METLYTE 8 CHEM PANEL (PICCOLO)

Effective Date: 
Thu, 12/20/2012
Reviewed: 
Tue, 01/10/2017
Policy: 

Prinicipal

The Piccolo® Metlyte 8 Reagent Disc, used with the Piccolo Blood Chemistry Analyzer or the Piccolo xpress™ Chemistry Analyzer, is intended to be used for the
in vitro quantitative determination of chloride, creatine kinase, creatinine, glucose,
potassium, sodium, total carbon dioxide and blood urea nitrogen (BUN) in heparinized whole blood, heparinized plasma, or serum.

The tests on this panel are waived under CLIA ‘88 regulations. If a laboratory modifies the test system instructions, then the tests are considered high complexity and subject to all CLIA requirements. For CLIA waived labs, only lithium heparin whole blood may be tested. For use in moderate complexity labs, lithium heparinized whole blood, lithium heparinized plasma, or serum may be used.

The Piccolo Metlyte 8 Reagent Disc and the Piccolo Blood Chemistry Analyzer or
the Piccolo xpress Chemistry Analyzer comprise an in vitro diagnostic system that aids the physician in diagnosing the following disorders.

 

  • Chloride: Dehydration, prolonged diarrhea and vomiting, renal tubular disease, hyperparathyroidism, burns, salt-losing renal diseases, overhydration and thiazide therapy.
  • Creatine Kinase: Myocardial infarction, progressive muscular dystrophy, dermatomyositis, rhabdomyolysis due to drug ingestion, hyperosmolality, autoimmune disease, delirium tremens, convulsions, Crush syndrome, hypothyroidism, surgery, severe exercise, intramuscular injection, physical inactivity, decreased muscle mass.
  • Creatinine: Renal disease and monitoring of renal dialysis.
  • Glucose: Carbohydrate metabolism disorders, including adult and juvenile diabetes mellitus and hypoglycemia, hypopituitarism, pancreatitis and renal disease.
  • Potassium: Renal glomerular or tubular disease, adrenocortical insufficiency, diabetic ketacidosis, excessive intravenous potassium therapy, sepsis, panhypopituitarism, in vitro hemolysis, hyperaldosteronism, malnutrition, hyperinsulinism, metabolic alkalosis and gastrointestinal loss.
  • Sodium: Dehydration, diabetes insipidus, loss of hypotonic gastrointestinal fluids, salt poisoning, selective depression of sense of thirst, skin losses, burns, sweating, hyperaldosteronism, CNS disorders, dilutional, depletional and delusional hyponatremia and syndrome of inappropriate ADH secretion.
  • Total Carbon Dioxide: Primary metabolic alkalosis and acidosis and primary respiratory alkalosis and acidosis.
  • Blood urea nitrogen (BUN): Renal and metabolic diseases.

See the Piccolo Blood Chemistry Analyzer or the Piccolo xpress Chemistry Analyzer Operator’s Manual, for the Principles and Limitations of the Procedure.

 

Reagents

Each Piccolo Metlyte 8 Reagent Disc contains dry test-specific reagent beads.  A dry sample blank reagent (comprised of buffer, surfactants, excipients and preservatives) is included in each disc for use in calculating concentrations of chloride (CL-), creatine kinase (CK), glucose (GLU), potassium (K+), sodium (NA+), total carbon dioxide (tCO2) and blood urea nitrogen (BUN). A dedicated sample blank is included in the disc to calculate concentrations of creatinine (CRE). Each disc also contains a diluent consisting of surfactants and preservatives.

Instructions for Reagent Handling

Reagent discs may be used directly from the refrigerator without warming. Do not allow discs sealed in their foil pouches to remain at room temperature longer than 48 hours prior to use.
Open the sealed foil pouch, remove the disc and use according to the instructions provided in the Piccolo Blood Chemistry Analyzer or the Piccolo xpress Chemistry Analyzer Operator’s Manual. A disc not used within 20 minutes of opening the pouch should be discarded.

Storage

Store reagent discs in their sealed pouches at 2-8°C (36-46°F). Do not expose opened or unopened discs to direct sunlight or temperatures above 32°C (90°F). Reagent discs may be used until the expiration date included on the package. The expiration date is also encoded in the bar code printed on the bar code ring. An error message will appear on the Piccolo Blood Chemistry Analyzer or the Piccolo xpress Chemistry Analyzer Display if the reagents have expired.

Indications of Reagent Disc Instability/Deterioration

A torn or otherwise damaged pouch may allow moisture to reach the unused disc and adversely affect reagent performance. Do not use a disc from a damaged pouch.

Sample Collection and Preparation

The minimum required sample size is ~100 μL of heparinized whole blood, heparinized plasma, serum or control material. The reagent disc sample chamber can contain up to 120 μL of sample.

