카트리지 형태의 현장 검사 혈액 가스 장비 i-Smart 300의 성능 평가 · 2016-12-20 · oxygen pressure, sodium, potassium, chloride, ionized calcium, and hematocrit

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dioxide pressure (pCO2), and partial oxygen pressure (pO2). More-

over, the simultaneous measurement of electrolytes such as so-

dium (Na+), potassium (K+), chloride (Cl-), and ionized calcium

(Ca2+) is available with hematocrit (Hct). Integration and immedi-

ate therapeutic response using these results allows for prompt

treatment and improvement of prognosis. Therefore, blood gas

analyzers are being demanded for both their rapid turn-around of

test results and sophisticated result accuracy. While most of the

blood gas analyzers are used on-site, such as in emergency de-

partments and ICUs for point of care (POC) testing, even bench-

top models are currently in use at most clinical laboratories.

In the use of POC analyzers, quality control is a big issue. The

users of POC analyzers are often unfamiliar with laboratory in-

struments and unacquainted with the maintenance and quality

control of the instrument. Therefore, cartridge-type instruments

are welcomed for most POC instruments, not only blood gas ana-

lyzers, but also molecular diagnostic analyzers [3]. If, however,

INTRODUCTION

Blood gas analysis is a critical tool in assessing a clinical diag-

nosis and in therapeutic monitoring of severely ill patients in the

emergency department and intensive care unit (ICU) [1, 2]. Most

blood gas analyzers measure the whole blood pH, partial carbon

카트리지 형태의 현장 검사 혈액 가스 장비 i-Smart 300의 성능 평가Performance Evaluation of Cartridge-Type Blood Gas Analyzer: i-Smart 300

이아람·김한아·문희원·허미나·윤여민Ahram Yi, M.D., Hanah Kim, M.D., Hee-Won Moon, M.D., Mina Hur, M.D., Yeo-Min Yun, M.D.

건국대학교 의학전문대학원 진단검사의학교실

Department of Laboratory Medicine, Konkuk University School of Medicine, Seoul, Korea

원저Lab Med OnlineVol. 7, No. 1: 20-27, January 2017https://doi.org/10.3343/lmo.2017.7.1.20

임상화학

Corresponding author: Yeo-Min YunDepartment of Laboratory Medicine, Konkuk University School of MedicineKonkuk University Hospital, 120-1 Neungdong-ro, Gwangjin-gu, Seoul 05030, KoreaTel: +82-2-2030-5582, Fax: +82-2-2030-5587, E-mail: [email protected]

Received: December 23, 2015Revision received: April 26, 2016Accepted: May 3, 2016

This article is available from http://www.labmedonline.org 2017, Laboratory Medicine Online This is an Open Access article distributed under the terms of the Creative Commons

Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Background: Blood gas analysis plays a crucial role in critical care settings, and immediate and precise analysis improves clinical outcomes through prompt treatment. We evaluated the performance of a cartridge-type blood gas analyzer, i-Smart 300 (i-SENS, Korea), according to the Clinical and Laboratory Standard Institute (CLSI) guidelines and compared it to a conventional blood gas analyzer.Methods: The precision was evaluated according to CLSI EP5-A3. The i-Smart 300 was compared to the Stat Profile Critical Care Xpress (STP CCX) (Nova CCX; Nova Biomedical, USA) according to CLSI EP9-A3 using the following eight parameters: pH, partial carbon dioxide pressure, partial oxygen pressure, sodium, potassium, chloride, ionized calcium, and hematocrit. Linearity was determined using five levels of control materials ac-cording to CLSI EP6-A.Results: Within-run precision and total precision, demonstrated as coefficients of variation, ranged from 0.02 to 2.50% and from 0.05 to 3.46%, respectively. Correlation analysis yielded a correlation coefficient from 0.966 to 0.996 between the i-Smart 300 and the conventional analyzer (Nova CCX). The i-Smart 300 showed excellent linearity at eight parameters with acceptable percent recovery.Conclusions: The i-Smart 300, a portable cartridge-type blood gas analyzer, showed high precision and good correlation with a traditional bench-top blood gas analyzer. It could be useful in critical care settings.

Key Words: i-Smart, Blood gas analyzer, Point-of-care systems, Performance

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이아람 외: Cartridge-Type Blood Gas Analyzer

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there are discrepant results between a POC analyzer and central

bench-top analyzer, this can confuse physicians and makes it more

dif�cult to treat patients properly. Therefore, the performance eval-

uation of blood gas analyzers and determination of analyzer-spe-

ci�c differences in bias and precision are important to reduce the

con�icting results between different instruments [4].

Recently, a brand new blood gas analyzer, i-Smart 300 (i-SENS,

Seoul, Korea) was launched and is a cartridge-type blood gas an-

alyzer, which is preferred in the clinical �eld. This study aims to

evaluate the analytical performance of this new cartridge-type

blood gas analyzer in comparison with the Stat Pro�le Critical Care

Xpress (Nova CCX; Nova Biomedical, Waltham, MA, USA) as a

reference method according to the Clinical and Laboratory Stan-

dard Institute (CLSI) guidelines.

