key guidelines and limitations of this evolving and promising technology.

Pediatric extracorporeal cardiopulmonary resuscitation during nights and weekends

AIM

Extracorporeal cardiopulmonary resuscitation (ECPR) is a lifesaving rescue therapy for patients with refractory cardiac arrest. Previous studies suggest that maintaining a 24/7 in-house surgical team may reduce ECPR initiation time and improve survival in adult patients. However, an association between cardiac arrest occurring during off-hours and ECPR outcome has not been established in children.

METHODS

This is a single institution, retrospective review of all pediatric patients who received ECPR from December 2008 to August 2015.

RESULTS

During the study period, ECPR was performed 54 times in 53 patients (20 weekday, 34 night/weekend). Interval from ECPR activation to initiation of extracorporeal life support was significantly longer during night/weekends (49min night/weekend vs. 33min weekday, p<0.001) as was the interval from ECPR activation to incision for cannulation (26min night/weekend vs. 14min Weekday, p<0.001). Rate of central nervous system (CNS) injury was higher in the night/weekend group (43% night/weekend vs. 15% weekday, p=0.04), with associated 75% mortality prior to hospital discharge. Time of arrest did not impact survival to hospital discharge (44% night/weekend vs. 55% weekday, p=0.57), one-year survival (33% night/weekend vs. 44% weekday, p=0.44), or neurologic outcome (Pediatric Cerebral Performance Score at 1-year post-ECPR, 1.45 weekday vs. 1.50 night/weekend, p=0.82).

CONCLUSIONS

Cardiac arrest occurring at night or during weekend hours is associated with a longer ECPR initiation time and higher rates of CNS injury. However, prolonged pre-ECPR support associated with off-hours cardiac arrest does not appear to impact survival or functional outcome in pediatric patients.

Echocardiography for patients undergoing extracorporeal cardiopulmonary resuscitation: a primer for intensive care physicians

Echocardiography is an invaluable tool in the management of patients with extracorporeal cardiopulmonary resuscitation (ECPR) and subsequent extracorporeal membrane oxygenation (ECMO) support and weaning. At the very beginning, echocardiography can identify the etiology of cardiac arrest, such as massive pulmonary embolism and cardiac tamponade. Eliminating these culprits saves life and may avoid the initiation of extracorporeal cardiopulmonary resuscitation. If the underlying causes are not identified or intrinsic to the heart (e.g., such as those caused by cardiomyopathy and myocarditis), conventional cardiopulmonary resuscitation (CCPR) will continue to maintain cardiac output. The quality of CCPR can be monitored, and if cardiac output cannot be maintained, early institution of extracorporeal cardiopulmonary resuscitation may be reasonable. Cannulation is sometimes challenging for extracorporeal cardiopulmonary resuscitation patients. Fortunately, with the help of ultrasonography procedures including localization of vessels, selecting a cannula of appropriate size and confirmation of catheter tip may become easy under sophisticated hand. Monitoring of cardiac function and complications during extracorporeal membrane oxygenation support can be done with echocardiography. However, the cardiac parameters should be interpreted with understanding of hemodynamic configuration of extracorporeal membrane oxygenation. Thrombus and blood stasis can be identified with ultrasound, which may prompt mechanical and pharmacological interventions. The final step is extracorporeal membrane oxygenation weaning. A number of studies investigated the accuracy of some echocardiographic parameters in predicting success rate and demonstrated promising results. Parameters and threshold for successful weaning include aortic VTI ≥ 10 cm, LVEF > 20-25%, and lateral mitral annulus peak systolic velocity >6 cm/s. However, the effectiveness of echocardiography in ECPR patients cannot be determined in observational studies and requires randomized controlled trials in the future. The contents in this review are well known to echocardiography specialists; thus, it should be used as an educational material for emergency or intensive care physicians. There is a trend that focused echocardiography is performed by intensivists and emergency physicians.

