Discussion
This study examines the association between diuretic weaning strategy
and duration of home oxygen in the year following discharge from the
NICU in infants with BPD in the setting of guidelines for management of
home oxygen. We found that actively weaning diuretics was not associated
with longer duration of home oxygen, but passively weaning diuretics was
associated with longer duration of home oxygen. We also found that
infants started on inhaled corticosteroids after NICU discharge and
whose parents weaned home oxygen off-protocol experienced a longer
duration of home oxygen.
Infants with BPD discharged with home oxygen therapy are often also
discharged with diuretics. It has been shown that diuretics in infants
with BPD may improve pulmonary mechanics such as improved pulmonary
compliance, lung function and oxygenation.2,4,10-13However, diuretics do not decrease oxygen dependence in the inpatient
setting, and evidence is limited regarding the impact of long term
treatment.3,14-16 The American Thoracic Society (ATS)
guidelines for outpatient management of diuretics suggest that infants
with post-prematurity respiratory disease who were discharged home with
diuretic therapy should have diuretics discontinued in a careful manner;
the guidelines also recommend avoiding routine use of
diuretics.4,6,16 Partially due to the wide variation
in both home oxygen and use of respiratory medication use between
centers, there are few recommendations regarding how and when to wean
diuretics specifically in conjunction with home oxygen
therapy.5,16 Bhandari et al. described an active
medication taper in infants with stable BPD, though few infants in that
study were also receiving home oxygen therapy. 17 Palm
et al. found that most infants with home oxygen therapy have diuretics
discontinued prior to home oxygen discontinuation, though this study did
not address the specific method of diuretic weaning.18 Using our guidelines, we were able to effectively
start many infants’ weaning process for supplemental oxygen and
diuretics in the same visit.
We found that infants started on inhaled corticosteroids after NICU
discharge had a longer duration of home oxygen therapy, similar to
recent findings by White and colleagues among patients in a trial of
recorded home oximetry.4 As with diuretics, the
prescribing pattern of inhaled corticosteroids varies between
institutions.18 Infants in our center are variably
discharged home from the NICU on inhaled corticosteroids; in clinic we
follow a guideline to prescribe inhaled corticosteroids only if the
infant has recurrent coughing and wheezing, following the recent
published ATS recommendations.6 It is unlikely that
the longer duration of home oxygen therapy was related to inhaled
corticosteroids themselves but rather to intercurrent illness; we also
noted that respiratory rehospitalizations, emergency department visits,
and systemic corticosteroid bursts were associated with longer duration
of home oxygen therapy. Nonetheless, our data provide reassurance that
starting routine inhaled corticosteroids in infants with BPD discharged
with home oxygen therapy does not appear beneficial in decreasing the
length of home oxygen.
We found that infants whose parents did not follow the home oxygen
weaning protocol ultimately had a longer duration of home oxygen.
Off-protocol weaning issues included some parents taking infants off
supplemental oxygen before being instructed to do so, or delays in
implementing the home oxygen weaning process. Since half of infants with
off-protocol weaning had either failed an overnight pulse oximetry study
or had ED visits or admissions, it may be that these infants had a
longer duration of home oxygen due to the severity of their illness,
rather than the weaning process itself. Other infants and their families
experienced delays in clinic appointments or ordering of home oximetry
testing to discontinue oxygen, which contributed to the longer duration
of home oxygen. For these infants and their families, implementing
additional educational and clinical interventions to reduce the family
impact of home oxygen therapy may have the potential to shorten the
length of oxygen. This cohort was followed before our newer strategy of
offering telehealth visits which helps families who have difficulty
getting back and forth. It will be interesting in future studies how the
utilization of remote health strategies effects the length of home
oxygen.
Strengths of this study were the high degree of follow up and use of
pre-specified clinical guidelines. This biggest limitation was that it
was a single-center study. We were not able to control the exact time of
appointments which may affect the exact duration of home oxygen and
medications. We did evaluate other proxy measures of home oxygen weaning
to try to mitigate this weakness. Some factors associated with prolonged
home oxygen weaning are hard to evaluate as “independent” risk
factors, such as use of systemic corticosteroids, respiratory
readmissions, and emergency department encounters, since these are all
likely single events related to acute illness.
In the setting of a standardized clinical guideline for weaning home
oxygen in infants with BPD, actively weaning diuretics was not
associated with longer duration of home oxygen. We did find that
beginning inhaled corticosteroids after NICU discharge and off-protocol
weaning were associated with a longer duration of home oxygen. These
data can serve as a baseline information to implement and test
standardized strategies for diuretic weaning. These results also
highlight the need for future studies regarding the use of inhaled
corticosteroids in infants with BPD, telehealth visits, more remote
health strategies for weaning home oxygen and parental education
interventions effects on the duration of home oxygen.