Ambulance Trial

Point-of-Care Testing
Wednesday, July 31, 9:30 am 5:00 pm
B-47
Evaluation of Point of Care (POC) Prehospital Testing for Troponin
I (cTnI) while in Hospital Transit via the Scottish Ambulance Service
(SAS)- a Preliminary Study using the Samsung LABGEOIB10
Analyzer
S. Scotland1, P. Lunts 2, G. Nicoll2, K. Barclay3, C. Baxter3, I. Archibald3,
G. Miller3, B. I. Bluestein4, E. Brennan4, D. Kim5, J. Grant6, K. Dean6.
1
Scottish Centre for Telehealth and Telecare/NHS24, Edinburgh, United
Kingdom, 2NHS Borders General Hospital, Melrose, United Kingdom,
3
Scottish Ambulance Service, Galashiels, United Kingdom, 4Nexus-DX,
San Diego, CA, 5Samsung Electronics Co.,Ltd., Suwon, Korea, Republic of,
6
Cisco-IBSG, San Jose, CA
Background: The Scottish Borders is a large sparsely populated area with a
population of 108,000. Within its immediate geographic connes, there is no major
medical center with capability of interventional cardiology and its largest town has a
population of 16,000. While patients presenting with chest pain are rapidly conrmed
as having myocardial infarction (MI) if their electrocardiogram (ECG) demonstrates
an ST-segment elevation (STEMI), diagnosis of non-ST segment elevation (NSTEMI)
require more information and time to conrm a positive diagnosis. In addition to
clinical symptoms, NSTEMI diagnoses are dependent on assessment of both clinical
symptoms and biochemical evaluation of cTnI cardiac marker elevations. The purpose
of this pilot study was to demonstrate the feasibility of testing NSTEMI chest pain
patients by measurement of cTnI in the ambulance during transit. Patients excluded
from the study were all STEMI patients who were immediately transferred directly to
the Catheter Lab at Edinburgh Royal Inrmary.
Principle and Methods: All ambulances were equipped with Samsung LABGEOIB10
Analyzers, small portable lightweight (2.4 kg) immunochemistry systems capable of
measuring from 1 to 3 cardiac biomarkers on a single 500 L whole blood aliquot
in approximately 20 minutes. Test devices are similar in conguration to a compact
disc. 57 paramedics were trained to operate the LABGEO Analyzers and perform the
cTnI tests. For this pilot study results were reported in print but the Analyzer may also
be congured to transmit data electronically. The main objective of this rst phase
was to assess the feasibility of performing such testing accurately and precisely in
a moving vehicle. Secondary objectives were to investigate the potential impact of
pre-hospital cTnI testing on subsequent patient pathways based on determinations of
clinical sensitivity and specicity.
Results: For prociency and training, external QC was run daily for this phase of
the study and was within manufacturer speci cation. Initiation of cTnI testing in the
ambulance reduced the average time to rst cTnI result by a mean of 2.5 h compared
to waiting until arrival at Borders General Hospital (BGH). Of 41 measurements taken
in the ambulance, 38 were negative when repeated at the hospital (92.7% specicity).
The other 4 were positive by both the LABGEO cTnI method and the BGH Lab cTnI
method.
Conclusions: While preliminary in nature, these ndings suggest that early
measurement of cTnI in NSTEMI patients, when denitively elevated, can aid in
disposition triage decisions in a fashion similar to STEMI ECG ndings. If negative
on initial measurement, standard of care protocols require serial measurements of
cTnI over 2 to 3 different time intervals. Based on this preliminary study, ambulance
measurement provides a documented Time 0 presentation greater than 2 h earlier than
waiting for hospital testing which leads to a reduction in actual time between a rst
and 2nd serial measurement.
B-48
Evaluation of the Gem Premier 3000 hematocrit and hemoglobin
parameters: a comparison between a POCT device and a CBC
analyzer in critically ill patients
E. Goedert1, T. Souza1, C. Silva1, C. F. A. Pereira2, P. Melo3, L. B. Faro2.
1
DASA, Recife, Brazil, 2DASA, São Paulo, Brazil, 3H. Jayme da Fonte,
Recife, Brazil
Background: Point of care testing (POCT) is dened as medical testing at or near
the site of patient care. This increases the likelihood that the patient, physician,
and care team will receive the results quicker, which allows for immediate clinical
management decisions to be made. The intensive care unit scenario offers one of
the best opportunities for these emergent technologies to ourish. The Diagnostic
companies are developing year over year more integrated, portable and affordable
instruments. Red blood cells (RBC) parameters, as hematocrit and hemoglobin levels,
S206
2013 AACC Annual Meeting Abstracts
provide indirect data about the oxygenation and blood volume in critically ill patients.
In certain emergency circumstances, these results allow a quick decision on clinical
intervention, thereby increasing the chances of survival in these patients. These
parameters are traditionally evaluated by robust, dedicated and specialized analyzers.
