Discussion
This multicenter study focuses on the impact of commonly available
demographic, clinical and technology-related parameters on the outcomes
of long-term NIV therapies in children. As children may improve over
time, particularly younger children, periodic evaluation of the need for
NIV is recommended. The presence of a CNS disorder implies worse
prognosis despite NIV use, with higher risk for hospitalization and
ongoing need for NIV use in the long-term while children with upper
airway abnormalities and children with bronchopulmonary dysplasia were
more likely to be able to discontinue NIV in the long-term. Higher
medical complexity, including higher number of co-morbidities and
additional technology use, predicts an increased risk for NIV failure
(switch to IMV or death), requiring a proactive approach during periodic
clinical evaluations and discussion with patients and families. The
technology type also has an impact on long-term outcomes with children
requiring BPAP generally showing more technology dependence in the
long-term and worse outcomes despite NIV. Finally, children using NIV
during the most recent period were more successful at maintaining NIV in
the long-term and prevent need for IMV or death than in previous epochs,
suggesting a positive learning curve of the medical team with improved
counselling, patient’s monitoring, and treatment strategies.
As a significant number of children discontinued NIV therapies due to
improvement of their underlying condition (16%), periodic re-evaluation
of their underlying sleep-related breathing disorder with
polysomnography should be warranted. According to our data, this is
especially relevant in younger children and children with upper airway
disorders, as they are more likely to improve and not require NIV in the
long-term. These results adds on previous data from our group showing
higher likelihood of NIV discontinuation due to improvement in
underlying condition (OR 2.04 (1.04 to 4.03)) in a study comparing NIV
outcomes in infants (<2 years of age) versus older
children13. These data are comparable with a previous
study describing NIV (CPAP and BPAP) discontinuation rates of 27% of
their overall cohort based on symptoms improvement and normalization of
gas exchange (oxygen and/or carbon dioxide levels)14.
In this study, children tend to be younger (median age 1.4 years) at NIV
discontinuation and the most frequently weaned children had upper airway
anomalies (40%), Prader Willi syndrome (10%) and bronchopulmonary
dysplasia (7%). Other cohorts, however, showed lower rates of NIV
discontinuation and no differences by diagnostic
category21-23, suggesting differences in the
population of children receiving NIV at different centers. While it is
clear from the results of this study that re-evaluation of the
underlying sleep-related breathing disorder and need for NIV support is
needed in young children and children with upper airway abnormalities or
bronchopulmonary dysplasia, this study does not analyze the periodicity
of such evaluations, for which further studies might be required.
The presence of high medical complexity seems to influence ongoing need
for NIV as well as higher risk for NIV failure resulting in escalation
to IMV or death and higher need for hospitalization despite NIV use.
Medically complex children have been defined as those having multiple
underlying conditions, impairment of daily functioning, and/or
technology dependence24,25. While previous research
have shown higher risk for escalation to IMV or death in children with
certain underlying conditions who are more prone to have high medical
complexity (neurologic, neuromuscular and cardiac
conditions)15, to our knowledge, the impact of
specific parameters of medical complexity in long-term NIV outcomes have
not been studied before. Although only a small proportion of children
using NIV in our cohort required switch to IMV or died in our cohort
(1% and 5% respectively), in alignment with data from previous
studies15,22,23,26-29, this study adds on critical
information about which patients are at higher risk for adverse
outcomes, allowing stakeholders to better plan for the care of children
with ongoing high medical needs after NIV initiation. Further these
results provide guidance to clinicians and families of medically complex
children regarding long-term expectations for NIV and counselling for
overall goals of care.
A frequent concern for clinicians caring for children using NIV is the
patient/family decision to discontinue NIV therapy (15% in our cohort),
particularly in children with OSA30. Although
patient/family-reported reasons for NIV declination were not analyzed in
this study, interesting data arose from these results. Unexpectedly, no
specific diagnostic category predicted the patient/family decision to
stop NIV therapy. The presence of OSA per se did not predict
patient/family NIV declination while children with obesity/metabolic
syndrome using NIV were more likely decline NIV. The reasons for these
findings are unclear. As highlighted in a previous qualitative study,
these children may have a different perception of their health and need
of NIV as well as psychological, social and health barriers for NIV
continuation31. The presence of NIV-related
complications was, not surprisingly, a significant predictor for NIV
declination. This has previously been examined in studies looking at
predictors of NIV adherence32. We, however, could not
find studies describing factors influencing the patient/family decision
to fully discontinue NIV. Knowing this information will allow clinicians
to anticipate which patients are more likely to stop NIV over time and
work with children and families to prevent dropouts. In addition, this
information highlights the need for ongoing close monitoring of children
using NIV to detect technology-related complications and implement early
interventions that mitigate such events and prevent therapy declination.
The outcomes of long-term NIV use appear more promising for children
using NIV in the most recent epoch period. While more children continue
using NIV therapy lately suggesting less patient/family NIV declination,
escalation to IMV or death has decreased compared to the previous
epochs. These findings are not surprising, as previous reports have
demonstrated similar learning curves resulting in higher long-term
adherence rates33,34. These improvements might be due
to changes that have taken place in our pediatric NIV programs over
time, including closer monitoring of children requiring NIV therapies
and early detection of NIV-related complications, barriers to NIV
initiation, family support and counselling, and larger availability of
mask interfaces for pediatric ages and more customization options
available, although these changes have not been included in this study
analysis33,35,36. This information is encouraging to
continue investing resources and time in the care of this group of
children.
There were some limitations to our study. There are likely to be more
co-variates that influence the outcomes we have examined; however, as
our study is a retrospective chart review, data collection was limited
to the information present in the patient’s medical records. In
addition, the data reported in the second follow-up visit (i.e. number
of NIV related complications) was only available in 61% of our cohort.
To account for this bias, we ran the statistics with and without the
second follow-up variable. Since the models did not significantly change
with the addition of this co-variate, we decided to include it into our
regression analysis.