Monitoring heparin therapy by the activated partial thromboplastin time--the effect of pre-analytical conditions.
Author(s): van den Besselaar AM, Meeuwisse-Braun J, Jansen-Grüter R, Bertina RM
Publication: Thromb Haemost, 1987, Vol. 57, Page 226-31
PubMed ID: 3603414 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of different reaction solutions used when measuring APTT as well as the effects of anticoagulant on blood specimens from normal donors. Specimens were stored at room temperature and centrifuged at 940 x g for 30 minutes. APTT was determined no longer than 4 hours after venepuncture.
Summary of Findings:
HEPES-buffered citrate plasma had a slightly higher APTT with Manchester reagent than citrate plasma did (p<0.05), but no other significant differences were found between anticoagulants. The choice of reaction solution significantly altered APTT with specimens measured using the Manchester reagent having the longest average APTTs and the widest spread while those measured with Cephotest had the shortest APTTs and the smallest spread (p<0.05).
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Morphology Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Anticoagulant HEPES-buffered citrate
Sodium citrate
Citrate-theophylline-adenosine-dipyridamole
Hematology/ auto analyzer Specific Reaction solution Actin-FS
Automated APTT
Cephotest
Manchester reagent
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Study Purpose
The purpose of this study was to determine the effects of centrifugation speed (600 x g, 940 x g, or 2200 x g), and duration (10 min instead of 30 min) on APTTs in specimens from patients receiving heparin. Measurement of APTTs took place 85, 200, or 315 minutes after venepuncture. Centrifugation and storage were at 4 degrees C.
Summary of Findings:
Low speed centrifugation (600 x g) and reduction of centrifugation time from 30 to 10 minutes each resulted in shorter APTTs (not always significantly) when compared to centrifugation at 940 x g for 30 minutes. Faster centrifugation then 940 x g did not significantly alter APTT.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Other diagnoses
Platform:
Analyte Technology Platform Morphology Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage duration 85 min
200 min
315 min
Storage Storage temperature 4 degrees C
Biospecimen Aliquots and Components Centrifugation Multiple durations compared
Multiple speeds compared
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Study Purpose
The purpose of this study was to determine the effects of anticoagulant, collection tube type, and storage prior to or after centrifugation on APTT of specimens from patients receiving heparin. Centrifugation and storage took place at room temperature.
Summary of Findings:
APTT decreased steadily when centrifuged or uncentrifuged blood was stored at room temperature and sodium citrate was used as the anticoagulant. However, the decrease in APTT was smaller when storage occurred after centrifugation. HEPES-buffered citrate specimens showed decreases in APTT with storage that were comparable to sodium citrate, however, starting APTTs were about 10% shorter. Blood collected in CTAD and stored prior to centrifugation showed less shortening of APTT than when collected in sodium citrate and APTT stayed relatively unchanged when storage occurred after centrifugation in these tubes. APTT increased over time when plasma was stored in polystyrene tubes at room temperature. In contrast, APTT decreased with storage when plasma was stored in siliconized vacutainer tubes.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Other diagnoses
Platform:
Analyte Technology Platform Morphology Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage conditions Plasma
Uncentrifuged blood
Centrifuged blood
Storage Time at room temperature 30 min
1 h
3 h
5 h
Biospecimen Acquisition Anticoagulant Citrate-theophylline-adenosine-dipyridamole
HEPES-buffered citrate
Sodium citrate
Biospecimen Acquisition Type of collection container/solution Polystyrene
Vacutainer
Biospecimen Aliquots and Components Centrifugation Centrifugation delays investigated
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Study Purpose
The purpose of this study was to determine the effects of storage temperature and duration on APTT of specimens from patients receiving heparin.
Summary of Findings:
Storage of blood specimens at 4 degrees C with either sodium citrate or CTAD increased APTT (p<0.05). At room temperature, sodium citrate specimens showed a significant decrease in APTT (p<0.05) with a decline in APTT apparent by 3 h. In contrast, APTT remained relatively constant for CTAD specimens over the storage period.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Other diagnoses
Platform:
Analyte Technology Platform Morphology Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage temperature 22 degrees C
4 degrees C
Storage Storage duration 1-1.5 h
3-3.5 h
5-5.5 h
Biospecimen Acquisition Anticoagulant Citrate-theophylline-adenosine-dipyridamole
Sodium citrate
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Study Purpose
The purpose of this study was to determine the effects of storage and anticoagulant on plasma platelet factor 4 (PF4) concentrations in two normal blood specimens.
Summary of Findings:
PF4 concentrations increased with storage and were higher with storage at room temperature compared to 4 degrees C. PF4 concentrations were significantly higher in sodium citrate specimens than in either CTAD or Thrombotect specimens.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Protein Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage temperature Room temperature
4 degrees C
Storage Storage duration 1 h
5 h
Biospecimen Acquisition Anticoagulant Citrate-theophylline-adenosine-dipyridamole
Sodium citrate
Thrombotect