(1206) Breathing Easy: Comparing NIPPV and NPV in Preventing Intubation

Introduction: Negative pressure ventilation (NPV) uses subatmospheric pressure on the thorax during inspiration, aiding alveolar airflow by promoting thoracic expansion and reducing pleural and alveolar pressures. 1980s studies suggest modern NPV can decrease FiO2 needs and enhance PCO2 elimination, potentially avoiding intubation in small pediatric populations. Nunez et al. reported that NPV supported 69% of pediatric patients with all-cause respiratory failure. This study aimed to compare PICU intubation rates between NIPPV and NPV.

Methods: This multicenter retrospective study analyzed data from the Virtual Pediatric Systems (VPS) database, including 20,391 patients under 3 years old treated with NIPPV or NPV for conditions like viral bronchiolitis, chronic lung disease, reactive airway disease/asthma, or viral/bacterial pneumonia. Patients were categorized based on ventilation mode into NPV (treatment) and NIPPV (control) groups. Propensity scores for assignment to NPV were calculated based on PRISM 3 score, age, sex, weight, and diagnosis, adjusting for unit as a fixed effect. Inferential statistics, including Chi-square and two-sample t-tests as appropriate, were used to compare outcomes between NPV and NIPPV groups before and after propensity score matching. A significance level of p < 0.05 was set for all statistical analyses.

Results: Before propensity score matching, unadjusted comparisons showed higher odds of intubation in the NPV group as compared to the NIPPV group (OR 3.24, 95% CI 2.29-4.51, p < 0.001) and significantly lower PICU length of stay (LOS) (95% CI for between group difference -37.0 hours to -7.4 hours, p = 0.003), with no significant difference in hospital LOS. After propensity score matching, the NPV group showed no statistically significant differences in odds of intubation (OR 1.64, 95% CI 0.92-2.93, p = 0.12), as well as no significant difference in PICU or hospital LOS.

Conclusions: This study suggests that NPV may be equivalent to NIPPV in children less than 3 years old admitted to the PICU for respiratory failure. The results support wider adoption of NPV as an alternative or rescue modality compared to NIPPV, although further study including randomized controlled trials remains necessary to establish equivalence or superiority of NPV versus NIPPV.