SIGMA DIAGNOSTICS ELECTROLYTE BUFFER

K963540 · Sigma Diagnostics, Inc. · JFL · Sep 27, 1996 · Clinical Chemistry

Device Facts

• Record ID: K963540
• Device Name: SIGMA DIAGNOSTICS ELECTROLYTE BUFFER
• Applicant: Sigma Diagnostics, Inc.
• Product Code: JFL · Clinical Chemistry
• Decision Date: Sep 27, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1160
• Device Class: Class 2

Intended Use

The Sigma Diagnostics methods use ion selective electrodes for determining sodium, potassium, and chloride and rate of pH change for determining carbon dioxide on the SYNCHRON CX®3 System.

Device Story

Reagent buffer for use on SYNCHRON CX®3 System; facilitates measurement of sodium, potassium, chloride, and CO2. Input: serum, plasma, urine, or CSF samples. Principle: ion selective electrodes for Na, K, Cl; rate of pH change for CO2. Output: quantitative analyte concentrations. Used in clinical laboratory settings by trained technicians. Results assist clinicians in diagnosing electrolyte imbalances associated with conditions like congestive heart failure, renal failure, Addison’s disease, and metabolic acid-base disorders.

Clinical Evidence

Bench testing only. Comparison studies performed against predicate device using serum, urine, and CSF samples. Correlation coefficients ranged from 0.891 to 0.999. Precision studies demonstrated within-run and total precision %CVs < 1.9% across all analytes and sample types. Linearity established for sodium (10-200 mmol/L), potassium (1-200 mmol/L), chloride (15-300 mmol/L), and CO2 (5-40 mmol/L) depending on sample matrix.

Technological Characteristics

Chemical reagent buffer for ion selective electrode (ISE) and pH-rate analysis. Designed for use on SYNCHRON CX®3 automated clinical chemistry analyzer. No electronic or software components integral to the reagent itself; relies on host system hardware for sensing and processing.

Indications for Use

Indicated for the measurement of sodium, chloride, potassium, and carbon dioxide concentrations in serum or plasma, sodium, potassium, and chloride concentrations in urine, and chloride concentrations in CSF on the SYNCHRON CX®3 System.

Regulatory Classification

Identification

A bicarbonate/carbon dioxide test system is a device intended to measure bicarbonate/carbon dioxide in plasma, serum, and whole blood. Bicarbonate/carbon dioxide measurements are used in the diagnosis and treatment of numerous potentially serious disorders associated with changes in body acid-base balance.

Predicate Devices

• Beckman Electrolyte Buffer Kit, Part No. 443325

Submission Summary (Full Text)

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K963540
SEP 27 1996

# 510(K) NOTIFICATION

Sigma Diagnostics
545 South Ewing Avenue
St. Louis, MO 63103

CX®3 Electrolyte Buffer
Procedure Number E3766
August 31, 1996

## SUMMARY OF SAFETY AND EFFECTIVENESS

Increased sodium levels are seen in congestive heart failure, nephrosis, hyperlipidemia and hyperglycemia. Decreased levels can be observed with excessive sweating and vomiting, with different types of diabetes, and with use of diuretic drugs.

Increased potassium levels can be due to renal failure and decrease mineralocorticoid activity such as in Addison’s disease. Decreased potassium levels can be caused by renal and adrenal conditions with metabolic alkalosis or acidosis.

Increased chloride levels may be due to hyperparathyroidism. Low levels may be due to Addison’s disease, intestinal obstruction, rickettsial disease and Waterhouse-Friderichsen Syndrome.

The CO₂ content is decreased in metabolic acidosis and respiratory alkalosis, whereas the level is increased in metabolic alkalosis and respiratory acidosis.

The Sigma Diagnostics methods use ion selective electrodes for determining sodium, potassium, and chloride and rate of pH change for determining carbon dioxide on the SYNCHRON CX®3 System.

The safety and effectiveness of Sigma Diagnostics Electrolyte Buffer, Procedure Number E3766, are demonstrated by its substantial equivalency to Beckman Electrolyte Buffer Kit, Part No. 443325. Both electrolyte buffers are used to measure sodium, chloride, potassium, and carbon dioxide concentrations in serum or plasma, sodium, potassium, and chloride concentrations in urine, and chloride concentrations in CSF on the SYNCHRON CX®3 System, and the reaction principles for both reagents are identical. In comparison studies, the following data was obtained:

| Serum Analyte | Correlation Coefficient | Regression equation |
| --- | --- | --- |
| Sodium | 0.963 | y = 0.90x + 13.48 |
| Potassium | 0.999 | y = 0.98x + 0.08 |
| Chloride | 0.973 | y = 0.91x + 10.52 |
| Total CO₂ | 0.992 | y = 0.95x + 1.54 |
| Urine Analyte | Correlation Coefficient | Regression equation |
| Sodium | 0.997 | y = 0.95x - 0.10 |
| Potassium | 0.998 | y = 0.97x + 0.49 |
| Chloride | 0.997 | y = 0.97x + 2.06 |

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510(K) NOTIFICATION

Sigma Diagnostics

545 South Ewing Avenue

St. Louis, MO 63103

CX®3 Electrolyte Buffer

Procedure Number E3766

August 31, 1996

# SUMMARY OF SAFETY AND EFFECTIVENESS(cont.)

| CSF Analyte | Correlation Coefficient | Regression equation |
| --- | --- | --- |
| Chloride | 0.891 | y = 0.98x + 4.00 |

With-in run precision and total precision for sodium demonstrated %CV's of less than 1.1 % on serum samples and less than 1.2 % on urine samples. With-in run precision and total precision for potassium demonstrated %CV's of less than 1.0 % on serum samples and less than 1.6 % on urine samples. With-in run precision and total precision for chloride demonstrated %CV's of less than 1.3 % on serum samples, less than 1.9 % on urine samples, and less than 1.8 % on CSF samples. The Sigma Diagnostics Electrolyte Buffer has been determined to be linear to the following limits on the SYNCHRON CX®3 System:

| Analyte | Serum (mmol/L) | Urine (mmol/L) | CSF (mmol/L) |
| --- | --- | --- | --- |
| Sodium | 100.0 - 200.0 | 10 - 200 | NA |
| Potassium | 1.00 - 15.00 | 2 - 200 | NA |
| Chloride | 50.0 - 200.0 | 15 - 300 | 50 - 200 |
| Total CO₂ | 5.0 - 40.0 | NA | NA |