Materials and Methods
Patients :
This prospective cohort study was conducted at the neonatal intensive
care unit of Kasr El Aini Hospital, a referral tertiary care university
hospital. The study was approved by the Institutional Research Ethics
Board and informed parental consents were obtained for all subjects
before recruitment. Infants were included in the study if they fulfilled
the following criteria: a) gestational age <34 weeks, b)
postnatal age <48 hours, and c) supported with invasive
mechanical ventilation for initial presentation with RDS. Infants were
excluded if they were extubated before 3 days of life or if they had any
of the following: a) major congenital anomalies, b) perinatal asphyxia,
or c) hemodynamic instability managed by inotropic administration at the
time of screening.
Demographic and clinical data were collected from the chart. Those data
included the use of antenatal steroids, infant’s sex, gestational age
(GA), birth weight (BW), small for gestational age status, Apgar scores
at 5 and 10 minutes, perinatal confirmed infections, and
intraventricular hemorrhage. Clinical parameters of hemodynamic
stability including systolic and diastolic blood pressures, heart rate,
urine output, and lactic acid at the time of assessment were collected.
Data on respiratory outcomes were collected; bronchopulmonary dysplasia
(BPD) was defined by the use of respiratory support or supplemental
oxygen to maintain oxygen saturation >90 by pulse oximeter
at 36 weeks of postmenstrual age for infants born ≤ 32 weeks of
gestation and the use of supplemental O2 at 28 days for
infants born at 33-34 weeks of gestation 10.
LUS and transthoracic focused cardiac ultrasound (FCUS) were performed
on postnatal days 3 and 7 for all recruited infants. The radiologist who
performed the studies (R.H.) was masked to the clinical details of
infants; likewise, the managing team was blinded to the ultrasound
results. If an infant was extubated after 3 days and before 7 days,
he/she would have only one study at 3 days of life.