MATERIALS AND METHODS

1. Analyzer

The i-Smart 300 blood gas analyzer consists of an operating in-

strument and a disposable cartridge containing all sensors, a re-

agents waste bag, tubing, and sample probe for analysis. The stand-

alone disposable cartridge is a self-contained miniature analyzer,

a functioning analyzing unit that contains all necessary parts: re-

agents, calibrators, reference solution, sample probe, valves, tubing,

and sensors. Therefore, equipment maintenance is very conve-

nient involving only replacing a cartridge. The i-Smart uses three

levels of aqueous quality control (QC) material, RNA QC 623 Blood

Gas-Electrolyte Control (RNA Medical, Devens, MA, USA), and

two levels of RNA QC 900 Hematocrit Control (RNA Medical, De-

vens, MA, USA). This analyzer measures the whole blood pH,

pCO2, pO2, Na+, K+, Cl-, Ca2+, and Hct using 80 μL heparinized

whole blood.

2. Specimens

In March 2015, a total of 40 heparinized whole blood specimens

were prospectively and consecutively collected. The specimens

were anaerobically drawn from arterial vessels using heparinized

blood sample kits, Becton Dickinson’s Preset (BD Becton Dickin-

son Co., Plymouth, UK), according to the CLSI guideline [5]. The

remaining specimens were used in anonymous way, and this study

was approved by the Institutional Review Board of the Konkuk

University Medical Center (KUH1200047).

To determine the imprecision of i-Smart for eight analytes, aque-

ous QC materials were used. For seven analytes, except Hct, three

levels of aqueous QC material, RNA QC 623 Blood Gas-Electrolyte

Control (RNA Medical, Devens, MA, USA) were used, and two

levels of RNA QC 900 Hematocrit Control (RNA Medical, Devens,

MA, USA) were used for Hct. For carry-over analysis, two levels of

QC materials were tested. Five calibration veri�cation materials

[RNA CVC 123 Calibration Veri�cation Controls and RNA CVC 9005

Hematocrit Calibration Veri�cation Controls (RNA Medical, De-

vens, MA, USA)] were used for linearity assessment.

3. Study Design

The total run imprecision was determined using within-labora-

tory precision with the CLSI EP5-A3. It uses a design with 20 test-

ing days, two runs per testing day, and two replicate measurements

per run (20×2×2) for each samples using a single reagent and

single calibrator lot. Carry-over was estimated with replicate mea-

surements of the high-low sequences and was calculated by the

equation: % carry-over= {L1-(L3+L4)/2}×100/{(H2+H3)/2-(L3+L4)/2}.

An acceptability criterion was % carry-over of less than 1% [6, 7].

Linearity analysis was performed with �ve levels of commercially

available linearity material with two repetitions of each level ac-

cording to the CLSI EP6-A. Acceptability criteria were a slope be-

tween 0.9 and 1.1 and a recovery of between 90% and 110% [8].

Method comparison and difference estimation were assessed

using a Nova CCX in the core laboratory. Forty heparinized whole

blood specimens were analyzed on the i-Smart and the Nova CCX

according to the CLSI EP9-A3 [9].

4. Statistical Analysis

Before statistical analysis, all data were processed to detect and

reject outliers according to the CLSI EP9-A3 [9]. To compare the

results of the i-Smart and Nova CCX, Pearson correlation coef�-

cient and Passing-Bablok regression analysis were used. Each es-

timated slope and intercept, as well as 95% con�dence intervals

(CI), was calculated. The Nova CCX is the laboratory’s current

method and not a recognized reference method, so the trueness

of the test methods could not be determined. The differences (ab-

solute and relative) by the Bland-Altman difference plot were cal-

culated. We used percent difference between the two methods,

so bias from difference of scale or units could be excluded.

Statistical analysis was performed using Analyse-it Software


https://doi.org/10.3343/lmo.2017.7.1.2022 www.labmedonline.org

(version 3.90.5; Analyse-it Software, Ltd., Leeds, UK) and MedCalc

Software (version 14.12.0; MedCalc Software, Mariakerke, Belgium).

P values of less than 0.05 were considered statistically signi�cant.

RESULTS

1. Precision and Carry-over

Total precision (percent coef�cients of variation, CV) of eight

parameters was determined by analyzing three levels of QC ma-

terial on 20 consecutive days according to the CLSI guidelines

(Table 1). Within-run CV ranged from 0.02 to 2.50%, and the total-

run CV ranged from 0.05 to 3.46%. The %CV of Na+ at low level,

Ca2+ at low level, Cl- at high level, and Hct at low level were: 0.52,

1.61, 0.73, and 1.83%, respectively, and narrowly escaped the de-

sirable precision criteria [10]. However, the other measured values

were within the allowable total error [11]. Carry-over ranged from

-0.04 to 0.05% and was acceptable within 5% [7].

