Material & Methods:
This retrospective study was conducted in five tertiary care neonatal
intensive care units (NICU) of South India over 29 months (January 2018
to May 2020). All neonates (both inborn and outborn) above 35 weeks of
gestation born by meconium-stained amniotic fluid with the onset of
distress within 12 hrs of life, requiring respiratory support beyond 24
hrs of life and chest x-ray showing features of MAS ((hyper-inflated
lung fields with diffuse non-homogenous opacity or reticulonodular
pattern or low volume lungs with reticulogranularity and
air-bronchograms)12 were eligible for enrolment.
Newborns with major life-threatening congenital malformations were
excluded. The Institutional Ethics committee approved the study at all
the centres.
Of the five centres participated, two centres were private sector
hospitals, one was public sector hospital, two were trust hospitals. All
the centres catered to sick term and preterm infants, both intra and
extra mural. The five centres had similar protocols in the respiratory
management of neonates with MAS. The primary respiratory support was
defined as the highest respiratory support required within the first 6
hours of admission. Surfactant was administered if FiO2 was above 40%
on CPAP or mechanical ventilation. Only one centre had access to inhaled
nitric oxide. The data was retrieved with the discharge diagnosis of
“Meconium aspiration syndrome” from the computerized database or
admission registers. The data was collected with respect to respiratory
support, timing of initiation of CPAP, timing of surfactant
administration, number of doses of surfactant, severity of PPHN,
vasodilators usage , antibiotic usage, indication for antibiotic usage
and number of days, length of stay in hospital till discharge and
survival outcomes were collected. The primary support beyond oxygen
included either CPAP or mechanical ventilation. The data were entered
into a web database and coded for each centre separately.
The prolonged hospital stay was arbitrarily defined as a stay beyond 7
days of life for the study purpose as there was no clear definition from
previous studies. Neonatal sepsis was diagnosed if the blood culture was
positive. Hypoxic Ischemic Encephalopathy (HIE) was classified using
Sarnat and Sarnat staging13. Persistent pulmonary
hypertension was diagnosed based on 2D-Echocardiographic findings of
elevated pulmonary artery systolic pressure (PASP). The PASP greater
than three quarters of systolic pressure was defined as moderate-severe
PPHN14. The hypoxemia in PPHN was stratified based on
the Oxygen saturation index (OSI). The OSI values correspond to half of
the oxygenation index (OI)15, and severity of
hypoxemia in PPHN was graded as mild < 7.5, moderate ≤ 7.5-
12.5, and severe >12.5.
The primary outcome measure was to identify morbidities predicting
prolonged length of stay (>7days). The secondary outcome
was to evaluate the proportion of associated morbidities in our cohort.