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This review aims to summarize the major changes in the 2010 Heart and Stroke foundation of Canada (HSFC) and the American Heart Association (AHA) Pediatric Basic and Advanced Life Support Guidelines. The Guidelines were based on the International Liaison Committee on Resuscitation’s (ILCOR) comprehensive, evidence-based review of the resuscitation literature. The key recommendations from the Guidelines include: the removal of "look, listen and feel" and a de-emphasis on the use of the pulse check by healthcare providers to diagnose cardiac arrest; a change in the sequence of resuscitation for patients in cardiac arrest from the previously well-known "A-B-C" i.e. Airway, Breathing, and Chest Compressions to "C-A-B" i.e. Chest Compressions first; modification to the appropriate depth of compression (at least 1/3 of the anterior-posterior depth of the chest wall or about 4 cm in infants and 5 cm in children); end-tidal CO2 monitoring (in intubated patients) to assess the quality of chest compressions and optimize cardiopulmonary resuscitation (CPR); and titrating Fi0O2 once "Return of Spontaneous Circulation" (ROSC) is achieved to maintain an oxygen saturation between 94-99%. Overall, pediatricians, family and community physicians who may care for acutely ill children should be aware of these updated guidelines in order to provide the best possible care to their patients.
In October 2010, the American Heart Association (AHA) and Heart and Stroke Foundation of Canada (HSFC) published updated Guidelines on Pediatric Basic Life Support (PBLS) and Pediatric Advanced Life Support (PALS). The present review highlights the significant changes made to the PBLS and PALS Guidelines relevant to pediatricians as well as family and community physicians. The complete guidelines are published in the journal Circulation, and can be accessed at www.circulationaha.org. Neonatal resuscitation is not included in this article, however the complete Neonatal Resuscitation Guidelines are available on-line at Circulation (Circulation, 2010; 122(suppl 3): S909-S919).1
The AHA/HSFC Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) are based on the ILCOR "Consensus on Science and Treatment Recommendations", the most up-to-date and comprehensive review of resuscitation literature.2 The ‘Levels of Evidence’ of these Guidelines is consistent with the format used by the American College of Cardiology Foundation and the American Heart Association. (Table 1)
The Guidelines have removed the use of "look, listen and feel" to diagnose a potential cardiac arrest victim. The new recommendation is to initiate CPR if the victim is unresponsive and not breathing (or only gasping). (Table 1 Class IIa, LOE C)
Lay rescuers should not use the pulse check to diagnose cardiac arrest. In addition, the assessment of a pulse by healthcare providers is not reliable. They should take no more than 10 seconds to check for a pulse (brachial in infant and carotid or femoral in a child). If within 10 seconds, no pulse can be felt or the provider is unsure of its presence, chest compressions should be started immediately. (Table 1 Class IIa, LOE C)
The 2010 HSFC and AHA Guidelines for PBLS changed the sequence of resuscitation for patients in cardiac arrest from the previously well-known "A-B-C" i.e. Airway, Breathing, and Chest Compression to "C-A-B" i.e. Chest Compressions first. The rationale for this change is as follows:
The compression-to-ventilation ratio of 30:2, for the lone rescuer, and 15:2, for two healthcare providers, is the same as the previous 2005 Guidelines. Once an advanced airway is in place, synchronization of chest compressions with ventilation is not required. Instead, chest compressions should be continued with no /or minimal interruption, at a rate of at least 100/min without pause for ventilation. The ventilation rate should be 8-10 breaths/min to avoid excessive ventilation. It is important to note the differences in resuscitation of the newly born in the delivery room as compared to that in infants and children. The compression-to-ventilation ratio for neonatal resuscitation is 3:1 with a pause for ventilation whether or not the infant has an advanced airway. This compression-to-ventilation ratio applies only to newborns in the delivery room and in the newborn nursery /or neonatal intensive care unit (NICU). Once the infant leaves the hospital, the resuscitation should be conducted with the usual 30:2 (one rescuer) or 15:2 (two rescuer) compression-to-ventilation ratios.
Cardiac arrests in children are typically asphyxial in nature precipitated by hypoxia or shock which progresses to cardiac arrest compared to that in adults where sudden cardiac arrest is frequent from a primary cardiac etiology. Animal studies demonstrate that hands-only CPR is sufficient to resuscitate VF cardiac arrest (which is common in adults) but not asphyxial cardiac arrest (which is common in children).8,9
A recent meta-analysis of randomized control trials showed an increase in survival to hospital discharge with hands-only compared to conventional CPR in adult cardiac arrest victims.10 However, a large pediatric out-of-hospital cardiac arrest study showed that cardiac arrest victims receiving conventional CPR had more favourable neurological outcomes compared to those who received hands-only CPR.
Thus, the new guidelines consider optimal CPR for infants and children to include both ventilation and chest compression (Table 1 Class I, LOE B). However, chest compression alone is preferable to no CPR if the bystander is unwilling or unable to perform conventional CPR.
High quality chest compressions are the cornerstone of successful CPR. Inadequate chest compression rate and depth are common during CPR even among healthcare providers.11,12 Evidence shows that cardiac arrest victims frequently receive excessive ventilation during CPR which increases intrathoracic pressure causing a decrease in venous return and cardiac output, barotrauma and aspiration.11 The new Guidelines recommend using only the force and tidal volume (TV) needed to just make the chest rise visibly. Each breath should be given over approximately one second at a rate of 8-10 breaths/minute if the patient is intubated.