2. Linearity

Linearity was demonstrated according to the CLSI guidelines

for all eight measurable parameters. Overall correlation coef�cients

(r) ranged from 0.9994 to 0.9998. The range of recovery was 94.3 –

120.6%. The slope and intercept of the regression equation are

shown in Table 2. The recovery of pO2 at low levels was 120.6%,

and narrowly escaped the acceptable criteria, while the other val-

ues lay within the criteria.

3. Method Comparison

The results of Passing-Bablok regression analysis and mean dif-

ference estimations are summarized in Table 3. Pearson correla-

Table 1. Evaluation of total precision for blood gas and electrolytes using three levels of control materials on the i-Smart 300 blood gas analyzer, with allowable precision, difference, and total error

Parameter Level MeanBetween-run Between-day Within-run Total-run

CVw*Desirable preci-sion criteria (%)*SD CV (%) SD CV (%) SD CV (%) SD CV (%)

pH Low 7.1604 0.0020 0.03 0.0033 0.05 0.0027 0.04 0.0047 0.07 0.2 0.1

Medium 7.4094 0.0036 0.005 0.0000 0.00 0.0014 0.02 0.0039 0.05

High 7.6433 0.0040 0.05 0.0042 0.05 0.0020 0.03 0.0061 0.08

pCO2 (mmHg) Low 18.77 0.23 1.24 0.05 0.25 0.12 0.61 0.26 1.40 4.0 2.0

Medium 39.23 0.45 1.14 0.00 0.00 0.16 0.40 0.47 1.20

High 66.21 0.50 0.76 0.24 0.36 0.45 0.67 0.71 1.08

pO2 (mmHg) Low 70.6 1.49 2.11 0.80 1.13 1.77 2.50 2.45 3.46 N/A N/A

Medium 90.5 2.13 2.24 0.70 0.73 1.02 1.08 2.46 2.60

High 126.5 2.40 1.90 0.00 0.00 1.20 0.95 2.68 2.12

Na+ (mmol/L) Low 113.7 0.00 0.00 0.36 0.32 0.46 0.41 0.59 0.52 0.6 0.3

Medium 132.4 0.40 0.30 0.00 0.00 0.46 0.35 0.61 0.46

High 154.8 0.37 0.24 0.41 0.26 0.46 0.30 0.72 0.46

K+ (mmol/L) Low 2.02 0.02 0.78 0.03 1.61 0.02 1.11 0.04 2.10 4.6 2.3

Medium 4.28 0.02 0.37 0.04 0.83 0.02 0.45 0.04 1.02

High 5.98 0.02 0.26 0.05 0.78 0.04 0.67 0.06 1.07

Cl- (mmol/L) Low 74.9 0.32 0.42 0.14 0.19 0.35 0.47 0.50 0.66 1.2 0.6

Medium 94.4 0.37 0.39 0.14 0.15 0.46 0.49 0.61 0.64

High 126.0 0.58 0.46 0.58 0.46 0.40 0.32 0.92 0.73

Ca2+ (mmol/L) Low 0.577 0.004 0.07 0.007 1.26 0.004 0.73 0.009 1.61 1.7 0.9

Medium 1.163 0.009 0.79 0.004 0.35 0.006 0.48 0.011 0.99

High 1.474 0.006 0.39 0.014 0.97 0.008 0.53 0.017 1.17

Hematocrit (%) Low 27.0 0.32 1.17 0.23 0.87 0.30 1.10 0.49 1.83 2.7 1.35

High 51.6 0.39 0.75 0.23 0.44 0.37 0.72 0.58 1.13

It uses a design with 20 testing days, two runs per testing day, and two replicate measurements per run (n=20×2×2=80) for each sample using a single reagent and single calibrator lot, according to the CLSI EP5-A3. Three levels of aqueous quality control (QC) material were used, RNA QC 623 Blood Gas-Electrolyte Control (RNA Medical, De-vens, MA, USA), and two levels of RNA QC 900 Hematocrit Control (RNA Medical, Devens, MA, USA) were used.*Within-subject variation and desirable analytical precision criteria are referenced from Ricos et al. [10], and the biological variation database specification on Westgard’s web-site (https://www.westgard.com/biodatabase1.htm) [11].Abbreviations: CV, coefficient variation; CVw, within-subject biological variation; NA, not available.



tion analysis yielded generally very high correlation coef�cients

ranging from 0.966 to 0.996 for all parameters being evaluated.

The slopes of the regression equations ranged from 0.88 to 1.29

for all analytes.

Bland-Altman plots showed the means of the paired difference

in the concentrations of eight analytes obtained using the i-Smart

300 and Nova CCX, which are shown in Fig. 1(B, D, F, H, J, L, N,

P). Comparison of the two blood gas analyzers showed accept-

able comparability for all analytes. According to the Bland-Altman

plots, most paired data lay within±1.96 standard deviation (SD).

DISCUSSION

It is well known that results of blood gas and electrolyte analy-

sis are crucial in managing the ICU and emergency department

[12]. Furthermore, emergency conditions in the operating room,

ICU, and emergency department require immediate and precise

analysis to treat patients promptly. The i-Smart 300, a portable

cartridge-type blood gas analyzer, can eliminate the time needed

to deliver samples to central laboratory and help physicians to as-

sess disease and treat patients promptly. Unlike a conventional

blood gas analyzer, the i-Smart 300 can be stored with the cartri-

dges and reagents at room temperature, without occupying space

in a refrigerator. Disposable cartridges include internal quality

control materials and reagents, so it is easy to operate and use in-

ternal quality controls and, thus, the results could be reliable even

when users are inexperienced.

