Competing interestsThe authors declare that they have no competing interests.Authors’ contributionsCFL conceived the study, participated in data collection, performed statistical analysis, interpreted results, and wrote the manuscript. VCW, TMH, YFL, YJJ, CTC, and CCS participated in data collection and manuscript revision. YCY, KCW, YYH, PRT, and NKC participated in data collection. FCH performed statistical analysis, participated in data interpretation and manuscript writing. WJK and KDW conceived the study and participated in manuscript revision. All authors read and approved the final manuscript.Supplementary MaterialAdditional file 1:A table showing the demographic and clinical characteristics of survivors stratified by follow-up duration.Click here for file(80K, DOC)NotesPlease see related letter by Lopes and Jorge, http://ccforum.com/content/16/6/467AcknowledgementsThis study was supported by the Ta-Tung Kidney Foundation, Mrs Hsiu-Chin Lee Kidney Research Fund, Taiwan National Science Council (grant NSC 96-2314-B-002-033-MY2, NSC 97-2314-B-002-155-MY2), and National Taiwan University Hospital (NTUH 098-001177, NTUH 100-001667). The authors would like to thank the all participants of the NSARF.
Shock states are defined by an acute circulatory failure leading to prolonged and intense tissue hypoxia that may lead to death. Tissue hypoxia is accompanied by a decreased production of ATP in the mitochondria. Hypoxia-inducible factor-1 (HIF1) is a heterodimer made of two sub-units (�� and ��) [1,2]. The gene coding for HIF1�� is on chromosome 14 (14q21-q24) [3]. HIF1�� protein concentration is correlated to cellular oxygen concentration [4]. In hypoxemic conditions, HIF1�� is not degraded and accumulates in the cellular nucleus [5]. The effects of HIF1�� are stimulation of erythropoiesis, glycolysis, angiogenesis, and vasodilation [1]. In normoxic conditions, HIF1�� and its messenger RNA (mRNA) have a very short half-life of five minutes [6,7]. This suggests that HIF1�� is an immediate surrogate marker of cellular oxygenation.In human shock states, plasma lactate is routinely used as a marker of tissue hypoxia. This marker has been validated for the detection of shock states as well as the prediction of patient outcomes [8,9]. However, plasma lactate concentrations are influenced by both the production and clearance of lactate.