Bloodstream infection (BSI) is a major cause of morbidity and mortality. This retrospective cohort study examined the discriminative ability of Systemic Inflammatory Response Syndrome (SIRS), quick Sepsis-Related Organ Failure Assessment (qSOFA), and a simplified quick form of the Pitt Bacteremia Score (qPitt) to predict mortality in patients with gram-negative (BSI).
Hospitalized adults with BSI due to aerobic gram-negative bacilli at Palmetto Health hospitals in Columbia, South Carolina from January 1, 2010 to December 31, 2013 were identified. Multivariate Cox proportional hazards regression was used to determine variables associated with 14-day mortality. Area under receiver operating characteristic curve (AUROC) was used to examine model discrimination.
Among 832 patients with gram-negative BSI, median age was 65 years, 449 (54%) were women and 444 (53%) had a urinary source of infection. After adjustments for age and Charleston comorbidity score, all five components of qPitt were independently associated with mortality: temperature <36 degrees C (hazard ratio [HR] 3.02, 95% confidence interval [CI] 1.95-4.62, p<0.001), systolic blood pressure <90 mmHg or vasopressor use (HR 2.40, 95% CI 1.37-4.13, p=0.002), respiratory rate ≥25/minute or mechanical ventilation (HR 3.01, 95% CI 1.81-5.14, p<0.001), cardiac arrest (HR 5.35, 95% CI 2.81-9.43, p<0.001), and altered mental status (HR 3.99, 95% CI 2.44-6.80, p<0.001). Among this cohort, 324 (39%), 450 (54%), and 771 (93%) patients had qPitt ≥2, qSOFA ≥2, and SIRS ≥2, respectively. qPitt had higher discrimination to predict mortality (AUROC 0.85) than both qSOFA (AUROC 0.77, p<0.001) and SIRS (AUROC 0.63, p<0.001). In patients with qPitt ≥2, mortality declined from 49% with inappropriate empirical antimicrobial therapy to 24% with appropriate therapy (p<0.001). There was no significant difference in mortality between inappropriate and appropriate therapy in patents with qPitt <2 (5% vs. 3%, p=0.36).
qPitt had high discrimination in identifying patients with life-threatening infections and performed better than other scores to predict mortality. In addition, appropriate empirical antimicrobial therapy improved survival in patients with a qPitt ≥2.
S. E. Battle,
P. B. Bookstaver, Rock Pointe: Content Developer , Consulting fee
C. M. Watson, None
W. Owens, None
J. Kohn, None
L. M. Baddour, None
M. N. Al-Hasan, None