Reference Manual
312 Pages
Preview
Page 1
ABL800 FLEX reference manual
ABL800 FLEX reference manual
Note to users of the ABL800 FLEX analyzers Introduction
This note to users gathers changes from previous note to users in one document and outlines some new changes to the reference manual of your ABL800 FLEX analyzer (from software version 6.10).
Instructions to user
Please remove the existing note to users from the binder of your manual and place this note to users in the binder instead.
Brief overview of the change
Changes/Description Interference – new interference results for ClO4–
–
ClO4 (drugs)
For ClO4– , interference on cK+ (4 mmol/L level) has been detected and there are new results for cCa2+ (1.25 mmol/L level) and cCl− (110 mmol/L level). The new interference results for ClO4– are as follows: Interference on…
Substance
Test Conc.
ClO4–
1.5 mmol/L
cK+ (4 mmol/L level)
cNa+
cCa2+
cCl−
(150 mmol/L (1.25 mmol/L (110 mmol/L level) level) level)
−0.3
-
−0.27**
4-30
** Depending on the pH level pH electrode – new pleura correction values
Text about the pleura constants added. Equation A+: When an additional correction is needed, equation A is first used together with the constants for the macromode S250 and FLEXMODE (195 and 165 µL, no message) mode. Then the obtained results are put back into equation A (for Pleura pH: the constants for Pleura pH (A)) as pH(sample) and then treated again, using the constants for the specific sample handling to obtain the corrected value. New pleura correction values:
ABL8xx FLEX analyzer no.:
Mode
A0
A1
Equation
837/827/817
Pleura pH (A)
1.02245
–0.155
A
Pleura pH (A+)
0.8006
1.491
A+
Pleura pH (A)
1.02245
–0.160
A
Pleura pH (A+)
0.8006
1.491
A+
830/820/810/
Pleura pH (A)
1.02245
–0.160
A
810 BG only FLEX
Pleura pH (A+)
0.8006
1.491
A+
805
Pleura pH (A)
1.02245
–0.160
A
Pleura pH (A+)
0.8006
1.491
A+
835/825/815
© 2012 Radiometer Medical ApS. All rights reserved. 995-940. 201206B.
pCO2 electrode – the equation for the equilibrium reaction has been corrected
The membrane allows any uncharged molecules of CO2, O2 and N2 to pass through it. Charged ions such as H+ will not pass. Consequently, dissolved CO2 from the sample will diffuse into the thin layer of bicarbonate electrolyte until the equilibrium is reached. This produces carbonic acid: H2O + CO2 ⇔ H2CO3 Carbonic acid dissociates according to the following equilibrium reaction: H 2 CO3 ⇔ H + + HCO3−
The release of H+ ions changes the H+ concentration, and therefore the pH of the solution on one side of the pH-sensitive glass membrane. The concentration gradient of H+ ions on the other side of the membrane affects the potential difference across the glass membrane. This change in potential across the glass membrane is measured by the voltmeter. The following stability criteria must be met to obtain a stable Glucose and lactate electrode – electrode response during calibration: the equation for I(Cal 1,upd.30) − I(Cal 1, upd.21) − 9 × Islope ≥ 0 the stability criteria has been Sd,zero < Sd,max corrected −9.5
τ =
log
ABL8x0/8x5 Performance characteristics
≤ 50
I(Cal 1,upd.21) − I(Cal 1,upd.11) I(Cal 1,upd.11) − I(Cal 1,upd.1)
Reference analyzers: For Pleura pH, the Roche cobas b 221 system was used as a reference. New numbers for pleura pH added: Performance test results - pH Pleura pH mode – bias: pH
