Transcript Evaluation of Beckton-Dickinson PST 2 and SST 2 blood

Evaluation of Beckton-Dickinson
PST II and SST II Blood
Collection Tubes
P Graham, B Martin, M Roser, G Jones
Department of Chemical Pathology,
St Vincent’s Hospital, Sydney
Background
• Becton-Dickinson have introduced new tubes for
plasma and serum.
• Acrylic gel separator.
• Terminology
– PST II - Plasma separator
– SST II - Serum separator
• No independent studies identified.
• Limited BD data available.
Our Questions?
1) Are the new BD gel tubes OK for routine use?
2) How long are samples stable when stored on
the gel?
3) Is it OK to re-centrifuge samples stored on the
gel?
3 Experiments
1) Tube comparison - to “gold standard”
2) Stability Study
- Healthy volunteers (all analytes)
- Patient samples (unstable analytes)
3) Re-Centrifugation study
- Patient samples +/- re-spin
Methods - Tube Comparison
•
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Blood collected from 5 volunteers
Non-gel clot activator, PST, PST II, SST, SST II
Centrifuged within 1 hour of collection
Analysed within 2-3 hours.
Results compared to the non-gel tube.
Differences evaluated using Student’s T test for
statistical significance
• Comparison to the RCPA AACB Allowable Limits of
Performance (ALP) for clinical significance.
– >0.25 x ALP used as screen for significance
Methods - Analysis
In str u m e n t
R o c h e H ita c h i
917
T e sts
U E C , L F T , C M P , L ip id s,
H D L A m y la se, L ip a se , C K ,
F e r r itin , F e , T r a n sfe r r in
B e c k m a n -C o u lte r B 1 2 , F o la te , In su lin
A c c e ss
A b b o tt A x S y m
L H , FSH , TSH , FT4, FT 3,
P r o la ctin
R a d io m ete r A B L
725
Io n ised C a , p H
A d v a n c ed
O sm o m e te r
O sm o la lity
Results - Tube Comparison
Relative differences compared to plain serum tube:
E x p ected
K
U n ex p ected
+
(in p lasm a)
(0 .3 m m o l/L )
TP
(in p lasm a)
(3 g /L )
ALT
(3 U /L )
TP
(in S S T II)
(2 .8 g /L )
P O 4 (in p lasm a)
(0 .0 8 m m o l/L )
F o late (in p lasm a)
(4 .0 n m o l/L )
LD
P ro lactin (in p lasm a)
(3 3 U /L )
(in p lasm a)
3 0 U /L
Tube Comparison Conclusion
• PST II and SST II tubes acceptable for all analytes
tested.
• Further testing showed folate acceptable for serum
and plasma on Access (Not on Centaur).
Methods - Storage Stability
• Tubes from comparison study
• PST II and SST II Gel tubes stored at (2-6 °C).
• Re-centrifuged and re-analysed at 1,3 and 7 days.
Stability Study - Raw data
Changes as multiples of ALP
2
1.5
1
0.5
0
-0.5
-1
-1.5
-2
Day 0
Day 1
PST II
Day 3
Day 7
Gluc
Bicarb
ALP
GGT
Alb
Chol
mg
Amyl
HDL
AST
Fruc
Trans
CK
K
Ferr
Folate
LH
PRL
FT4
CK-MB
Creat
2
Bili
ALT
1.5
Prot
Phos
Trig
1
LDH
UA
0.5
Urea
Ca
0
Fe
Lase
-0.5
Na
Cl
B12
-1
Insulin
FSH
-1.5
TSH
FT3
-2
Day 0
Day 1
Day 3
SST II
Day 7
Category 1 - Stable Analytes
2
PST II
1.5
1
0.5
0
-0.5
-1
-1.5
Test
B12
HDL
ALP
Lase
Bili
TSH
FT3
Folate
FT4
Amyl
Creat
Urea
CK-MB
Prot
Trans
GGT
Alb
Fe
CK
UA
Mg
Insulin
Chol
Fruc
AST
LH
FSH
Trig
PRL
ALT
-2
Day 0
Day 1
Day 3
Day 7
2
SST II
1.5
1
0.5
0
-0.5
-1
-1.5
-2
Day 0
Day 1
All Averages (nearly) within +/- 0.5 ALP
Day 3
Day 7
Category 1 - Stable Analytes
• Roche Hitachi 917
– Albumin, ALT, ALP, amylase, AST, cholesterol,
CK, creatinine, GGT, HDL cholesterol, iron,
magnesium, total protein, transferrin, triglycerides,
uric acid, urea
• Beckman Coulter Access
– Vitamin B12, folate, insulin
• Abbott AxSYM
– LH, FSH, TSH, FT4, FT3, CK-MB, PRL
Category 2: Analytes with poor
precision
2
1.5
HCO3 in PSTII
1
Ptn A
0.5
Ptn B
Ptn C
0
Ptn D
-0.5
Ptn E
Average
-1
-1.5
-2
2
1.5
D0
D1
D3
D7
Sodium in PSTII
1
Ptn A
0.5
Ptn B
Ptn C
0
Ptn D
Ptn E
Average
-0.5
-1
-1.5
-2
D0
D1
D3
D7
•Sodium, Chloride,
Bicarbonate, Calcium
•No obvious pattern
Category 2: Analytes with poor
Category
precision2
Analyte
Betw ee n D ay C V %
H917
P S T II
S S T II
Na
1.0
0.8
1.0
Ca
1.2
1.6
1.0
CO2
3.7
1.3
3.9
Cl
1.0
1.4
0.9
• Variation in results was similar to between-day
precision.
• Accepted as stable to 7 days.
Category 3 - Clearly unstable
For Further Analysis
2
2
Ferritin
1.5
1
Phosphate
0.5
1.5
1
0.5
LDH
0
-0.5
0
-0.5
Potassium
-1
-1.5
Glucose
-2
-1
-1.5
-2
Day 0
Day 1
Day 3
PST II
Day 7
Day 0
Day 1
Day 3
SST II
Day 7
Methods Re-Spin Study
20 SST II
20 PST II
Baseline
5 SST II
5 PST II
8 hrs Room Tem p
5 SST II
5 PST II
1 day 4 deg C
5 SST II
5 PST II
2 days 4 deg C
5 SST II
5 PST II
3 days 4 deg C
Change in Potassium
(mmol/L)
Effect of Re-Centrifugation
3
2.5
2
P: Unspun
1.5
P: Re-spun
S: Unspun
1
S: Re-spun
0.5
0
-0.5
Initial
Day 1
Day 2
Day 3
Analytes limited to <7 days
Analyte
Glucose
Phosphate
LD
Potassium
Ferritin
Tubes
PST II
SST II
Both
Both
Both
Both
Stability
1 Day
3 days
3 days
3 days
3 days
2 days
Instructions
Do not re-spin
Do not re-spin
Do not re-spin
Do not re-spin
Conclusion
• The PST II and SST II gel tubes from BD are
suitable for routine use.
• Most analytes are suitable for analysis up to 7
days storage at 2-8°C. Limits have been placed
on analysis of stored samples for some analytes.
• Samples for Glucose, LD and K+ should not be
re-spun in primary tube.
We acknowledge the support of Becton Dickinson for supply
of tubes for testing.
These powerpoint slides will be available at
www.sydpath.stvincents.com.au after the conference.