Effective predictions of lactate levels and mortality risk can be provided with a few clinical variables when the temporal aspect and variability of patient data are considered.

Introduction: Consensus guidelines recommend sepsis screening for adults with systemic inflammatory response syndrome (SIRS), but the epidemiology of SIRS among adult emergency department (ED) patients is poorly understood. Recent emphasis on cost-effective, outcomes-based healthcare prompts the evaluation of the performance of large-scale efforts such as sepsis screening. We studied a nationally representative sample to clarify the epidemiology of SIRS in the ED and subsequent category of illness.Methods: This was a retrospective analysis of ED visits by adults from 2007 to 2010 in the National Hospital Ambulatory Medical Care Survey (NHAMCS). We estimated the incidence of SIRS using initial ED vital signs and a Bayesian construct to estimate white blood cell count based on test ordering. We report estimates with Bayesian modified credible intervals (mCIs).Results: We used 103,701 raw patient encounters in NHAMCS to estimate 372,844,465 ED visits over the 4-year period. The moderate estimate of SIRS in the ED was 17.8% (95% mCI: 9.7 to 26%). This yields a national moderate estimate of approximately 16.6 million adult ED visits with SIRS per year. Adults with and without SIRS had similar demographic characteristics, but those with SIRS were more likely to be categorized as emergent in triage (17.7% versus 9.9%, p<0.001), stay longer in the ED (210 minutes versus 153 minutes, p<0.0001), and were more likely to be admitted (31.5% versus 12.5%, p<0.0001). Infection accounted for only 26% of SIRS patients. Traumatic causes of SIRS comprised 10% of presentations; other traditional categories of SIRS were rare.Conclusion: SIRS is very common in the ED. Infectious etiologies make up only a quarter of adult SIRS cases. SIRS may be more useful if modified by clinician judgment when used as a screening test in the rapid identification and assessment of patients with the potential for sepsis. [West J Emerg Med. 2014;15(3):329–336.]

Background Admission hyperglycemia has been reported as a mortality risk factor for septic nondiabetic patients; however, hyperglycemia’s known association with hyperlactatemia was not addressed in these analyses. Objectives The objective was to determine whether the association of hyperglycemia with mortality remains significant when adjusted for concurrent hyperlactatemia. Methods This was a post hoc, nested analysis of a retrospective cohort study performed at a single center. Providers had identified study subjects during their ED encounters; all data were collected from the electronic medical record (EMR). Nondiabetic adult ED patients hospitalized for suspected infection, two or more systemic inflammatory response syndrome (SIRS) criteria, and simultaneous lactate and glucose testing in the ED were enrolled. The setting was the ED of an urban teaching hospital from 2007 to 2009. To evaluate the association of hyperglycemia (glucose > 200 mg/dL) with hyperlactatemia (lactate ≥ 4.0 mmol/L), a logistic regression model was created. The outcome was a diagnosis of hyperlactatemia, and the primary variable of interest was hyperglycemia. A second model was created to determine if coexisting hyperlactatemia affects hyperglycemia’s association with mortality; the main outcome was 28-day mortality, and the primary risk variable was hyperglycemia with an interaction term for simultaneous hyperlactatemia. Both models were adjusted for demographics; comorbidities; presenting infectious source; and objective evidence of renal, respiratory, hematologic, or cardiovascular dysfunction. Results A total of 1,236 ED patients were included, and the median age was 77 years (interquartile range [IQR] = 60 to 87 years). A total of 115 (9.3%) subjects were hyperglycemic, 162 (13%) were hyperlactatemic, and 214 (17%) died within 28 days of their initial ED visits. After adjustment, hyperglycemia was significantly associated with simultaneous hyperlactatemia (odds ratio [OR] = 4.14, 95% confidence interval [CI] = 2.65 to 6.45). Hyperglycemia and concurrent hyperlactatemia were associated with increased mortality risk (OR = 3.96, 95% CI = 2.01 to 7.79), but hyperglycemia in the absence of simultaneous hyperlactatemia was not (OR = 0.78, 95% CI = 0.39 to 1.57). Conclusions In this cohort of septic adult nondiabetic patients, mortality risk did not increase with hyperglycemia unless associated with simultaneous hyperlactatemia. The previously reported association of hyperglycemia with mortality in nondiabetic sepsis may be due to the association of hyperglycemia with hyperlactatemia.

Objective To determine if metformin use affects the prevalence and prognostic value of hyperlactatemia to predict mortality in septic adult Emergency Department (ED) patients. Methods Single-center retrospective cohort study. ED providers identified study subjects; data was collected from the medical record. Patients Adult ED patients with suspected infection and 2 or more Systemic Inflammatory Response Syndrome Criteria. The outcome was 28-day mortality. The primary risk variable was serum lactate (< 2.0; 2.0–3.9; ≥4.0 mmol/L) categorized by metformin use; covariates-demographics, Predisposition, Infection, Response, Organ Dysfunction score, and metformin use contraindications. Setting Urban teaching hospital; 2/1/2007 to 10/31/2008. Results 1947 ED patients were enrolled; 192 (10%) were taking metformin; 305 (16%) died within 28-days. Metformin users had higher median lactate levels than non-users [2.2 mmol/L (IQR 1.6–3.2) vs. 1.9 mmol/L (IQR 1.3–2.8)] and a higher, though non-significant, prevalence of hyperlactatemia (lactate ≥ 4.0 mmol/L) (17% vs. 13%) (p=0.17). In multivariate analysis (reference group non-metformin users, lactate < 2.0 mmol/L), hyperlactatemia was associated with an increased adjusted 28-day mortality risk among non-metformin users (OR = 3.18, p < 0.01), but not among metformin users (OR = 0.54, p=0.33). Additionally, non-metformin users had a higher adjusted mortality risk than metformin users (OR = 2.49, p < 0.01). These differences remained significant when only diabetics were analyzed. Conclusions In this study of adult ED patients with suspected sepsis, metformin users had slightly higher median lactate levels and prevalence of hyperlactatemia. However, hyperlactatemia did not predict an increased mortality risk in patients taking metformin.

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