In this study, we evaluated the i-Smart 300 by comparing preci-

sion, carry-over, linearity, and correlation with a conventional blood

gas analyzer. For precision evaluation, various judgment parame-

ters were applicable. Generally, the desirable analytical precision

criteria are used according to intra-individual biologic variation

[13]. Typically, if precision is within 50% of the intra-individual bi-

ologic variation, it is regarded as suitable clinical test. Also, in a

speci�c patient, when followed by serial tests, it means the ana-

lytical errors allow for distinguishing between normal biologic

variation and clinically signi�cant changes [10, 14, 15]. For the pre-

cision performance analysis of the i-Smart 300 using quality con-

trol materials, each parameter’s within-run precision and total pre-

cision were demonstrated as coef�cients of variation and ranged

Table 2. Evaluation of linearity from eight parameters using five levels of control materials with the i-Smart 300 blood gas analyzer

Parameter (unit) Test rangeObserved

linear range

Manufacturer claimed AMR Correla-tion (r)

Regression % Recovery P valuei-Smart 300 Nova CCX

pH (pH unit) 6.867-7.802 6.867-7.802 6.500-8.000 6.500-8.000 0.9994 y=0.9992x+0.0175 100.0–100.4 <0.0001

pCO2 (mmHg) 12.7-83.7 12.7-83.7 5.0-150.0 3.0-200 0.9994 y=0.9726x+0.3973 96.1–99.8 <0.0001

pO2 (mmHg) 41.0-462.5 69.0-462.5 5-700 0-800 0.9998 y=0.9959x+2.8820 98.6–120.6* <0.0001

Na+ (mmol/L) 86.0-160.5 86.0-160.5 80-200 80-200 0.9998 y=0.9879x+0.1835 98.5–99.4 <0.0001

K+ (mmol/L) 1.60-11.30 1.60-11.30 1.0-20.0 1.0-20.0 0.9998 y=1.0150x-0.1078 95.0–100.9 <0.0001

Cl- (mmol/L) 67.5-130.0 67.5-130.0 50-150 50-200 0.9998 y=1.0200x-1.0100 94.3–101.9 <0.0001

Ca2+ (mmol/L) 0.265-3.345 0.265-3.345 0.25-5.00 0.1-2.7 0.9998 y=1.0190x-0.0292 100.0–101.6 <0.0001

Hematocrit (%) 21.5-69.0 21.5-69.0 10-70 12-70 0.9998 y=0.9934x+0.3701 100.0–102.4 <0.0001

*The % recovery of pO2 ranged from 98.6% to 120.6%. Except for the coded concentration 34, the % recovery of pO2 ranged from 98.6% to 101.5%.Abbreviation: AMR, analytical measurement range.

Table 3. Comparison of results obtained using the i-Smart 300 and Nova CCX (n=40)

Parameter Test range Correlation (r) (95% CI) Slope* (95% CI) Intercept* (95% CI) Mean difference† (95% CI)

pH (pH unit) 7.067-7.540 0.982 (0.967-0.991) 1.33 (1.25 to 1.40) -2.36 (-2.94 to -1.79) 0.0424 (0.0330 to 0.0518)

pCO2 (mmHg) 19.9-77.9 0.979 (0.958-0.988) 0.95 (0.85 to 1.05) -3.38 (-7.44 to 0.68) -5.41 (-6.053 to -4.762)

pO2 (mmHg) 37.2-225.8 0.993 (0.987-0.996) 1.08 (1.03 to 1.12) -3.00 (-8.97 to 2.97) 5.73 (3.10 to 8.36)

Na+ (mmol/L) 124.5-144.8 0.966 (0.936-0.982) 1.02 (0.93 to 1.10) -3.09 (-14.24 to 8.06) -1.01 (-1.36 to 0.66)

K+ (mmol/L) 2.67-6.59 0.996 (0.993-0.998) 0.88 (0.86 to 0.91) 0.34 (0.23 to 0.45) -0.128 (-0.161 to -0.095)

Cl- (mmol/L) 88.8-116.7 0.970 (0.943-0.984) 1.05 (0.95 to 1.14) -4.17 (-14.22 to 5.88) 0.86 (0.49 to 1.23)

Ca2+ (mmol/L) 0.78-1.51 0.975 (0.952-0.987) 1.05 (0.95 to 1.15) -0.15 (-0.27 to -0.03) -0.091 (-0.100 to -0.082)

Hematocrit (%) 24-53 0.974 (0.951-0.986) 1.07 (0.99 to 1.15) -5.08 (-8.08 to -2.08) -2.6 (-3.0 to -2.1)

*Determined using Deming fit; †Mean difference is defined as measured values of the i-Smart 300 minus Nova CCX. Abbreviation: CI, confidence interval.



