A Piglet Perinatal Asphyxia Model to Study Cardiac Injury and Hemodynamics after Cardiac Arrest, Resuscitation, and the Return of Spontaneous Circulation.

Neonatal piglets have been extensively used as translational models for perinatal asphyxia. In 2007, we adapted a well-established piglet asphyxia model by introducing cardiac arrest. This enabled us to study the impact of severe asphyxia on key outcomes, including the time taken for the return of spontaneous circulation (ROSC), as well as the effect of chest compressions according to alternative protocols for cardiopulmonary resuscitation.

Reliability of pulse oximetry in hypoxic newborn pigs.

Objective: The reliability of pulse oximetry in the lower SaO2-ranges has not been fully investigated. We wanted to investigate pulse oximeter performance in a pig model of perinatal asphyxia.

Methods: Asphyxia was induced in 22 newborn pigs.

Brain inflammation induced by severe asphyxia in newborn pigs and the impact of alternative resuscitation strategies on the newborn central nervous system.

Background: We compared the current guidelines for neonatal resuscitation with alternative measures and aimed to find out whether this modulated brain inflammation.

Methods: Progressive asphyxia was induced in 94 newborn pigs until asystole. With the reference being resuscitation guidelines, 30 s of initial positive-pressure ventilation before compression (C) and ventilation (V) (C:V; 3:1) in 21% oxygen, pigs were randomized to (i) ventilation for 30, 60, or 90 s before chest compressions; (ii) C:V ratios of 3:1, 9:3, or 15:2; or (iii) 21% or 100% oxygen.

Lung Injury in Asphyxiated Newborn Pigs Resuscitated from Cardiac Arrest - The Impact of Supplementary Oxygen, Longer Ventilation Intervals and Chest Compressions at Different Compression-to-Ventilation Ratios.

Introduction: Non-specific lung inflammatory events caused by severe asphyxia may be intensified by the way we resuscitate the newly born. Assessing lung injury is potentially important because if alternative resuscitation approaches induces similar inflammatory responses or less lung injury. then we may choose the resuscitation approach that is most gentle, and easiest to perform and learn.

Antioxidant protects against increases in low molecular weight hyaluronan and inflammation in asphyxiated newborn pigs resuscitated with 100% oxygen.

Background: Newborn resuscitation with 100% oxygen is associated with oxidative-nitrative stresses and inflammation. The mechanisms are unclear. Hyaluronan (HA) is fragmented to low molecular weight (LMW) by oxidative-nitrative stresses and can promote inflammation.

Return of spontaneous circulation with a compression:ventilation ratio of 15:2 versus 3:1 in newborn pigs with cardiac arrest due to asphyxia.

Objective: International guidelines recommend a compression to ventilation (C:V) ratio of 3:1 in neonates, and 15:2 for other paediatric age groups. The authors aimed to compare these two C:V ratios in a neonatal swine model of cardiac arrest following asphyxia.

Design: Experimental animal study.

Delayed onset of cardiac compressions in cardiopulmonary resuscitation of newborn pigs with asphyctic cardiac arrest.

Background: When 30 s of initial positive pressure ventilation fails to stabilize the heart rate (HR) of newborns in the delivery room, the International Liaison Committee on Resuscitation guidelines recommend initiation of cardiac compressions. However, it may take longer than 30 s to establish effective pulmonary gas exchange. Whether a longer period of initial ventilation to reverse asphyxia would result in less need for cardiac compressions is unknown.

Extended series of cardiac compressions during CPR in a swine model of perinatal asphyxia.

Background: The rationale for a compression to ventilation ratio of 3:1 in neonates with primary hypoxic, hypercapnic cardiac arrest is to emphasize the importance of ventilation; however, there are no published studies testing this approach against alternative methods. An extended series of cardiac compressions offers the theoretical advantage of improving coronary perfusion pressures and hence, we aimed to explore the impact of compression cycles of two different durations.

Materials And Methods: Newborn swine (n = 32, age 12-36 h, weight 2.

Resuscitation of severely asphyctic newborn pigs with cardiac arrest by using 21% or 100% oxygen.

Background: In spite of evidence suggesting that resuscitation with 100% O(2) is detrimental, international guidelines still recommend its use. Clinical studies comparing 21% and 100% O(2) included many infants with only mild and moderate asphyxia.

Objectives: We aimed to investigate the effect of these oxygen fractions on haemodynamic parameters, arterial blood gases, oxygen saturation indices and markers of inflammation and hypoxic damage when resuscitating asystolic newborn pigs following asphyxia.

Blood pressure in the neonate: three non-invasive oscillometric pressure monitors compared with invasively measured blood pressure.

Aim: To compare blood pressure in neonates obtained from three different oscillometer blood pressure monitors (Dinamap, Criticare, Hewlett-Packard) with arterial blood pressure (Hewlett-Packard' invasive unit).

Study Design: A total of 32 randomized, non-invasive blood pressure series, each consisting of three measurements from each monitor, were obtained from 20 neonates (birthweight 531-4660 g). Each measurement was compared with the invasive pressure.