Bias
7.1
0.001
7.3
0.014
7.5
0.026
Pleura pH – imprecision: pH
S0
SX
7.1
0.013
0.029
7.3
0.009
0.019
7.5
0.005
0.027
ABL8x7 Performance characteristics
Reference analyzers: For Pleura pH, the Roche cobas b 221 system was used as a reference. New numbers for pleura pH added: Performance test results – pH, pCO2, pO2 Pleura pH mode – bias: pH
Bias
7.1
–0.001
7.3
0.016
7.5
0.027
Pleura pH – imprecision:
Measured Parameters
pH
S0
SX
7.1
0.012
0.029
7.3
0.009
0.020
7.5
0.006
0.028
Changes to the following parameters: Pleura pH Definition
Indicates the acidity or alkalinity of the pleura sample
Unit
-
Measuring range
6.300-8.000
If the measured values obtained lie outside the test range, Radiometer advises you to repeat the measurement by means of another method. Alternatively, national or local regulations may allow you to establish wider reportable ranges for your device. cCrea Definition
Concentration of creatinine in blood
Unit
µmol/L; mg/dL
Measuring range
µmol/L: 10-1800 mg/dL: 0.11-20.4
Reference range
m: 55-96 µmol/L, 0.6-1.1 mg/dL f: 40-66 µmol/L, 0.5-0.8 mg/dL
Conversion of units
cCrea (µmol/L) = 88.40 × cCrea (mg/dL)
27. Tietz Burtis CA. Ashwood ER, Bruns DE. Tietz textbook of clinical chemistry and molecular diagnostics. United States of America: Elsevier Inc, 2006. New COHb bias values for a sample with tHb = 15 g/dL, sO2 = 100%, and COHb ~ 0%
Based on a COHb comparison test, the new bias values are as follows:
ABL8x0/8x5 analyzer performance characteristics: FCOHb – macro modes: Bias: FCOHb
ABL835/25
ABL830/20
ctHb (g/dL)
sO2 (%)
FCOHb (%)
S195
FM*
S85
15
100
0
0.36
0.41
0.45
7
100
20
N/A
0.47
N/A
15
100
20
N/A
0.10
N/A
25
100
20
N/A
−0.47
N/A
* FM = FLEXMODE (no message) FCOHb – micro modes: Bias: FCOHb
ABL835/25
ctHb (g/dL)
sO2 (%)
FCOHb (%)
S95
C95
S85
C55
C35
15
100
0
0.43
0.43
0.45
0.41
0.41
7
100
20
N/A
N/A
N/A
N/A
N/A
15
100
20
N/A
N/A
N/A
N/A
N/A
25
100
20
N/A
N/A
N/A
N/A
N/A
FCOHb
ABL830/20
ctHb (g/dL)
sO2 (%)
FCOHb (%)
FM*
C55
C35
15
100
0
0.41
0.41
0.41
7
100
20
N/A
N/A
N/A
15
100
20
N/A
N/A
N/A
25
100
20
N/A
N/A
N/A
* FM = FLEXMODE (no message) ABL8x7 analyzer performance characteristics: S250 mode – bias: FCOHb (%)
Bias
ctHb (g/dL)
sO2 (%)
FCOHb (%)
15
100
0
0.36
7
100
20
N/A
15
100
20
N/A
25
100
20
N/A
S85 mode – bias: FCOHb (%)
Bias
ctHb (g/dL)
sO2 (%)
FCOHb (%)
15
100
0
N/A
7
100
20
N/A
15
100
20
N/A
25
100
20
N/A
C125 mode – bias: FCOHb (%)
Bias
ctHb (g/dL)
sO2 (%)
FCOHb (%)
15
100
0
0.43
7
100
20
N/A
15
100
20
N/A
25
100
20
N/A
C55 mode – bias: FCOHb (%)
Bias
ctHb (g/dL)
sO2 (%)
FCOHb (%)
15
100
0
N/A
7
100
20
N/A
15
100
20
N/A
25
100
20
N/A
C35 OXI mode – bias: FCOHb (%)
Bias
ctHb (g/dL)
sO2 (%)
FCOHb (%)
15
100
0
N/A
7
100
20
N/A
15
100
20
N/A
25
100
20
N/A
FHbF - fetal blood
The FHbF (%) – fetal blood – should read 80% instead of 0%:
S250 mode – bias: FHbF (%)
Bias
FHbF (%)
ctHb (g/dL)
80
10
5.9
80
15
3.3
80
20
2.6
S250 mode – imprecision: FHbF (%)
ctHb (g/dL)
sO2 (%)
S0
SD
SABL
SX
80
10
100
4
5
5
9
80
15
100
3
3
6
8
80
20
100
2
3
6
7
NOTES: a, b.
S85 mode – bias: FHbF (%)
Bias
FHbF (%)
ctHb (g/dL)
80
10
N/A
80
15
N/A
80
20
N/A
S85 mode – imprecision: FHbF (%)
ctHb (g/dL)
sO2 (%)
S0
SD
SABL
SX
80
10
100
4
5
6
9
80
15
100
3
3
6
8
80
20
100
2
3
6
7
NOTES: a, b.
