Effect of different pre-analytical conditions on plasma lactate concentration.
Author(s): Rako I, Mlinaric A, Dozelencic M, Juros GF, Rogic D
Publication: Biochem Med (Zagreb), 2018, Vol. 28, Page 020701
PubMed ID: 29666554 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of tube type, pre-centrifugation storage temperature, and post-centrifugation storage tube on lactate levels and hemolysis index in plasma.
Conclusion of Paper
Lactate levels were comparable between NaF/K3EDTA and NaF/KOX tubes but increased in both tube types when analysis was delayed by 24 h. Heparin plasma had significantly higher lactate levels than NaFK3EDTA plasma. When not aliquoted before storage, lactate levels were considered clinically inaccurate in 14% of lithium heparin specimens, but were considered clinically accurate in all specimens when plasma was aliquoted before storage. Lactate levels were significantly lower and hemolysis index higher when blood specimens in NaF/K3EDTA tubes were transported on ice rather than at room temperature.
Studies
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Study Purpose
This study investigated the effects of tube type, pre-centrifugation storage temperature, and post-centrifugation storage on lactate levels and hemolysis index in plasma. Comparisons of NaF/K3EDTA and NaF/KOX tubes was performed using the blood from seven patients in the department of thoracic surgery and 13 volunteers. The effect of pre-centrifugation storage temperature was investigated by storing blood from 50 patients in NaF/K3EDTA at room temperature and in an ice bath until centrifugation (15 min after collection). Blood specimens were collected after an overnight fast with minimal stasis and, 15 min after collection, were centrifuged at 2000 x g for 10 min. Blood specimens were stored at room temperature until centrifugation unless otherwise specified. After centrifugation, lactate and the hemolysis index were measured within 1 h using a Cobas c501 analyzer. Specimens in NaF/K3EDTA and NaF/KOX were then refrigerated and analyzed again after 24 h.
Summary of Findings:
While lactate levels were on average 0.25 mmol higher when analysis was delayed by 24 h (statistics not presented), lactate levels were not significantly different between NaF/K3EDTA and NaF/KOX tubes when analyzed immediately or after 24 h. Lactate levels were significantly lower (P<0.001) and hemolysis index higher (P<0.001) when blood specimens in NaF/K3EDTA tubes were transported on ice rather than at room temperature. However, transport on ice did not cause a proportional or constant error and there was no correlation between lactate levels and hemolysis index.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Protein Clinical chemistry/auto analyzer Small molecule Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Anticoagulant Sodium fluoride/EDTA
Sodium fluoride/potassium oxalate
Storage Specimen transport duration/condition On ice
Room temperature
Storage Storage duration 0 h
24 h
Biospecimen Acquisition Type of collection container/solution NaF/K3EDTA
NaF/KOX
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Study Purpose
This study compared lactate levels in plasma from blood collected in lithium heparin tubes with specimens collected in NaF/K3EDTA tubes and also investigated the effect of aliquoting plasma from heparin tubes into new tubes on lactate levels. Blood was obtained in NaF/K3EDTA and lithium heparin tubes from 107 patients in the department of thoracic surgery who had suspected hypo perfusion or hypoxia. Blood was stored at room temperature for 15 min before centrifugation at 2000 x g for 10 min. After centrifugation, heparin plasma was transferred to a new tube (aliquoted) or stored in the original tube. Lactate and hemolysis index were determined within 1 h of blood collection using a Cobas c501 analyzer.
Summary of Findings:
Heparin plasma had significantly higher lactate levels than NaFK3EDTA plasma (P<0.001). The constant error relative to NaF/K3EDTA plasma was higher for aliquoted than unaliquoted heparin plasma (0.13 mmol/L and 0.07 mmol/L); however, the proportional error was higher for unaliquoted heparin plasma than aliquoted heparin plasma (1.37 mmol/L versus 1.0 mmol/L). Importantly, lactate levels were considered clinically inaccurate in 14% of heparin specimens when not aliquoted before storage, but were considered clinically accurate in all specimens when heparin plasma was aliquoted before storage.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Other diagnoses
Platform:
Analyte Technology Platform Small molecule Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Type of collection container/solution NaF/K3EDTA tube
Lithium heparin tube
Storage Storage conditions In original tube
In new tube
Biospecimen Acquisition Anticoagulant Sodium fluoride/EDTA
Lithium heparin