Whole blood samples obtained by venipuncture must be homogeneous before transferring a sample to the reagent disc. Gently invert the collection tube several times just prior to sample transfer. Do not shake the collection tube; shaking may
cause hemolysis.

Hemolysis may cause erroneously high results in potassium assays. This problem may go undetected when analyzing whole blood (release of potassium from as few as 0.5% of the erythrocytes can increase the potassium serum level by 0.5 mmol/L). In addition, even unhemolyzed specimens that are not promptly processed may have increased potassium levels due to intracellular potassium leakage.

Whole blood venipuncture samples should be run within 60 minutes of collection.

Refrigerating whole blood samples can cause significant changes in concentration of creatinine. The sample may be separated into plasma or serum and stored in capped sample tubes at 2-8°C (36-46°F) if the sample cannot be run within
60 minutes.

Use only lithium heparin (green stopper) evacuated specimen collection tubes for whole blood or plasma samples. Use no-additive (red stopper) evacuated specimen collection tubes or serum separator tubes (red or red/black stopper) for serum samples.

The concentration of total carbon dioxide is most accurately determined when
the assay is done immediately after opening the tube and as promptly as possible after collection and processing of the blood in the unopened tube. Ambient
air contains far less carbon dioxide than does plasma, and gaseous dissolved carbon dioxide will escape from the specimen into the air, with a consequent decrease in carbon dioxide value of up to 6 mmol/L in the course of 1 hour.

Calibration

The Piccolo Blood Chemistry Analyzer or the Piccolo xpress Chemistry Analyzer is calibrated by the manufacturer before shipment. The bar code printed on the bar code ring provides the analyzer with disc-specific calibration data.

Quality Control

Controls should be run with each new lot # or each new shipment of reagents or every 30 days, whichever comes sooner. Run both levels of NOD Liquid Assayed Chemistry + Lipid controls (Nova-One Diagnostics).

Enter controls in Harvest LIS. Do not report patient results if controls do not fall within the designated ranges.

 

 

Procedure: 

Preparing the Reagent Disc

Note: Analysis must begin immediately (no more than 10 minutes) after dis-pensing the sample into the reagent disc.

CAUTION: Discs are fragile — always handle with care. Do not tap discs on the table or work bench to empty the sample port. Do not use a disk that has been dropped.
Inspect every reagent disc for damage before use.Never use a damaged disc.

Dispense the Sample

Use a micropipette (one is included with the piccolo xpress™) or other transfer device to dispense approximately 100 μL of sample into the disc via the sample chamber.

Fill the sample chamber.

  1. Using the Piccolo 100 μl volume pipette, firmly attach a new tip to the end of the pipette. DO NOT touch the tip (this could cause a false elevation of amylase).
  2. With your index finger or thumb, push the pipette button to the stop position and hold it down for sample pickup.
  3. Immerse the tip 2–3 mm below the surface of the sample, as shown at right.
  4. SLOWLY release the button to pick up the sample. Pause, then remove the pipette from the sample tube.
  5. Make sure there are no air bubbles or air gaps in the pipette tip.
  6. Place the pipette tip into the disc’s sample chamber, and tilt the disc to 45° with the sample port above the fill line, so that the entire sample flows into the sample chamber. The tip should touch the sample chamber.
  7. Push the plunger down with a slow, continuous motion. Take care not to overfill the sample chamber. A 90 μL sample will fill the sample chamber and form a line between the two arrows molded on the disc. More than 120 μL of sample will overfill the chamber.
  8. Discard the pipette tip into a biohazard container.
  9. Clean the reagent disc. Use a lint-free tissue to remove any sample spilled on the outside of the disc, taking care that the tissue does not withdraw any sample from the sample port. Dispose of the tissue in a biohazard container.

Running a Patient Sample

  1. Turn on the analyzer by pressing the Power button on the front of the analyzer. Do this before removing reagent discs from the refrigerator.
  2. The analyzer starts up, then performs a self test. If the analyzer needs time to warm the disc chamber to operating temperature, the display shows “Warming Up.” When the analyzer reaches operating temperature, it displays “Analyze” on the Home screen, as shown at right.
  3. Press Analyze on the touchscreen to open the disc drawer.
  4. Place the disc in the recessed area in the drawer.
  5. Press CLOSE on the touchscreen. The analyzer then closes the drawer.
  6. Enter the operator ID (tech initials) using the attached keyboard, then press Done.
  7. Select the sample type from those shown in the display.
  8. Enter an ID number for the patient (SID number) then press Done.
  9. Enter an ID number for the sample (Acc#), then press Done.
  10. The analyzer then checks the disc type, and begins processing the sample.
     

