End diastolic pressure (BP_ED) expressed as a percentage change from before cord clamping measured in <i>in utero</i> (•) or <i>ex utero</i> (○) lambs before and after umbilical cord occlusion (designated as time 0).

<p>Data are mean ± SEM. * p&lt;0.05 <i>in utero</i> vs <i>ex utero</i>.</p

Blood vessel profiles.

<p>Number of blood vessel profiles with serum extravasation in the subcortical white matter (A), periventricular white matter (B) and cortical grey matter (C) in lambs that received conventional ventilation (no SI, n = 6; ■), a single 30 s sustained inflation (single SI, n = 6; ○) or 5 consecutive 3 s sustained inflations (multiple SI, n = 5; ●). Data presented as median (IQR). One animal in the multiple SI group was omitted from analysis due to poor tissue quality.</p

Maximum expired CO₂ levels against tidal volume in preterm infants.

<p>A demonstrates data from all preterm infants studied (A; n = 10 infants and 517 breaths). The individual relationships between ECO₂ and V_T for each infant are displayed in (B) and (C) for clarity.</p

Lamb arterial blood gases and physiological parameters at the end of asphyxia.

<p>BP, arterial blood pressure; PaCO₂, partial pressure of carbon dioxide; PaO₂, partial pressure of oxygen; SaO₂, oxygen saturation; BE, base excess. Data are mean ± SD. * p&lt;0.05 <i>in utero</i> vs <i>ex utero</i>.</p><p>Lamb arterial blood gases and physiological parameters at the end of asphyxia.</p

Representative images of blood vessel profiles.

<p>Representative images of blood vessel profiles (indicated by arrowheads) with serum extravasation (indicated by asterisk) in the subcortical white matter of a lamb that received a single 30 s sustained inflation (single SI; A) and 5 consecutive 3 s sustained inflations (multiple SI; B). Representative images of blood vessel profiles (indicated by arrowheads) with no serum extravasation in the subcortical white matter of a lamb that received no sustained inflation (no SI; C). Scale bar represents 90μm.</p

Parameters of ECO₂, HR at start of mask ventilation in preterm infants.

<p>Values are median (interquartile range).</p

Expired CO₂ levels and tidal volumes measured in a newborn lamb during the first 18 minutes after birth.

<p>Expired CO₂ levels (ECO₂) are demonstrated in the top panel and tidal volumes (V_T) in the bottom panel. Tidal volumes were increased at “A” and “B” by increasing the inflation pressure and then the ventilation mode was changed to volume guarantee at “C” to target a V_T of 8 mL/kg. ECO₂ levels and V_T were closely associated.</p

Airway pressure, gas flow, expired CO₂ levels and tidal volumes measured in a preterm infant during positive pressure ventilation.

<p>This preterm infant received positive pressure ventilation that was initially applied via facemask and then followed by intubation. Before intubation, little expired CO₂ (ECO₂) could be detected, despite a good tidal volume (V_T) and no detectable facemask leak. Following intubation, ECO₂ levels rapidly increased with increasing V_T and preceded the increase in heart rate, which increased from 75 beats/min at “A” to 100 beats/min at “B”.</p

Max dP/dt expressed as a percentage change from before cord clamping measured in <i>in utero</i> (•) or <i>ex utero</i> (○) lambs before and after umbilical cord occlusion (designated as time 0).

<p>Data are mean ± SEM. * p&lt;0.05 <i>in utero</i> vs <i>ex utero</i>.</p

Relationship between expired CO₂ levels at end-expiration and tidal volumes in lambs.

<p>Relationship between expired CO₂ levels at end-expiration and tidal volumes in lambs.</p