Editor’s Note: This is the first installment of an ongoing series highlighting researchers sponsored by the Emergency Medicine Foundation (EMF) and illustrating the impact EMF-funded research is having on emergency medicine.

Study Title: Sepsis-associated pulmonary complications in emergency department patients monitored with serial lactate: an observational cohort study¹

Authors: Matthew R. Dettmer, MD, Nicholas M. Mohr, MD, MS, and Brian M. Fuller, MD, MSCI

Researcher Information: Dr. Dettmer completed residency training in emergency medicine at the Washington University School of Medicine/Barnes-Jewish Hospital residency program in St. Louis. He is presently in his final year of fellowship in critical care medicine at Cooper University Hospital in Camden, New Jersey. He identified early sepsis resuscitation as an area of interest given its high mortality rate and high prevalence in the emergency department and performed the present study to identify the real-world implications of serial lactate monitoring of patients with severe sepsis and septic shock. He hopes to continue this research interest as he continues his career as an attending physician who divides his clinical time between the ED and the intensive care unit.

Dr. Mohr is an attending physician in the departments of emergency medicine and anesthesia at the Roy J. and Lucille A. Carver College of Medicine at the University of Iowa in Iowa City. He contributed to acute respiratory distress syndrome (ARDS) adjudication and writing of the final manuscript.

Dr. Fuller is an attending physician in the departments of emergency medicine and anesthesiology at the Washington University School of Medicine in St. Louis. He served as research mentor and, with Dr. Dettmer, conceived study design, performed data analysis and interpretation, performed ARDS adjudication, and contributed to writing of the final manuscript.

Study Background: Severe sepsis and septic shock are disease states commonly encountered in the ED. Prior studies have demonstrated the importance of quantitative resuscitation in the early resuscitation of these critically ill patients. Patients with severe sepsis and septic shock are at high risk for a number of complications, including development of ARDS. There are limited data on early interventions for the prevention of ARDS (including interventions initiated in the ED). The goal of the study was to examine the association between serial lactate monitoring and the incidence of ARDS within five days of hospital admission.

Study Design: We performed a retrospective cohort study of patients presenting to the ED with severe sepsis and septic shock with an initial lactate value greater than 4 mmol/L. Patients were dichotomized based on the use of serial lactate monitoring as part of their resuscitation. A total of 243 enrolled patients were assigned to either serial lactate monitoring (SL, n=132) or no serial lactate monitoring (NL, n=111). The primary outcome of interest was a composite of two major pulmonary complications: 1) development of ARDS and 2) new respiratory failure after hospital admission. Patients developing ARDS were also analyzed separately, and an a priori subgroup of patients receiving mechanical ventilation while in the ED was evaluated for progression to ARDS.

Patients with severe sepsis and septic shock are at high risk for a number of complications, including development of ARDS. There are limited data on early interventions for the prevention of ARDS (including interventions initiated in the ED).

Results: Twenty-eight patients (21 percent) in the SL group and 37 patients (33 percent) in the NL group developed the primary outcome (P=0.03). Multivariate analysis demonstrated an association between the NL group and the development of major pulmonary complications (adjusted odds ratio, 2.1; 95% CI, 1.15–3.78). Mechanical ventilation in the ED was independently associated with ARDS (adjusted odds ratio, 3.5; 95% CI, 1.8–7.0). In the subgroup of patients mechanically ventilated in the ED (n=97), those who subsequently developed ARDS received higher tidal volumes when compared to patients who did not develop ARDS (8.7 mL/kg predicted body weight [interquartile range 7.6–9.5] versus 7.6 [interquartile range 6.8–9.0]; P<0.01).

Projected Impact: Our data extend the work on ED-based quantitative resuscitation by showing that important pulmonary complications can be prevented by interventions performed in the ED. The projected impact of this and related studies is twofold. First, our work supports the idea that monitoring serial lactates as a method to quantify the effectiveness of early resuscitation is a valuable practice and associated with improved outcomes. The second area of impact is related to ventilator management in the ED. We demonstrated improved outcomes for ED patients who were managed with lung-protective strategies. We hope that this will encourage providers to be conscientious about early ventilator management. While these data are drawn from retrospective studies, we acknowledge their limitations and hope that future work in prospective trials will support these early findings.

Dr. Dettmer is a critical care medicine fellow at Cooper University Hospital in Camden, New Jersey.

Reference

1. Dettmer MR, Mohr NM, Fuller BM. Sepsis-associated pulmonary complications in emergency department patients monitored with serial lactate: an observational cohort study. J Crit Care. 2015;30(6):1163-1168.