key: cord-1014598-hoc2f00x authors: Walter, Daniel C.; Chan, Hei Kit; Crowe, Remle P.; Osborn, Lesley; Jarvis, Jeffrey; Wang, Henry E. title: Out‐of‐hospital, non‐invasive, positive‐pressure ventilation for acute dyspnea date: 2021-11-04 journal: J Am Coll Emerg Physicians Open DOI: 10.1002/emp2.12542 sha: 6437212d11a2db3da642fb5bc65b0057ec8b3b27 doc_id: 1014598 cord_uid: hoc2f00x BACKGROUND: Emergency medical services (EMS) patients with acute dyspnea require prompt treatment. Limited data describe out‐of‐hospital dyspnea treatment with non‐invasive, positive‐pressure ventilation (NIPPV), including continuous positive airway pressure (CPAP) or bi‐level positive air pressure (BPAP). We sought to determine the course and outcomes of out‐of‐hospital acute dyspnea patients treated with NIPPV. METHODS: We analyzed retrospective data on 1289 EMS agencies from the ESO Data Collaborative (ESO, Inc., Austin, TX) between January and December 2018. We defined acute dyspnea as adults with an initial respiratory rate ≥ 30 breaths/min (bpm), with a primary or secondary EMS subjective impression of a respiratory condition, who received oxygen and/or a respiratory medication and had 2 or more recordings of respiratory rate (RR). We excluded patients with trauma and those with altered mental status. We identified cases receiving care with and without NIPPV. The primary outcome was change in respiratory rate (RR), censored at 90 minutes of treatment. We compared baseline characteristics between NIPPV and non‐NIPPV patients. We compared RR changes between NIPPV and non‐NIPPV patients at 20 and 40 minutes of treatment. Using mixed linear, fractional polynomial, and multiple spline models, we examined the association of out‐of‐hospital NIPPV with overall change in RR. Secondary outcomes included whether the patient received advanced airway treatment (intubation, supraglottic airway device, and/or cricothyroidotomy). RESULTS: We analyzed 33,585 EMS encounters for patients with acute dyspnea, including 8,750 (26.1%) NIPPV and 24,835 (73.9%) non‐NIPPV encounters. Median treatment duration was similar between NIPPV and non‐NIPPV (23.3 minutes vs 23.6 minutes, rank‐sum P = 0.266). Common concurrent treatments included albuterol (NIPPV, 48.8%; non‐NIPPV, 46.2%), ipratropium bromide (27.9%, 24.8%), and methylprednisolone (24.9%, 18.5%). At 20 minutes, mean RR change was slightly lower for the NIPPV group than non‐NIPPV; −6.0 versus −6.8 breaths/min. At 40 minutes, mean RR change was similar between NIPPV and non‐NIPPV groups; −7.7 versus −7.9 breaths/min. On linear mixed modeling adjusted for age, sex, incident location, race, ethnicity, agency type, initial RR, and medication use, NIPPV was associated with a smaller RR decrease across time than NIPPV; [NIPPV × time] interaction P < 0.001. Out‐of‐hospital advanced airway placement (endotracheal intubation or supraglottic airway insertion) was higher for NIPPV than non‐NIPPV group (2.3% vs 1.3%, odds ratio = 2.23, 95% confidence interval = 2.01–2.47). CONCLUSIONS: NIPPV has been proven to be an effective treatment for out‐of‐hospital patients experiencing acute dyspnea through prior studies. Our findings provide detailed insight into characteristics and use of NIPPV and highlight the commonality of this treatment modality with use in over 1 in 4 patients in respiratory distress. mean RR change was similar between NIPPV and non-NIPPV groups; −7.7 versus −7.9 breaths/min. On linear mixed modeling adjusted for age, sex, incident location, race, ethnicity, agency type, initial RR, and medication use, NIPPV was associated with a smaller RR decrease across time than NIPPV; [NIPPV × time] interaction P < 0.001. Out-of-hospital advanced airway placement (endotracheal intubation or supraglottic airway insertion) was higher for NIPPV than non-NIPPV group (2.3% vs 1.3%, odds ratio = 2.23, 95% confidence interval = 2.01-2.47). Conclusions: NIPPV has been proven to be an effective treatment for out-of-hospital patients experiencing acute dyspnea through prior studies. Our findings provide detailed insight into characteristics and use of NIPPV and highlight the commonality of this treatment modality with use in over 1 in 4 patients in respiratory distress. Although prior studies describe out-of-hospital NIPPV, these efforts have important limitations. These mainly occurred in single EMS agencies with limited sample sizes. A meta-analysis of 10 studies totaling 190 BPAP and 610 CPAP patients included mainly EMS systems with physicians in Europe and provided limited insights of the course and outcomes of patients receiving out-of-hospital NIPPV. 3 Limited data characterize NIPPV in the care of acute dyspnea in United States EMS systems. We sought to determine the course and outcomes of out-of-hospital acute dyspnea patients treated with NIPPV. We included 911 calls for adult (≥18 years of age) patients treated by a paramedic level service with acute dyspnea. We defined acute dyspnea as an initial respiratory rate ≥30 breaths/min (bpm) with a primary or secondary EMS subjective impression of a respiratory condition (Appendix 1), who received an intervention involving oxygen and/or a respiratory medication, and had 2 or more recordings of RR. We excluded patients presenting with trauma or altered mental status, those patients who expired on scene, and any patient vital signs after the point of intubation (Figure 1 ). The primary exposure was the out-of-hospital use of NIPPV. We defined NIPPV as use of CPAP or BPAP. The comparison group consisted of patients with acute dyspnea that did not receive NIPPV. The primary outcome was change in RR during the EMS encounter. F I G U R E 1 Study population. Acute dyspnea defined as adults with an initial respiratory rate ≥30 breaths/min (bpm), with a primary or secondary EMS subjective impression