Clinical Predictors of Adverse Outcomes in Severe Sepsis Patients with Intermediate Lactate Level

Background:

Determining what clinical variables are associated with adverse outcomes in severe sepsis with an intermediate lactate level (2–4 mM) may assist clinicians to better triage and manage these patients who immediately may not need intensive care. We hypothesized that there are clinical variables available at hospital admission that are associated with the outcome of severe sepsis patients having intermediate lactate levels.

Methods:

This study was a single‐center retrospective cohort of severe sepsis patients with initial lactate of 2–4 mM presenting to a tertiary academic medical center from 2009 to 2011. Patients were excluded if comfort or hospice care was initiated within 72 hours of presentation. The primary outcome was defined as the occurrence of any of the following events after hospital admission to the general medical ward: (1) death, (2) use of vasopressor(s) within 48 hours, (3) requiring mechanical ventilation within 48 hours, or )4) increase in lactate to ≥4 mM within 48 hours. The effect of 72 clinical variables on the primary outcome was assessed using logistic regression.

Results:

Enrolled were 241 patients, age 59 ± 19 years, 44.8% female, with an initial lactate of 2.6 ± 0.5 mM. The primary outcome occurred in 20.3% of patients, with 0% who died, 12.0% on a vasopressor, 12.0% requiring mechanical ventilation, and 5.8% with increased lactate to ≥4 mM within 48 hours of admission. Among 13 common comorbidities, chronic obstructive pulmonary disease (COPD) had an odds ratio (OR) of 2.6 (95% confidence interval, 1.2–6.0) for the primary outcome. Altered mental status, oxygen requirement on admission, and pulmonary infection had ORs of 1.39 (95% CI, 1.02–1.89), 2.91 (95% CI, 1.34–6.34), and 2.12 (95% CI, 1.16–4.13) for the primary outcome, respectively. Temperature, heart rate, blood pressure, respiratory rate, complete blood count, and complete metabolic panel were not associated with the primary outcome.

Conclusions:

Our study suggests that we should be cautious in admitting to the general medical ward severe sepsis patients having intermediate lactate levels, a history of COPD, altered mental status, oxygen requirement, and pulmonary infection.