Assessment of Lung Aeration at Birth

Despite recent advances in perinatal-neonatal care, there is an increasing trend of bronchopulmonary dysplasia (BPD) among survivors of prematurity1. Most infants developing BPD are born prematurely, and 75% of affected babies weigh less than 1000g at birth2. The risk of developing BPD increases with decreasing birth weight with reported incidence as high as 85% in neonates weighing between 500g and 699g, but only 5% in infants with birth weights over 1500g2. Alberta has the highest rate (10%) of delivering premature infants in Canada. In Edmonton approximately 200 premature infants <1250 g birth weight are born annually and up to 50% will develop BPD. This puts a heavy burden on health resources since these infants require frequent hospital re-admission in the first two years after birth and, even as adolescents have persistent respiratory symptoms. Hypothesis Preterm infants <33 weeks gestation requiring breathing support at birth, the delivery of SIs (SI group) before mask ventilation compared to standard mask ventilation (IPPV group) will reduce the incidence of BPD. Aim To determine if respiratory support at birth with initial sustained inflation compared to IPPV decreases BPD. Study population Entry criteria Infants <33 weeks gestation born in the Royal Alexandra Hospital who require respiratory support for resuscitation in the delivery room. Exclusion criteria Infants will be excluded if they have a congenital abnormality or condition that might have an adverse effect on breathing or ventilation, e.g. congenital pulmonary or airway anomalies, congenital diaphragmatic hernia, or congenital heart disease requiring intervention in neonatal period. Infants will also be excluded if their parents refuse to give consent to this study. Description of interventions "SI group" Infants randomized into the "SI group" will receive two initial sustained inflations before PPV or CPAP. "IPPV group" Infants randomized into the "IPPV group" will receive mask IPPV with an initial PIP of 20 cmH2O and PEEP of 5 cm H2O, and a ventilation rate of 40-60 inflations/min until spontaneously breathing, at which time CPAP will be provided. "Failed SI or IPPV" Babies who fail to improve or remain apneic, bradycardic or hypoxemic despite two SIs and/or 30 seconds of effective IPPV require an alternative airway. Unit policy also dictates elective intubation and instillation of surfactant if, despite CPAP, a preterm infant continues to have increased work of breathing or requires a sustained inspiratory oxygen concentration over 40%.

Lung aeration, Bronchopulmonary dysplasia, Positive Pressure Respiration, Sustained Inflation, Continuous Positive Airway Pressure

Infants randomized into the "SI group" will receive two initial sustained inflations with a PIP of 20 cm H2O. After the two initial SIs infants will receive PEEP of 5 cm H2O and then CPAP if breathing spontaneously or, if found to have apnea or laboured breathing, mask IPPV with a PIP of 20 cm H2O and PEEP of 5 cm H2O at a rate of 40 to 60 bpm until spontaneously breathing, at which time CPAP will be provided.

Infants randomized into the "IPPV group" will receive mask IPPV with an initial PIP of 20 cmH2O and PEEP of 5 cm H2O, and a ventilation rate of 40-60 inflations/min until spontaneously breathing, at which time CPAP will be provided.

Infants randomized into the "IPPV group" will receive mask IPPV with an initial PIP of 20 cmH2O and PEEP of 5 cm H2O, and a ventilation rate of 40-60 inflations/min until spontaneously breathing, at which time CPAP will be provided.

Infants randomized into the "SI group" will receive two initial sustained inflations with a PIP of 20 cmH2O. After the two initial SIs infants will receive PEEP of 5 cm H2O and then CPAP if breathing spontaneously or, if found to have apnea or laboured breathing, mask IPPV with a PIP of 20 cmH2O and PEEP of 5 cmH2O at a rate of 40 to 60 bpm until spontaneously breathing, at which time CPAP will be provided

Difference in bronchopulmonary dysplasia as defined by need for oxygen or respiratory support at 36 weeks corrected gestational age.

Inclusion Criteria: Infants <33 weeks gestation born in the Royal Alexandra Hospital who require respiratory support for resuscitation in the delivery room. Exclusion Criteria: Infants will be excluded if they have a congenital abnormality or condition that might have an adverse effect on breathing or ventilation, e.g. congenital pulmonary or airway anomalies, congenital diaphragmatic hernia, or congenital heart disease requiring intervention in neonatal period. Infants will also be excluded if their parents refuse to give consent to this study.

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