In clinical testing, the collection and storage of blood samples are key steps in obtaining accurate test results. Blood collection tubes containing heparin lithium are widely used in medical practice. However, the question of whether the sample can be left overnight after sampling involves many factors, such as whether it will have adverse effects on the cellular components, metabolites, and coagulation factors of the sample due to overnight storage. To ensure the accuracy of clinical diagnosis, let's take a look at whether it can be left overnight.

Heparin lithium powder

The anticoagulant mechanism and characteristics of lithium heparin

1. Anticoagulation mechanism

Heparin lithium, as a commonly used anticoagulant, its anticoagulant effect is mainly based on intervention in the coagulation process. Heparin lithium can specifically bind to antithrombin III (AT-III), causing structural changes in AT-III and greatly enhancing its inhibitory activity on coagulation factors. It mainly inhibits coagulation factors IIa, IXa, Xa, XIa, XI2a, etc., and achieves anticoagulant effects by blocking multiple links in the coagulation cascade reaction. This anticoagulant mechanism allows blood to remain liquid in the blood collection tube, facilitating subsequent testing operations.

2. Non irreversible anticoagulant properties

Heparin anticoagulant is a non irreversible anticoagulant, which is one of its important characteristics. Unlike some irreversible anticoagulants, the inhibitory effect of heparin lithium on coagulation factors in the blood is not long-term. Under specific conditions, the activity of coagulation factors may gradually recover. This means that over time, there is a potential for coagulation in the blood sample collected from the blood collection tube, and even under the anticoagulant effect of heparin lithium, the stability of the blood will gradually change. This characteristic imposes strict requirements on the storage time and conditions of the samples.

Leaving overnight may have an impact on the sample

1. Changes in cellular components

If the blood collection tube containing heparin lithium is sampled and left overnight, a series of changes will occur in the cellular components of the blood. Red blood cells may undergo morphological changes, such as wrinkling or swelling, which may affect the accuracy of red blood cell related parameters in blood routine, such as red blood cell count and hemoglobin measurement. The activity of white blood cells may also be affected, and their phagocytic function, chemotaxis, etc. may change, leading to deviations in white blood cell classification and counting results. After prolonged storage, platelets may aggregate or activate, affecting platelet count and the detection of platelet function related indicators.

2. Accumulation of metabolites

Cells in the blood still undergo metabolic activities outside the body. After overnight storage, acidic substances and lactic acid produced by cellular metabolism will gradually accumulate, leading to a decrease in the pH value of the blood. This change in pH value may affect the activity of certain enzymes, thereby affecting the detection results of related biochemical indicators. For example, the rate of some enzymatic reactions may change due to changes in pH, resulting in errors in the results of detection items such as blood glucose, blood lipids, liver function, and kidney function. Meanwhile, the accumulation of metabolites may also cause changes in the chemical balance of certain substances in the blood, affecting the accuracy of detection.

3. Changes in coagulation factor activity

Although lithium heparin has anticoagulant properties, its inhibitory effect on coagulation factors gradually weakens over time. After being left overnight, the activity of coagulation factors may partially recover, which increases the risk of blood clotting. Once blood tends to coagulate, even slight coagulation can affect the fluidity and uniformity of the blood, leading to inaccurate test results.

Related regulations and suggestions

1. Based on the anticoagulant properties of heparin lithium and the many adverse effects of overnight storage on samples, relevant medical testing standards state that the test should be completed within 6 hours after blood collection in heparin lithium anticoagulant tubes. This regulation has been validated through extensive experimental research and clinical practice. Within 6 hours, the stability of the blood sample is relatively good, with relatively small changes in cellular components, metabolites, and coagulation factors, which can largely ensure the test results. After more than 6 hours, the quality of the sample will gradually decrease, and the risk of detection errors will significantly increase.

2. In practical clinical work, there may be some situations where the test cannot be completed within 6 hours. At this point, corresponding measures should be taken to minimize the decline in sample quality. For example, the blood collection tube can be placed in a suitable temperature environment, and it is generally recommended to store it at 4 ℃ to slow down the recovery of cell metabolism and coagulation factor activity. Even if refrigeration measures are taken, the storage time of the samples cannot be indefinitely extended, and the inspection should still be completed as soon as possible.

Product packaging

Hubei Xindesheng Material Technology Co., Ltd., as a supplier of blood collection tube additives, has been widely praised in the market for its anticoagulant properties and heparin lithium. The heparin lithium carefully developed and produced by Xindesheng has stable anticoagulant effect and can accurately inhibit blood coagulation, providing reliable samples for subsequent testing. If you have purchasing intentions, please feel free to click on the website for consultation at any time!