of a respiratory condition, who received oxygen and/or a respiratory medication, and had 2 or more recordings of respiratory rate. EMS, emergency medical services; RR, respiratory rate; NIPPV, non-invasive positive pressure ventilation Where linked to hospital data, we determined ICD10 discharge diagnoses and Charlson comorbidity index score of hospitalized patients. We compared patient age, sex, race, ethnicity, initial RR, agency type, and incident location between NIPPV and non-NIPPV patients. We compared initial vital signs, response time, scene time, transport time, and treatment time between NIPPV and non-NIPPV patients. We determined the association between NIPPV use and the change in RR using a t-test. We used linear mixed modeling for comparison between the NIPPV and non-NIPPV group with the change in RR as the dependent outcome and the use of NIPPV as the primary exposure. We Our study was retrospective and subject to recall and reporting bias. Vital sign measurement intervals varied widely from patient to patient. Although many agencies likely imported vital signs from their patient care monitors, the source of the vital signs was not included in the dataset and, therefore, respiratory rates may have been objectively measured. We estimated the RR at 20-minute and 40-minute intervals using a linear regression between the last recorded RR prior to the interval and the first recorded RR after the interval but acknowledge that additional changes may have occurred beyond this point that were not captured in our analysis. We included the change between the first and last recorded respiratory rate as well but the length of treatment time varied between patients. Airway NIPPV is used widely in the out-of-hospital treatment of acute dyspnea. We present one of the largest descriptions of out-ofhospital NIPPV use in the United States, encompassing 8,750 patients. Although these data represent a sample of convenience, the included records are national in scope, spanning care from over 1,200 EMS agencies. More than 1 in 4 patients presenting with acute dyspnea were treated with NIPPV. Our study has important limitations and should not be used to formulate conclusions regarding the efficacy of NIPPV. Although we observed larger reduction in respiratory rate with non-NIPPV, our series was not randomized and vulnerable to confounding by indication. Confounders likely influencing the association between NIPPV use and RR include comorbidities, severity of illness, and caregiver selection bias. We note that patients were older and baseline vital signs were worse in the NIPPV than non-NIPPV groups. Another Although not performed in the out-of-hospital setting, Arsude et al 8 found that there was a significant improvement in Borg score at 4, 12, and 24 hours after initial presentation. Although our study was limited to the use of respiratory rate, we were able to include a larger selection of patients with a range of etiologies for acute dyspnea. We were also able to provide more detailed insight into patient demographics and clinical course associated with out-of-hospital NIPPV treatment. NIPPV plays a practical role in the out-of-hospital care of dyspnea. NIPPV is non-invasive, easy to implement, and relatively inexpensive. NIPPV can even be implemented by basic life support personnel. 9 Pharmacologic treatments available for the out-of-hospital treatment of acute dyspnea generally include the use of nitroglycerin, diuretics, beta-agonists, steroids, magnesium sulfate, and epinephrine; NIPPV provides an important adjunct to these therapies and creates an alternative to endotracheal intubation in cases of worsened respiratory distress or failure. Acknowledging its limitations, our study adds to existing knowledge regarding NIPPV use, supporting its use across a range of clinical settings in the United States. Future study is important to help delineate the role, methods and indications for out-of-hospital NIPPV as well as the best indicators of benefit. In summary, NIPPV has been proven to be an effective treatment for out-of-hospital patients experiencing acute dyspnea through prior studies. Our findings provide detailed insight into characteristics and use of NIPPV and highlight the commonality of this treatment modality with use in over 1 in 4 patients in respiratory distress. DCW and HEW designed the study. DCW, HEW, HKC, and REC worked on data acquisition and analysis. All study authors assisted with data interpretation. DCW and HEW prepared the manuscript. All authors worked on review and revision of the manuscript, and gave approval for final version to be published. DCW takes responsibility for the paper as a whole. National characteristics of emergency medical services responses in the United States Biphasic positive airway pressure (BIPAP)-a new mode of ventilatory support Prehospital noninvasive ventilation for acute respiratory failure: systematic review, network metaanalysis, and individual patient data meta-analysis Efficacy and safety of noninvasive positive pressure ventilation therapy in acute pulmonary edema Reproducibility of Borg scale measurements of dyspnea during exercise in patients with COPD Resting Borg score as a predictor of safe discharge of chronic obstructive pulmonary disease from the emergency department observation unit Out-of-hospital continuous positive airway pressure ventilation versus usual care in acute respiratory failure: a randomized controlled trial Outcome of noninvasive ventilation in acute respiratory failure AUTHOR BIOGRAPHY He holds a Bachelor of Out-of-hospital, non-invasive, positive-pressure ventilation for acute dyspnea Respiratory condition due to chemicals, gases, fumes, and vapors The authors declare no conflicts of interest. Dr. Wang was not involved in the review or acceptance of this manuscript.