A

22

6.9

7

7.1

7.2

7.3

7.4

7.5

7.6

7.7

6.9 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7

Mea

n of

pH

-i-S

mar

t 300

Mean of pH - STP CCX

pH

pH

17

18

19

20

21

22

23

24

25

26

27

28

‐0.120

‐0.080

‐0.040

0.000

0.040

0.080

0.120

7 7.1 7.2 7.3 7.4 7.5 7.6

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)

Mean of pH

Allowable

difference (Total

error) = ± 0.04

(A)

(B)

y = 1.33x - 2.36

r = 0.982

Mean

difference

= 0.0424

7.7

7.6

7.5

7.4

7.3

7.2

7.1

7.0

6.9

Mea

n of

pH

- i-

Smar

t 300

Mean of pH - Nova CCX

6.9 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7

y=1.33x-2.36r=0.982

Diff

eren

ce (i

-Sm

art 3

00 -

Nov

a CC

X)

B

22

6.9

7

7.1

7.2

7.3

7.4

7.5

7.6

7.7

6.9 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7

Mea

n of

pH

-i-S

mar

t 300

Mean of pH - STP CCX

pH

pH

17

18

19

20

21

22

23

24

25

26

27

28

‐0.120

‐0.080

‐0.040

0.000

0.040

0.080

0.120

7 7.1 7.2 7.3 7.4 7.5 7.6

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)

Mean of pH

Allowable

difference (Total

error) = ± 0.04

(A)

(B)

y = 1.33x - 2.36

r = 0.982

Mean

difference

= 0.0424

0.12

0.08

0.04

0.00

-0.04

-0.08

-0.12

Mean of pH

7.0 7.1 7.2 7.3 7.4 7.5 7.6

Mean difference= 0.0424

Allowable difference (Total error)=±0.04

pH

C

24

10

20

30

40

50

60

70

80

90

10 20 30 40 50 60 70 80 90

Mea

n pC

O2

-i-S

mar

t 300

(mm

Hg)

Mean of pCO2 - STP CCX (mmHg)

pCO2

35

36

37

38

39

40

41

42

43

44

45

46

47

Fig. 1. (continued)48

‐12.0

‐10.0

‐8.0

‐6.0

‐4.0

‐2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

20 30 40 50 60 70 80 90

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)(m

mH

g)

Mean of pCO2(mmHg)

Allowable difference

(Total error) = 5.7%

(A)

y = 0.95x -3.38

r = 0.979

Mean

difference

= - 5.41

(B)

pCO2

90

80

70

60

50

40

30

20

10

Mea

n pC

O2 -

i-Sm

art 3

00 (m

mH

g)

Mean of pCO2 - Nova CCX (mmHg)

20 30 40 50 60 70 80 90

y = 0.95x-3.38 r = 0.979

pCO2

D

24

10

20

30

40

50

60

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90

10 20 30 40 50 60 70 80 90

Mea

n pC

O2

-i-S

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(mm

Hg)

Mean of pCO2 - STP CCX (mmHg)

pCO2

35

36

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39

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46

47


‐12.0

‐10.0

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20 30 40 50 60 70 80 90

Diff

eren

ce (i

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STP

CC

X)(m

mH

g)

Mean of pCO2(mmHg)


(Total error) = 5.7%

(A)

y = 0.95x -3.38

r = 0.979

Mean

difference

= - 5.41

(B)

pCO2 121086420

-2-4-6-8

-10-12Di

ffer

ence

(i-S

mar

t 300

- N

ova

CCX)

(mm

Hg)

Mean of pCO2 (mmHg)

20 30 40 50 60 70 80 90

Allowable difference (Total error)=5.7%

Mean difference=-5.41

pCO2

25

25

50

75

100

125

150

175

200

225

250

25 50 75 100 125 150 175 200 225 250

Mea

n of

pO

2-i

-Sm

art 3

00 (m

mH

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Mean of pO2 - STP CCX (mmHg)

pO2

49

50

51

52

53

54

55

56

57

58

59


‐65.0

‐55.0

‐45.0

‐35.0

‐25.0

‐15.0

‐5.0

5.0

15.0

25.0

35.0

45.0

55.0

65.0

20 40 60 80 100 120 140 160 180 200 220 240

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X) (m

mH

g)

Mean of pO 2 (mmHg)

y = 1.08x – 3.00

r = 0.993

Mean

difference

= 5.73

(A)

(B) pO2 Allowable difference

(Total error) = ±3SD

E

250

225

200

175

150

125

100

75

50

25

Mea

n of

pO

2 - i-

Smar

t 300

(mm

Hg)

Mean of pO2 - Nova CCX (mmHg)

50 75 100 125 150 175 200 225 250

y=1.08x–3.00 r=0.993

pO2

F

Diff

eren

ce (i

-Sm

art 3

00 -

Nov

a CC

X) (m

mH

g)

25

25

50

75

100

125

150

175

200

225

250

25 50 75 100 125 150 175 200 225 250

Mea

n of

pO

2-i

-Sm

art 3

00 (m

mH

g)

