A VERY COMPREHENSIVE review and evidence-based set of recommendations for the resuscitation of newborns, infants, and children with heart disease was published in 2018 by the American Heart Association.
1
They were developed through consensus by an experienced and expert panel of clinicians who routinely care for children with heart disease. We recommend that it be read and studied closely by anyone taking care of children with heart disease on a regular basis. There have been no subsequent data published that alter these recommendations. The 2 most important points to take away are that (1) the latest basic and advanced life support recommendations from the American Heart Association,2
, 3
with the focus on high-quality chest compressions, are no different for the resuscitation of children with heart disease; and (2) appropriate management during the pre-arrest phase is critical. The intent of this commentary is not to summarize the extensive list of recommendations contained within the consensus statement; rather the goal is more pragmatic: to provide an overview of risk, the difficulties that clinicians face when managing a child with heart disease who has an acute deterioration, and a functional approach to understanding the often complex pathophysiology.Limitations in Knowledge Access and Translation
Congenital heart disease (CHD) is complex. There are many variations and combinations of anatomical configurations, and it is simply not possible for most noncongenital heart disease clinicians (ie, nonexperts, including general anesthesiologists, emergency responders, pediatricians, and emergency care clinicians) to comprehend the anatomy and blood flow patterns, especially during acute resuscitation. The access to detailed and relevant information, such as recent echocardiographic imaging or catheterization data, is usually very limited during acute resuscitation, unless the experts caring for that patient are present at the time. While the comprehensive consensus statement is a useful resource, it is not readily accessible and not formatted as a memory aid to use during acute resuscitation of children with CHD.
While pediatric patients with CHD are typically managed and followed by centers with expertise in this area, improving the care of these patients in these centers depends on continued knowledge gathering and transitioning practices. Advances in the past 3 decades have led to the majority of patients with CHD reaching adulthood and surviving beyond these specialty centers. Even though there are more adults with CHD than newborns, many adults with CHD are lost to follow-up and are often followed by clinicians who are not experts in CHD.
4
Moreover, the burden of illness they carry lowers their tolerance of acute illness and often limits their physiologic response to conventional cardiopulmonary resuscitation (CPR).The language of CHD and cardiac surgery is also unique to the specialty and does not translate into everyday medical terminologies. Defects are often described with letters (for example, simple VSD for ventricular septal defect, TGA for transposition of the great arteries, TAPVC for total anomalous pulmonary vein connection, and so on) or other unfamiliar terms such as isomerism to describe the morphology of the atria and venous return. Eponyms are often used to describe defects and surgical repairs (such as Ebstein's anomaly of the tricuspid valve, Norwood operation for stage 1 palliation of hypoplastic left heart syndrome, or the Fontan operation for total cavopulmonary connection). Such a unique language facilitates discussion among experts, but it is difficult to translate to nonexperts. In many cases, resuscitation of children with heart disease is undertaken by nonexperts, and trying to translate a complex language for clinical decision-making under conditions of uncertainty, inadequate knowledge, and high acuity during resuscitation is intimidating, confusing, and distracting.
Burden of Disease and Risk
Children with heart disease are a vulnerable population and have an increased risk for cardiopulmonary arrest (CPA), particularly in the setting of intercurrent illness. It is estimated that for newborns, infants, and children with heart disease, the in-hospital risk for CPA is up to 10 times higher than observed in children hospitalized without heart disease.
5
, 6
, 7
The frequency has been reported to be higher in dedicated cardiac intensive care units, and more common in newborns and infants and particularly in patients with single ventricle physiology.8
, 9
, 10
It is important to appreciate that in-hospital CPA as reported above usually refers to patients in a monitored critical care environment. While this is the predominant at-risk population, particularly after cardiac surgery, it is important to understand that children with cardiac disease have an ongoing risk when managed in procedural areas, under anesthesia, in the general ward, or in the emergency department, even in centers with well-established cardiac programs for children.
The frequency of CPA in children with CHD in the cardiac operating room and cardiac catheterization laboratory is considerably higher than that reported of perioperative cardiac arrest in pediatric patients with structurally normal hearts undergoing general anesthesia. The frequency of CPA has been reported from a single center as high as 0.8 and 1.0/100 procedures in the cardiac operating room and catheterization laboratory, respectively.
