title: 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).
  
  
  OBJECTIVE
  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.
authors.affiliation: Division of Neonatology and Pediatric Critical Care, Department of Pediatrics and Adolescent Medicine, Ulm University, Ulm, Germany.
authors.forename: Marc R
authors.initials: MR
authors.lastname: Mendler
authors.forename: Miriam
authors.initials: M
authors.lastname: Maurer
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Hassan
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.forename: Markus
authors.initials: M
authors.lastname: Waitz
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mayer
authors.forename: Helmut D
authors.initials: HD
authors.lastname: Hummler
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001784:Blood Gas Analysis; D002245:Carbon Dioxide; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000628:therapy*; D006439:Hemodynamics; D008297:Male; D010100:Oxygen; D011175:Positive-Pressure Respiration / Q000379:methods*; D011659:Pulmonary Gas Exchange; D013552:Swine; D012122:Ventilators, Mechanical
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen