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Park, Ko, Kim, and Song: Performance Evaluation of the Piccolo xpress Point-of-care Chemistry Analyzer
Original Article

Korean J Leg Med 2009;29(5):430-438.

Published online: 14 January 2009

DOI: https://doi.org/10.3343/kjlm.2009.29.5.430

Performance Evaluation of the Piccolo xpress Point-of-care Chemistry Analyzer

Hyunwoong Park, M.D.1, 2, Dae-Hyun Ko, M.D.1, 2, Jin Q Kim, M.D.1, 3, Sang Hoon Song, M.D.1, 2

1Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea

2Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea

3Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Korea

Corresponding author: Sang Hoon Song, M.D. Department of Laboratory Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam 463-707, Korea Tel: +82-31-787-7693, Fax: +82-31-787-4015 E-mail: cloak21@snu.ac.kr

      Revised 29 July 200910 August 2009       Accepted 8 September 2009

Copyright © 2009 Korean Society for Legal Medicine

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background:

Point-of-care (POC) tests are used increasingly due to fast results and simple test procedures, which enables rapid diagnosis and therapeutic monitoring. We evaluated the performance of the Piccolo xpress Chemistry Analyzer (Abaxis, USA) a POC chemistry analyzer.

Methods:

Fourteen analytes, Na+, K+, Cl-, Ca2+, total carbon dioxide, AST, ALT, total bilirubin, alkaline phosphatase, blood urea nitrogen, creatinine, albumin, total protein, and glucose; were measured simultaneously with a 100 μL of whole blood sample using a Comprehensive Metabolic Reagent disk. Within-run and total precision and linearity were evaluated according to CLSI EP15-A and EP6-A guidelines, respectively. Comparison with a central laboratory chemistry analyzer was performed using 144 patient samples.

Results:

The coefficients of variations of within-run and total precision were all within 5% for three levels except for total carbon dioxide, ALT, alkaline phosphatase, total bilirubin, and creatinine in low level, and creatinine in middle level. The results of 14 analytes were linear within a commonly encountered range in clinical samples (r2≥0.98). More than 10% of samples in Na+, AST, ALT, glucose, BUN did not satisfy CLIA analytical quality requirement.

Conclusions:

The Piccolo xpress Chemistry Analyzer can analyze multiple analytes with a minimal amount of whole blood in a short time. It showed an acceptable performance for precision, linearity and comparison with central laboratory analyzer. It can be useful as a screening tests modality in mobile clinics, ambulances, and field clinics for military use, and for pediatric patients from whom enough sample volume is difficult to obtain.

Keywords: Point-of-care systems, Analytical chemistry, Evaluation studies

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Fig. 1.
Measuring sequence of Piccolo xpress Chemistry Analyzer. (A) Blood sample is applied and diluent container is opened. (B) Diluent and blood sample enter the quality control cuvettes and blood sample enters the centrifugal chamber. (C) Centrifuge is performed. (D) Centrifuged sample and diluent are mixed. (E) The assay cuvettes are filled and analysis is performed (This schematic diagram was permitted from Abaxis system).
kjlm-29-430f1.tif
Fig. 2.
Correlations of 14 analytes of Comprehensive Metabolic Reagent disk between Piccolo xpress Chemistry Analyzer and TBA 200-FR. Dashed line indicates mean bias.
Abbreviations: tCO2, total carbon dioxide; ALP, alkaline phosphatase; BUN, blood urea nitrogen.
kjlm-29-430f2.tif
Table 1.
Principles of procedures of Piccolo xpress Chemistry Analyzer
Analyte Principle
Albumin Dye-Binding BCP
ALP PNPP, AMP buffer
ALT UV without P5P
AST UV without P5P
BUN Urease with GLDH (coupled enzyme)
Ca2+ Arsenazo III Dye
Cl- Enzymatic Reaction (activation of α-amylase)
Creatinine Enzymatic Reaction (creatinine amidohydrolase/Sarcosine oxidase)
Glucose Hexokinase, Colorimetry
K+ Enzymatic Reaction (activation of pyruvate kinase)
Na+ Enzymatic Reaction (activation of β-galactosidase)
tCO2 Enzymatic Reaction (PEPC)
Total bilirubin Enzymatic bilirubin oxidase
Total Protein Biuret

Abbreviations: ALP, alkaline phosphatase; BUN, blood urea nitrogen; tCO2, total carbon dioxide.