C125 mode – bias: FHbF (%)
Bias
FHbF (%)
ctHb (g/dL)
80
10
5.9
80
15
3.3
80
20
2.6
C125 mode – imprecision: FHbF (%)
ctHb (g/dL)
sO2 (%)
S0
SD
SABL
SX
80
10
100
4
5
6
9
80
15
100
3
3
6
8
80
20
100
2
3
6
7
NOTES: a, b.
C55 mode – bias: FHbF (%)
Bias
FHbF (%)
ctHb (g/dL)
80
10
N/A
80
15
N/A
80
20
N/A
C55 mode – imprecision: FHbF (%)
ctHb (g/dL)
sO2 (%)
S0
SD
SABL
SX
80
10
100
4
5
6
9
80
15
100
3
3
6
8
80
20
100
2
3
6
7
C35 OXI mode – bias: FHbF (%)
Bias
FHbF (%)
ctHb (g/dL)
80
10
N/A
80
15
N/A
80
20
N/A
C35 OXI mode – imprecision: FHbF (%)
ctHb (g/dL)
sO2 (%)
S0
SD
SABL
SX
80
10
100
4
5
6
9
80
15
100
3
3
6
8
80
20
100
2
3
6
7
NOTES: a, b.
NOTES: a.
pH = 7.4 ± 0.1. FHbF is adjusted with the pH sensitivity to a nominal pH = 7.4. For further details please refer to the Interference Tests section for oximetry parameters.
b.
Specifications for imprecision are derived from worst-case values found during internal laboratory tests. 40 % relative is then added as a safety factor.
The certificate of traceability for Cleaning Met II solution has been missing in the manual.
Technical documentation
Data in this document will be added to the manual next time it is updated.
Radiometer Medical ApS Åkandevej 21 2700 Brønshøj Denmark www.radiometer.com
Contents
ABL800 FLEX
Reference manual
1.
Potentiometric measuring principles
2.
Amperometric measuring principles
3.
Optical measuring principles
4.
User-defined corrections
5.
Performance specifications
6.
Parameters
7.
Solutions and gas mixtures
Index
Date of Issue
System performance The procedures described in this manual must be observed in order to ensure proper system performance, and to avoid hazards. Radiometer cannot provide or verify system performance characteristics if the system is not installed, used and maintained in accordance with Radiometer procedures or if accessories not meeting the specifications provided by Radiometer are used. Radiometer warrants that the data media on which the software included in the system is furnished is free from defects in material and workmanship under normal use for three (3) months from the date of delivery as evidenced by a copy of invoice or receipt. Third-party software and trademarks The ABL800 FLEX analyzers comprise the Microsoft WindowsXP Embedded, VxWorks and Sybase SQL Anywhere software. By using the system, you accept the terms of the Software License Agreement(s) of the provider(s) of the above software as shown in the End User License Agreement(s) in the analyzer start up picture and to the terms of the Microsoft WindowsXP Embedded End-User Agreement included in the operator's manual. If you cannot accept the terms of the Software License Agreement(s), you should not use the system, but immediately contact your provider for a return of the system and a refund of the purchase price. Microsoft® and Windows® are trademarks of Microsoft Corporation. VxWorks is a registered trademark of WindRiver Systems Incorporated. Sybase SQL Anywhere is a registered trademark of Sybase Incorporated. Warranties and disclaimer Radiometer makes no warranties, express or implied, other than expressly stated. Any warranties expressly stated in this document are conditional upon the system being installed, used and maintained in accordance with Radiometer procedures, including that only accessories meeting the specifications provided by Radiometer are used. Radiometer disclaims any liability for system performance if the system is not installed, used and maintained in accordance with Radiometer procedures or if accessories not meeting the specifications provided by Radiometer are used. Further, Radiometer disclaims any liability for loss of data and direct, consequential or other damages, including loss of profit or loss of business, whether such claim for damages is based upon contract, negligence or tort (including strict liability), and even if Radiometer has knowledge of the possibility of the potential damage or loss.
Confidentiality The contents of this document shall not be reproduced or communicated to any third party without the prior written consent of Radiometer.
