Welcome back to REBEL Cast, I am your host Salim Rezaie.  In this episode we are going to review a recent focused 2019 update to the American Heart Association (AHA) pediatric advanced life support (PALS) guidelines from 2018-19. This 2019 PALS Update addresses 3 concerns:

1. Pediatric advanced airway management in pediatric cardiac arrest
2. Extracorporeal cardiopulmonary resus (ECPR/ECMO) in pediatric cardiac arrest
3. Pediatric targeted temperature management (TTM) during post-arrest care

REBEL Cast Episode 75 – 2019 PALS Update

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Advanced Airway

• PALS Recommendation #1- BMV is reasonable compared with advanced airway interventions (endotracheal intubation or SGA) in the management of children during cardiac arrest in the out-of-hospital setting (Class 2a; Level of Evidence C-LD). 
• We know that most pediatric cardiac arrests are due to respiratory compromise, therefore airway and ventilation management are critical components of PALS.  
• Use of advanced airways in pediatric cardiac arrest was last reviewed in 2010 with the following recommendations: “In the prehospital settings it is reasonable to ventilate and oxygenate infants and children with a bag-mask device, especially if transport time is short (Class IIa, LOE B).” 
• This 2019 focused update reaffirms the 2010 recommendations with no significant changes:
  • Bag Valve Mask (BVM): Though the majority of children can be successfully ventilated with a BVM, this method is suboptimal as it is associated with interruptions in chest compressions, barotrauma and a high risk of aspiration. 
  • Endotracheal Intubation (ETI): Considered an ideal definitive secure airway, however requires specialized equipment and skilled providers. Given the reality that pediatric airways are different from that of adults, endotracheal intubation is often more difficult for providers who do not routinely intubate pediatric patients.
  • Supraglottic Airway (SGA): Such as the LMA may be easier but it is also not a definitive airway and does not mitigate the risks of aspiration.

• Systematic review of 14 studies performed (1 clinical trial, 3 propensity- adjusted studies, 8 retrospective cohort studies, and 2 retrospective studies) examined the outcomes of endotracheal (ET) intubation versus BMV during pediatric cardiac arrest.
• Of these, the only clinical trial in the review which randomized pediatric patients with out-of-hospital cardiac arrest (OHCA) was to either BMV alone or BMV followed by endotracheal intubation. There was no significant difference between the groups in favorable neurological outcome or survival to hospital discharge. 
  • Gausche M et al. Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: a controlled clinical trial. JAMA. 2000 Feb 9;283(6):783-90. [1]
    • Primary Outcome: Survival to hospital discharge and neurological status at discharge from an acute care hospital compared by treatment group.
    • Results: No significant difference in survival between the BVM group (30%) vs the ETI group (26%) (OR 0.82; 95% CI 0.61-1.11) or in the rate of achieving a good neurological outcome (BVM 23% vs ETI 20%) (OR 0.87; 95% CI, 0.62-1.22).
    • Huge CAVEAT: Out of hospital intubation success rate average was 60-70% intubation, and there was a high dislodgment rate; esophageal intubations, and mainstem intubation (Success improved with increasing age of child)
    • Conclusion: The addition of out-of-hospital endotracheal intubation to a paramedic scope of practice that already includes BVM did not improve survival or neurological outcome of pediatric patients treated in an urban EMS system.
  • REBEL Thoughts: Though this was a decent size trial for a pediatric study, it was performed in an urban area with “rapid transport” (average was 5 mins on scene time, and total transport time 20 mins) which is an important limitation in this study, as outcomes could be different in more remote areas. Securing the airway post-intubation  to prevent dislodgment needs to be addressed as this was the highest complication of the successful intubations. Given this study was focused on out-of-hospital care, findings should not be extrapolated to those in-hospital physicians with pediatric expertise who should work to establish a definitive airway in the ED.

ECMO/ECPR in Cardiac Arrest

PALS Recommendation # 2: ECPR may be considered for pediatric patients with cardiac diagnoses who have IHCA in settings with existing ECMO protocols, expertise, and equipment (Class 2b; Level of Evidence C-LD).