11
, 12
Factors associated with increased risk for CPA in children during noncardiac anesthesia include younger age, higher ASA status, and emergency procedures. Although the frequency of cardiac arrest during noncardiac anesthesia specifically in patients with CHD is unknown, it is likely to be increased based on the risk inherent to the disease and typically higher ASA status. Given the longer-term outcomes for patients with CHD and the diverse communities in which they live, it is expected that more of these patients will be presenting for noncardiac-related procedures and anesthesia.An Approach to Resuscitation
CHD encompasses many variants and broadly refers to structural abnormalities of the heart or intrathoracic great vessels. There is a spectrum of complexity, but it can be categorized in the following way:
- 1.Simple defects such as an atrial septal defect, simple ventricular septal defects, or patent ductus arteriosus, in which surgical or catheter-based interventions can be viewed as a cure, and long-term complications are rare.
- 2.Complex defects that can be broadly classified as 2- or 1-ventricle defects:
- a.In 2-ventricle defects, there is a systemic and pulmonary ventricle (usually of left ventricle and right ventricle morphology, respectively, but not in all circumstances), and the circulation in series (ie, cardiac output [CO] = systemic blood flow [Qs] = pulmonary blood flow [Qp]). Common examples include atrioventricular canal defects, tetralogy of Fallot, and transposition of the great arteries. Although these defects are amenable to complete surgical repair, there is the risk of residual disease or developing new complications over time. In other words, the disease is corrected but not cured, and these patients require lifelong follow-up.
- b.In 1-ventricle defects, a single ventricle (of either left or right ventricle morphology) ejects to both the systemic and pulmonary circulations (ie, a parallel circulation where CO = Qs + Qp). These defects cannot be cured or corrected anatomically. Rather, patients typically undergo a series of 3-stage procedures, ultimately achieving around 2 to 3 years of age a modified Fontan circulation in which the single ventricle ejects only to the systemic circulation and the source of pulmonary blood flow is through a superior vena cava-inferior vena cava-pulmonary artery connection (ie, there is no pulmonary ventricle). It is viewed as palliative circulation because of the unique physiology and as a functional repair because the systemic and pulmonary circulations are separated and in series. However, the word “palliative” should not be misconstrued; 15-year survival after the Fontan operation is reported to be as high as 97%.13
- a.
The anatomic and physiological substrates of congenital heart defects can limit the effectiveness of conventional CPR. Given the complexity of these patients and the urgency required during resuscitation, trying to appreciate the implications of the anatomy or the surgical repair can be a distraction and delay management. Rather a functional approach should be taken, based on the natural history of congenital cardiac defects being largely determined by their effect on blood flow patterns through the heart and lungs. Essentially, hundreds of anatomic and surgical combinations can be distilled into a small number of physiologic considerations that impact CPA risk and CPR effectiveness. The resulting physiologies are because of one or any combination of systolic or diastolic ventricular dysfunction, obstructed inflow or outflow to the heart, stenotic or regurgitant valves, arrhythmias, and pulmonary hypertension. The effect is either a volume load or pressure load on the ventricles, limited or excessive pulmonary blood flow, and potential for lower cardiac output state with an imbalance of systemic and pulmonary blood flow.
The following are considerations regarding the functional state of a patient with CHD, and worthwhile understanding in the preoperative assessment (consider pre-arrest phase) and certainly when faced with acute and unexpected resuscitation (arrest phase):
- Anatomic: How does blood flow into and through the heart and lungs?
- 1.Is the circulation in series or parallel (ie, are there 2 ventricles or a single ventricle)?
- a.Previous surgical or catheter-based interventions: complete repair or palliative
- b.Known complications, including heart failure, arrhythmia
- a.
- 2.What are the sources of pulmonary blood flow?
- a.Native pulmonary artery
- b.Shunt from the systemic circulation
- c.Cavopulmonary artery connection (also called Glenn procedure for superior vena cava (SVC) to pulmonary artery connection, and modified Fontan operation when SVC and inferior vena cava blood flow is connected directly to the pulmonary artery)
- a.
- Physiologic: What is the functional state and baseline risk for failure?
- 3.What is the baseline oxygenation saturation while breathing room air?
- 4.Is there poor systolic or diastolic function of the myocardium?
- a.Systolic dysfunction: limits contractility and stroke volume (SV); the importance of early inotrope support and consideration for afterload reduction
- b.Diastolic dysfunction (also referred to as restrictive physiology): often preserved systolic function, but myocardium is unable to relax or fill. Limits SV, high risk for myocardial ischemia; primarily vasopressor support indicated rather than augmenting contractility.
- a.
