There were 415 culture-negative patients (41.5%) and 586 culture-positive patients (58.5%). Gram-positive bacteria were isolated in 257 patients, and gram-negative bacteria in 390 patients. Culture-negative patients were more often women and had fewer comorbidities, less tachycardia, higher blood pressure, lower procalcitonin levels, lower Acute Physiology and Chronic Health Evaluation II [median 25.0 (interquartile range 19.0-32.0) versus 27.0 (21.0-33.0), P = 0.001] and Sequential Organ Failure Assessment scores, less cardiovascular, central nervous system, and coagulation failures, and less need for vasoactive agents than culture-positive patients. The lungs were a more common site of infection, while urinary tract, soft tissue and skin infections, infective endocarditis and primary bacteremia were less common, in culture-negative than in culture-positive patients. Culture-negative patients had a shorter duration of hospital stay [12 days (7.0-21.0) versus 15.0 (7.0-27.0), P = 0.02] and lower ICU mortality than culture-positive patients. Hospital mortality was lower in the culture-negative group (35.9%) than in the culture-positive group (44.0%, P = 0.01), the culture-positive subgroup which received early appropriate antibiotics (41.9%, P = 0.11), and the culture-positive subgroup which did not (55.5%, P less than 0.001). After adjusting for covariates, culture positivity was not independently associated with mortality on multivariable analysis.
Wednesday, February 19, 2014
Culture positive versus culture negative sepsis
This study looked at 1001 septic patients and compared attributes and outcomes between the culture positive and culture negative groups: