High initial tidal volumes in emergency department patients at risk for acute respiratory distress syndrome

Abstract

Purpose: Emergency department (ED) patients are at high risk for the acute respiratory distress syndrome (ARDS). Settings only 1 mL/kg above recommended tidal volumes confers harm for these patients. The purpose of this study was to determine whether ED physicians routinely initiate mechanical ventilation with low tidal volumes in patients at risk for ARDS.

Materials and methods: We retrospectively reviewed the charts of all adult patients who were intubated in an urban, academic ED. The charts were analyzed to identify patients in whom ARDS developed within 48 hours after ED admission. Patients were eligible for inclusion if they had bilateral infiltrates on imaging, had a Pao2/Fio2 ratio less than 300 mm Hg and did not have heart failure contributing to their presentation. The tidal volumes set in the ED were then compared with the recommended tidal volume of 6 mL/kg of predicted body weight.

Results: The initial tidal volumes set in the ED were higher than recommended by an average of 80 mL (95% confidence interval, 60-110, P < .0001) or 1.5 mL/kg (95% confidence interval, 1.0-1.9). Only 5 of the 34 patients received the recommended tidal volume ventilation setting.

Conclusions: In an academic, tertiary hospital, newly intubated ED patients in whom ARDS developed within 48 hours after intubation were ventilated with tidal volumes that exceeded recommendations by an average of 1.5 mL/kg.

Keywords: Acute Lung Injury; Acute Respiratory Distress Syndrome; Emergency Medicine; Mechanical Ventilation; Tidal Volume.