Electronic supplementary material
Early blood lactate area as a prognostic marker in pediatric septic shock
Young A Kim, Eun-Ju Ha, Won Kyoung Jhang, Seong Jong Park
Division of Pediatric Critical Care Medicine, Department of Pediatrics,
Asan Medical Center Children’s Hospital, University of Ulsan College of Medicine, Seoul,
Republic of Korea
Supplement to methods
The institutional review board of Asan Medical Center approved the study protocol and waived the
requirement for informed consent (20120512).
Supplement to results
Patients
Four patients were excluded according to the exclusion criteria. One patient with primary liver
failure of unknown origin and one patient with MELAS were excluded. Two patients whose hospital
stay was shorter than 24 hours, were also excluded.
Six patients received bone marrow transplantation and two of these patients died. Four patients had
undergone liver transplantation at least one year previously due to Budd-Chiari syndrome (n = 1),
biliary atresia (n = 2) or fulminant hepatitis (n = 1) and they were all on immunosuppressive agents.
Relationship between clinical variables
The relationship of the lactate variables with the PRISM III score, PELOD score and the number of
organ dysfunctions were determined by calculating the Spearman correlation coefficient and the twotailed significance.
There was a significant correlation between the PRISM III score and the lactate variables (vs. initial
lactate: r = 0.521, p < 0.001; vs. lactate clearance: r = -0.582, p < 0.001; vs. lactate area: r = 0.702, p
< 0.001). There was also a significant correlation of the PELOD score, the initial lactate level, and the
lactate area (vs. initial lactate: r = 0.435, p < 0.001; vs. lactate clearance: r = -0.141, p = 0.270; vs.
lactate area: r = 0.503, p < 0.001). The number of organ dysfunctions and lactate variables also
showed a significant correlation (vs. initial lactate: r = 0.261, p = 0.036; vs. lactate clearance: r = 0.394, p = 0.01; vs. lactate area: r = 0.472, p < 0.001).
Supplement to discussion
The overall mortality rate of our study patients was higher than that seen in previous studies of
pediatric severe sepsis [1, 2]. As our medical center is a tertiary referral center, most of our patients
have underlying co-morbidities with a high proportion of hemato-oncologic disease and a high
severity of illness. In this study, most of the patients were admitted to the PICU in an advanced state
of disease and with multiple organ dysfunction with a higher mean PRISM III score, and thus
requiring more ventilatory support and inotropic/vasoactive agents, compared with the patients seen in
a previous study [2].
Referances
1.
Watson RS, Carcillo JA, Linde-Zwirble WT, Clermont G, Lidicker J, Angus DC
(2003) The epidemiology of severe sepsis in children in the United States. Am J
Respir Crit Care Med 167:695-701
2.
Kutko MC, Calarco MP, Flaherty MB, Helmrich RF, Ushay HM, Pon S, Greenwald
BM (2003) Mortality rates in pediatric septic shock with and without multiple organ
system failure. Pediatr Crit Care Med 4:333-337
Table E1. The area under the curve of the lactate levels at each time point as a predictor of
mortality.
Variables
AUC
P value
95% CI
6-hr lactate
0.790
< 0.001
0.659 – 0.921
12-hr lactate
0.852
< 0.001
0.743 – 0.960
18-hr lactate
0.866
< 0.001
0.760 – 0.973
24-hr lactate
0.831
< 0.001
0.719 – 0.942
Figure E1. The KaplanMeier survival curves for the lactate area of the patient groups as
measured above and below 96 mmol/lh. Their survival was followed for 28 days. The log
rank test was performed (p = 0.004).