In the morning, the doctor looked at the results of the 35-bed patient and wondered how the lactic acid value had risen so much after only one day. The doctor called the laboratory and asked for a new blood, but the results were still high.
Just when the doctor was puzzled, the nurse who passed by said that the patient had been found by the night nurse who had secretly drunk alcohol last night. The morning night nurse didn't want to draw his blood, and he insisted on drawing it, saying he was responsible for the results.
The doctor suddenly understood that this was a diabetic patient who needed to draw blood for re-examination this morning. Nurses had informed him yesterday that he was going to take blood on an empty stomach this morning, but this patient secretly drank alcohol last night, resulting in an increase in lactic acid.
Blood samples are an important basis for doctors to diagnose diseases and formulate treatment plans, and every link of the correct retention, collection, transportation and laboratory tests of specimens is crucial. When the test results are abnormal, most people will attribute the problem to the blood collection technology of the laboratory department, or think that there is a problem in the laboratory department, but few think that the patient is also one of the influencing factors. These 4 factors of the patient will affect the test results.
Psychological factors
Case
Sister Jiao took the intern Xiao Xiao to collect blood. The patient said he was a little nervous and scared. Sister Jiao did not rush to let Xiao Xiao go to collect blood, but let her chat with the patient first, and when the patient said that she was completely relaxed, she instructed Xiao Xiao to draw blood.
After the blood was drawn, Jiaojie told Xiaoxiao that for patients who are nervous or have experience of blood sickness, we must first let the patient relax, because the emotion will also lead to obvious changes in the patient's breathing and heart rate, which in turn will lead to changes in blood composition, so that the test results are abnormal.
Explained
A variety of factors, such as patients with needle sickness, concerns about laboratory blood collection techniques, and fear and anxiety about blood collection, can change a patient's breathing and heart rate. When breathing is accelerated or slowed, the pH of the blood will be correspondingly increased or decreased, which will affect the binding of calcium ions in the blood to proteins, which will cause the serum calcium test value to deviate. When the patient is extremely afraid or nervous, severe pain, the blood hemoglobin and white blood cells will also increase.
Response
After the doctor prescribes the test form, we should communicate with the patient, inform the patient of the time and project to draw blood, and eliminate the patient's nervousness and fear. Before blood collection, we should also explain the precautions to the patient, do a good job of psychological care, let the patient relax, so that the patient can collect blood in a quiet state, and avoid affecting the quality of blood samples due to mental tension or fear.
If a patient encounters a needle in the outpatient or emergency department, it is recommended to take a recumbent position and divert their attention to prevent fainting during blood collection.
Dietary factors
The 45-bed patient had to draw blood the next day. In the evening, the patient took leave to go home and said that he would come back on time tomorrow morning to draw blood. The nurse told him not to eat again after dinner. The patient said he knew.
The next day, the results of the blood draw showed an increase in blood ammonia and plasma urea. The doctor asked. The patient said that the night before, a relative at home sent many shrimp and crabs, he did not hold back for a while, he ate some, did not expect to lead to abnormal results in blood draw.
The day before the blood collection, the nurse will inform the patient to fast in the morning and fast water to draw blood, but there are always some patients who do not tell the nurse after eating, resulting in abnormal blood sample results.
After eating, the proportion of blood components in the human body will change, making the test results inaccurate, such as a high-fat diet will greatly increase triglycerides. If it is after a meal, the serum in the collected blood will appear chylolisthea. Drinking water will also make the blood temporarily dilute hemoglobin, and the red blood cell measurement results are low.
On the other hand, patients who spend more than 16 hours on an empty stomach will also reduce albumin, blood sugar levels, and increase blood bilirubin.
1, a few days before blood collection should be a light diet, blood collection in the early morning to fasting, the patient who checks blood lipids should avoid eating high-fat foods 1d before blood draw; blood lipid examination must be drawn after 12h on an empty stomach (and meat, eggs and milk are forbidden to eat 3d before the examination).
2. It is best to collect blood from 7:00-9:00 a.m. on the same day, and indicate the time of blood collection in the laboratory form. Urgent and special patients can draw blood at any time as needed, and the time of blood collection should be indicated on the test sheet so that clinicians can comprehensively analyze the test report according to their particularity.