Table 2.
Precision of the Piccolo xpress Chemistry Analyzer by Liquid Unassayed Multiqual®
Analytes (unit) Cases N Mean Within-run Total
SD CV (%) SD CV (%)
Na+ (mmol/L) Low 20 110.6 1.44 1.3 1.33 1.2
  Middle 20 138.7 1.53 1.1 2.22 1.6
  High 20 157.9 1.74 1.1 2.05 1.3
K+ (mmol/L) Low 20 2.1 0.08 3.9 0.07 3.5
  Middle 20 3.8 0.09 2.4 0.10 2.5
  High 20 7.1 0.16 2.3 0.16 2.2
Cl- (mmol/L) Low 20 85.5 0.95 1.11 1.07 1.25
  Middle 20 98 1.27 1.3 1.76 1.8
  High 20 114.3 1.71 1.5 1.71 1.5
Ca2+ (mg/dL) Low 20 5.8 0.27 4.6 0.26 4.5
  Middle 20 9.4 0.25 2.7 0.23 2.4
  High 20 11.7 0.46 3.9 0.43 3.7
tCO2 (mmol/L) Low 20 17.5 1.00 5.7 0.98 5.6
  Middle 20 23.8 0.98 4.1 1.09 4.6
  High 20 29.2 1.34 4.6 1.31 4.5
AST (U/L) Low 20 41 0.94 2.3 1.15 2.8
  Middle 20 100.4 1.31 1.3 1.20 1.2
  High 20 218.9 1.75 0.8 2.63 1.2
ALT (U/L) Low 20 28.9 3.09 10.7 3.50 12.1
  Middle 20 77.9 2.10 2.7 2.65 3.4
  High 20 163.4 3.27 2 3.43 2.1
ALP (U/L) Low 20 34 3.47 10.2 3.09 9.1
  Middle 20 181.7 4.36 2.4 4.18 2.3
  High 20 390.7 5.86 1.5 5.08 1.3
Total bilirubin (mg/dL) Low 20 0.6 0.05 7.8 0.05 8
  Middle 20 2.8 0.04 1.3 0.07 2.5
  High 20 6.3 0.08 1.2 0.11 1.7
Albumin (g/dL) Low 20 2.8 0.09 3.2 0.10 3.5
  Middle 20 3.7 0.11 2.9 0.11 2.9
  High 20 4.5 0.07 1.5 0.10 2.2
Total protein (g/dL) Low 20 4.2 0.09 2.1 0.08 2
  Middle 20 5.6 0.05 0.9 0.05 0.9
  High 20 7.1 0.09 1.2 0.09 1.3
BUN (mg/dL) Low 20 14.5 0.52 3.6 0.52 3.6
  Middle 20 35.9 0.93 2.6 0.90 2.5
  High 20 66.5 0.67 1 1.06 1.6
Creatinine (mg/dL) Low 20 0.7 0.11 15.1 0.09 13.3
  Middle 20 1.9 0.11 5.9 0.11 5.6
  High 20 6.4 0.12 1.8 0.10 1.6
Glucose (mg/dL) Low 20 66.7 1.53 2.3 1.87 2.8
  Middle 20 126.1 0.88 0.7 1.13 0.9
  High 20 359.2 2.51 0.7 2.87 0.8

Abbreviations: tCO2, total carbon dioxide; ALP, alkaline phosphatase; BUN, blood urea nitrogen.

Table 3.
Linearity of the Piccolo xpress Chemistry Analyzer
Analytes Unit Range Slope Intercept R2 Analytes Unit Range Slope Intercept R2
Na+ mmol/L 132.2-162.3 1.000 <0.001 0.9900 ALP U/L 29.5-827.5 1.000 <0.001 0.9997
K+ mmol/L 4.3-8.3 1.000 <0.001 0.9821 Total bilirubin mg/dL 0.6-5.1 1.000 <0.001 0.9995
Cl- mmol/L 101.3-123.0 1.000 <0.001 0.9759 Glucose g/dL 74.0-495.8 1.000 <0.001 0.9999
Ca2+ mg/dL 9.3-14.8 1.000 <0.001 0.9955 BUN g/dL 8.3-51.5 1.000 <0.001 0.9987
tCO2 mmol/L 19.3-30.5 1.000 <0.001 0.9829 Creatinine mg/dL 0.6-8.9 1.000 <0.001 0.9988
AST U/L 25.8-1,093.3 1.000 <0.001 0.9998 Albumin mg/dL 3.7-5.7 1.000 <0.001 0.9933
ALT U/L 21.0-1,931.8 1.000 <0.001 0.9999 Total protein mg/dL 7.1-9.0 1.000 <0.001 0.9905

