C-reactive protein serum levels as an early predictor of outcome in patients with pandemic H1N1 influenzaA virusinfection

Abstract number: LB2397

Zimmerman O., Rogowski O., Aviram G., Mizrahi M., Zeltser D., Justo D., Dahan E., Arad R., Touvia O., Tau L., Tarabeia J., Berliner S., Paran Y.

Objective: To retrospectively examine whether the admission serum C-reactive protein (CRP) levels of patients with pandemic influenza A (H1N1) infection can serve as a predictor of illness severity.

Methods: Included were consecutive adult patients who presented to our emergency department (ED) between May and December 2009, with a flu-like illness, a confirmed diagnosis of pandemic influenza A (H1N1) infection and a serum CRP level that was measured within 24 hours of presentation. Patients with a proven additional concurrent acute illness were excluded. Outcome measures were intensive care unit (ICU) admission, initiation of mechanical ventilation and death.

Results: Seventeen of the 191 enrolled patients (9%) were admitted to the ICU, of whom eight required mechanical ventilation and three died. The median admission serum CRP levels were significantly higher among patients who subsequently required ICU care and those who required mechanical ventilation compared to patients who did not (123 vs. 40 mg/L, p < 0.001 and 112 vs. 43 mg/L, p = .017, respectively).

Admission serum CRP level and auscultatory finding over the lungs (bronchial breath sounds or crackles) were independent prognostic factors for the need of ICU care. The CRP hazard ratio (95% CI) for being transferred to the ICU was 1.09 (1.06–1.12) for each increase of 10 mg/L in CRP level. The admission serum CRP level was the only independent prognostic factor for mechanical ventilation. The CRP hazard ratio (95% CI) for mechanical ventilation was 1.09 (1.05–1.13) for each increase of 10 mg/L in CRP level.

A Kaplan–Meier estimate of the two outcome measures, i.e., the need for ICU admission and for mechanical ventilation, was performed using tertiles of serum CRP levels (i.e., <28, 28–69 and geqslant R: gt-or-equal, slanted70 mg/L). At the 30-day time point since their presentation to the ED, none of the patients with a serum CRP level <28 mg/L needed to be admitted to the ICU or required mechanical ventilation (Figure 1). At the same time point, 19% of the patients with a serum CRP level geqslant R: gt-or-equal, slanted70 mg/L needed to be admitted to the ICU and 8% required mechanical ventilation. The differences in the rates between the lower vs. upper tertile groups were significant (Log-Rank p < 0.001 for ICU and p < 0.024 for mechanical ventilation).

Conclusions: Serum CRP levels in patients with pandemic H1N1 influenza A infection can serve as a useful measurement to predict disease course and assist in patient management as early as ED admission.

Figure 1. Kaplan–Meier analysis displaying the cumulative probability of not reaching the outcome measure of intensive care unit admission (left box) or mechanical ventilation (right box) for patients according to tertiles of serum CRP levels at admission into the emergency department. The solid line represents <28 mg/L, the dense dotted line 28–69 mg/L, and the thin dotted line geqslant R: gt-or-equal, slanted70 mg/L.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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