Discussion
This prospective study of children with a tracheostomy found that the diagnosis of BPD had a statistically significant impact on time to ventilator liberation as well as decannulation. Children with BPD obtaining a tracheostomy required increased duration of ventilation and took longer to achieve decannulation compared to non-BPD children. Additionally, BPD was associated with a lower hazard of mortality, although this effect was influenced by the presence of pulmonary hypertension. This data can further guide clinicians as they care for this critical population of tracheostomy patients.
The presence of BPD was associated with an increased time to ventilator liberation. Prior studies have similarly demonstrated that successful liberation from the ventilator is likely within the first few years of life across patients with different classes of BPD severity.17,20 While these findings are encouraging, it remains important to note that increased durations of mechanical ventilation are likely to be required by children with BPD. This increased duration of mechanical ventilation can have a significant impact on not only the quality of life of the patient, but also their caregivers. These impacts manifest as patients and their families navigate challenges associated with medical equipment, physician visits, financial responsibilities, and potential complications such as infections that may necessitate readmission.4,13,25 In order to improve care for this vulnerable population, physicians should recognize how social determinants of health can impact outcomes. Further studies examining these factors will be beneficial when managing BPD patients with a tracheostomy.
Children with BPD on mechanical ventilation had increased times to tracheostomy decannulation. Patients who undergo tracheostomy are more likely to be medicaly complex and thus more likely to experience higher rates of complications due to the presence of comorbid conditions.33,34 Moreover, children with a tracheostomy for respiratory support in the setting of BPD have higher rates of hospitalization and morbidity.14 These findings suggest that BPD is associated with an increased duration that a tracheostomy remains in place. This may be due to higher rates of complications in pediatric tracheostomy patients such as respiratory infections and subsequent readmissions that have been examined in prior studies.25 Of note, the median time to ventilator liberation and eventual decannulation for our study population was 2.3 and 1.9 years, respectively. This result is likely the consequence of children who did not require mechanical ventilation undergoing decannulation earlier than their peers who did require advanced respiratory support which adds to the overall time that the tracheostomy is in place.35 At present there are no studies that have directly examined the relationship between the presence of BPD, pulmonary hypertension, and time to decannulation. However, existing literature does suggest that decannulation within the first few years of life is likely across a spectrum of BPD severity with excellent survival rates.17, 28 The addition of BPD to a complex patient profile may also contribute to the development of other exacerbating pathologies such as pulmonary hypertension that worsen overall clinical status.5,16,18 It is likely that the added complexity of BPD and its sequelae contributed to the increased time to decannulation amongst BPD patients when compared to non-BPD patients within this study. Further studies directed at intervention strategies to reduce complications associated with BPD may provide further insight into these findings and allow for better care of this vulnerable patient population.
While the presence of BPD was associated with a decreased mortality hazard ratio, the additional diagnosis of pulmonary hypertension was associated with an increased mortality hazard ratio. Prior studies have found an increased risk of mortality amongst patients with moderate to severe BPD and comorbid pulmonary hypertension.36,37This increase in mortality has previously been hypothesized as being related to prolonged hypoxemic events that are associated with BPD-associated pulmonary hypertension.38 These recurrent episodes of hypoxemia may also offer insight into the increased prevalence of disability identified amongst patients within the present sample. While adequate oxygenation and pulmonary function is of well-understood importance in premature newborns, it may play an even more significant role in long term outcomes than previously anticipated in those with BPD and pulmonary hypertension. Thus, the increased prevalence of disability identified by this study as well as others8,39 suggests that neurodevelopmental follow up to evaluate for additional care needs may be warranted to optimize outcomes for this vulnerable patient population, even after eventual ventilator liberation and decannulation.
There are multiple limitations to this study. First, this study was conducted using data with unidentified factors influencing the outcomes of this study not controlled for during analysis. Additionally, given the variance of criteria for diagnosis of BPD across institutions, these findings may not be generalizable to all populations based on non-homogenous standards of diagnosis as previously discussed. To minimize misclassification bias, multiple authors of this study verified diagnoses and other key datapoints collected from patient charts. The risk of misclassification is also mitigated by the fact that this data is from a single institution and is thus not as susceptible to variations in diagnostic criteria. Finally, children who have undergone tracheostomy are more likely to present with multiple medical comorbidities that may complicate the respiratory-related outcomes examined within this sample. Though variables of interest like BPD and pulmonary hypertension were directly examined, it is possible that there are other unidentified factors that influenced the outcomes of this study. Despite these limitations, this study allows for the exploration of the relationship between BPD and comorbidities like pulmonary hypertension and their associations with key respiratory outcome measures. This study was also conducted utilizing data from patients who were cared for at a tertiary care children’s hospital with a Level I pediatric trauma center and Level IV neonatal intensive care unit (NICU). As a result, this study was able to capture important data on a high number of clinically complex patients, thus offering further information on a particularly vulnerable population with a stable incidence across the United States.
Overall, this information can generalize and inform individuals caring for pediatric tracheostomy patients with BPD and pulmonary hypertension. The presence of these two comorbid diseases did impact respiratory-related outcomes, particularly time to decannulation, as anticipated. Thus, this data may inform teams caring for this vulnerable patient population as they seek to provide high-quality long-term care for these children with regards to ventilator liberation and decannulation. Regarding future research opportunities, comorbidities like subglottic stenosis or reasons for delays in decannulation such as a failed sleep study thus requiring adenotonsillectomy could be further explored. These efforts could further guide care efforts for this patient population and eventually lead to optimization of existing protocols for these individuals.