Management of the Low Cardiac Output Syndrome Following Surgery for Congenital Heart Disease

The purpose of this review is to discuss the management of the low cardiac output syndrome (LCOS) following surgery for congenital heart disease. The LCOS is a well-recognized, frequent post-operative complication with an accepted collection of hemodynamic and physiologic aberrations. Approximately 25% of children experience a decrease in cardiac index of less than 2 L/min/m2 within 6-18 hours after cardiac surgery. Post-operative strategies that may be used to manage patients as risk for or in a state of low cardiac output include the use of hemodynamic monitoring, enabling a timely and accurate assessment of cardiovascular function and tissue oxygenation; optimization of ventricular loading conditions; the judicious use of inotropic agents; an appreciation of and the utilization of positive pressure ventilation for circulatory support; and, in some circumstances, mechanical circulatory support. All interventions and strategies should culminate in improving the relationship between oxygen supply and demand, ensuring adequate tissue oxygenation.

Extracorporeal Life Support for Pediatric Heart Failure

Extracorporeal life support (ECLS) represents an essential component in the treatment of the pediatric patient with refractory heart failure. Defined as the use of an extracorporeal system to provide cardiopulmonary support, ECLS provides hemodynamic support to facilitate end-organ recovery and can be used as a salvage therapy during acute cardiorespiratory failure. Support strategies employed in pediatric cardiac patients include bridge to recovery, bridge to therapy, and bridge to transplant. Advances in extracorporeal technology and refinements in patient selection have allowed wider application of this therapy in pediatric heart failure patients.

Duration of conventional cardiopulmonary resuscitation prior to extracorporeal cardiopulmonary resuscitation and survival among adult cardiac arrest patients

PURPOSE

The purpose of this study was to evaluate the association between survival and the duration of conventional cardiopulmonary resuscitation (CCPR) prior to extracorporeal cardiopulmonary resuscitation (ECPR) and possible confounding factors.

METHODS

This was a retrospective analysis of 31 adults who received ECPR at an academic medical center between 2004 and 2013. Odds of 30-day survival and Kaplan Meier survival curves were compared among patients who received CCPR ⩾ 45 min (n=8, 26%) vs. <45 min (n=23, 74%).

RESULTS

There was a trend for greater survival up to 14 days in patients who received CCPR <45 vs. ⩾ 45 minutes (57% vs. 50%) with no significant difference at 30 days (OR 1.09, 95% CI 0.22-5.45) and survival did not differ by demographic factors.

CONCLUSION

More than half of all patients who received ECPR survived to 30 days. Longer duration CCPR was associated with reduced survival within 2 weeks, but not at 30 days.

Extracorporeal membrane oxygenation for cardiac arrest during moyamoya cerebral revascularization surgery: case report

The authors describe the case of a 51-year-old man with bilateral moyamoya disease and prior strokes who developed an asystolic cardiac arrest while undergoing revascularization surgery under mild hypothermia. The patient was successfully treated with venoarterial (VA) extracorporeal membrane oxygenation (ECMO) after manual cardiopulmonary resuscitation (CPR) was unsuccessful for 45 minutes. ECMO is a cardiopulmonary support system that is indicated for respiratory failure in pediatric and adult patients. It is increasingly being used as an extension to mechanical CPR for patients who have suffered cardiac arrest if the underlying cause of cardiac arrest is thought to be reversible. Identifying which patients should be placed on emergency ECMO after cardiac arrest is controversial given its high morbidity and mortality. ECMO in neurosurgical settings has associated risks of intracranial hemorrhage and neurological compromise, while resource utilization is paramount given the high costs of this treatment. This paper is significant because it describes the use of ECMO in an unindicated setting. Limited data are available for ECMO usage after cardiac arrest with baseline cerebral ischemia. Furthermore, this paper raises important considerations for extracorporeal CPR use in a patient who had recently undergone craniotomy. The patient in this report remained on ECMO for 48 hours, after which he was successfully weaned. He developed a pericardial effusion and compartment syndrome from the ECMO but made a complete neurological recovery. Use of ECMO emergently in an appropriately chosen neurosurgical patient is safe, even in the setting of baseline cerebral ischemia and recent craniotomy.

Association of bleeding and thrombosis with outcome in extracorporeal life support

OBJECTIVE

Changes in technology and increased reports of successful extracorporeal life support use in patient populations, such as influenza, cardiac arrest, and adults, are leading to expansion of extracorporeal life support. Major limitations to extracorporeal life support expansion remain bleeding and thrombosis. These complications are the most frequent causes of death and morbidity. As a pilot project to provide baseline data for a detailed evaluation of bleeding and thrombosis in the current era, extracorporeal life support patients were analyzed from eight centers in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Collaborative Pediatric Critical Care Research Network.