Mean of pO2 - STP CCX (mmHg)

pO2

49

50

51

52

53

54

55

56

57

58

59


‐65.0

‐55.0

‐45.0

‐35.0

‐25.0

‐15.0

‐5.0

5.0

15.0

25.0

35.0

45.0

55.0

65.0

20 40 60 80 100 120 140 160 180 200 220 240

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X) (m

mH

g)

Mean of pO 2 (mmHg)

y = 1.08x – 3.00

r = 0.993

Mean

difference

= 5.73

(A)

(B) pO2 Allowable difference


6555453525155

-5-15-25-35-45-55-65

Mean of pO2 (mmHg)

20 40 60 80 100 120 140 160 180 200 220 240




pO2

Fig. 1. Comparison of pH, pCO2, pO2, Na+, K+, Cl-, Ca2+, and Hematocrit results tested by the i-Smart 300 and STP CCX for 40 samples. (A, C, E, G, I, K, M, O) Correlation between the i-Smart 300 and Nova CCX. Solid line, Passing-Bablok regression; dashed line, identity line. (B, D, F, H, J, L, N, P) Dif-ference between the i-Smart 300 and Nova CCX. Bold line, mean difference between values; dotted lines, desirable specification for allowable to-tal error. (continued to the next page)

from 0.02 to 2.50% and from 0.05 to 3.46%, respectively. All pa-

rameters except Na+, Cl-, Ca2+, and Hct �t the total desirable preci-

sion criteria. Therefore, pH, pCO2, pO2, and K+ can be used for as

a patient follow-up purposes [11]. Cl- and Hct were among the four

parameters that did not meet the precision criteria, however, they

met the minimum precision criteria, which is 75% of biological

variation [16].

The i-Smart 300 showed excellent carry-over, all of the parame-

pH



ters’ carry-over were within 1.0%, and values were similar to a

conventional blood gas analyzer. The speci�c carry-over ranged

between -0.04% and 0.05%. Typically, the goal is within 1%, there-

fore, the carry-over of the i-Smart 300 is excellent [17]. All eight

analytes showed excellent linearity within the acceptable recov-

ery range. Moreover, correlation statistics between the i-Smart 300

and Nova CCX using Pearson’s correlation coef�cients all were grea-

ter than 0.96, meaning high correlation.

According to the Bland-Altman plots, most analytes of the i-Smart

300 such as pCO2, Na+, K+, Ca2+, and Hct showed lower values com-

pared to those measured by the Nova CCX.

Some of the limitations of our study are that the results of the

Nova CCX, which we use as the standard, have not been veri�ed

as the true value.

I

27

‐0.50

‐0.40

‐0.30

‐0.20

‐0.10

0.00

0.10

0.20

0.30

0.40

0.50

2.5 3 3.5 4 4.5 5 5.5 6 6.5

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

Mean of K +(mmol/L)

K+ Allowable

difference (Total

error) = 5.61%

2.5

3

3.5

4

4.5

5

5.5

6

6.5

7

2.5 3 3.5 4 4.5 5 5.5 6 6.5 7

Mea

n of

K+

-i-S

mar

t 300

(mm

ol/L

)

Mean of K+ - STP CCX (mmol/L)

K+

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99


y = 0.88x +0.34

r = 0.996

Mean

difference

= -0.128

(A)

(B)

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

Mea

n of

K+ -

i-Sm

art 3

00 (m

mol

/L)

Mean of K+ - Nova CCX (mmol/L)

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0

y = 0.88x+0.34 r = 0.996

K+

J

27

‐0.50

‐0.40

‐0.30

‐0.20

‐0.10

0.00

0.10

0.20

0.30

0.40

0.50

2.5 3 3.5 4 4.5 5 5.5 6 6.5

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

Mean of K +(mmol/L)

K+ Allowable

difference (Total

error) = 5.61%

2.5

3

3.5

4

4.5

5

5.5

6

6.5

7

2.5 3 3.5 4 4.5 5 5.5 6 6.5 7

Mea

n of

K+

-i-S

mar

t 300

(mm

ol/L

)

Mean of K+ - STP CCX (mmol/L)

K+

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99


y = 0.88x +0.34

r = 0.996

Mean

difference

= -0.128

(A)

(B)

0.5

0.4

0.3

0.2

0.1

0.0

-0.1

-0.2

-0.3

-0.4

-0.5

Diff

eren

ce (i

-Sm

art 3

00 -

Nov

a CC

X) (m

mol

/L)

Mean of K+ (mmol/L)

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5

Allowable difference (Total error) = 5.61%

Mean difference= -0.128

K+

Fig. 1. Continued. 28

85

90

95

100

105

110

115

120

85 90 95 100 105 110 115 120

Mea

n of

Cl-

-i-S

mar

t 300

(mm

ol/L

)

Mean of Cl- - STP CCX (mmol/L)

Cl-

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115


‐4.0

‐3.0

‐2.0

‐1.0

0.0

1.0

2.0

3.0

4.0

85 90 95 100 105 110 115 120

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

Mean of Cl - (mmol/L)