Changes This document is subject to change without notice. While every effort is made to ensure the correctness of the information provided in this document as changed from time to time, Radiometer disclaims any liability for errors and omissions. Radiometer, the Radiometer logo, ABL, AQT, TCM, RADIANCE, AQURE, PICO, CLINITUBES and QUALICHECK are trademarks of or used under license by Radiometer Medical ApS. © 2012 Radiometer Medical ApS. All rights reserved.
Contents 1. Potentiometric measuring principles ... 1-1 Overview...1-1 General information ...1-2 Reference electrode...1-8 pH electrode...1-9 pCO2 electrode ...1-15 Electrolyte electrodes...1-23 References...1-37
2. Amperometric measuring principles ... 2-1 Overview...2-1 General information ...2-2 pO2 electrode...2-4 Glucose and Lactate electrodes...2-13 Crea electrodes...2-23 References...2-31
3. Optical measuring principles... 3-1 Overview...3-1 Optical system...3-2 Correcting for interferences ...3-7 Measurement and corrections ...3-9 References...3-15
4. User-defined corrections ... 4-1 Overview...4-1 General information ...4-2 Correction factors for oximetry parameters and bilirubin...4-4 Electrolyte and metabolite parameters ...4-7
5. Performance characteristics ... 5-1 Overview...5-1 Definition of terms...5-3 Overview...5-6 Test conditions...5-7 Performance test results – chart description ...5-8 Performance test results – pH ...5-11 Performance test results – pCO2 ...5-13 Performance test results – pO2 ...5-16 Performance test results – cK+ ...5-19
Contents
ABL800 FLEX Reference Manual
Performance test results – cNa+ ...5-21 Performance test results – cCl– ...5-23 Performance test results – cCa2+ ...5-25 Performance test results – cGlu ...5-27 Performance test results – cLac ...5-29 Performance test results – ctHb ...5-31 Performance test results – oximetry...5-33 Performance test results – bilirubin ...5-43 Additional information about FLEXMODE ...5-49 Overview...5-50 Test conditions...5-51 Performance test results – pH, pCO2, pO2 ...5-52 Performance test results – electrolytes...5-60 Performance test results – cGlu, cLac...5-64 Performance test results – ctHb ...5-66 Performance test results – oximetry...5-69 Performance test results – bilirubin ...5-88 Performance test conditions and results – cCrea ...5-92 Interference tests ...5-112 References...5-124
6. Parameters ... 6-1 Overview...6-1 General information ...6-2 Measured parameters ...6-5 Input parameters ...6-14 Derived parameters ...6-17 Units of derived parameters ...6-22 List of equations...6-28 Oxyhemoglobin dissociation curve (ODC)...6-44 Conversion of units...6-49 Default values ...6-51 Altitude correction ...6-52 References...6-53
7. Solutions and gas mixtures ... 7-1 Overview...7-1 General information ...7-2 Calibration solutions ...7-3 Rinse and Cleaning solutions...7-6 Electrolyte solutions...7-8
ABL800 FLEX Reference Manual
Contents
S5362 Hypochlorite Solution...7-10 Gas mixtures (Gas 1 and Gas 2) ...7-11 Traceability certificates...7-12
Index Date of issue
Contents
ABL800 FLEX Reference Manual
1. Potentiometric measuring principles Overview Introduction
This chapter describes the potentiometric measuring principles and the pH, pCO2 and electrolyte electrodes that are based on this principle. Throughout this chapter, "ABL8xx FLEX" or "ABL8xx FLEX analyzer" is used for all ABL8xx FLEX analyzers, i.e.: ABL837/835/830/827/825/820/817/815/ 810/805 and ABL810 BG only. The abbreviation "ABL8x7 FLEX" or "ABL8x7 FLEX analyzer" is used for the ABL837/27/17 FLEX analyzers throughout this chapter.
Contents
This chapter contains the following topics. General information ...
1-2
Reference electrode...
1-8
pH electrode ...
