Application of POCT in Hospital Setting : hospital
experience Irwan Idris
Outline of Presentation
n POCT in General n POCT in Glucose measurement n POCT in Blood Gas Analysis n POCT in Troponin I measurement n Summary
Role of Lab. Manager
n Need a POCT ? n Cost ? n Central / Satellite / Stat Lab n How to choose POCT n Who should perform (trained) n Accurate & Precision n Results LIS / HIS
Choose POCT
n Manual / MSDS n Accuracy & Precision n Evidence based (Clinical study) n FDA approved n QA n Functional sensitivity (Immunology) n Each cartridge packed n Cost
Quality Assurance
n System QC n Test Cartridge QC n External QC
System QC
n The Reader has error checking and self diagnostic function (to confirm acceptable operator technique, sample handling and assay performance)
n If a problem is detected, a message is displayed
n Sample results are displayed only after all QC performance requirements have been met
Test Cartridge QC
n Every Test cartridge has an internal standard zone (QC)
n If the internal QC control does not met specifications no results
POCT : BG Meter
n Accurate – especially at low glucose concentration
n Reliable – good precision, CV <5% n Test method (Specific) – no interferences n Easy to use – simple, quick, low blood
volume
POCT : BG Meter n Nursery : high Hematocrit, low level of
Glucose (precision) n TAT < 20” n Each test packed
n Do we need Keton level n ISO 15197 compliant n Easy to interface
ISO 15197 criteria (BG Meter) 95 % of glucose values should fall within 15 mg/dL of the target value at a glucose concentration < 76 mg/dL (<4.2 mmol/L) and within 20% of the target value at a glucose concentration ≥ 76 mg/dL (> 4.2 mmol/L) CVw Glucose 5.7 % (Cited from Scand J Clin Lab Invest 1999;59:491-500. Updated on 2010)
Analyte Serum
Bias % Imprecision %
TEa (%) p<0.05
Method CV (%)
SGPT 12 12.2 15.2 3.2 Albumin 1.3 1.6 3.9 3.4
Bil-total 11.4 11.9 31.1 3 Ca total 0.8 1 2.4 2.2 Cholesterol 4 2.7 8.5 2.3 Creatinine 3.8 2.7 8.2 1 Glucose 2.2 2.9 6.9 1.7 Sodium 0.3 0.4 0.9 0.7 Uric acid 4.6 4.5 12.4 0.7 HB 1.8 1.4 4.1 1
Cited from Scand J Clin Lab Invest 1999;59:491-500. Updated on 2010
POCT : Blood Gas Analyzer
n Each Test cartridge has an Internal QC n If Internal QC fail No results n Reagent and Electrode single use Stable Good Accuracy & Precision
n Bedside TAT <<
n Costly
Test Range N = 50
POCT
Deming Regression
pH 7.014-7.531
AE B6
Y=1.23X-31.8 Y=1.05X-7.2
pO2 24.7-185.5 mmHg
AE B6
Y=0.45X+21 Y=0.99X+0.89
pCO2 5.5-56.7 mmHg
AE B6
Y=0.94X+0.67 Y=0.99X+0.89
Correlation of POCT results with Central Lab
Preceeding of Singapore Healthcare.Vol. 20. Number 3. 2011
POCT : Troponin I
n The lower limit of detection (LLD) TnI is the lowest TnI level that can be distinguished from 0.
n Functional sensitivity and CV ?
POCT : Troponin I
n Method n Flow Through EIA n Flow Through Chemiluminescence
IA
n Chemiluminescence IA (Magnetic separation)
Functional Sensitivity
n 0.1 ng/mL : CV 20% n 0.2 ng/mL : CV 10 %
BG Meter Blood Gas A. Troponin I
Pre- Analytic
Capillary Volume ?
Bubble ? Immediate Anticoagulant ? Ca++ : (lyophilized L. Heparin /Ca balance L. Heparin
W. blood : EDTA/ Heparin
Analytic Hypotension/ Shock, Ht Uric Acid Ascorbic acid Drugs
RF/ Heterophyl Antibody Anti Mouse Ig G
Summary
n Glucose : Clinical Analyzer more Accurate & Precise than POCT
n BGA : POCT more Accurate & Precise than BG Analyzer
n Troponin I : Method, Functional sensitivity and CV
Thank you For your Attention