24 - tPA

KYJ24- tPA. Tissue plasminogen Activator.
One of our social media mates impactednurse.com (Ian Miller) crafted a fantastic step by step guide to the use of tenectoplase, a common tPA.

I thought I'd dedicate this post to helping you develop a greater understanding of this family of drugs.

First some normal physiology.
For years Japanese car manufacturers dreamed of producing a car tyre that when punctured, would automatically detect air leak and seal the hole.

Our blood vessels have done this for thousands of years. Constantly, your vessels endothelial cell linings become damaged and expose the underlying collagen layer to the blood circulating within. When this occurs, platelets stick to the exposed puncture site and activate a clotting cascade that attracts other platelets, and initiate fibrinogen (a plasma protein ) to convert to Fibrin strands. This latter chemical reaction exists to repair vessel damage but is initiated to stop bleeding. The process is simply the symphony of clotting and coagulation.

This process happens hundreds or thousands of times/day in your body.  You are making clots, and probably did it while you read this sentence.

So there are substances that these endothelial cells (lining your blood vessels) make. One such chemical is called tissue plasminogen activator (tPA).

TPA is released when a clot is detected. It's job is to convert a plasma protein called Plasminogen into an enzyme that gobbles up clots, and particularly Fibrin.  The enzyme is called Plasmin.

Summary: tPA released from Vessel wall cells, converts plasminogen into the active enzyme Plasmin, which dissolves fibrin clots.

Now... Let's look at Tenectoplase.  This is a tPA. Genetically manufactured from Chinese Hamster Ovarian cells.

When injected into the blood stream of patients suffering Myocardial infarction, Stroke, or Pulmonary Embolism, the tPA goes to work converting the patient's plasminogen into the enzymatic Plasmin.  This intern indiscriminately seeks and destroys all clots in the patient's body.

Can you imagine the patient who has had a recent wound, surgery or injury?  They could start bleeding from these areas, as the Plasmin is not fussy which clots it dissolves.  Catastrophic haemorrhage, wound dehiscence and strokes are potential complications from treatment with tPA. Look for ALOC, signs of shock and frank bleeding in the urine/faeces.

Minor side effects are things like microscopic haematuria, bleeding gums, and ready bruising.  If the patient had had venepunctures, they may ooze blood from these sites.

This tPA is a genetically modified version of your own natural ability to dissolve your own clots, but in appropriate conditions, is a life saver.