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Kim, Shin, Kim, Jeong, and Lim: Evaluation of i-STAT CHEM8+ Point-of-Care Chemistry Analyzer
Original Article
Clinical Chemistry

Laboratory Medicine Online 2015; 5(2): 57-62.

Published online: 1 April 2015

DOI: https://doi.org/10.3343/lmo.2015.5.2.57

Evaluation of i-STAT CHEM8+ Point-of-Care Chemistry Analyzer

Do-kyun Kim, M.D., Hwachoon Shin, M.T., Byungkwang Kim, M.T., Soon-Ho Jeong, M.T., Jong-Baeck Lim, M.D.

Department of Laboratory Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.

Corresponding author: Jong-Baeck Lim. Department of Laboratory Medicine, Yonsei University College of Medicine, Gangnam Severance Hospital, 211 Unju-ro, Gangnam-gu, Seoul 135-752, Korea. Tel: +82-2-2019-3533, Fax: +82-2-2057-8926, jlim@yuhs.ac

Received 21 June 2014       Revised 10 October 2014       Accepted 13 October 2014

© 2015, Laboratory Medicine Online

(open-access):

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

We evaluated the analytical performance of the Abbott i-STAT CHEM8+, a point-of-care testing system that measures 8 basic chemical analytes, namely, sodium, potassium, chloride, total carbon dioxide, BUN, creatinine, glucose, and ionized calcium.

Methods

The precision and linearity of 8 analytes were evaluated according to the CLSI guidelines EP15-A and EP6-A, respectively, using standard material provided by the manufacturer. i-STAT CHEM8+ and other primary methods (e.g. Hitachi Clinical Analyzer 7600 for 7 analytes, Nova CCX for ionized calcium) were also compared according to the CLSI guideline EP9-A2, using 113 patient samples.

Results

The standard deviation (SD) of within-run and total precision of 7 analytes except chloride was within the claimed SD or within the verification value. The coefficient of variation of total precision of 7 analytes except creatinine was within 2%. With regard to linearity, all 8 analytes showed first-order equation or at least no statistical difference with the first-order equation. We observed that the efficiency of i-STAT CHEM8+ was comparable to that of primary methods, and that this method has potential applications in the clinical laboratory.

Conclusions

i-STAT CHEM8+ showed good precision and linearity, and an efficiency comparable to that shown by routine chemistry analyzers; thus, it has potential applications in the clinical laboratory. It can provide much faster results and relatively accurate value to clinicians in need of immediate results, such as in an emergency unit or in the intensive care unit.

Keywords: Clinical chemistry tests, Evaluation studies, Point of care systems, Verification

Figures and Tables

Table 1

Precision of i-STAT CHEM8+

lmo-5-57-i001
Analyte Unit Sample Claimed value Evaluated value Verification value
Mean Within SD Total SD Mean Within SD (CV%) Total SD (CV%) Within SD Total SD
Na+ mmol/L Low 119.40 0.46 0.46 119.45 0.34 (0.29) 0.54 (0.45) 0.62 0.94
High 160.80 0.53 0.53 161.15 0.50 (0.31) 0.49 (0.30) - -
K+ mmol/L Low 2.85 0.04 0.04 2.80 0.00 (0.00) 0.00 (0.00) - -
High 6.30 0.04 0.04 6.40 0.02 (0.35) 0.02 (0.35) - -
Cl- mmol/L Low 75.50 0.54 0.54 75.35 0.74 (0.98) 0.97 (1.28) 0.75 0.76
High 109.50 0.56 0.56 109.75 0.79 (0.72) 0.79 (0.72) 0.78 0.74
tCO2 mg/dL Low 19.20 0.62 0.62 19.00 0.00 (0.00) 0.00 (0.00) - -
High 32.40 0.62 0.62 33.70 0.52 (1.53) 0.46 (1.37) - -
Creatinine mg/dL Low 0.64 0.04 0.04 0.64 0.05 (7.33) 0.05 (7.77) 0.05 0.05
High 4.07 0.13 0.13 4.04 0.09 (2.35) 0.12 (2.91) - -
BUN mg/dL Low 4.90 0.45 0.45 5.00 0.00 (1.20) 0.00 (1.36) - -
High 62.40 0.76 0.76 63.75 0.76 (0.00) 0.87 (0.00) 1.03 1.02
iCa mmol/L Low 0.77 0.01 0.01 0.78 0.00 (0.77) 0.00 (0.98) - -
High 1.48 0.02 0.02 1.50 0.01 (0.41) 0.01 (0.64) - -
Glucose mg/dL Low 40.90 0.68 0.68 41.60 0.41 (0.98) 0.52 (1.25) - -
High 286.60 2.40 2.40 290.50 0.89 (0.31) 1.34 (0.46) - -
Table 2

