Page 35 - Physiological based CPAP for preterm infants at birth Tessa Martherus

intermittent pressurisation of the mask (5). Most very preterm infants breathe in between inflations and the mean tidal volumes generated by these spontaneous breaths in are commonly at least as large on CPAP as the tidal volumes those generated by PPV (5). Since infants generate their own tidal volume when breathing spontaneously, it is likely that ideally titrated CPAP during the transition at birth will cause less harm.
Supporting breathing of preterm infants at birth
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Figure 1. Why is positive pressure ventilation (PPV) often inadequate and/or injurious? The success of PPV is determined by pressure settings, mask technique and newborn physiology. During mask leak, the flow escapes and the baseline shifts up and the infant only generates small tidal volumes. When the mask is pressurised too tight to the face or when the larynx is closed gas flow is obstructed; the flattened flow line shows the air is unable to enter the lungs and small tidal volumes are generated. When the infant breaths coinciding with PPV inflations the tidal volumes rise unexpectedly above safety ranges (4-8 mL/kg; red lines). Inadequate and high tidal volumes can cause injury to the premature lungs and brain.
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