Key elements of high quality CPR:
Pediatric cardiac arrest victims with a shockable rhythm (VF or pulseless VT) require rapid defibrillation, which may be achieved through either a manual defibrillator or an AED. Manual defibrillation is preferred in infants and children and the recommended first shock energy dose is 2-4 J/kg. Subsequent defibrillation attempts should use energy doses of at least 4 J/kg (but not to exceed 10 J/kg). If a manual defibrillator is not available, an AED with a pediatric dose attenuator is preferred for both infants (below one year of age) and in children below eight years of age. However, if neither is available, an AED without a dose attenuator may be used (Table 1 Class IIb, LOE C). It is important to resume chest compressions immediately after the shock, without stopping to analyze the cardiac rhythm, and continue until it is time for the next rhythm check (2 minutes or about 5 cycles of CPR).
Several changes have been made to the Pediatric Advanced Life Support Guidelines and a summary of the key changes is presented below.
Key PALS issues and major changes in the 2010 HSFC and AHA Guidelines:
ETCO2 monitoring may be used as an indicator of the quality of chest compressions and be useful to guide therapy. If the ETCO2 is consistently <10-15 mm Hg, CPR may need to be modified to ensure adequate cardiac output by pushing fast and hard, avoiding hyperventilation and minimizing interruptions. Hyperventilation increases intra-thoracic pressure, decreases preload to the heart and hence decreases cardiac output.
Return of Spontaneous Circulation (ROSC) may be preceded by an abrupt and sustained increase in ETCO2 which is a marker of increased pulmonary blood flow. It can be used as a physiological marker of ROSC, instead of pulse checks, thus avoiding unnecessary interruptions in chest compressions.
The use of both cuffed and uncuffed endotracheal tubes are acceptable when intubating infants and children (Table 1 Class IIa, LOE C). The cuffed endotracheal tube size can be estimated by using the following formula for children older than two years of age:
For infants less than 1 year of age, and children between 1 and 2 years of age, it is reasonable to use a cuffed endotracheal tube with an internal diameter of 3.0 mm and 3.5 mm, respectively.
There is inadequate evidence to recommend the routine use of cricoid pressure when intubating a child or infant with cardiac arrest. (Table 1 Class III, LOC C)
Resuscitation should be conducted with 100% oxygen until circulation is restored. Once ROSC is achieved, adjust the FiO2 to maintain oxygen saturation between 94% and 99% (Table 1 Class IIb, LOE C), as hyperoxia can increase reperfusion injury after an ischemic insult. In a recent multicenter, cohort study of patients admitted to ICU after resuscitation from cardiac arrest, the mortality was significantly higher in the hyperoxia group compared to the hypoxia and normoxia groups.13
The use of therapeutic hypothermia (32°C-34°C) is reasonable for adolescents who remain comatose after resuscitation from sudden, witnessed, out-of-hospital VF arrest (Table 1 Class IIb, LOE C). It may be considered for infants and children who remain comatose after cardiac arrest (Table 1 Class IIb, LOE C).
To calculate resuscitation medication, use the actual (and not the ideal) body weight of the child, or use a body length tape with pre-calculated doses (Table 1 Class IIa, LOE C) regardless of the habitus of the child, but not to exceed the standard dose recommended for adults.
Wide complex tachycardia may be ventricular or supraventricular in origin. Consultation with an expert in pediatric arrhythmias is strongly recommended before treatment in stable patients as all anti-arrhythmics can cause serious side effects. Recent evidence suggests that adenosine is relatively safe for both treatment and diagnosis of regular, monomorphic, wide-complex tachycardia (Table 1 Class IIb, LOE B). However, adenosine should not be given if the rhythm is irregular, or polymorphic and/or an unstable wide-complex tachycardia as it may cause VF. Adenosine should not be used for wide-complex tachycardia in patients with known Wolff-Parkinson-White syndrome.
Cardiac ion channelopathies such as long QT syndrome are increasingly recognized as an important cause of Sudden Cardiac Death (SCD) in young people. When SCD occurs in children or young adults, a complete past medical and family history are essential (see important screening questions) and review of previous ECGs, if available, may be helpful in identifying families at risk. Victims of unexplained SCD should, if resources allow, have an unrestricted, complete autopsy ideally performed by a pathologist with experience in cardiovascular pathology. Their family members should be referred for screening (Table 1 Class I, LOE C) to healthcare providers or centers with expertise in arrhythmias.
Important past medical and family screening questions for sudden cardiac arrest include:
Cardiac arrest outcomes depend heavily on the performance of CPR by lay rescuers and healthcare providers. Maximizing survival from cardiac arrest requires improvements in education and the implementation of systems that support the delivery of high-quality resuscitation and post-arrest care, including mechanisms to systematically monitor resuscitation performance of community-based and hospital-based systems.
For lay rescuers, one significant factor that can affect their willingness to perform CPR (a major determinant of survival) is recent training.14 Family physicians may be able to improve survival from cardiac arrest by promoting CPR training of their patients and families and may themselves serve as examples by keeping their basic life support certification up to date. Interestingly, CPR skills can be learned equally well and retained with short (e.g. 22 minutes) video-based self-instruction courses combined with synchronous hands-on practice and by longer traditional training courses. (Table 1 Class I, LOE A)
Emergency Medical Services dispatchers should provide CPR instructions to callers reporting a potential cardiac arrest victim who is unresponsive and not breathing or gasping as this has been shown to increase the willingness of bystanders to perform CPR and patient survival. For a complete reference on the important issues in education and implementation of resuscitation programs, the reader is referred to the complete guidelines in the journal Circulation (Circulation, 2010;122(suppl 3):S920-S933).
Cardiac arrest remains an important issue in the care of pediatric and adult patients. This article reminds practitioners of the differences in the etiology of pediatric and adult cardiac arrests while also describing the major updates to the new guidelines for the management of pediatric cardiac arrest. Further improvement in the care of all cardiac arrest patients is likely to occur through education and appropriate implementation of resuscitation programs and quality assurance.