Abstract 205: Effect of Prehospital Noninvasive Positive Pressure Ventilation for Rescue of Acute Respiratory Distress

Abstract

Background: Emergency medical services (EMS) patients in respiratory distress require prompt rescue treatment. Only limited data describe the outcomes of prehospital rescue treatment with non-invasive positive pressure ventilation (NIPPV), including continuous positive airway pressure (CPAP) or bilevel positive air pressure (BiPAP). We sought to characterize the outcomes of prehospital CPAP/BiPAP in a national EMS cohort. Methods: We analyzed 2018 cross-sectional data on 1289 EMS agencies from ESO Solutions, Inc. (Austin, Texas). We included adult (age ≥18 years) patients with respiratory distress (respiratory rate (RR) ≥30 breaths/min. We divided the patients between those receiving NIPPV and standard care (SC). The primary outcome was change in RR during EMS care. We censored the analysis at 40 minutes of treatment. We compared baseline characteristics between NIPPV and SC. Using mixed linear, fractional polynomial and multiple spline models, we determined the associations of prehospital NIPPV with changes in RR. Results: Of the 6,156,846 adult 911 cases, we included 87,219 with respiratory distress, including 11,271 (12.9%) NIPPV (11,206 CPAP and 65 BiPAP) and 75,948 (87.1%) SC. Median treatment duration were: NIPPV 20.0 minutes (IQR 13.5-29.2 minutes), SC 18.5 minutes (IQR 11.1-27.6 minutes). Common concurrent treatments for NIPPV and SC included: Albuterol (48.6%, 20.9%), Ipratropium (27.9%, 11.2%) and Methylprednisolone (23.7%, 7.8%). At 20 minutes, mean RR change was greater for SC than NIPPV; SC -7.8 breaths/min vs. NIPPV -6.0 breaths/min, difference 2.3 (95% CI 1.9-2.6), p<0.001. At 40 minutes, mean RR change was greater for SC than NIPPV; SC -9.5 breaths/min vs. NIPPV -8.2 breaths/min, difference 1.6 (95% CI 0.8 - 2.5), p<0.001. On linear mixed modeling adjusted for age, sex, incident location, race, ethnicity, agency type, initial RR, and medication use, SC was associated with a larger decrease in respiratory rate across time than NIPPV; [NIPPV X time] interaction p<0.001. Conclusions: In this multicenter series of prehospital respiratory distress, SC was associated with greater reductions in RR than NIPPV.