3. Items with special requirements for blood samples and testing time should contact the laboratory department, and indicate the inspection requirements after detailed inquiry and send them for examination in time.
Drug factors
A patient came to check and the test result was high in cholesterol. The patient expressed doubts because he usually had a very light diet, how could he have such high cholesterol. Under the detailed inquiry of the doctor, it was found that the patient often took vitamins on their own, especially after hearing that more vitamin D supplementation was needed to supplement calcium, so they took it for a long time. Didn't expect to cause elevated cholesterol.
The effect of drugs on the test results is very complex, a variety of drugs interfere with the test results, such as isoniazid, rifampicin, butamikacin, etc. can increase the ammonia transaminases, aspartate aminotransferase; ACTH, diuretics, glucose large long-term transfusion, gentamicin, etc. can reduce blood potassium; long-term application of thiazide diuretics, vitamin A, vitamin D, etc. can increase cholesterol; a large number of penicillins will make liver anhydride, albumin, total protein and aspartate aminotransferase and other liver function indicators can be falsely reduced Aspirin can raise blood sugar by affecting the metabolism of blood sugar.
1. The influence of drugs on the test results is very complex, and it is advisable to suspend various drugs before sampling and examination. If a drug is not discontinued, it is important to understand the possible effects on test results.
2. When drug monitoring, blood should be collected according to the peak and stabilization period of drug concentration.
3. When the patient is infused, if emergency blood collection is required, blood should be collected in the limb on the opposite side of the infusion; blood should be collected after infusion, at least 1h after infusion. If bacterial cultures are required, blood should preferably be taken when the patient has a fever before antibiotics are used.
Motor factors
The 21-bed patient had a high blood potassium result, and the doctor asked the nurse whether he was drawing blood from the infusion limb or whether the blood sample had been left for too long. The nurse said no. Later, under the doctor's questioning, the patient said that he did not feel that there was any big problem, so he went out in the morning to take the morning transport. Worried that he would not be able to catch up with the nurse's blood collection time, he trotted all the way back.
Exercise can also lead to abnormal test results, because after strenuous exercise, breathing is accelerated, resulting in a significant change in the amount of body fluids and its distribution. Studies have shown that in strenuous exercise for more than 0.5 hours, glucose, potassium, calcium, sodium and albumin in the blood will increase by more than 1 times, while creatine phosphotransferase will increase by more than 4 times, alanine can be temporarily significantly increased due to exercise, and lactic acid can be increased to 3 times.
Strenuous exercise should be avoided 1d days before blood collection, and exercise should be minimized on the day of blood collection, such as stopping morning exercise, avoiding long-distance cycling, and collecting specimens in a quiet state or normal activity.
A qualified blood test result requires the cooperation of inspectors, blood collection personnel and patients. In today's increasingly mature vacuum blood collection technology, the examiner must not only strive to improve his intravenous blood collection technology, but also be aware of the various factors that affect the blood collection results.
Before blood collection, patients should be informed in detail of the precautions for blood collection, so as to cooperate with their own work, eliminate various human factors, and minimize the influencing factors of the test results to ensure the accuracy and reliability of the test results and provide a more accurate treatment basis for doctors.
【Reference】
Wang Xuemei,Zhang Yingwei,Zhang Yawen. Influencing Factors and Control of Intravenous Blood Collection Test Results[J]. China Medical Herald,2013,15(11):1886-1887
Liu Fuxiang. Factors Influencing The Accuracy of Results in the Analysis of Blood Biochemical Specimens[J]. Chinese Community Physicians, 2019, 35(27): 113-114
Yang Ying. Common problems and nursing measures in blood sample collection[J]. Inner Mongolia Journal of Traditional Chinese Medicine, 2014, 21: 169-170
Hu Yuhua,Guo Huiling. Preventricular Factors Affecting the Quality of Outpatient Vacuum Blood Collection Specimens and Countermeasures[J]. Modern Clinical Nursing, 2007, 6(1): 64-66
Source: China Medical Network
Edited by: Yeah Reviewer: Xiao Ran