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

Abstract

Background: There are no evidence-based recommendations on the use of different techniques of respiratory support and chest compressions (CC) during neonatal cardiopulmonary resuscitation (CPR). Objectives: We studied the short-term effects of different ventilatory support strategies along with CC representing clinical practice on gas exchange [arterial oxygen saturation (SaO₂), arterial partial pressure of oxygen (PaO₂) and arterial partial pressure of carbon dioxide (PaCO₂)], 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 SaO₂ 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. Methods: Thirty newborn piglets with asystole were randomized into three groups and resuscitated for 20 min [fraction of inspired oxygen (FiO₂) = 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 H₂O, rate 30/min] with inflations interposed between CC (3:1 ratio). Group 2 received ventilation using a SIB (PIP of 20 cm H₂O 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 H₂O, rate 30/min). CC were applied with a rate of 120/min without synchrony to inflations. Results: We found no significant differences in SaO₂ between the three groups. However, there was a trend toward a higher SaO₂ [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 PaCO₂ [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. Conclusions: We found no significant effect on gas exchange using different respiratory support strategies during CPR.

Effect of Different Respiratory Modes on Return of Spontaneous Circulation in a Newborn Piglet Model of Hypoxic Cardiac Arrest

“…However, no study looking at the effects of TPR or SIB has been undertaken in an in vivo resuscitation model. In a previous study, we investigated the influence of the use of a TPR and SIB on gas exchange [4] and on accuracy of pulse oximetry during CPR in an in vivo animal model with cardiac arrest secondary to hyperkalemia [17] . We found no significant differences in gas exchange comparing the 3 modes of respiratory support [4] .…”

“…In a previous study, we investigated the influence of the use of a TPR and SIB on gas exchange [4] and on accuracy of pulse oximetry during CPR in an in vivo animal model with cardiac arrest secondary to hyperkalemia [17] . We found no significant differences in gas exchange comparing the 3 modes of respiratory support [4] . However, the setting of the newborn infant with cardiac arrest secondary to asphyxia is probably clinically more relevant.…”

“…In a previous study, we investigated the short-term influence of the different techniques of respiratory support mentioned above along with CC representing clinical practice on gas exchange in a hyperkalemia model of cardiac arrest [4] . We were unable to detect significant differences between the groups.…”

Variations of Postresuscitation Lung Function after Thrombolysis Therapy in a Cardiac Arrest Porcine Model Caused by Pulmonary Thromboembolism

“…The dysfunctions of gas delivery and exchange are the studying focuses on treatment of postresuscitation,[2425] to which V/Q ratio, oxygen transport, and oxygen utilization are crucial factors. The Raw was a transient increase which was different from CA model caused by ventricular fibrillation.…”

Tidal Volume Delivery and Endotracheal Tube Leak during Cardiopulmonary Resuscitation in Intubated Newborn Piglets with Hypoxic Cardiac Arrest Exposed to Different Modes of Ventilatory Support

“…ILCOR guidelines recommend CC if the heart rate is <60 beats/min despite adequate ventilation with supplementary oxygen for 30 s, with lung inflations during a pause after every 3 CC to limit interaction with each other [1]. We did not observe differences in gas exchange using different techniques of respiratory support during cardiopulmonary resuscitation (CPR) in a previous study [2]. Schmölzer et al [3] reported interaction of CC with lung inflations in about a quarter of inflations.…”