Allowable

difference (Total

error)= 1.5%

y = 1.05x -4.17

r = 0.970

Mean

difference

= 0.86

(A)

(B)

Cl-

28

85

90

95

100

105

110

115

120

85 90 95 100 105 110 115 120

Mea

n of

Cl-

-i-S

mar

t 300

(mm

ol/L

)

Mean of Cl- - STP CCX (mmol/L)

Cl-

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115


‐4.0

‐3.0

‐2.0

‐1.0

0.0

1.0

2.0

3.0

4.0

85 90 95 100 105 110 115 120

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

Mean of Cl - (mmol/L)

Allowable

difference (Total

error)= 1.5%

y = 1.05x -4.17

r = 0.970

Mean

difference

= 0.86

(A)

(B)

Cl-

K

120

115

110

105

100

95

90

85

Mea

n of

Cl-

- i-

Smar

t 300

(mm

ol/L

)

Mean of Cl- - Nova CCX (mmol/L)

85 90 95 100 105 110 115 120

y = 1.05x -4.17 r = 0.970

Cl-

L

Diff

eren

ce (i

-Sm

art 3

00 -

Nov

a CC

X) (m

mol

/L)

4

3

2

1

0

-1

-2

-3

-4

Mean of Cl- (mmol/L)

85 90 95 100 105 110 115 120

Allowable difference (Total error)= 1.5%


Cl-

26

120

122.5

125

127.5

130

132.5

135

137.5

140

142.5

145

120 122.5 125 127.5 130 132.5 135 137.5 140 142.5 145

Mea

n of

Na+

-i-S

mar

t 300

(mm

ol/L

)

Mean of Na+ - STP CCX (mmol/L)

Na+

61

62

63

64

65

66

67

68

69

70

71

72

73

74


‐4.0

‐3.0

‐2.0

‐1.0

0.0

1.0

2.0

3.0

4.0

122.5 125 127.5 130 132.5 135 137.5 140 142.5 145

Diff

eren

ce (

i-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

Mean of Na + (mmol/L)

Na+

Allowable

difference (Total

error)= 0.73%

y = 1.02x - 3.09

r = 0.966

Mean

difference

= -1.01

(A)

(B)

G

26

120

122.5

125

127.5

130

132.5

135

137.5

140

142.5

145

120 122.5 125 127.5 130 132.5 135 137.5 140 142.5 145

Mea

n of

Na+

-i-S

mar

t 300

(mm

ol/L

)

Mean of Na+ - STP CCX (mmol/L)

Na+

61

62

63

64

65

66

67

68

69

70

71

72

73

74


‐4.0

‐3.0

‐2.0

‐1.0

0.0

1.0

2.0

3.0

4.0

122.5 125 127.5 130 132.5 135 137.5 140 142.5 145

Diff

eren

ce (

i-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

Mean of Na + (mmol/L)

Na+

Allowable

difference (Total

error)= 0.73%

y = 1.02x - 3.09

r = 0.966

Mean

difference

= -1.01

(A)

(B)

145.0

142.5

140.0

137.5

135.0

132.5

130.0

127.5

125.0

122.5

120

Mea

n of

Na+ -

i-Sm

art 3

00 (m

mol

/L)

Mean of Na+ - Nova CCX (mmol/L)

122.5 125.0 127.5 130.0 132.5 135.0 137.5 140.0 142.5 145

y = 1.02x - 3.09 r = 0.966

Na+

Diff

eren

ce (i

-Sm

art 3

00 -

Nov

a CC

X) (m

mol

/L)

H

4

3

2

1

0

-1

-2

-3

-4

Mean of Na+ (mmol/L)

122.5 125 127.5 130 132.5 135 137.5 140 142.5 145


Allowable difference (Total error)= 0.73%

Na+



29

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6

Mea

n of

Ca2

+-i

-Sm

art 3

00 (m

mol

/L)

Mean of Ca2+ - STP CCX (mmol/L)

Ca2+

117

118

119

120

121

122

123

124

125

126

127

128

129


131

‐0.18

‐0.14

‐0.10

‐0.06

‐0.02

0.02

0.06

0.10

0.14

0.18

0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5Mean of Cl - (mmol/L)

Allowable

difference (Total

error) = 2.0%

Ca2+

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

y = 1.05x – 0.15

r = 0.975

Mean

difference

= -0.091

(A)

(B)

M

29

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6

Mea

n of

Ca2

+-i

-Sm

art 3

00 (m

mol

/L)

Mean of Ca2+ - STP CCX (mmol/L)

Ca2+

117

118

119

120

121

122

123

124

125

126

127

128

129


131

‐0.18

‐0.14

‐0.10

‐0.06

‐0.02

0.02

0.06

0.10

0.14

0.18

0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5Mean of Cl - (mmol/L)

Allowable

difference (Total

error) = 2.0%

Ca2+

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X)(m

mol

/L)

y = 1.05x – 0.15

r = 0.975

Mean

difference

= -0.091

(A)

(B)

1.6

1.5

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

Mea

n of

Ca2+

- i-

Smar

t 300

(mm

ol/L

)