Abbreviations: tCO2, total carbon dioxide; ALP, alkaline phosphatase; BUN, blood urea nitrogen.

Table 4.
Correlations between Piccolo xpress Chemistry Analyzer and TBA 200-FR
Analytes Unit Range Slope (95% CI) Intercept (95% CI) Bias (Mean±SD) P value∗ Bias% (Mean±SD) CLIA requirement Percent of samples not satisfying CLIA requirement† R
Na+ mmol/L 110-170 0.977 (0.919-1.036) 6.0 (-2.1-14.2) 2.9±4.0 <0.001 2.1±3.2 Target±4 34.7 0.9355
K+ mmol/L 2.9-8.5 0.968 (0.942-0.993) 0.19 (0.05-0.33) 0.0±0.2 0.198 0.8±5.1 Target±0.5 1.4 0.9874
Cl- mmol/L 80-133 0.943 (0.907-0.978) 4.8 (1.0-8.7) -1.4±2.8 <0.001 -1.3±2.6 Target±5% 4.2 0.9748
Ca2+ mg/dL 6.4-16.0 0.955 (0.930-0.980) 0.75 (0.49-1.01) 0.3±0.5 <0.001 3.4±5.5 Target±1.0 3.5 0.9879
tCO2 mmol/L 10-37 0.696 (0.592-0.799) 9.4 (7.0-11.9) 2.3±3.5 <0.001 11.9±16.5 NA NA 0.6534
AST U/L 16-269 0.889 (0.877-0.902) 11.8 (11.2-12.4) 8.0±5.1 <0.001 41.9±28.2 Target±20% 10.5 0.9966
ALT U/L 8-560 0.846 (0.834-0.858) 11.2 (10.4-12.1) 5.5±10.9 <0.001 47.6±56.1 Target±20% 42.7 0.9965
ALP U/L 30-601 0.798 (0.786-0.810) 5.4 (3.4-7.4) -19.4±25.4 <0.001 -13.4±7.0 Target±30% 0 0.9960
Total bilirubin mg/dL 0.4-13.4 0.902 (0.891-0.913) 0.17 (0.15-0.20) 0.1±0.23 0.006 19.5±26.8 Target±0.4 or ±20% (greater) 1.4 0.9973
Glucose g/dL 44-451 0.938 (0.916-0.960) -0.5 (-3.5-2.5) -7.9±9.4 <0.001 -1.9±58.2 Target±6 or ±10% (greater) 25.0 0.9905
BUN g/dL 5-101 0.982 (0.968-0.997) -0.9 (-1.3~-0.6) -1.3±1.4 <0.001 -6.3±11.8 Target±2 or ±9% (greater) 14.7 0.9963
Creatinine mg/dL 0.2-10.8 1.045 (1.033-1.057) -0.26 (-0.28~-0.23) -0.2±0.2 <0.001 -21.1±15.9 Target±0.3 or ±15% (greater) 2.2 0.9978
Albumin mg/dL 1.6-4.9 1.058 (1.011-1.105) -0.61 (-0.80~-0.42) -0.4±0.2 <0.001 -10.1±6.9 Target±10% 3.5 0.9646
Total protein mg/dL 4.3-9.5 1.080 (1.024-1.136) -0.34 (-0.72-0.04) 0.2±0.3 <0.001 3.0±4.0 Target±10% 2.8 0.9520

∗ P values were determined by using the paired t-test.

† Percentage of the samples which does not satisfy CLIA requirement derived from the regression equation.

Abbreviations: tCO2, total carbon dioxide; ALP, alkaline phosphatase; BUN, blood urea nitrogen.

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