Results:
In the original cohort of 204 infants, 41 needed GT placement before
discharge. In the validation cohort of 187 infants, 37 needed GT
placement. Respiratory parameters were highly associated with need for
GT at discharge in the original test cohort (Table 1) and the validation
cohort (Table 2).
We examined both a broader categorization of respiratory support defined
as high support (CPAP, NIPPV, CV, HFV) vs. low support (HFNC, LFNC, no
support) (Figure 3), as well as the more detailed distribution of
respiratory mode (Figure 4). When examined in more detail, the
difference in respiratory support in the two groups (GT vs. non-GT) is
quite striking. Infants who failed to achieve full oral feeding were on
significantly more respiratory support, as well as higher oxygen
(Figure3), throughout the NICU course. Both FiO2 and the level of
respiratory support do improve over time regardless of GT outcome
(Figure 1). Every variable examining duration of continuous respiratory
support, including total ventilator days, total ventilator + CPAP days,
PMA at last ventilator day, and PMA at last CPAP day (Figure 4), were
significantly different between the GT and non-GT infants.
We also looked specifically at need for HFV and GT status. At MUSC, HFV
is used as a rescue mode after failure to achieve adequate ventilation
and/or oxygenation on conventional ventilator support; hence, infants
exposed to HFV at some point during their NICU course would have had
significantly higher respiratory support needs at that time. In both the
original and validation cohorts, infants who later received a GT were
significantly more likely to have some exposure to HFV
(P<0.0001).
Given the large differences between respiratory variables in GT and
non-GT infants, we also examined the association between respiratory
support and PMAff (Figure 2). In the original test cohort for the
predictive model, infants who received a GT had their first oral feeding
attempt at 40.3w PMA while the non-GT infants’ PMAff on average was 33.6
weeks.6 All variables measuring duration of
respiratory support were also highly correlated with PMAff with r values
of 0.642- 0.884 and with p values all < 0.001.
To further investigate an additional pulmonary complication seen in the
NICU, we examined the incidence of bronchopulmonary dysplasia (BPD)
between GT and non-GT infants in the original test cohort (Table 1).