- 5.Is there inflow (atrioventricular valve, ie, tricuspid or mitral) or outflow (semilunar valve, ie, pulmonary and aortic) stenosis or regurgitation?
- a.Inflow obstruction: limits ventricular filling and elevates atrial pressures
- b.Inflow regurgitation: volume loads and dilates ventricle, limiting contractility
- c.Outflow obstruction: induces ventricular hypertrophy and restrictive physiology, and in the end-stage transitions to a dilated ventricle with poor contractility
- d.Outflow regurgitation: creates volume load and dilation of the ventricle with reduced contractility, reduced SV, elevated end-diastolic volume, risk for coronary ischemia
- a.
- 6.Is there pulmonary hypertension?
- a.Fixed obstruction (pulmonary arteries or veins)
- b.Reactive vasculature (responsive to pulmonary vasodilators, specifically inhaled nitric oxide during resuscitation)
- c.Secondary to elevated systemic ventricular end-diastolic pressure or left atrial hypertension, such as restrictive cardiomyopathy or mitral valve stenosis
- a.
- 7.Is there stenosis or obstruction to great vessels (pulmonary arteries and aortic arch)?
- Prior experience: Are there problems or complications related to previous management:
- 8.History of arrhythmias and treatment?
- 9.Concerns for access: known blood vessel occlusion (eg, femoral or jugular veins after previous interventions and catheters); known airway abnormalities
- 10.Knowledge of long-acting medications that may mask typical signs of stress or accentuate decline once the patient starts to deteriorate, including beta-blockers, antiarrhythmic drugs, vasodilators, and anticoagulation
Limitations for Effective CPR
CPR is inefficient, with chest compressions providing only up to 30% to 40% of normal blood flow to the heart and the brain.
14
The inherent inefficiency associated with CPR can be further exacerbated in the patient with CHD, in which the underlying anatomy limits effective pulmonary blood flow, systemic blood flow, and cerebral perfusion.There are 3 functional considerations that limit the effectiveness of conventional CPR in children with congenital heart disease.
- 1.Limited SV with chest compressions, such as from:
- a.Atrioventricular or semilunar valve regurgitation, (in this circumstance, Qs = SV with compressions – regurgitant volume), or
- b.Restrictive myocardium: poor filling of the ventricle because of high end-diastolic pressure and reduced ventricular volume; the low end-diastolic volume means that SV is reduced with each compression.
- a.
- 2.Limited effective pulmonary blood flow and oxygenation with compressions, such as from:
- a.Pulmonary outflow obstruction from any cause, such as pulmonary valve or artery stenosis,
- b.Elevated pulmonary artery pressure or pulmonary vascular resistance, or
- c.Cavopulmonary connection (no pulmonary ventricle; Qp dependent on the trans-pulmonary gradient = SVC pressure – atrial pressure (or end-diastolic pressure in the ventricle)).
- d.Chest compressions may limit flow from the SVC to the pulmonary arteries and poor release of compressions may prevent adequate filling of the atrium.
- a.
- 3.Limited cerebral perfusion, such as from:
- a.Cavopulmonary connection with elevated superior vena cava pressure, or
- b.Semilunar valve regurgitation or aortopulmonary runoff across a shunt or collateral vessels: effective Qs = SV with compressions – regurgitant volume – runoff across aorto to pulmonary artery connections.
- a.
There are no specific recommendations in these circumstances to modify the technique for conventional CPR from that recommended for patients with structurally normal hearts.
12
However, it is important these functional considerations are discussed and appreciated before and during resuscitation. The monitoring of effective CPR is critical. Appropriate depth and rate of chest compressions must be continually observed, and it may be necessary to reduce the rate to allow effective venous return in patients with a cavopulmonary artery connection and in patients with restrictive myocardium. Careful palpation of extremity pulses and distal perfusion using plethysmography during chest compressions can guide chest compressions. End-tidal CO2 monitoring is an important indicator of pulmonary blood flow, particularly in patients with limited pulmonary blood flow.Extracorporeal Life Support
Use of extracorporeal life support (ECLS) to support failed conventional CPR (ie, ECPR) in children with CHD in highly specialized environments has allowed the resuscitation of some patients who would otherwise have died. The 2015 Pediatric Advanced Life Support Guidelines and the American Heart Association Scientific Statement include recommendations for children with heart disease for the setting where extracorporeal cardiopulmonary resuscitation (ECPR) is undertaken; specifically, “If cardiac arrest develops in the child with heart disease and there is no prompt return of circulation, it is reasonable to initiate ECPR (Class IIa; Level of Evidence C), and that ECPR can be most effectively deployed in locations with rapid access to ECLS equipment, skilled ECLS personnel, and adequate space to accommodate a large team (Class IIa, LOE C).”