• The use of ECMO (extracorporeal membrane oxygenation) as a form of mechanical circulatory rescue for failed conventional CPR has gained popularity.
• Reviewed 3 retrospective studies
• There is insufficient evidence to recommend for/or against the use of ECPR for pediatric patients experiencing OHCA or for pediatric patients with in-hospital cardiac arrest  with non-cardiac disease refractory to conventional CPR
• There were no prospective comparative analyses comparing survival and neurological outcomes between conventional CPR and ECPR (There would be ethical issues with conducting such a study)
• However, extrapolating data from large multicenter registries and retrospective analyses in adult and pediatric populations, ECPR may provide a significant survival benefit when used for refractory cardiac arrest
• Currently there is insufficient information about neurological complications and outcomes (ie, hemorrhagic/ischemic stroke, seizure) associated with the use of ECPR in infants and children.
• REBEL Thoughts: If you have ECMO capacity at the receiving center, initiating ECMO protocol for OHCA is likely effective. Clearly not enough studies on this yet but would imagine higher survival in kids compared to adults in OHCA given fewer co-morbidities. 

 Therapeutic Hypothermia

• PALS Recommendation #3: Continuous measurement of core temperature during TTM is recommended (Class 1; Level of Evidence B-NR).
• PALS Recommendation #3: For infants and children between 24 hours and 18 years of age who remain comatose after OHCA or IHCA, it is reasonable to use either TTM 32°C to 34°C followed by TTM 36°C to 37.5°C or to use TTM 36°C to 37.5°C (Class 2a; Level of Evidence B-NR).
• Historically original studies suggested therapeutic hypothermia goals of (32°C – 34°C), however these studies did not include fever prevention, which led to worse outcomes
• More recent studies compared therapeutic hypothermia (32°C – 34°C) with controlled normothermia (36°C – 37.5°C), with fever actively treated. These treatment modalities are now referred to as (TTM 32°C to 34°C) and (TTM 36°C to 37.5°C) respectively. 
• Unlike previous ILCOR reviews and several earlier AHA PALS guidelines, this 2019 PALS focused update is based only on evidence from pediatric studies & did not consider evidence extrapolated from adult studies.  
• They reviewed: THAPCA-IH trial – a large, multi-institutional, prospective, randomized controlled study of infants and children 2 days to 18 years of age.  
  • Primary outcome: Favorable neurobehavioral outcome at 1 year, with secondary outcomes of survival at 1 year and change in neurobehavioral outcome.
  • Included: Post cardiac arrest kids, GCS < 5, intubated, received CPR > 2 mins, and got a return of spontaneous circulation (ROSC) 
  • Temperature targets were actively maintained for 120 hours 
  • THAPCA-IH was halted for futility after enrollment of 59% of targeted patients because the primary outcome (favorable neurobehavioral outcome at 1 year) did not differ significantly between the TTM 32°C to 34°C (36%, 48 of 133) and TTM 36°C to 37.5°C (39%, 48 of 124) (RR 0.92% 95% CI 0.67–1.27; P = 0.63) groups. Secondary outcomes also did not differ between the two groups. 
  • There is insufficient evidence to support a recommendation about treatment duration. The THAPCA (Therapeutic Hypothermia After Pediatric Cardiac Arrest) trials used 2 days of TTM 32°C to 34°C followed by 3 days of TTM 36°C to 37.5°C or used 5 days of TTM 36°C to 37.5°C. 
• REBEL Thoughts: We know fever is associated with poorer prognosis, and empirically preventing fever is important, hence continuous monitoring of temperature makes sense. However what target temperature we should aim for is still not well defined. The last paragraph of their recommendations sums it up nicely

“Given the uncertainty of the effect of TTM, limitations of the data analysis, and lack of demonstrable harm, we agree that it is reasonable for clinicians to use TTM to 32°C to 34°C followed by TTM 36°C to 37.5°C or to use TTM 36°C to 37.5°C. Clinicians should consistently implement the strategy that can most safely be performed for a specific patient in a specific clinical environment. Regardless of strategy, providers should strive to prevent fever >37.5°C.”

Clinical Bottom Line:

Overall not life-changing recommendations.

1. AIRWAY: OHCA-airway BVM is better than intubation, but in the ED definitive airway is important for prevention of aspiration and secure airway.
2. ECMO can be helpful, and should be utilized if you have access to it, but very limited data, especially in pediatrics.
3. Temperature management with continuous monitoring via application of cooling protocols is beneficial, and fever prevention is particularly important 

Co-Host

References:

1. Gausche M et al. Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: a controlled clinical trial. JAMA. 2000 PMID: 10683058
2. Duff J et al. 2019 American Heart Association Focused Update on Pediatric Advanced Life Support – An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2019. PMID: 31722551

Post Peer Reviewed By: Salim R. Rezaie, MD (Twitter: @srrezaie)