We decided to evaluate the performance of one POCT device for the RBC parameters
comparing it with a regular bench top Complete Blood Cells (CBC) Analyzer.
Methods: Laboratory instruments from companies Instrumentation Laboratory®
(Gem Premier 3000) and Sysmex ® (XT 1800i) were used for the measurement of
erythrocyte parameters in 70 adult patients from intensive care unit of Jayme da Fonte
Hospital, Recife, Brazil. The Gem Premier (GP) 3000 uses the direct conductivity
methodology for hematocrit (Ht) and hemoglobin (Hb) determinations. The Sysmex
XT (XT) 1800i uses the spectrophotometry for Hb dosage and electrical impedance
for the Ht determination. The mean values and standard deviation were analyzed for
both parameters and methodologies, as well as the coefcient of determination (R2).
Results: The medium Hb measurement obtained in GP and XT instruments were
respectively 9.3g/dL ± 1.9 and 9,5g/dL ± 1.8. The medium Ht estimate in GP was
30% ± 6.3; in the XT we obtained a score of 29.8% ± 5.1. There was no statistically
signi cant difference when analyzing the variance of the different hemoglobin levels
(p = 0.59) and hematocrit (p = 0.78). The determination coef cient was calculated at
approximately 85% for both parameters.
Conclusion: Physicians in intensive care units need to obtain accurate and reliable
results in a very short period of time to manage appropriately critical care patients.
Therefore, the availability and use of a POCT device that provides trustful results of
hematological parameters can be cost-effective. The Gem 3000 instrument HT and Hb
results were evaluated and considered in agreement with the same tests provided by
XT 1800i, and are now offered regularly in this diagnostic scenario.
B-49
Evaluation of three whole blood point of care lactate methods by
comparison to plasma lactate and a laboratory developed whole blood
ow-injection MS/MS method.
N. V. Tolan1, A. M. Wockenfus1, C. D. Koch1, D. J. Dietzen2, B. S.
Karon1. 1Mayo Clinic, Rochester, MN, 2St. Louis Childrens Hospital and
Washington University School of Medicine, St. Louis, MO
Introduction: Compliance with international sepsis resuscitation guidelines,
including point of care (POC) whole blood lactate testing, contributes to decreased
ICU mortality from sepsis. This study evaluated three whole blood POC lactate
methods against two plasma lactate methods and a  ow-injection MS/MS method
testing ZnSO4 precipitated whole blood.
Methods: The Nova StatStrip (Nova Biomedical), i-STAT CG4+(Abbott Point
of Care) and Radiometer ABL90 (Radiometer Medical ApS) lactate methods were
evaluated. The mean of plasma lactate measured on the Cobas Integra 400 Plus (Roche
Diagnostics) and Vitros 350 (Ortho Clinical Diagnostics) provided a plasma reference.
Additionally, methods were compared to a  ow-injection MS/MS assay measuring
lactate in whole blood extracts. Intra- (n=20) and inter-assay (n=20) coefcients of
variation (CV) were determined for the POC methods using QC material covering
the ranges between 0.3-1.3, 1.5-2.5 (except Nova) and 5.4-9.6 mmol/L lactate.
Method comparison was performed by collecting specimens from normal donors at
rest (n=15), exerted (n=41) and with lactic acid-spiked samples (n=25). Due to rare
outliners observed during Nova precision studies, samples were run in duplicate on
two separate meters, whereas all other methods involved only duplicate testing. For
the MS/MS method, whole blood aliquots were immediately precipitated with 0.1M
ZnSO4. This method incorporated 13C3-lactate IS and lactate measurement by owinjection tandem mass spectrometry (AB Sciex API 3200 QTrap) in negative MRM
mode. POC results were compared to the plasma values and MS/MS concentrations
by mean bias, Bland-Altman plots, and through clinical concordance.
Results: Intra-assay precision was <5% while inter-assay precision was <8% CV
for the Nova, i-STAT, and ABL90 methods. Total imprecision of the MS/MS assay
across the dynamic range was less than 5% CV. For concentrations <10 mmol/L,
the mean (SD) of bias between whole blood and plasma lactate for Nova (n=248),
i-STAT (n=124), ABL90 (n=121) were -0.06±0.95, 0.12±0.61 and 0.18±0.53 mmol/L
respectively. Among plasma values within the normal range (0-2.3 mmol/L), Nova
was found to be clinically discordant in 3/72 (4%) measurements, while all i-STAT
and ABL90 values were concordant (n=36). Of plasma values within the elevated
range (2.4-3.9 mmol/L), 11/60 (18%), 8/30 (27%) and 6/30 (20%) measurements were
discordant for Nova, i-STAT and ABL90 methods, respectively. For samples above
the cut-off for sepsis recognition ( 4.0 mmol/L), 8/192 (4%) measurements were
discordant by Nova, while all i-STAT and ABL90 values were concordant (n=96).
Due to strip errors, 7/324 (2%) of Nova measurements were outliers, as duplicate

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