Linearity of i-STAT CHEM8+

lmo-5-57-i002
Analytes Unit Range Slope Intercept R2
Na+ mmol/L 98.4-180.0 1.0170 -2.4485 0.99986
K+ mmol/L 2.08-7.86 0.9929 0.0026 0.99988
Cl- mmol/L 70.3-123.2 0.9880 1.4451 0.99952
tCO2 mg/dL 13.3-46.0 0.9757 0.6476 0.99253
BUN mg/dL 2.1-123.9 1.0009 0.1850 0.99997
Creatinine mg/dL 0.36-14.36 1.0175 -0.0586 0.99253
Glucose mg/dL 27.2-618.1 0.9943 1.7806 0.99995
iCa mmol/L 0.25-2.21 0.9993 0.0060 0.99991
Table 3

Best-fit equation and non-linearity% of i-STAT CHEM8+

lmo-5-57-i003
Analytes Unit Best-fit equation Assigned value Nonlinearity% Analytes Unit Best-fit equation Assigned value Nonlinearity%
Na+ mmol/L y = 1.017x-2.448 98.4 - BUN mg/dL y = 1.001x+0.185 2.1 -
119.4 - 4.9 -
133.4 - 10.6 -
160.8 - 62.4 -
180.0 - 123.9 -
K+ mmol/L y = -0.004x3+0.062x2+0.6985x+0.411 2.1 1.4% Creatinine mg/dL y = 1.018x-0.0586 0.36 -
2.8 -0.6% 0.64 -
3.8 -0.8% 1.84 -
6.4 0.4% 4.07 -
7.9 -0.1% 14.36 -
Cl- mmol/L y = 0.988x+1.445 70.3 - Glucose mg/dL y = -0.001x2+1.025x-0.3584 27.2 -4.9%
75.5 - 40.9 -2.3%
89.9 - 124.1 0.7%
109.5 - 286.6 0.9%
123.2 - 618.1 -0.2%
tCO2 mg/dL y = 0.001x3+0.042x2+0.115x+5.316 13.3 -4.8% iCa mmol/L y = 0.999x+0.0060 0.253 -
19.2 -1.6% 0.773 -
22.6 1.0% 1.264 -
46.0 -2.2% 1.475 -
32.4 5.4% 2.209 -
Table 4

Range of value and correlation coefficient of comparison between i-STAT CHEM8+ and main chemistry analyzer

lmo-5-57-i004
Analyte n Comparison method Range of value r
Comparison i-STAT
Na+ 113 Hitachi 7600 125-146 126-146 0.845
K+ 113 Hitachi 7600 2.50-4.65 2.40-4.80 0.964
Cl- 113 Hitachi 7600 95.0-109.7 92.0-109.0 0.855
tCO2 113 Hitachi 7600 19.2-33.2 22.0-36.0 0.710
BUN 113 Hitachi 7600 3.6-25.0 3.0-26.0 0.991
Creatinine 113 Hitachi 7600 0.26-1.36 0.30-1.70 0.889
Glucose 113 Hitachi 7600 125.0-217.0 23.0-214.0 0.981
iCa 57 Nova CCX 0.63-1.37 0.79-1.41 0.906
Table 5

