Evolution of inflammation in non-ICU patients with infections: pilot prospective cohort study

Introduction

Statins may prevent organ dysfunction in patients with infections, but the optimal time for this therapy is unknown. Our objective was to determine the evolution of inflammation in patients treated for infection on general wards and the impact of previous statin use.

Methods

We performed a single-centre prospective cohort study (April to September 2008) in unselected patients admitted to medical wards with infection, collecting data on demographics, comorbidities, and statin use before admission; and 10-day follow-up data on intensive care or high-dependency unit (ICU/HDU) admission and death, systemic inflammatory response syndrome (SIRS) criteria and organ dysfunction (using a modified Sequential Organ Failure Assessment (SOFA) score), and infection markers (C-reactive protein (CRP), white blood cells (WBC)). Evolution of organ dysfunction, SIRS, WBC and CRP were analysed descriptively; continuous data are expressed as the mean (SD) or median (Q1 to Q3). The effect of statins was explored in regression models accounting for within-patient correlation, with P < 0.05 taken as statistically significant.

Results

Two hundred and nine patients were admitted with infections (lung 51.0%, urinary 34.2%, skin/soft tissue 18.5%, other 5.2%; ≥ 1 infection/patient possible): age 63.8 years (20.7), 49.8% male, Charlson score 2 (1 to 3), previous statin users 27.8%, WBC 15.6 (12.0) × 10⁹/l, CRP 105 (113) mg/l. On admission, 88.9% had ≥ 1 SIRS criterion (median 2 (1 to 3)) and 72.3% had modified SOFA score ≥ 1 (median 1 (0 to 2)), with no statin versus non-statin group differences. CRP, WBC, and the proportion of patients with ≥ 1 SIRS criterion and modified SOFA score ≥ 1 decreased over time (P < 0.0001), but generalized linear mixed models showed no effect of statins (P = 0.98, 0.51, 0.55, and 0.25) when adjusted for time, age, sex, and Charlson score. By day 10, seven patients were admitted to the ICU/HDU, four patients had died, and 64 patients had ≥ 1 day with a higher modified SOFA score versus admission. Overall, 35.9% of patients developed this combined outcome (statin (44.8%) vs. non-statin (32.5%); OR = 1.66, 95% CI = 2.85 to 3.25 after adjustment for age, sex, Charlson score).

Conclusion

Ward patients with infection often develop some organ dysfunction, but the risk of death/higher care is low. Trials of statins to prevent such clinically important outcomes would need to be large.