STUDY DESIGN

Retrospective analysis of patients (< 19 yr) reported to the Extracorporeal Life Support Organization registry from eight Collaborative Pediatric Critical Care Research Network centers between 2005 and 2011.

SETTING

Tertiary children's hospitals within the Collaborative Pediatric Critical Care Research Network.

SUBJECTS

The study cohort consisted of 2,036 patients (13% with congenital diaphragmatic hernia).

INTERVENTIONS

None.

MAIN RESULTS

In the cohort of patients without congenital diaphragmatic hernia (n = 1,773), bleeding occurred in 38% of patients, whereas thrombosis was noted in 31%. Bleeding and thrombosis were associated with a decreased survival by 40% (relative risk, 0.59; 95% CI, 0.53-0.66) and 33% (odds ratio, 0.67; 95% CI, 0.60-0.74). Longer duration of extracorporeal life support and use of venoarterial cannulation were also associated with increased risk of bleeding and/or thrombotic complications and lower survival. The most common bleeding events included surgical site bleeding (17%; n = 306), cannulation site bleeding (14%; n = 256), and intracranial hemorrhage (11%; n = 192). Common thrombotic events were clots in the circuit (15%; n = 274) and the oxygenator (12%; n = 212) and hemolysis (plasma-free hemoglobin > 50 mg/dL) (10%; n = 177). Among patients with congenital diaphragmatic hernia, bleeding and thrombosis occurred in, respectively, 45% (n = 118) and 60% (n = 159), Bleeding events were associated with reduced survival (relative risk, 0.62; 95% CI, 0.46-0.86) although thrombotic events were not (relative risk, 0.92; 95% CI, 0.67-1.26).

CONCLUSIONS

Bleeding and thrombosis remain common complications in patients undergoing extracorporeal life support. Further research to reduce or eliminate bleeding and thrombosis is indicated to help improve patient outcome.

Percutaneous left atrial decompression in patients supported with extracorporeal membrane oxygenation for cardiac disease

OBJECTIVES

Left atrial decompression using cardiac catheterization techniques has been described at centers with extracorporeal membrane oxygenation programs. Left atrial decompression can decrease cardiogenic edema, minimize ventricular distension, and allow myocardial recovery. We describe Boston Children's Hospital's experience with percutaneous left atrial decompression techniques, acute outcomes, and clinical impact of left atrial decompression in extracorporeal membrane oxygenation patients.

SUBJECTS

Patients supported with extracorporeal membrane oxygenation undergoing percutaneous left atrial decompression were identified and assigned to two groups 1) myocarditis/suspected myocarditis or 2) nonmyocarditis cardiac disease.

INTERVENTIONS

Three techniques including vent placement, static balloon dilation, and stent implantation were used.

MEASUREMENTS AND MAIN RESULTS

Change in left atrial pressure and severity of pulmonary edema on chest radiography pre and post procedure, impact of timing and technique of left atrial decompression on resolution of left atrial hypertension, and extracorporeal membrane oxygenation survival were evaluated. Furthermore, we evaluated the presence of residual atrial septal defect during follow-up. Percutaneous left atrial decompression was performed in 44 of 419 extracorporeal membrane oxygenation cases (10.5%) and was frequently used for myocarditis (22 of 44 patients; 50%). Techniques included 25 vents, 17 static balloon dilations, and two stents. All techniques were equally successful and significantly reduced left atrial pressure and pulmonary edema. Survival to hospital discharge was not associated with extracorporeal membrane oxygenation duration prior to left atrial decompression, change in left atrial pressure, or technique used. Persistent atrial septal defect was noted in five surviving patients (excluding transplant recipients and deceased), two required closure.

CONCLUSIONS

Left atrial decompression can be performed effectively in children on extracorporeal membrane oxygenation using various percutaneous techniques. Reduction in pulmonary venous congestion is usually evident by chest radiography within 48 hours of intervention. Persistent atrial septal defect may require closure at the time of extracorporeal membrane oxygenation decannulation or during long-term follow-up.