Comparison of i-STAT CHEM8+ with routine chemistry analyzer at the medical decision level by Deming regression

lmo-5-57-i005
Analytes Slope (95% CI) Intercept (95% CI) Decision level Acceptable performance Low limit High limit Expected value Percent of samples not satisfying CLIA requirement
Na+ 0.825 (0.687-0.962) 24.630 (5.050-44.200) 135 ± 4 mmol/L 131 139 135.99 0.00%
150 ± 4 mmol/L 146 154 148.37
K+ 1.098 (1.038-1.158) -0.429 (-0.657--0.201) 3 ± 0.5 mmol/L 2.5 3.5 2.87 0.88%
6 ± 0.5 mmol/L 5.5 6.5 6.16
Cl- 1.213 (1.084-1.341) -22.470 (-35.690--9.249) 90 ± 5 mmol/L 85 95 86.67 0.00%
112 ± 5 mmol/L 107 117 113.35
tCO2 1.299 (1.072-1.526) -4.424 (-10.210-1.364) 20 ± 5 mg/dL 15 25 21.55 19.47%
33 ± 5 mg/dL 28 38 34.54
BUN 1.195 (1.151-1.239) 2.802 (-3.280--2.324) 6 ± 2 mg/dL 4 8 4.37 8.85%
27 ± 2 mg/dL 25 29 29.46
Creatinine 0.968 (0.849-1.087) 0.145 (0.061-0.229) 0.8 ± 0.3 mg/dL 0.2 1.1 0.92 5.31%
1.6 ± 0.3 mg/dL 1.3 1.9 1.69
6.0 ± 0.3 mg/dL 5.7 6.3 5.95
Glucose 0.974 (0.937-1.011) 2.989 (-0.653-6.631) 45 ± 6 mg/dL 44 56 46.55 6.19%
120 ± 6 mg/dL 108 132 119.15
180 ± 6 mg/dL 162 198 177.23
iCa 0.834 (0.694-0.973) 0.234 (0.066-0.401) 1.1 ± 5% 1.05 1.16 1.15 21.05%
1.3 ± 5% 1.24 1.37 1.32

Notes

This article is available from http://www.labmedonline.org

References

1. Park H, Ko DH, Kim JQ, Song SH. Performance evaluation of the Piccolo xpress Point-of-care Chemistry Analyzer. Korean J Lab Med. 2009; 29:430–438.
crossref
2. St John A. The Evidence to Support Point-of-Care Testing. Clin Biochem Rev. 2010; 31:111–119.
3. Nichols JH. Point of care testing. Clin Lab Med. 2007; 27:893–908.
crossref
4. Matteucci E, Della Bartola L, Rossi L, Pellegrini G, Giampietro O. Improving CardioCheck PA analytical performance: three-year study. Clin Chem Lab Med. 2014; 52:1291–1296.
crossref
5. Clinical and Laboratory Standards Institute. User Demonstration of Performance for Precision and Accuracy; Approved Guideline. Document EP15-A. 2001. p. 67.
6. Clinical and Laboratory Standards Institute. Evaluation of the linearity of quantitative measurement procedure: a statistical approach; Approved guideline. Document EP6-A. Wayne, PA: Clinical and Laboratory Standards Institute;2003. p. 23.
7. Clinical and Laboratory Standards Institute. Method comparison and bias estimation using patient samples; Approved guideline-2nd edition. Document EP9-A2. Wayne, PA: Clinical and Laboratory Standards Institute;2002. p. 22.
8. Statland BE. Clinical Decision Levels for Laboratory Tests. Second Edition. Oradell, NJ: 1987.
9. Centers for Disease Control and prevention. Clinical Laboratory Improvement Amendments Regulation, Standards and Certification: Laboratory Requirements (42 CFR 493). uptated on OCT 2003. http://wwwn.cdc.gov/CLIA/Regulatory/default.aspx.
10. Rhee AJ, Khan RA. Laboratory point-of-care monitoring in the operating room. Curr Opin Anaesthesiol. 2010; 23:741–748.
crossref
11. Gault MH, Harding CE. Evaluation of i-STAT portable clinical analyzer in a hemodialysis unit. Clin Biochem. 1996; 29:117–124.
crossref
12. Tendl KA, Christoph J, Bohn A, Herkner KR, Pollak A, Prusa AR. Two site evaluation of the performance of a new generation point-of-care glucose meter for use in a neonatal intensive care unit. Clin Chem Lab Med. 2013; 51:1747–1754.
crossref
13. Tortella BJ, Lavery RF, Lavery RF, Siegel JH. Precision, accuracy, and managed care implications of a hand-held whole blood analyzer in the prehospital setting. Am J Clin Pathol. 1996; 106:124–127.
crossref
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