Comparison of three approaches to infant cardiopulmonary resuscitation through an asphyxiated swine model and assessment of the associated human factors through simulation
Creators: Morin, Chelsea M
Publisher: name: University of Alberta Library
Year: 2024

<p>Background<br>
Cardiopulmonary resuscitation is rare in neonates and infants, and although outcomes have improved over the last few decades, there is still significant room for improvement. Currently, neonates are resuscitated with three chest compressions (CCs) to every one ventilation (=3:1 C:V). This approach focuses on ventilation, as asphyxia is the most common cause of cardiac arrest in the delivery room. Infants, on the other hand, are resuscitated with continuous CCs with 20-30 asynchronous ventilations (=CCaV) per minute once an endotracheal tube has been established. There is no evidence to guide the timing to switch from 3:1 C:V to CCaV, which is sometimes done at 28 days old but practice varies between institutions. Further, a novel resuscitation approach, chest compression with sustained inflation (CC+SI), has resulted in improved survival, duration of resuscitation, and time to return of spontaneous circulation (ROSC) in neonatal and infant animal models and neonates. Aims of the studies included in this thesis were: (i) compare survival and duration of resuscitation between 3:1 C:V and CCaV in asphyxiated infant piglets (equivalent to ~25-35-day-old infants) with severe bradycardia, (ii) compare survival and duration of resuscitation between CCaV and CC+SI in asphyxiated infant piglets (equivalent to ~25-35-day-old infants) with severe bradycardia, and (iii) assess the human factors for CC+SI compared to standard (3:1 C:V or CCaV) in a standardized simulation model of infant cardiac arrest.<br>
Methods<br>
Piglets, aged 5-10 days (n=10/group), were obtained on their respective day of experimentation for the two piglet studies. Piglets were anesthetized and surgically instrumented then given time to recover for one hour prior to asphyxiation, until defined bradycardic cardiac arrest was achieved. Piglets were randomized to one of three interventions (i.e., 3:1 C:V or CCaV for the first study; CC+SI or CCaV for the second) and resuscitated until ROSC was achieved, or a maximum of 11 minutes. To minimize the number of piglets used, the same CCaV piglets were used for both studies, and statistical analyses were carried out separately. Hemodynamic and respiratory parameters and intrathoracic pressure were recorded throughout.<br>
 For the simulation study, twenty teams of two neonatal healthcare workers participated in two standardized neonatal resuscitation simulations. Order of scenario and resuscitation technique were randomized. Cognitive load was assessed by National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire. Recordings were assessed for performance [Ottawa Global Rating Scale (OGRS)] and thematic analysis of debrief sessions.<br>
Results<br>
Baseline characteristics were not different for piglets resuscitated with CCaV compared to either 3:1 C:V or CC+SI. Survival was similar between 3:1 C:V and CCaV (7/10 vs 6/10, p=1.00) with no difference in median [interquartile range (IQR)] duration of resuscitation [206 (118-660) vs 660 (189-660) sec]. Further, there was no difference in hemodynamic parameters between the two methods. Peak inflation pressure and flow were higher and peak end expiratory pressure was lower with CCaV compared to 3:1 C:V, due to the different ventilation equipment used.<br>
Survival was similar between CC+SI and CCaV (8/10 vs 6/10, p=0.628), but duration of resuscitation was shorter with CC+SI compared to CCaV [179 (104-447 vs 660 (189-660) sec, p=0.05]. There was no difference in hemodynamic parameters, but respiratory parameters, including minute ventilation and carbon dioxide clearance were improved with CC+SI compared to CCaV. Further, intrathoracic pressure was significantly higher during CPR with CC+SI compared to CCaV (p&lt;0.05).<br>
There was no difference in paired NASA-TLX scores between CC+SI and standard CPR (3:1 C:V or CCaV) for any dimension, adjusting for CPR order. Performance by OGRS was not different between CC+SI and standard CPR. Although participants had less experience and were less familiar with CC+SI, by thematic analysis it was generally considered easier to perform and better for both switching roles and communicating than standard CPR.</p>

<p>Conclusions<br>
There was no difference in survival or duration of resuscitation with 3:1 C:V compared to CCaV. Duration of resuscitation was improved and relatively more piglets survived, although not statistically significant, with CC+SI compared to CCaV. More studies are warranted to assess the best approach to resuscitation in this age group. Further, CC+SI was found to be no more physically or cognitively demanding than 3:1 C:V or CCaV in a neonatal simulation model. No significant barriers to implementation of CC+SI were uncovered.</p>