Anticoagulants

Allied Guru

Introduction

  • Anticoagulants ek important role play karte hain blood samples ko fluid state mein banaye rakhne ke liye — jisse testing, storage, aur transfusion possible ho.
  • Alag-alag tests ya procedures ke liye different anticoagulants use kiye jaate hain.
  • Har anticoagulant ka apna specific mode of action, advantages, aur limitations hote hain.
  • Neeche commonly used anticoagulants ka detail description diya gaya hai – unke uses, action ka mechanism, faayde aur nuksaanon ke saath:

Ethylenediaminetetraacetic Acid (EDTA)

 Uses:

  • Mainly use hota hai hematology tests ke liye jaise CBC, blood smear, aur flow cytometry.

  • Blood cells, especially WBCs aur platelets, ko preserve karne ke liye ideal hai.

  • Blood typing aur cross-matching mein bhi blood banks mein use hota hai.

 Mode of Action:

  • EDTA calcium ions (Ca²⁺) ko bind karta hai. Calcium clotting ke liye essential hota hai.
  • Jab calcium available nahi hota, toh coagulation cascade ruk jaata hai – isse clot nahi banta.

Advantages:

  • Cellular morphology (cells ka shape/structure) ko achhe se preserve karta hai.

  • Platelet clumping ko prevent karta hai, jisse platelet count accurate aata hai.

  • Room temperature pe kaafi time tak stable rehta hai – sample kharab nahi hota.

Disadvantages:

  • Coagulation tests (PT, aPTT) ke liye suitable nahi hai – calcium dependent tests ko interfere karta hai.

  • Agar sample zyada time stored rahe, toh RBCs shrink ho jaate hain – MCV (Mean Corpuscular Volume) galat aa sakta hai.

  • Electrolyte assays mein interfere karta hai – calcium aur potassium levels affect ho jaate hain.

Sodium Citrate

Uses:

  • Commonly use hota hai coagulation studies jaise PT (Prothrombin Time), aPTT ke liye.

  • Blood banks mein plasma preparation aur apheresis mein use hota hai.

  • ESR (Erythrocyte Sedimentation Rate) test ke liye bhi use hota hai.

Mode of Action:

  • Sodium citrate bhi calcium ko bind karta hai, lekin reversibly.
  • Yani agar calcium dobara add kiya jaye, toh clotting process fir se shuru ho sakta hai – is wajah se yeh coagulation tests ke liye ideal hai.

Advantages:

  • Reversible action hone ki wajah se coagulation studies mein use hota hai.

  • Zyadatar biochemical ya hematological tests mein interference nahi karta.

  • Apheresis aur plasma separation ke time clotting minimize karta hai.

Disadvantages:

  • Blood ko dilute karta hai – agar patient ka hematocrit high ho toh correction factor lagana padta hai.

  • Routine hematology tests ke liye suitable nahi hai – RBCs ka shape/size badal deta hai.

  • Accurate ratio (1:9) maintain karna zaroori hai – galat ratio se test results inaccurate ho sakte hain.

Heparin

Uses:

  • Use hota hai biochemistry aur clinical chemistry tests mein – jaise blood gas, electrolytes, aur hormone tests.

  • Cytogenetics mein bhi kabhi-kabhi use hota hai jab EDTA ya citrate cell viability ko affect karte hain.

  • Blood banks mein plasma preparation ke liye bhi kabhi use hota hai.

Mode of Action:

  • Heparin directly clot formation ko inhibit karta hai by activating antithrombin – jo thrombin aur Factor Xa ko inactivate karta hai.
  • EDTA ya citrate jaise yeh calcium ko bind nahi karta.

Advantages:

  • Biochemical analysis, especially electrolytes, mein interfere nahi karta.

  • Jaldi kaam karta hai, urgent tests (blood gas, electrolytes) ke liye ideal hai.

  • Long-term plasma storage mein kuch analytes degrade nahi hote.

Disadvantages:

  • Hematology tests, specially cell counting mein interfere karta hai – WBC clumping ho sakta hai.

  • Coagulation studies ke liye suitable nahi hai – directly clotting ko rokta hai.

  • Agar properly store na kiya jaye, toh fibrin clots ban sakte hain – test results galat ho sakte hain.

Acid Citrate Dextrose (ACD)

Uses:

  • Blood donation, apheresis, aur platelet preparation ke liye use hota hai.