Mean of Ca2+ - Nova CCX (mmol/L)

0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6

y = 1.05x – 0.15 r = 0.975

Ca2+

Diff

eren

ce (i

-Sm

art 3

00 -

Nov

a CC

X) (m

mol

/L)

N

0.18

0.14

0.10

0.06

0.02

-0.02

-0.06

-0.10

-0.14

-0.18

Mean of Cl- (mmol/L)

0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5

Allowable difference (Total error) = 2.0%


O

30

‐7

‐6

‐5

‐4

‐3

‐2

‐1

0

1

2

3

4

5

6

7

20 25 30 35 40 45 50 55

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X) (%

)

Mean of Hematocrit (%)


(Total error)=3.97%

20

25

30

35

40

45

50

55

20 25 30 35 40 45 50 55

Mea

n of

Hem

atoc

rit -

i-Sm

art 3

00 (%

)

Mean of Hematocrit - STP CCX (%)

Hematocrit

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154


y = 1.07x - 5.08

r = 0.974

Mean

difference

= -2.5

(B)

(A)

Hematocrit

55

50

45

40

35

30

25

20

Mea

n of

Hem

atoc

rit -

i-Sm

art 3

00 (%

)

Mean of Hematocrit - Nova CCX (%)

20 25 30 35 40 45 50 55

y = 1.07x - 5.08 r = 0.974

Hematocrit

P

30

‐7

‐6

‐5

‐4

‐3

‐2

‐1

0

1

2

3

4

5

6

7

20 25 30 35 40 45 50 55

Diff

eren

ce (i

-Sm

art 3

00 -

STP

CC

X) (%

)



(Total error)=3.97%

20

25

30

35

40

45

50

55

20 25 30 35 40 45 50 55

Mea

n of

Hem

atoc

rit -

i-Sm

art 3

00 (%

)

Mean of Hematocrit - STP CCX (%)

Hematocrit

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154


y = 1.07x - 5.08

r = 0.974

Mean

difference

= -2.5

(B)

(A)

Hematocrit 76543210

-1-2-3-4-5-6-7Di

ffer

ence

(i-S

mar

t 300

- N

ova

CCX)

(%)


20 25 30 35 40 45 50 55

Allowable difference(Total error)=3.97%


Hematocrit

Fig. 1. Continued.

We also used samplers, which contain lyophilized heparin, so

that we could avoid the dilution effect.

In conclusion, this study is the �rst evaluation of the newly laun-

ched i-Smart 300 according to the CLSI guidelines. The i-Smart

300 showed excellent precision, linearity, carry-over, and inter-

analyzer correlation, even though it is a portable, cartridge-type

blood gas analyzer. There are advantages in terms of the conve-

nience to users and the stability of the analyzer, so the i-Smart 300

can be utilized in various clinical settings, such as ICU, operating

room, and emergency department as a blood gas analyzer.

요 약

배경: 혈액가스 분석은 의료 분야에 있어서 중요한 역할을 하고 있

고, 즉각적이고 정확한 분석은 즉각적인 치료를 통해 임상적 결과를

향상시킨다. 우리는 카트리지 형태의 혈액가스 분석 장비인 i-Smart

300의 분석능을 기존 혈액가스 분석 장비와 비교하여, Clinical and

Laboratory Standard Institute (CLSI) 지침에 따라 평가하였다.

방법: 정밀도는 CLSI EP5-A3에 따라 검증하였다. i-Smart 300은 다

음과 같은 8가지 지표에 대하여 Stat Pro�le Critical Care Xpress

(STP CCX) (Nova CCX; Nova Biomedical, USA)와 비교 평가를 시

행하였다. : pH, partial carbon dioxide pressure (pCO2), partial ox-

ygen pressure (pO2), sodium (Na+), potassium (K+), chloride (Cl-),

ionized calcium (Ca2+), and hematocrit (Hct). 직선성은 CLSI EP6-A

에 근거하여 5가지 농도의 control 물질을 이용하여 판정하였다.

결과: 검사차례내 정밀도는 0.02–2.50%, 총 정밀도는 0.05–3.46%

로 낮은 변이계수를 보였다. 장비 간 비교에서 상관계수는 0.966–

0.996의 값을 보였다. 8가지 측정항목에서 우수한 직선성과 수용

할 수 있는 범위내의 기대값 대비 회수율을 보였다.

결론: 본 연구는 i-Smart 300의 CLSI 가이드라인에 근거한 최초의

분석능 평가라는 의의를 갖는다. i-Smart 300은 이동식 카트리지

형태의 혈액가스 분석 장비로서, 높은 정밀도와 기존 장비와의 좋

은 상관관계를 보였다. 그러므로 의료 환경 내에서 유용하게 쓰일

수 있을 것으로 생각된다.

Ca2+



AUTHORS’ DISCLOSURES OF POTENTIAL

CONFLICTS OF INTERESTS

No potential con�icts of interest relevant to this article were re-

ported.

ACKNOWLEDGEMENTS

This study was supported by i-SENS.

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