Supplementary Material for: Different Techniques of Respiratory Support Do Not Significantly Affect Gas Exchange during Cardiopulmonary Resuscitation in a Newborn Piglet Model

<b><i>Background:</i></b> There are no evidence-based recommendations on the use of different techniques of respiratory support and chest compressions (CC) during neonatal cardiopulmonary resuscitation (CPR). <b><i>Objectives:</i></b> We studied the short-term effects of different ventilatory support strategies along with CC representing clinical practice on gas exchange [arterial oxygen saturation (SaO<sub>2</sub>), arterial partial pressure of oxygen (PaO<sub>2</sub>) and arterial partial pressure of carbon dioxide (PaCO<sub>2</sub>)], hemodynamics and cerebral oxygenation. We hypothesized that in newborn piglets with cardiac arrest, use of a T-piece resuscitator (TPR) providing positive end-expiratory pressure (PEEP) improves gas exchange as measured by SaO<sub>2</sub> during CPR as compared to using a self-inflating bag (SIB) without PEEP. Furthermore, we explored the effects of a mechanical ventilator without synchrony to CC. <b><i>Methods:</i></b> Thirty newborn piglets with asystole were randomized into three groups and resuscitated for 20 min [fraction of inspired oxygen (FiO<sub>2</sub>) = 0.21 for 10 min and 1.0 thereafter]. Group 1 received ventilation using a TPR [peak inspiratory pressure (PIP)/PEEP of 20/5 cm H<sub>2</sub>O, rate 30/min] with inflations interposed between CC (3:1 ratio). Group 2 received ventilation using a SIB (PIP of 20 cm H<sub>2</sub>O without PEEP, rate 30/min) with inflations interposed between CC (3:1 ratio). Group 3 received ventilation using a mechanical ventilator (PIP/PEEP of 20/5 cm H<sub>2</sub>O, rate 30/min). CC were applied with a rate of 120/min without synchrony to inflations. <b><i>Results:</i></b> We found no significant differences in SaO<sub>2</sub> between the three groups. However, there was a trend toward a higher SaO<sub>2</sub> [TPR: 28.0% (22.3-40.0); SIB: 23.7% (13.4-52.3); ventilator: 44.1% (39.2-54.3); median (interquartile range)] and a lower PaCO<sub>2</sub> [TPR: 95.6 mm Hg (82.1-113.6); SIB: 100.8 mm Hg (83.0-108.0); ventilator: 74.1 mm Hg (68.5-83.1); median (interquartile range)] in the mechanical ventilator group. <b><i>Conclusions:</i></b> We found no significant effect on gas exchange using different respiratory support strategies during CPR.