2
, 3
Early deployment is critical, and ideally the discussion about suitability for ECPR should be held before anesthesia, along with the known availability of a team experienced with cannulation for ECLS.15
, 16
Bridging the Knowledge Gap
Given the rising numbers of patients surviving with CHD in the general population, anesthesiologists without subspecialized training in pediatric or cardiac anesthesia are likely to be confronted with children with CHD who require general anesthesia. It is important therefore to be prepared and appreciate the heightened risk for CPA in this vulnerable population, and this should be communicated at the time of the pre-procedural huddle. In circumstances when CPA occurs, or if confronted with uncertainty, it is easy to be distracted and be unaware of cues, patterns and information that spans across time and organization. Simulation and Just-in-Time training and education at the bedside is used in centers that routinely manage children with CHD. It is unreasonable for such specific simulation and training to be undertaken universally. It is therefore important to concentrate on what is known at the time. Start effective and well-monitored CPR according to established guidelines for patients with structurally normal hearts. Gather information about the functional status of the underlying heart disease rather than trying to interpret complex anatomy and language. Apply that functional knowledge to guide effective advanced life support and communicate this effectively to your team. If unable to be present during resuscitation, try to get information and advice from experts where possible. And be prepared to ask parents and families for information; they usually know specific information about their child's CHD, procedures, and functional status that can help direct decisions made during resuscitation.
Conflict of Interest
This author has no conflicts of interest to declare.
References
- Cardiopulmonary resuscitation in infants and children with cardiac disease. Consensus statement, American Heart Association.Circulation. 2018; 137: e691-e782
- Part 6: Pediatric basic life support and pediatric advanced life support 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations.Circulation. 2015; 132: S177-S203
- Correction to: Part 6: Pediatric basic life support and pediatric advanced life support: 2015 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations.Circulation. 2016; 134: e121
- Changing mortality in congenital heart disease.J Am Coll Cardiol. 2010; 56: 1149-1157
- Incidence and outcomes of cardiopulmonary resuscitation in PICUs.Crit Care Med. 2016; 44: 798-808
- American Heart Association Get With the Guidelines–resuscitation investigators: Survival trends in pediatric in-hospital cardiac arrests: An analysis from Get With the Guidelines-Resuscitation.Circ Cardiovasc Qual Outcomes. 2013; 6: 42-49
- Outcome of cardiopulmonary resuscitation in a pediatric cardiac intensive care unit.Crit Care Med. 2000; 28: 3296-3300
- Epidemiology and outcomes of cardiac arrest in pediatric cardiac ICUs.Pediatr Crit Care Med. 2017; 18: 935-943
- Cardiopulmonary resuscitation in hospitalized children with cardiovascular disease: Estimated prevalence and outcomes from the Kids’ Inpatient database.Pediatr Crit Care Med. 2013; 14: 248-255
- Cardiac arrest in the pediatric cardiac ICU: Is medical congenital heart disease a predictor of survival?.Pediatr Crit Care Med. 2019; 20: 233-242
- The frequency of cardiac arrests in patients with congenital heart disease undergoing cardiac catheterization.Anesth Analg. 2014; 118: 175-182
- The frequency of anesthesia-related cardiac arrests in patients with congenital heart disease undergoing cardiac surgery.Anesth Analg. 2007; 105: 335-343
- Redefining expectations of long-term survival after the Fontan procedure: Twenty-five years of follow-up from the entire population of Australia and New Zealand.Circulation. 2014; 130: S32-S38
- Cardiopulmonary resuscitation quality: Improving cardiac resuscitation outcomes both inside and outside the hospital: A consensus statement from the American heart association.Circulation. 2013; 128: 417-435
- Establishing and sustaining an ECPR program.Front Pediatr. 2018; 6: 1-10
- Outcomes after extracorporeal cardiopulmonary resuscitation of pediatric in-hospital cardiac arrest: A Report From the Get With the Guidelines-Resuscitation and the Extracorporeal Life Support Organization Registries.Crit Care Med. 2019; 47: e278-e285
Article info
Publication history
Published online: July 26, 2019
Identification
Copyright
© 2019 Elsevier Inc. All rights reserved.
