Culture-Negative Severe Sepsis: Nationwide Trends and Outcomes.
BACKGROUND
Although 28% to 49% of severe sepsis hospitalizations have been described as being "culture negative," there are very limited data on the epidemiology and outcomes of those with culture-negative severe sepsis (CNSS). The objectives of this study were to investigate the proportion and trends of CNSS and its association with mortality.


METHODS
Using the Nationwide Inpatient Sample (NIS) database from 2000 to 2010, we identified adults hospitalized with severe sepsis. Those without any specific organism codes were identified as "with CNSS." We examined the proportion of CNSS hospitalizations and rates of mortality associated with it. We also assessed the independent effect of CNSS on mortality.


RESULTS
Of 6,843,279 admissions of patients with severe sepsis, 3,226,406 (47.1%) had culture-negative results. The age-adjusted proportion of CNSS increased from 33.9% in 2000 to 43.5% in 2010 (P < .001). Those with CNSS had more comorbidities, acute organ dysfunction (respiratory, cardiac, hepatic, and renal dysfunction), and in-hospital mortality (34.6% vs 22.7%; P < .001), although acute kidney injury requiring dialysis was less frequent (5.3% vs 6.1%; P < .001). CNSS was an independent predictor of mortality in those with severe sepsis (OR, 1.75; 95% CI, 1.72-1.77).


CONCLUSIONS
CNSS among hospitalized patients is common, and its proportion is on the rise. CNSS is associated with greater acute organ dysfunction and mortality. Having CNSS is an independent predictor of death.
Division of Infectious Diseases, Department of Pediatrics, Children's Hospital of Michigan, Detroit, MI.
Shipra
S
Gupta
Division of Nephrology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI. Electronic address: asakhuja@alumni.mcw.edu.
Ankit
A
Sakhuja
Department of Critical Care, Phoebe Putney Memorial Hospital, Albany, GA.
Gagan
G
Kumar
Division of Infectious Diseases, Department of Pediatrics, Children's Hospital of Michigan, Detroit, MI.
Eric
E
McGrath
Department of Pulmonary and Critical Care Medicine, Medical College of Wisconsin, Milwaukee, WI.
Rahul S
RS
Nanchal
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Mayo Clinic, Rochester, MN.
Kianoush B
KB
Kashani
D017677:Age Distribution; D015897:Comorbidity; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D018805:Sepsis / Q000453:epidemiology* / Q000208:ethnology / Q000401:mortality; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology
culture; mortality; sepsis