Blood glucose monitoring is an important part of comprehensive diabetes treatment, which provides an objective basis for disease progression and therapeutic intervention. A scientific blood glucose monitoring program can guide blood glucose control to reach the standard, delay the progress of complications, guarantee the effectiveness and safety of treatment, and at the same time save unnecessary medical resources consumption. Therefore, the standardized use of portable blood glucose testers (hereinafter referred to as blood glucose meters), which is one of the common methods for monitoring the effect of blood glucose control, is also gaining more and more attention. The Ministry of Health promulgated the “Management and Clinical Practice of Portable Blood Glucose Testers in Medical Institutions (for Trial Implementation)” in January 2011, and since then the use and management of blood glucose meters have a more unified standard.
Ensure the accurate measurement of blood glucose meter
Circumstances in which the blood glucose meter must be calibrated: when using for the first time; when using a new bottle of test strips; when suspecting problems with the blood glucose meter or test strips; after the blood glucose meter has fallen.
Calibration method: Use the simulated blood glucose solution of known concentration to calibrate, the simulated blood glucose solution is valid for 3 months after opening the bottle, and should not be stored at a temperature ≥ 30 ℃, nor should it be refrigerated or frozen.
There should not be blood stains, dust and other pollutants in the testing area of the blood glucose meter, and it is advisable to wipe it gently with a soft cloth dipped in water, without cleaning agents or organic solvents such as alcohol to clean the blood glucose meter.
Before measuring blood glucose, check whether the blood glucose meter functions normally and whether the power is sufficient; whether the blood glucose test paper is stored in a dry and cool place at 1 ℃~40 ℃, whether it is dry within the validity period, whether there are cracks and folds, etc.; ensure that the number (batch number) on the blood glucose meter is the same as the test paper number (batch number), etc.
Control of nosocomial infection
Blood collection needles are uniformly used with disposable blood collection needles to avoid cross-infection and puncture injuries caused by improper operation of medical and nursing staff.
In the control of nosocomial infection, we emphasize the disinfection of blood glucose meter and hand disinfection during the monitoring between 2 patients, and the timely disposal of needles and blood test paper to prevent the occurrence of infection from the source.
After each monitoring, the blood glucose monitoring results are uniformly registered on the patient’s bedside blood glucose monitoring form by the medical and nursing staff, and registered in the medical record once a day to achieve timely and accurate.
Understanding the influencing factors
Blood glucose results may be high in anemic patients measured by blood glucose meter, and low in erythrocytosis, dehydration or plateau area.
Excessive patient stress can raise blood glucose.
Patient’s use of certain medications can affect the measurement results, such as large amounts of vitamin C and glutathione can make the results low.
Intravenous drip of glucose will make the result high, and large amount of infusion will also affect the result.
Steps and precautions when measuring blood glucose by blood glucose meter
Before operation, medical personnel should wash their hands, prepare and check the relevant materials (including blood glucose monitor, matching blood glucose test paper, blood collection needle, finger prick pen, disinfection swab, disinfection solution, record book and pen).
(Dirt bucket, sharps box, dry hand sanitizer, etc.). Check and disinfect the patient’s finger, and collect blood after the disinfectant solution has dried. Select the blood collection needle according to the thickness of the finger epidermis, remove the protective cap, press the end firmly against the skin and press the button. Rotate the blood collection site alternately and do not prick one place for a long time to avoid forming scars. Blood collection from the side of the finger is less painful and has a sufficient amount of blood. After aspirating blood with the test paper, apply dry cotton swabs to gently press the needle eye of the patient’s finger, and after collecting blood, apply sufficient pressure to stop bleeding for 1 to 2 minutes and discard the blood collection needle in the sharps box. Turn the patient’s finger and gently squeeze both sides of the finger to make enough blood, avoid excessive massage and forceful squeezing of blood. Remove the test strip from the instrument, aspirate the blood by pressing the side of the test area against the blood drop and observe the blood covering the test area (the test area of the test strip turns completely red). Remove the used test paper and discard it in the dirt bucket, turn off the blood glucose meter, and explain the precautions before leaving. Immediately insert the test strip into the blood glucose meter, and do not move the test strip or shake the meter while reading the blood glucose value. For patients who need to monitor blood glucose for a long time, the patient should also be taught the method of blood glucose monitoring. Record the blood glucose value and monitoring time in the record book.
Procedure of blood glucose test operation specification
Preparation before testing
1. Check whether the test strips and quality control products are properly stored.
2.Check whether the expiration date and barcode of the test strips are in accordance.
3.Clean the blood glucose meter.
4.Check the expiration date of quality control products.
Blood glucose testing
1.Wipe the blood collection site with 75% ethanol and wait for the skin puncture after drying.
2.The blood collection site usually adopts peripheral capillary whole blood such as fingertips and both sides of the heel, and edema or infected parts are not suitable for blood collection.
3.After skin puncture, discard the first drop of blood and place the second drop of blood on the designated area on the test paper.
4. Perform the test in strict accordance with the operating instructions and operating procedures (SOP) provided by the instrument manufacturer.
5.The record of the measurement result includes the name of the tested person, date, time, result, unit and signature of the test person.
6. The following measures should be taken in case of abnormal blood glucose results: repeat the test once; take different intervention measures; retest intravenous biochemical blood glucose if necessary.
The main factors affecting the detection result of blood glucose meter
The blood glucose meter detects capillary whole blood glucose, while the laboratory detects venous serum or plasma glucose, the value of blood glucose meter with plasma calibration is closer to the laboratory value in fasting, and the capillary glucose value is slightly higher than the venous glucose after meal or taking sugar, if the value of blood glucose meter with whole blood calibration is about 12% lower than the laboratory value in fasting, the capillary glucose value is slightly higher than the venous glucose after meal or taking sugar. The glucose value is closer to the venous plasma glucose.
Since the terminal capillaries are the intersection of arteries and veins, there are both venous and arterial blood components, so the glucose content and oxygen content in their blood samples are different from those of venous blood samples.
Since most of the blood samples used in the blood glucose meter are whole blood, the red blood cell piezoelectricity has a greater influence. At the same plasma glucose level, the whole blood glucose detection value will gradually decrease as the red blood cell piezoelectricity increases. If the blood glucose meter with red blood cell piezometric correction can minimize this difference.
At present, the detection technology of blood glucose meter in clinical use adopts biological enzyme method, mainly there are two kinds of glucose oxidase (GOD) and glucose dehydrogenase (GDH), and GDH also needs to be combined with different coenzymes, which are pyrroloquinoline quinone glucose dehydrogenase (PQQ-GDH), flavin adenine dinucleotide glucose dehydrogenase (FAD-GDH) and nicotinamide adenine dinucleotide glucose dehydrogenase (NAD-GDH). (NAD-GDH). GOD glucose meter has high specificity for glucose and is not interfered by other sugar substances, but is easily interfered by oxygen. GDH glucose meter does not need the participation of oxygen and is not interfered by oxygen. The blood glucose meter of the PQQ-GDH principle cannot distinguish sugar substances such as maltose and galactose from glucose, and the mutation-modified Mut.Q-GDH principle blood glucose meter does not interfere with sugar substances such as maltose and xylose.
Interference of endogenous and exogenous drugs, such as acetaminophen, vitamin C, salicylic acid, uric acid, bilirubin, triglycerides, oxygen, maltose and xylose, are common interferers. When a large number of interfering substances are present in the blood, the blood glucose value will be deviated.
The pH value, temperature, humidity and altitude can all have an effect on the test results of blood glucose meters.