Objectives To characterize the use of mechanical ventilation in the emergency department (ED), with respect to ventilator settings, monitoring, and titration; and to determine the incidence of progression to acute lung injury (ALI) after admission, examining the influence of factors present in the ED on ALI progression. Methods This was a retrospective, observational cohort study of mechanically ventilated patients with severe sepsis and septic shock (June 2005 to May 2010), presenting to an academic ED with an annual census of >95,000 patients. All patients in the study (n = 251) were analyzed for characterization of mechanical ventilation use in the ED. The primary outcome variable of interest was the incidence of ALI progression after ICU admission from the ED and risk factors present in the ED associated with this outcome. Secondary analyses included ALI present in the ED and clinical outcomes comparing all patients progressing to ALI versus no ALI. To assess predictors of progression to ALI, statistically significant variables in univariable analyses at a p ≤ 0.10 level were candidates for inclusion in a bidirectional, stepwise, multivariable logistic regression analysis. Results Lung-protective ventilation was used in 68 patients (27.1%), and did not differ based on ALI status. Delivered tidal volume was highly variable, with a median tidal volume delivered of 8.8 mL/kg ideal body weight (IBW) (IQR 7.8 to 10.0), and a range of 5.2 to 14.6 mL/kg IBW. Sixty-nine patients (27.5%) in the entire cohort progressed to ALI after admission to the hospital, with a mean onset of 2.1 days (SD ± 1 day). Multivariable logistic regression analysis demonstrated that a higher body mass index, higher Sequential Organ Failure Assessment score, and ED vasopressor use were associated with progression to ALI. There was no association between ED ventilator settings and progression to ALI. Compared to patients who did not progress to ALI, patients progressing to ALI after admission from the ED had an increase in mechanical ventilator duration, vasopressor dependence, and hospital length of stay. Conclusions Lung-protective ventilation is uncommon in the ED, regardless of ALI status. Given the frequency of ALI in the ED, the progression shortly after ICU admission, and the clinical consequences of this syndrome, the effect of ED-based interventions aimed at reducing the sequelae of ALI should be investigated further.

Deep sedation in mechanically ventilated patients, as evaluated in a small number of qualifying heterogeneous randomized controlled trials and observational studies, was associated with increased mortality and lengths of stay. Interventions targeting early sedation depth assessment, starting in the emergency department and subsequent ICU admission, deserve further investigation and could improve outcome.

Monitoring in the setting of critical illness must be linked to beneficial therapy in order to affect clinical outcome. Elevated serum lactate is associated with an increase in mortality in Emergency Department (ED) patients with severe sepsis and septic shock. The reduction of lactate levels towards normal during acute resuscitation is associated with improved clinical outcomes. The majority of data demonstrating the interventions used to achieve a reduction in lactate levels, and the associated clinical outcomes, have been obtained during protocolized randomized trials. We therefore conducted a retrospective observational cohort study of 243 adult patients with severe sepsis and septic shock to assess the interventions associated with non-protocolized serial lactate monitoring, and to assess clinical outcomes. A multivariable model was used to assess outcome differences between the serial lactate (SL) and no serial lactate (NL) cohorts. The SL group received more crystalloid resuscitation (3.6 vs. 2.5 liters, p<0.01) central venous oxygen saturation monitoring (30% vs. 12%, p<0.01), and central venous pressure monitoring (23.5% vs. 11.8%, p=0.02). By day 28, a total of 31 patients in the SL group (23.5%) and 44 in the NL group (39.6%) had died. Multivariable logistic regression analysis demonstrated that the lack of serial lactate monitoring was independently associated with mortality (adjusted OR 2.09; 95% confidence interval [CI], 1.12 to 3.89; p=0.02). The SL group also showed greater improvement in 24 hour SOFA scores (1.16 vs. 0.19, p=0.03), decreased intensive care unit length of stay in days (4.6 vs 6.0, p=0.04), more ventilator-free (19.9 vs. 16, p=0.05) and vasopressor-free (21.6 vs. 17.9 p=0.02) days. In the setting of routine clinical care, serial lactate monitoring is associated with an increase in crystalloid administration, resuscitation interventions, and improved clinical outcomes in ED patients with severe sepsis and septic shock. This suggests that serial lactate monitoring, targeting a reduction in lactate levels to normal, is a generalizable resuscitation target in the ED.

Despite the magnitude of the public health challenge posed by the prolonged mechanical ventilation population, only 14 articles in the biomedical literature have tested patient-level factors associated with long-term mortality. Further research is needed to inform optimal patient selection for prolonged mechanical ventilation.