DISCUSSION:
In the current study, we noted a significant association between the
presence of a hemodynamically significant PDA and extubation failure,
which is in concurrence with previous studies [16, 17] that have
reported a similar association.
We speculate that PDA may contribute to extubation failure due to
pulmonary edema, leading to increased work of breathing. The PDA may
become more hemodynamically significant after reduction of mean airway
pressure applied to the lungs after extubation.
It is not known if proactively evaluating for PDA prior to extubation
and its treatment would be associated with an improved likelihood of
successful extubation. The data from the current study are hypothesis
generating and may serve as a basis for future prospective observational
and randomized controlled trials to evaluate the role of treatment for
PDA prior to extubation to improve the cardiorespiratory outcomes of
these infants.
There is no consensus on the definition of extubation success for
premature infants. We defined extubation success as need for re
intubation within five days of extubation as a significant proportion
(25%) of infants might fail extubation beyond 48-72 hours of
extubation. [13]
Current study had some limitations. As this was an observational study,
we cannot establish a cause-and-effect relationship between presence of
PDA and extubation failure. Endotracheal intubation, extubation and
reintubation, were at the discretion of the primary clinical team.
Strengths of the current study include inclusion of all eligible infants
using well defined criteria with no selection bias. All infants were
born in a single center that reduced the variability in clinical
practice.