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.