Update and outcomes in extracorporeal life support

The Extracorporeal Life Support Organization Registry has collected outcome data of almost 56,000 patients receiving extracorporeal life support (ECLS) over the last 24 years. The use of neonatal respiratory ECLS declined from a peak of 1516 cases in 1992 to 750-865 cases from 2008 to 2012. The 26,583 cases of neonatal respiratory ECLS (75% survival) represent the largest patient population in the registry. Indicating the rapid growth in other patient populations, 2013 marks the first year where the number of neonatal respiratory ECLS cases is less than 50% of the registry. Stagnant at ~200 cases/year from 1993 to 2004, growth is occurring in the use of pediatric respiratory ECLS with 331-448 cases/year from 2008 to 2012 (58% survival). Similarly, adult respiratory ECLS use increases have been seen from ~100 cases/year from 1996 to 2007 to 480-846 cases/year from 2009 to 2012 (58% survival). Just over 15,000 cardiac ECLS patients have survival rates of 40%, 49%, and 40% for neonates, pediatric, and adults, respectively.

Clinical management of the extracorporeal membrane oxygenation circuit

The clinical management of patients on extracorporeal membrane oxygenation should be standardized and follow clear guidelines or protocols. However, due to the diversity of cannulation strategies and the complex situations that extracorporeal membrane oxygenation is now used in, each extracorporeal membrane oxygenation program has developed its own clinical management strategies. These vary widely across the globe. Extracorporeal membrane oxygenation provides partial or complete support of ventilation and oxygenation, as well as univentricular or biventricular support of myocardial function, either individually or in combination. High-flow extracorporeal membrane oxygenation can also provide circulatory support in profound vasoplegic shock. Improvements in technology and greater understanding of disease pathophysiology, coupled to refinements in technology, which lessen the adverse interaction between the circuit and the patient, all contribute to fewer mechanical and patient complications on extracorporeal membrane oxygenation. Earlier and more appropriate use of extracorporeal membrane oxygenation has been associated with improved patient outcomes. These clinical management strategies are reviewed in this article, part of the Pediatric Cardiac Intensive Care Society/Extracorporeal Life Support Organization Joint Statement on Mechanical Circulatory Support.

Pediatric mechanical circulatory support: future directions

The field of extracorporeal support is moving forward rapidly. New technology, improved experience with a variety of patients, and successful outcomes in groups previously excluded from extracorporeal life support are increasing the use of this technique in patient support. Although initial reports of outcome are encouraging, they are often taken from single-center reports or large databases without specific detail to answer many of the relevant questions or for eras that do not reflect the effects of new technology. Collaboration between investigators, rigorous scientific data collection and analysis, and careful short- and long-term outcomes for patients receiving extracorporeal life support are imperative to avoid improper use of this high-resource, high-cost technology and to establish the efficacy of new devices and techniques. Bleeding and thrombosis remain devastating complications and efforts to reduce complications and improve anticoagulation regimens or eliminate the need for anticoagulation would be of major benefit to the field.

Extracorporeal Life Support Organization Registry Report 2012

In this article, summary data from the annual international Extracorporeal Life Support Organization (ELSO) Registry Reports through July 2012 are presented. Nearly 51,000 patients have received extracorporeal life support (ECLS). Of the patients, 50% (>25,000) were neonatal respiratory failure, with a 75% overall survival to discharge or transfer. Congenital diaphragmatic hernia remains a major use of ECLS in this population with 51% survival. Extracorporeal life support use for pediatric respiratory failure has nearly doubled since 2000, with approximately 350 patients treated per year in the past 3 years examined (56% survival). Previously stable at about 100 cases a year for a decade, adult respiratory failure ECLS cases increased dramatically in 2009 with the H1N1 influenza pandemic and publication of the Conventional ventilation or ECMO for Severe Adult Respiratory failure (CESAR) trial results and have remained at approximately 400 cases a year through 2011 (55% survival). Use of ECLS for cardiac support represents a large area of consistent growth. Approximately 13,000 patients have been treated with survival to discharge rates of 40%, 49%, and 39% for neonates, pediatric, and adults, respectively.