  • Blood preservation for transfusion ya tissue typing mein use hota hai.

  • DNA analysis ya genetic testing ke liye research labs mein use hota hai.

Mode of Action:

  • Citrate calcium ko bind karta hai – clotting ko rokh deta hai.

  • Dextrose cells ko energy deta hai, jisse longer storage ke liye viable bante hain.

Advantages:

  • Cells ki integrity maintain karta hai – long-term blood preservation ke liye ideal.

  • Hemolysis (RBC breakdown) kam karta hai – blood zyada time tak stable rehta hai.

  • Genetic testing aur platelet function studies ke liye suitable hai.

Disadvantages:

  • Blood sample dilute hota hai – kuch tests mein volume adjustment zaroori hai.

  • Routine clinical ya hematological tests ke liye suitable nahi – cell morphology alter hoti hai.

  • Coagulation studies ke liye commonly use nahi hota.

Sodium Fluoride

Uses:

  • Glucose testing ke liye sabse important anticoagulant hai – RBCs ke glycolysis ko prevent karta hai.

  • Lactate aur ethanol testing mein bhi use hota hai – metabolites ko preserve karta hai.

Mode of Action:

  • Sodium fluoride glycolysis inhibitor hai – RBCs glucose ko breakdown nahi kar paate.

  • Potassium oxalate calcium ko bind karta hai – clot formation prevent karta hai.

Advantages:

  • Glucose levels ko accurate banaye rakhta hai – long duration ke samples ke liye best hai.

  • Ethanol level preservation ke liye suitable hai – enzymes ko inhibit karta hai.

  • Long storage ke liye stable hota hai – delay hone par bhi sample kharab nahi hota.

Disadvantages:

  • Hematology tests ke liye suitable nahi – cells ka morphology damage karta hai.

  • Kuch enzyme tests ko interfere karta hai – specially glycolysis pathway wale.

  • Potassium oxalate se hemolysis ho sakti hai agar storage proper na ho.

Citrate Phosphate Dextrose (CPD)

Uses:

  • Blood collection bags mein whole blood donation aur transfusion preservation ke liye use hota hai.

  • Jab adenine ke saath combine hota hai (CPDA-1), tab blood ka shelf life aur extend ho jaata hai.

Mode of Action:

  • Citrate calcium ko bind karta hai – clotting prevent hoti hai.

  • Phosphate pH maintain karta hai.

  • Dextrose RBCs ko energy deta hai – storage ke time viable rakhta hai.

Advantages:

  • RBCs ka viability increase karta hai – 21 din tak preserve kar sakta hai (CPDA-1 ke saath 35 din).

  • Hemolysis reduce karta hai – blood transfusion ke liye ideal.

  • Blood banks mein widely used hai.

Disadvantages:

  • Lab testing ke liye suitable nahi – multiple assays mein interfere karta hai.

  • Proper storage zaroori hai – cell viability maintain karne ke liye.

  • Time limit ke baad blood use nahi ho sakta – discard ya process karna padta hai.

 

Clot Activator

Uses:

  • Used for biochemistry tests (e.g., liver function tests, renal profile, lipid profile)

  • Serology tests (e.g., HIV, Hepatitis, Dengue antibodies)

  • Immunological assays (e.g., hormone levels, thyroid function tests, CRP)

  • Drug level monitoring

  • Collection of serum for storage or transportation

Mode of Action:

  • Is tube mein clot activator hota hai (jaise silica particles), jo blood ko jaldi clot karne mein madad karta hai.

  • Ye particles platelet activation ko trigger karte hain, jisse clot formation fast hota hai.

  • Blood clot hone ke baad sample ko centrifuge karke serum alag kiya jaata hai for testing.

Advantages:

  • Fast clotting: Sample jaldi clot hota hai, isse testing mein delay nahi hota.

  • Serum separation ke liye ideal hai – commonly used for biochemistry, serology, aur immunology tests.

  • No interference with most biochemical assays.

  • Simple storage and handling – no anticoagulant needed.

Disadvantages:

  • Clot ho chuka blood repeat testing ke liye use nahi kiya ja sakta.

  • Not suitable for hematology or coagulation studies – kyunki serum mein clotting factors absent hote hain.

  • Agar mixing ya clotting incomplete ho, toh fibrin strands serum mein reh jaate hain – jo instruments ko block kar sakte hain.

  • Agar turant centrifuge na kiya jaaye, toh hemolysis ho sakti hai.