serum sodium

Serum sodium refers to the concentration of sodium ions in the serum. Sodium ion is the most abundant cation in extracellular fluid (such as blood), which is important for maintaining extracellular fluid volume, regulating acid-base balance, maintaining normal osmotic pressure and cell physiological function, and participating in maintaining normal neuromuscular stress. . The change of sodium concentration in extracellular fluid can be caused by the change of any content of water and sodium, so the disorder of sodium balance is often accompanied by water balance disorder. The normal metabolism and balance of water and sodium are important factors in maintaining the stability of the human body. Therefore, serum sodium determination has important clinical significance, especially for the treatment of dehydration. Basic Information Specialist classification: inspection classification: biochemical examination Applicable gender: whether men and women apply fasting: fasting Tips: Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. Normal value The enzymatic analysis was 136 to 146 mmol/L (136 to 146 mEq/L). The ion selective electrode method is 145 to 155 mmol/L (145 to 155 mEq/L). Clinical significance 1, increased clinically less common, can be seen in 1 severe dehydration, excessive sweating, high fever, burns, diabetic polyuria. 2 adrenal hyperfunction, primary or secondary aldosteronism, cerebral hypernatremia (brain trauma, cerebrovascular accident and pituitary tumors, etc.). 3 improper diet or treatment leads to excessive intake of sodium. 2, reduce 1 kidney loss of sodium, such as renal cortical insufficiency, severe pyelonephritis, diabetes and so on. Increased urinary sodium excretion, severe damage to the renal tubules, reduced reabsorption, and a large loss of sodium in the urine. 2 gastrointestinal loss of sodium (such as gastrointestinal drainage, pyloric obstruction, vomiting and diarrhea). 3 Apply excessive antidiuretic hormone. 4 heart failure, kidney failure, excessive water supply. 5 hyperlipidemia, due to more lipids in the serum, sodium concentration decreased. 6 cardiovascular diseases, such as congestive heart failure, acute myocardial infarction, etc. can cause hyponatremia. 7 brain diseases such as encephalitis, brain trauma, cerebral hemorrhage, brain abscess, meningitis, etc., due to a series of neurohumoral factors leading to a decrease in serum sodium. After extensive burns, trauma, loss of sodium in the skin, and sweating, body fluids and sodium are largely lost from the wound surface, only water is added and the electrolyte is added. Low results may be diseases: hyponatremia, hyperosmolar dehydration results may be high disease: hypernatremia, adrenal crisis precautions 1 linear range of the law: Na+ direct method: 100 to 180 mmol/L (serum). 30 to 190 mmol/L (urine). Indirect method: 100 to 180 mmol/L (serum). 25 ~ 150mmol / L (urine). 2 Hemolysis, anticoagulant containing ammonium ions, sodium citrate, oxalate and EDTA interfered with the test. 3 Determination of potassium and sodium in urine by ISE method has a limited linear range and is susceptible to interference by ionic components in urine. 4 Certain drugs, such as iodine phosphate, can act on the electrode membrane by iodine, causing a K+ pseudo-reduction. Commercial quality control serum often uses ethylene glycol as a protective agent. When the content reaches 30% (common concentration of ethylene glycol), it will cause positive interference to the Na+ measurement, and the deviation is 4.0% to 9.5%, which cannot be ignored. 5 The temperature affects the activity of the ions, so the specimens and reagents that have just been taken out of the refrigerator should be returned to room temperature for measurement. Inspection process Ion selective depolarization There are two methods for measuring sodium using an ion selective electrode, one is a direct potential method and the other is an indirect potential method. 1 Direct potential method: sample (serum, plasma, whole blood) or standard solution directly into the ISE pipeline for potential analysis without dilution. This method can truly reflect the activity of ions in serum that is physiologically significant, so the reporting method is serum sodium mmol/L activity. 2 Indirect potential method: the sample (serum, plasma, cerebrospinal fluid) and the standard solution should be diluted with a dilution of the specified ionic strength and pH, and then sent to the electrode tube to determine its potential. At this time, the pH of the sample and the standard solution are The ionic strength tends to be uniform, and the ion activity of the measured solution is equal to the ion concentration. Reported in mmol/L concentration. Different models of ISE analyzers operate differently. Generally, the following steps are required: A. Turn on the instrument and clean the pipe. The electrode is activated with an activating solution. B. Two-point calibration with a low and high value slope calibrator suitable for the instrument. C. The sample of the indirect potential method is automatically diluted by the instrument and then measured. The direct potential method can directly measure the sample into the electrode tube. D. The measurement result is calculated by computer processing in the instrument and the data is printed out. E. After using it every day, clean the electrodes and pipes and then turn off the power, or not. Not suitable for the crowd No indication of indications. Adverse reactions and risks Discomfort: There may be pain, swelling, tenderness, and visible subcutaneous ecchymosis at the puncture site.