Mechanical Ventilation and ARDS in the ED: A Multicenter, Observational, Prospective, Cross-sectional Study

Abstract

Background: There are few data regarding mechanical ventilation and ARDS in the ED. This could be a vital arena for prevention and treatment.

Methods: This study was a multicenter, observational, prospective, cohort study aimed at analyzing ventilation practices in the ED. The primary outcome was the incidence of ARDS after admission. Multivariable logistic regression was used to determine the predictors of ARDS.

Results: We analyzed 219 patients receiving mechanical ventilation to assess ED ventilation practices. Median tidal volume was 7.6 mL/kg predicted body weight (PBW) (interquartile range, 6.9-8.9), with a range of 4.3 to 12.2 mL/kg PBW. Lung-protective ventilation was used in 122 patients (55.7%). The incidence of ARDS after admission from the ED was 14.7%, with a mean onset of 2.3 days. Progression to ARDS was associated with higher illness severity and intubation in the prehospital environment or transferring facility. Of the 15 patients with ARDS in the ED (6.8%), lung-protective ventilation was used in seven (46.7%). Patients who progressed to ARDS experienced greater duration in organ failure and ICU length of stay and higher mortality.

Conclusions: Lung-protective ventilation is infrequent in patients receiving mechanical ventilation in the ED, regardless of ARDS status. Progression to ARDS is common after admission, occurs early, and worsens outcome. Patient- and treatment-related factors present in the ED are associated with ARDS. Given the limited treatment options for ARDS, and the early onset after admission from the ED, measures to prevent onset and to mitigate severity should be instituted in the ED.

Trial registry: ClinicalTrials.gov; No.: NCT01628523; URL: www.clinicaltrials.gov.

Figures

Figure 1 –

Flow diagram depicting the patients analyzed to achieve each objective of the study. LOS = length of stay; MV = mechanical ventilation.

Figure 2 –

Delivered Vt in the ED. Of the 219 patients mechanically ventilated in the ED, 122 (55.7%) received lung-protective ventilation (< 8 mL/kg PBW) and 25 (11.4%) were ventilated with a tidal volume > 10 mL/kg PBW. PBW = predicted body weight; Vt = tidal volume.

Figure 3 –

Hospital d 0 refers to the ED. Incidence of ARDS represents the development of new cases of ARDS on an individual hospital day (eg, seven new cases of ARDS development on hospital d 2). Prevalence of ARDS represents the total number of ARDS cases present on an individual hospital d, excluding those cases experiencing death.

Figure 4 –

Probability of survival to hospital discharge in patients mechanically ventilated in the ED.