3.6.3 Techniques and devices to control bleeding and shock

Read through these techniques. Then have a look at the map at the foot of the page and see how they fit into the context of blood conservation.

FOR BLEEDING

Direct pressure

The blood supply to very vascular organs can be isolated, using clamps or clips before surgery begins.  The blood supply is restored after the operation.

Ice packs

Ice packs can reduce the extent of bleeding.

Elevate body part above level of heart

Positioning a patient on the operating table so that the operation site is above the heart can often reduce bleeding.

Haemostatic agents

Topical

Packs, pads, sponges, pastes, powders, meshes, solutions and special dressings can be applied to a wound to promote clotting.

·         Surgical adhesives

Substances made from human clotting factors. These clotting factors can be harvested from donor blood plasma or from a patient's own blood plasma. Fibrin glue can be applied to a bleeding vessel. It both blocks the vessel from bleeding and activates normal clotting/coagulation activity.

·         Tissue sealants

See tissuesealing.com.

·         Platelet gel

A concentrate made from a patient's own blood plasma, mixed with calcium and clotting compounds produced in cows. Platelet gel concentrates can be applied during the course of surgery to control bleeding.

Injectable

·         Tranexamic acid

This acts against breakdown of clots (by inhibiting or stopping plasminogen activation and fibrinolysis), and so it is useful in stopping severe blood loss as it increases clot formation.

·         E-Aminocaproic acid

Used for treatment of acute bleeding syndromes due to excessive fibrinolysis and for the prevention and treatment of postsurgical hemorrhage.

·         Desmopressin

Desmopressin may temporarily raise Factor VIII levels in a patient with mild hemophilia A.  Factor VIII is a coagulation factor.

·         Vitamin K

An antihaemorhagic factor.  It aids blood coagulation and is necessary for the formation of prothrombin (a chemical substance which interacts with calcium salts to produce thrombin - to help form the basis of a blood clot).

Other agents

·         Aprotinin

·         Conjugated oestrogens

·         Vasopressin

·         Cryoprecipitate

·         Recombinant Factor VIIa

·         Albumin

This major protein constituent of blood is often given to individuals who need to retain more fluid in their bloodstream, such as burn victims or patients with liver failure or extremely heavy bleeding (hemorrhage). Albumin (along with clotting factors, growth factors, and immunoglobulins) is sometimes referred to as a minor blood fraction.

Prompt surgery

Acting quickly to stop bleeding reduces the need for blood transfusion.

Tourniquet

A tourniquet can be applied above the surgical site.  Used especially for procedures on extremities such as the knee.

Controlled hypotension

Also called hypotensive anaesthesia.  A patient's blood pressure is lowered using medication or anaesthetic thechniques.  The amount of blood lost during surgery is thereby reduced.

FOR SHOCK

Trendelenberg/shock position

A technique in which the patient is placed in a position where the head is lower than the legs.This helps in shock by maintaining adequate blood flow to the brain which is more sensitive to a lack of oxygen that any other organ.

Medical anti-shock trousers (M.A.S.T.)

Medical Anti-Shock Trousers (MAST) is an inflatable garment that surrounds the legs and torso. They have three separate compartments that can be inflated. They are capable of sustaining internal pressure of approximately 100 torr. The primary use is to help slow the progress of shock, but they are also used for other purposes as well.

At first, it was thought that MAST helped reverse the signs of shock by squeezing blood out of the lower extremities into the central circulation. The theory was that the MAST worked to reverse shock in different ways. The first was by stopping any bleeding in the lower extremities (like applying direct pressure to a cut on an arm). The second was by increasing peripheral vascular resistance the lower body (squeezes more blood out but lets less blood enter the lower extremity). The third was the belief that the body was able to better perfuse the upper body while MAST were in place. Current studies have shown that MAST work in different but similar ways than originally believed. One of these is by increasing blood flow to the brain and other vital organs.

Appropriate volume replacement after bleeding controlled