Blood pressure variability as an indicator of sepsis severity in adult emergency department patients

Quantify the correlation between blood pressure variability (BPV) and markers of illness severity: serum lactate (LAC) or Sequential Organ Failure Assessment (SOFA) scores. We performed a secondary analysis of data from a prospective, observational study evaluating fluid resuscitation on adult, septic, ED patients. Vital signs and fluid infusion volumes were recorded every 15 min during the 3 h following ED arrival. BPV was assessed via average real variability (ARV): the average of the absolute differences between consecutive BP measurements. ARV was calculated for the time periods before and after 3 fluid infusion milestones: 10-, 20-, and 30-mL/kg total body weight (TBW). Spearman's rho correlation coefficient analysis was utilized. A p-value < 0.05 was considered statistically significant. Forty patients were included. Mean fluid infusion was 33.7 mL/kg TBW (SD 22.1). All patients received fluid infusion ≥ 10 mL/kg TBW, 25 patients received fluid infusion > 20 mL/kg TBW, and 16 patients received fluid infusion > 30 mL/kg TBW. Mean initial LAC was 4.0 mmol/L (SD 3.2). Mean repeat LAC was 3.1 mmol/L (SD 3.2), obtained an average of 6.6 h (SD 5.3) later. Mean SOFA score was 7.0 (SD 4.4). BPV correlated with both follow-up LAC (r = 0.564; p = 0.023) and SOFA score (r = 0.544; p = 0.024) among the cohort that received a fluid infusion > 20-mL/kg TBW. With the finding of a positive correlation between BPV and markers of illness severity (LAC and SOFA scores), this pilot study introduces BPV analysis as a real-time, non-invasive tool for continuous sepsis monitoring in the ED.