Results

The results calculated by the analyzer are stored in memory and printed automatically, and can also be recalled and printed later as needed.

Each reagent disc contains reagents to detect exposure to extreme conditions such as temperature and humidity. The message “QC OK” is printed on the results when results from these reagents are within the expected ranges. Otherwise, no results are printed, and the analyzer opens the disc drawer.

Results outside the reference range are indicated in the results by an asterisk (*) printed next to the analyte concentration.

Results outside the dynamic range are indicated in the results by a “less than” sym
bol (<) printed next to the lowest value of the dynamic range, or a “greater than”
symbol (>) printed next to the highest value of the dynamic range. For example, the dynamic range of glucose is 10–700 mg/dL. A sample concentration of glucose below this range would be printed as <10 mg/dL, and a concentration above this range would be printed as >700 mg/dL. Results outside the dynamic range should be reported as being below or above the value indicated.

The symbols “~~~” are printed in place of numbers when a result cannot be deter-
mined — that is, when the result is suppressed. A result may be suppressed due to improper mixing of a reagent bead with diluted sample, a nonlinear reaction, an
endpoint of a particular reaction not reached, or a concentration outside the ana-
lyzer’s capabilities. When a chemistry is suppressed (~~~), the analyzer prompts
the operator to print an error report.

HEM, LIP, or ICT is printed in place of the analyte concentration if hemolysis,
lipemia, or icterus, respectively, has adversely affected the results. LIP is also
printed if both lipemia and icterus have been affected. HEM is also printed if
hemolysis and icterus, hemolysis and lipemia, or hemolysis, lipemia, and icterus
have affected a particular analyte. Examine the sample indices to determine if
more than one interferent is affecting a particular result.

The sample indices are included at the bottom of the results printout. These indices
indicate the degree of hemolysis, icterus,and lipemia found in the sample. Hemol-
ysis, icterus, and lipemia are measured on a scale of 0 (clear), 1+ (slight), 2+ (mod-
erate), and 3+ (gross).

Normal Ranges

Chloride
98-108 mmol/L

Creatine Kinase (Female)
30-190 U/L

Creatine Kinase (Male)
39-380 U/L

Creatinine
0.6-1.2 mg/dL

Glucose
73-118 mg/dL

Potassium
3.6-5.1 mmol/L

Sodium
128-145 mmol/L

Total Carbon Dioxide
18-33 mmol/L

Blood Urea Nitrogen (BUN)
7-22 mg/dL

Key Points: 

Limitations of Procedure

The only anticoagulant recommended for use with the Piccolo Blood Chemistry or the Piccolo xpress Chemistry Analyzer System is lithium heparin. Abaxis has performed studies demonstrating that EDTA, fluoride, oxalate and any anticoagulant containing ammonium ions will interfere with at least one chemistry contained in the Piccolo Metlyte 8 Reagent Disc.

Samples with hematocrits in excess of 62-65% packed red cell volume (a volume fraction of 0.62-0.65) may give inaccurate results. Samples with high hematocrits may be reported as hemolyzed. These samples may be spun down to get plasma then re-run in a new reagent disc.

Any result for a particular test that exceeds the assay range should be analyzed by another approved test method or sent to a referral laboratory. Do not dilute the sample and run it again on the Piccolo Blood Chemistry Analyzer or the Piccolo xpress Chemistry Analyzer. 

Warning:Extensive testing of Piccolo Blood Chemistry Analyzer or the Piccolo xpress Chemistry Analyzer System has shown that, in very rare instances, sample dispensed into the reagent disc may not flow smoothly into the sample chamber. Due to the uneven flow, an inadequate quantity of sample may be analyzed and several results may fall outside the reference ranges. The sample may be re-run using a new reagent disc.

The Piccolo Blood Chemistry System or the Piccolo xpress Chemistry Analyzer
suppresses any results that are affected by >10% interference from hemolysis, lipemia or icterus. “HEM”, “LIP”, or “ICT” respectively, is printed on the result card
in place of the result.

Extremely elevated amylase levels (>9,000 U/L) will have a significant effect, >10% increase, on the chloride result. The concentration of amylase is not evaluated
by the Piccolo system for each specimen.

The potassium assay in the Piccolo system is a coupled pyruvate kinase (PK) / lactate dehydrogenase (LDH) assay. Therefore, in cases of extreme muscle trauma or highly elevated levels of creatine kinase (CK), the Piccolo may recover a falsely elevated potassium (K+) value. In such cases, unexpected high potassium recoveries need to be confirmed utilizing a different methodology.

References

Piccolo Metlyte 8 Reagent Disc Package Insert Dec 2009 Rev G Abaxis, Inc

Piccolo xpress Chemistry Analyzer Operators Manual 2007 Rev C Abaxis, Inc