Identifying a suspected imbalance in electrolytes or acid/base imbalance
KS, NAS, CL: Potentiometric, Indirect Ion-Selective Electrode
HCO3: Photometric/Enzymatic
AGAP: Calculated Result
Electrolyte panel
Lytes
Serum
Patient's age and sex are required.
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 0.5 mL
Collection Instructions:
1. Serum gel tubes should be centrifuged within 2 hours of collection.
2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
0.4 mL
Gross hemolysis | Reject |
Gross lipemia | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated | 24 hours |
Identifying a suspected imbalance in electrolytes or acid/base imbalance
The electrolyte panel is ordered to identify electrolyte, fluid, or pH imbalance. Electrolyte concentrations are evaluated to assist in investigating conditions that cause electrolyte imbalances such as dehydration, kidney disease, lung diseases, or heart conditions. Repeat testing of the electrolyte or its components may be used to monitor the patient’s response to treatment of any condition that may be causing the electrolyte, fluid or pH imbalance.
Electrolyte and acid-base imbalances can often be indicative of many acute and chronic illnesses. For this reason, the electrolyte panel is often used in the hospital and emergency settings to evaluate patients.
SODIUM
<1 year: not established
> or =1 year: 135-145 mmol/L
POTASSIUM
<1 year: not established
> or =1 year: 3.6-5.2 mmol/L
CHLORIDE
<1 year: not established
1-17 years: 102-112 mmol/L
> or =18 years: 98-107 mmol/L
BICARBONATE
Males
<1 year: not established
1-2 years: 17-25 mmol/L
3 years: 18-26 mmol/L
4-5 years: 19-27 mmol/L
6-7 years: 20-28 mmol/L
8-17 years: 21-29 mmol/L
> or =18 years: 22-29 mmol/L
Females
<1 year: not established
1-3 years: 18-25 mmol/L
4-5 years: 19-26 mmol/L
6-7 years: 20-27 mmol/L
8-9 years: 21-28 mmol/L
> or =10 years: 22-29 mmol/L
ANION GAP
<7 years: not established
> or =7 years: 7-15
With an imbalance of a single electrolyte, such as sodium or potassium, repeat testing may be ordered of that particular electrolyte, can be used to monitor the imbalance until remedied. With an acid-base imbalance, blood gases may be ordered, which will measure the oxygen, carbon dioxide, and pH levels in the arterial blood. These tests assist in evaluating the acuteness of the imbalance and monitoring the response to treatment.
No significant cautionary statements
1. Oh MS: Evaluation of renal function, water, electrolytes, and acid-base balance. In Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd edition. Edited by RA McPherson, MR Pincus. Philadelphia, PA: Elsevier Saunders; 2011:chap 14
2. AACC: Lab Tests Online: Access 03/22/2017. Available at https://labtestsonline.org/understanding/analytes/electrolyes
KS, NAS, CL:
Ion-selective electrode (ISE) (indirect potentiometry). The ISE module performs indirect measurement of electromotive force (EMF). The ISE module measures the EMF difference between an ion-selective electrode and a reference electrode. The EMF of the ion-selective electrode is dependent on the ion concentration of the sample. The EMF of the reference electrode is constant. An electronic calculation circuit converts EMF of the sample to the ion concentration of the sample.(Package insert: Roche Diagnostics ISE reagent; Indianapolis, IN, 2006)
HCO3:
This is a photometric rate reaction. Bicarbonate (HCO3-) reacts with phosphoenolpyruvate (PEP) in the presence of phosphoenolpyruvate carboxylase (PEPC) to produce oxaloacetate and phosphate. The oxaloacetate produced is coupled with NADH in the presence of malate dehydrogenase (MDH) to produce malate and NAD. The consumption of NADH causes a decrease in absorbance and is monitored in the UV range of 320 nm to 400 nm. The rate of change is directly proportional to the concentration of bicarbonate.(Package insert: Roche Bicarbonate reagent, Indianapolis, IN, July 2000)
AGAP:
This is a calculated result. The following equation is used to calculate the anion gap (A gap):
A gap = Na - (Cl + HCO3)
Monday through Sunday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
80051-Electrolyte Panel (if all 4 are performed)
82435-Chloride (if all 4 are not performed)
84295- Sodium (if all 4 are not performed)
84132-Potassium (if all 4 are not performed)
82374-Bicarbonate (if all 4 are not performed)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
ELPSR | Electrolyte Panel, S | 24326-1 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
AGAP | Anion Gap | 33037-3 |
CL | Chloride, S | 2075-0 |
HCO3 | Bicarbonate, S | 1963-8 |
NAS | Sodium, S | 2951-2 |
KS | Potassium, S | 2823-3 |