**3.2 Cannulation procedure during CPR**

Determination of a patient's ECPR candidacy and feasibility of cannulation should preferably be done prior to cardiac arrest. Criteria for determination of candidacy may vary from center to center, and there are no universal guidelines for this. Though the AHA recommends considering ECMO for pediatric IHCA, there are no specific guidelines for the actual implementation of ECMO during CPR.

**3.3 Elements of an ECPR program**

*DOI: http://dx.doi.org/10.5772/intechopen.92381*

*Pediatric Cardiac Arrest*

Deployment of ECPR requires that a well-coordinated, streamlined, and efficient sequence of activities takes place. For success of an ECPR program, it is essential that clinical teams are always ready since time is of the essence. Important elements to a successful ECPR program include (i) prior identification of patients that would be offered ECMO in the case of cardiac arrest, (ii) prior establishment of a system of emergently notifying all required parties in the event of cardiac arrest (e.g., through paging), (iii) ready availability of primed ECMO circuits and blood products, and (iv) effectively trained and prepared team members [80, 81].

Some ECPR programs have crystalloid-primed or non-blood colloid-primed circuits always on standby [57, 76, 81, 82]. Sixty-five percent of 1828 pediatric ECPR cases reported to ELSO from 2011 to 2015 had an ECMO circuit primed with blood products [44]. Different considerations go into the choice of prime solution for rapid deployment. Blood-primed circuits are dependent on the rapid availability of blood products and cannot be stored long-term. Some programs do not keep preprimed circuits if blood can be obtained quickly [83]. Crystalloid-primed circuits may be stored for up to 30 days but may require adjustment of pH and addition of blood prior to use [57, 76, 81]. Cost must also be considered in the decision to have pre-primed circuits on standby. For example, as published in 2017 by Erek et al., their pediatric ECPR program in Turkey avoids pre-primed ECMO circuits due to cost. Instead they emergently deploy cardiopulmonary bypass circuits for ECPR

Teams must be effectively trained and prepared. Simulation has proven to be an

Survival after ECPR in pediatrics is around 43% in all age groups, according to ELSO [44]. Only a few pediatric studies have compared conventional CPR (CCPR) with ECPR [48, 87, 88]. In an analysis published in 2016 of almost 600 pediatric IHCA patients from the GWTG-R registry, there were increased odds of survival to

Taeb et al. compared CPR quality between ECPR and CCPR in pediatric cardiac intensive care patients. They found that CPR duration was significantly longer for patients who received ECPR than those who received CCPR [30 min (9.5–33 min) vs. 5.5 min (4–12.5 min); *p* = 0.016]. Rate of ROSC, intensive care unit length of stay, and hospital length of stay were not different between the groups [88].

Neurological outcomes after ECPR are important metrics, but there is a general

paucity of data on this topic. Multiple single-center and registry studies have reported on neurologic status at hospital discharge using the Pediatric Cerebral Performance Category (PCPC) scale [37, 57, 61, 64, 73, 81, 87, 89–91]. However, many of those studies have incomplete data, and designation of a patient's PCPC is also subjective. In addition, the definition of favorable neurologic outcome scores using PCPC varies. All these make interpretation of the data somewhat difficult. In the 2019 study of merged ELSO and GWTG-R data, discharge PCPC was only available in 48% of 241 pediatric ECPR survivors; 93% of those had a PCPC ≤2

effective method for ECPR team training and has been used in many programs

hospital discharge for patients who received ECPR compared to CCPR only (adjusted OR 2.76; 95% CI 2.08–3.65; *p* < 0.0001) [87]. An earlier study published in 2013 did not demonstrate an association between ECPR and improved survival to discharge compared to CCPR, but that study had a small ECPR subgroup and was

then transition to ECMO circuits later in the course [52].

around the world with good results [84–86].

**3.4 Pediatric ECPR outcomes**

unable to match controls [48].

which was considered favorable [68].

**35**

Site of cannulation varies in pediatrics and could be central or peripheral. Central (transthoracic) cannulation is more frequently performed in cardiac surgical patients, some of whom may already have an open sternum [52–54] . Peripheral cannulation could be via right neck vessels (internal jugular vein and carotid artery) or femoral vessels. Data is conflicting on the presence of a correlation between cannulation site and outcomes in pediatric ECPR [55–62].

Questions also remain surrounding (i) the appropriate timing of initiating a request for ECMO implementation during CPR, (ii) the use of timed cycled interruptions of chest compressions to allow for cannulation, and (iii) the ongoing administration of epinephrine (adrenaline) during ECPR cannulation. From a review of the literature, clinical practice varies in regard to how long after the initiation of chest compressions that ECMO is requested for pediatric IHCA [57, 60, 63–66]. A cross-sectional survey of pediatric cardiac intensive care practitioners published in 2018 showed that 38% of respondents reported activating ECMO after just one dose of epinephrine, while more than 80% called for ECMO after the second dose [67]. The timing of initiation of ECMO cannulation during CPR is important because it contributes to total CPR duration. Based on this, it would seem prudent to request ECMO early into the resuscitation effort. But caution must also be taken to avoid deployment prematurely, for example, if return of spontaneous circulation (ROSC) could have been achieved without ECMO. The effect of total CPR duration on survival and neurological outcomes after pediatric ECPR is unclear. In a recent large study using data from both ELSO and GWTG-R registries, a linear relationship was demonstrated between CPR duration and odds of death before hospital discharge [68]. Multiple single-center studies have also shown worse outcomes from pediatric ECPR if duration of CPR is longer [52, 60, 63, 64, 66, 69–72]. However, still other studies have shown no correlation between ECPR duration and outcomes [37, 53, 57, 73–79]. The patient population possibly dictates the effect of ECPR duration on outcome. Compared to other illness categories, pediatric cardiac surgical patients have been shown to have a higher probability of favorable neurologic outcomes despite ECPR of prolonged duration [37].

The use of timed cycled interruptions of chest compressions to facilitate cannulation during ECPR is practiced in some centers, but there is no literature to show how widespread this practice is or whether it has positive effects on outcomes. Without timed cycled interruptions, chest compressions are paused randomly, usually at the discretion of the cannulating surgeon, and they are paused for varying amounts of time. With timed cycled interruptions, pauses in chest compressions are on a cycle—compressions are not paused unless a minimum time has passed (e.g., 2 min), and they are only paused for a maximum amount of time (e.g., 30–45 s). With the cycled method, the cannulating surgeon is only able to work in short bursts of time, and it is possible that overall CPR duration is therefore longer. However, it is also likely that CPR "no-flow" time is less. This is an area that needs to be studied.

Epinephrine administration for CPR during ECMO cannulation is also an area of research interest. Proponents of the cessation of epinephrine administration during ECMO cannulation for CPR argue that ongoing administration would only increase systemic vascular resistance (which would impede ECMO flow subsequently and hamper myocardial recovery) and is futile for ROSC since the decision would have already been made to cannulate. However, the 2009 study of 199 pediatric ECPR recipients from GWTG-R registry demonstrated no statistically significant difference between survivors and non-survivors in cumulative dose of epinephrine received during ECPR [73]. Also, in the cross-sectional survey of pediatric cardiac critical care clinicians published in 2018, only 19% of respondents reported limiting epinephrine to 1–3 doses during CPR before ECMO cannulation [67].
