Prolonged ventilation and postnatal growth of preterm infants

Background Extremely premature infants often need invasive respiratory support from birth, but have low nutritional reserves and high metabolic demands. Our aim was to determine if there was a relationship between prolonged ventilation and reduced postnatal growth in such infants. Methods A retrospective, observational study was undertaken. Data from infants born at less than 28 weeks of gestational age and ventilated for 7 days or more were collected and analysed including gestational age, gender, birth and discharge weight, birth and discharge head circumference, days of invasive mechanical ventilation and use of postnatal corticosteroids. The duration of invasive mechanical ventilation and the differences in weight (ΔWz) and head circumference (ΔHz) z-score from birth to discharge were calculated. Results Fifty-five infants were studied with a median [interquartile range (IQR)] gestational age at birth of 25.3 (24.3-26.7) weeks and birth weight of 0.73 (0.65-0.87) kg. The median duration of mechanical ventilation was 45 (33-68) days. Both ΔWz and ΔHz were significantly negatively correlated to the number of invasive mechanical ventilation days (P = 0.01 and P = 0.03, respectively), but not to the use of postnatal corticosteroids. Conclusion Poor postnatal growth is significantly negatively associated with a longer duration of mechanical ventilation in extremely prematurely born infants.