1-9
pCO2 electrode ... 1-15 Electrolyte electrodes ... 1-23 References ... 1-37
1. Potentiometric measuring principles
ABL800 FLEX reference manual
General information Potentiometric method
The potential of an electrode chain is recorded using a voltmeter, and related to the concentration of the sample (the Nernst equation). An electrode chain describes an electrical circuit consisting of a sample, electrode, reference electrode, voltmeter, membranes and electrolyte solutions. Voltmeter
V
Reference electrode
Electrolyte solution
Sample
Membrane
Electrolyte solution
Electrode
Membrane
Every element in the electrode chain contributes a voltage to the total potential drop through the chain. Thus: When immersed in the appropriate electrolyte solution, both electrodes have separate potentials The membrane junctions between the sample and electrolyte solutions also have separate potentials The potentiometric measuring principle is applied to pH, pCO2 and electrolyte electrodes. Nernst equation The complete electrode chain potential therefore is the sum of these separate potentials and is the quantity measured by the voltmeter. Etotal = Esample – ERef where the final unknown potential (Esample) can be calculated knowing the total electrode chain potential (Etotal) and the reference potential (ERef is constant between two subsequent calibrations). Having measured the unknown potential (Esample), the Nernst equation is then applied to determine the activity (ax) of the species under study: 2.3RT log a x E sample E 0 nF where:
E0 R T
= = =
standard electrode potential gas constant (8.3143 Joule K1 mol1) absolute temperature (310 K (37 oC )) Continued on next page
1-2
ABL800 FLEX reference manual
1. Potentiometric measuring principles
General information, Continued Nernst equation (continued)
n F
= =
charge on the ion Faraday constant (96487 coulomb mol1)
ax
=
activity of x
The Nernst equation is rearranged to express the activity as a function of the potential Esample. Having measured Esample the activity can be calculated since all other quantities are already known. Finally the analyzer converts activity to concentration. Strictly speaking, the potential of an electrode chain or the magnitude of current flowing through an electrical chain is related to the activity of a substance, and not its concentration. Activity expresses the "effective concentration" of a species, taking non-ideality of the medium into account. Activity and concentration are related by the following equation: ax = cx
where: ax = the activity of the species x
= the activity coefficient of species x under the measurement conditions (for ideal systems = 1)
cx
= the concentration of species (mmol/L)
NOTICE: To be exact, activity is related to the molality of species x, i.e., the number of mmoles per kg of solvent. However, molality is converted to concentration (molarity).
The analyzer automatically converts activities into concentrations 1. The term concentration is therefore used in explanations of the measuring principles for each of the electrodes further on in this chapter. The potentiometric measuring principle is applied in the pH, pCO2 and electrolyte electrodes. It is slightly different for the pCO2 electrode, however, since the Nernst equation is not directly applied. Calibration
Calibration is an analytical process defining the functional relationship between the obtained readings or analytical responses and the concentration or other quantities present in the calibration material (liquid or gas). Thus, a calibrating solution or a gas mixture (for pCO2 calibrations) is drawn into the measuring chamber and the analyzer adjusts itself to measure the known value of the liquid or gas. Continued on next page
1-3
1. Potentiometric measuring principles
ABL800 FLEX reference manual
General information, Continued Calibration (continued)
The electrodes are active elements and must be calibrated regularly. Signals from the electrodes change because of, e.g., protein build-up, worn-out membranes, aging electrodes, etc. The responses from the electrodes when measuring on the calibrating solutions are checked to ensure that the amplified signals from the electrodes are converted to accurate values for an unknown sample. The relationship between the electrode amplifiers’ output and the pH/pCO2 /electrolyte electrodes are simple mathematical functions. Calibration data can therefore be determined by relating the electrode signals during the calibration process to the values of the calibrating solutions.
Calibration line The calibration line expresses the relationship between the potential measured at an electrode, and the concentration of the species specific to the electrode. The calibration line forms the basis of the scale used by the analyzer to convert electrode chain potentials to concentrations. Each electrode has a different calibration line.
The pH electrode is used as an example to illustrate how the calibration line is derived from two calibration solutions with known pH. The calibration solutions give the following two points: 64 mV at pH 6.802 (Cal 2) and 100 mV at pH 7.398 (Cal 1) Within the coverage range 6.300 to 8.000 the pH electrode is linear, and the relationship between potential and pH is linear, so a line can be drawn between the two points, as shown below: Measured potential (mV) 64
Calibration line
97 100
6.802
7.346 7.398
pH of Cal 2 sol.
pH of sample pH of Cal 1 sol.
This is a 2-point calibration. In 1-point calibration, only the position of the calibration line is determined. The slope of the calibration line is maintained from the last 2point calibration.
pH
The calibration line is stored in the computer and is used during measurement to convert the potential measured at the pH electrode during sample analysis to an actual pH value. Continued on next page
1-4