Patient Characteristics, Management, and Predictors of Outcome from Severe Community-Onset Staphylococcal Sepsis in Northeast Thailand: A Prospective Multicenter Study

Abstract

AbstractStaphylococcus aureus infection is a persistent threat in resource-restricted settings in southeast Asia but informative data about this disease remain limited. We analyzed characteristics, management, and predictors of outcome in severely septic patients with community-onset S. aureus infection in northeast Thailand. We performed a prospective, multicenter observational cohort study of community-onset S. aureus sepsis in four referral hospitals recruiting patients at least 14 years of age admitted between March 2010 and December 2013. One hundred and nineteen patients with severe staphylococcal sepsis were enrolled. Diabetes was the most common underlying condition. Methicillin-resistant infection was rare. Twenty-eight-day mortality was 20%. Ninety-two percent of patients received appropriate antibiotic therapy and 82% were administered intravenous fluids on the first hospital day, although only 14% were managed in an intensive care unit (ICU). On univariable analysis, clinical variables at enrollment significantly associated with death at 28 days were coagulopathy or respiratory failure. Plasma interleukin (IL)-8 concentration alone accurately predicted mortality (area under the receiver operating curve = 0.82, 95% confidence interval = 0.73-0.90). In multivariable analysis, addition of IL-8 concentration to a mortality prediction model containing clinical variables further improved the predictive ability of the model. We conclude that severe staphylococcal sepsis in northeast Thailand causes significant mortality. Diabetes is a common preexisting condition and most patients are managed outside the ICU even if they receive vasoactive/inotropic agents or mechanical ventilation. While clinical factors apparent on presentation including coagulopathy and respiratory failure predict death, plasma IL-8 improves this prediction.

Figure 1.

Study flow chart.

Figure 2.

Plasma cytokine concentrations in patients with severe staphylococcal sepsis. (A) The distribution of interleukin (IL)-6 and IL-8 concentrations in study subjects. Boxes show 25th, 50th, and 75th percentiles. Bottom and top whiskers show 25th percentile minus 1.5 times the interquartile range (IQR) and 75th percentile plus 1.5 times the IQR, respectively. (B) and (C) Mortality in patients with severe staphylococcal sepsis by quartile of IL-8 (B) or IL-6 (C) concentrations. P for trend = 3.5 × 10⁻⁶ and P for trend = 0.001, respectively.

Figure 3.

Receiver operating curves for prediction of death. (A) Log₁₀ interleukin (IL)-6 (white circles) and log₁₀ IL-8 (black diamonds). (B) A baseline model of clinical variables (grey circles) with the addition of either log₁₀ IL-6 (white diamonds) or log₁₀ IL-8 (black squares). (C) A model of clinical variables and log₁₀ IL-8 (white circles) with the addition of log₁₀ IL-6 (black diamonds).