Which anticoagulant is preferred for blood gas studies?

Lithium heparin is the preferred anticoagulant for blood gas studies because it effectively inhibits thrombin and prevents clot formation, ensuring the integrity of the sample. Heparin does not interfere with the measurement of gases such as carbon dioxide or oxygen, which are critical in blood gas analysis. Additionally, it maintains the pH of the blood sample, a crucial factor for accurate results.

The choice of heparin, specifically lithium heparin, is also significant because patients who are undergoing routine laboratory testing may often have elevated levels of sodium or other electrolytes, potentially skewing results. Lithium heparin avoids this problem while also providing rapid and effective anticoagulation, which is essential for the timely analysis required in blood gas tests.

In contrast, other anticoagulants like sodium citrate and ammonium oxalate can alter the sample's characteristics and do not provide optimal conditions for the precise measurements needed in blood gas analysis. Sodium citrate, while useful for other types of coagulation studies, can interfere with the results by binding calcium, which is not ideal for gas measurements. Ammonium oxalate similarly can have adverse effects on the analysis, making them less suitable choices for this particular application.