Occult hypoperfusion and mortality in patients with suspected infection.
OBJECTIVE
To determine, in the early stages of suspected clinically significant infection, the independent relationship of the presenting venous lactate level to 28-day in-hospital mortality.


METHODS
Prospective, observational cohort study.


METHODS
Urban, university tertiary-care hospital.


METHODS
One thousand two hundred and eighty seven adults admitted through the emergency department who had clinically suspected infection and a lactate measurement.


RESULTS
Seventy-three [5.7% (95% CI 4.4-6.9%)] patients died in the hospital within 28 days. Lactate level was strongly associated with 28-day in-hospital mortality in univariate analysis (p<0.0001). When stratified by blood pressure, lactate remained associated with mortality (p<0.0001). Normotensive patients with a lactate level >or=4.0 mmol/l had a mortality rate of 15.0% (6.0-24%). Patients with either septic shock or lactate >or=4.0 mmol/l had a mortality rate of 28.3% (21.3-35.3%), which was significantly higher than those who had neither [mortality of 2.5% (1.6-3.4%), p<0.0001. In a model controlling for age, blood pressure, malignancy, platelet count, and blood urea nitrogen level, lactate remained strongly associated with mortality. Patients with a lactate level of 2.5-4.0 mmol/l had adjusted odds of death of 2.2 (1.1-4.2); those with lactate >or=4.0 mmol/l had 7.1 (3.6-13.9) times the odds of death. The model had good discrimination (AUC=0.87) and was well calibrated.


CONCLUSIONS
In patients admitted with clinically suspected infection, the venous lactate level predicts 28-day in-hospital mortality independent of blood pressure and adds significant prognostic information to that provided by other clinical predictors.
Howell
Michael D
MD
Beth Israel Deaconess Medical Center and Harvard Medical School, Department of Medicine, KB-23, 330 Brookline Avenue, Boston, MA 02215, USA. mhowell@bidmc.harvard.edu
Donnino
Michael
M
Clardy
Peter
P
Talmor
Daniel
D
Shapiro
Nathan I
NI
D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D042241:Early Diagnosis; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D020896:Hypovolemia; D019344:Lactic Acid / Q000032:analysis / Q000097:blood; D008297:Male; D008875:Middle Aged; D010477:Perfusion; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012772:Shock, Septic / Q000175:diagnosis*; D014218:Triage; D014481:United States / Q000453:epidemiology
D019344:Lactic Acid