Use of admission serum lactate and sodium levels to predict mortality in necrotizing soft-tissue infections.
OBJECTIVE
Simple admission laboratory values can be used to classify patients with necrotizing soft-tissue infection (NSTI) into high and low mortality risk groups.


METHODS
Chart review.


METHODS
Public teaching hospital.


METHODS
All patients with NSTI from 1997 through 2006.


METHODS
Variables analyzed included medical history, admission vital signs, laboratory values, and microbiologic findings. Data analyses included univariate and classification and regression tree analyses.


METHODS
Mortality.


RESULTS
One hundred twenty-four patients were identified with NSTI. The overall mortality rate was 21 of 124 (17%). On univariate analysis, factors associated with mortality included a history of cancer (P = .03), intravenous drug abuse (P < .001), low systolic blood pressure on admission (P = .03), base deficit (P = .009), and elevated white blood cell count (P = .06). On exploratory classification and regression tree analysis, admission serum lactate and sodium levels were predictors of mortality, with a sensitivity of 100%, specificity of 28%, positive predictive value of 23%, and negative predictive value of 100%. A serum lactate level greater than or equal to 54.1 mg/dL (6 mmol/L) alone was associated with a 32% mortality, whereas a serum sodium level greater than or equal to 135 mEq/L combined with a lactate level less than 54.1 mg/dL was associated with a mortality of 0%.


CONCLUSIONS
Mortality for NSTIs remains high. A simple model, using admission serum lactate and serum sodium levels, may help identify patients at greatest risk for death.
Yaghoubian
Arezou
A
Department of Surgery, Los Angeles Biomedical Research Institute, CA, USA.
de Virgilio
Christian
C
Dauphine
Christine
C
Lewis
Roger J
RJ
Lin
Matthew
M
D000328:Adult; D005260:Female; D006801:Humans; D007773:Lactates / Q000097:blood*; D008297:Male; D009336:Necrosis; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012307:Risk Factors; D012964:Sodium / Q000097:blood*; D018461:Soft Tissue Infections / Q000097:blood* / Q000382:microbiology / Q000401:mortality*
D007773:Lactates; D012964:Sodium