Coagulants
Promote clotting
Anticoagulants
Inhibit clotting
What happens when damage occurs to blood vessels?
The body's coagulation mechanism begins clot formation to prevent excessive blood loss.
How are damaged blood vessels controlled intraoperatively?
With the use of thermal hemostasis or mechanical hemostasis
What are topical hemostatics?
Coagulants used on areas of capillary bleeding as an adjunct to natural hemostasis
Systemic anticoagulants are used to prevent or delay the onset of what?
The coagulation sequence during surgical procedures used on blood vessels.
What is a thrombus?
Blood clot
What are thrombolytics?
Used to speed up clot breakdown.
Stage 1 of clot formation
Thromboplastin is formed
Stage 2 of clot formation
Thromboplastin converts prothrombin into thrombin
Stage 3 of clot formation
Thrombin converts fibrinogen
Two pathways used in Stage 1 of clot formation
Extrinsic and Intrinsic
The extrinsic pathway is initiated by what?
Factors outside the blood
The intrinsic pathway is initiated by what?
Substances contained in the blood
What is required at all stages of clot formation?
Calcium
What is clotting that takes place within an unbroken blood vessel?
Thrombosis
Two major categories of coagulants
hemostatics and systemic coagulants
What are hemostatics?
Agents that enhance or accelerate blood clotting at a surgical site.
How can hemostatics be applied topically?
In the form of films, powder, sponges, or solutions.
What are absorbable gelatin hemostatics made from?
Animal in origin, made from purified porcine skin gelatin USP
Are absorbable gelatin hemostatics mechanical or chemical in action?
Mechanical
How long does it take for absorbable gelatin hemostatics to absorb?
Absorbed completely in 4-6 weeks
When can absorbable gelatins not be used?
in the presence of infection
Where should absorbable gelatins never be placed?
intravascularly
Examples of gelatin hemostatics
Gelfilm as well as Gelfoam powder and sponges and Surgifoam
What are absorbable collagen sponges made from?
Purified bovine collagen
What do absorbable collagen sponges promote when applied to bleeding surfaces?
Platelet aggregation
absorbable collagen sponges should not be applied prior to placement of what?
Methyl Methacrylate (bone cement)
Examples of absorbable collagen sponges
Collastat, Helistat, Hemopad, and Instat
What are the two types of microfibrillar collagen hemostats?
Avitene MCH and Instat MCH
What is Avitene MCH?
Dry, fibrous preparation of purified bovine corium collagen
Avitene MCH causes a formation of what when applied directly to bleeding surfaces?
Fibrin clot
Avitene MCH should be applied with what and why?
Dry instruments only; because wetting decreases its hemostatic efficiency
What is Instat MCH?
Derived from bovine deep flexor tendon, a source of pure collagen
What is the onset of Instat MCH?
2-4 minutes
Oxidized cellulose swells and becomes what?
a gelatinous mass that serves as a nucleus for clotting
Oxidized regenerated cellulose removal is recommended after what is acheived?
Hemostasis
OCR is available in what?
Knitted gauze strips or fiber form
Examples of OCR
Surgicel gauze, Surgicel Nu-knit and Surgicel Fibrillar
Surgicel absorbable hemostat is what?
Bactericidal and effective against a wide range of gram-positive and gram-negative microorganisms
OCR has a low ____ and should not be used with any agent containing ______ or _____ thrombin.
pH; bovine; human
What is Thrombin?
a topical liquid hemostatic agent of bovine origin
How can thrombin come prepared?
A spray bottle kit or in a powder form that must be reconstituted with sterile water or saline.
When should thrombin be used?
Immediately after preparation, or it should be refrigerated and used immediately after reconstituting.
Thrombin works by catalyzing the conversion of _______ to _____, thus increasing the speed of the natural clotting mechanism.
Fibrinogen; fibrin
Thrombin is measured in what?
Units
Thrombin comes in strengths of what?
1000-20000
Thrombin (bovine) gelatin sponge
Thrombi-Gel
Thrombin (bovine) nonwoven
Thrombi-Pad
Thrombin, topical (human)
Evithrom
Thrombin, topical (recombinant)
Recothrom
Thrombin and microfibrillar collagen
Vitagel
Fibrin sealant
Tisseel and Evicel
Thrombin, topical (human) and gelatin granules
Floseal
What topical hemostatic agent is made from beeswax?
Bone Wax
A hemostatic agent that is made from an astringent plant?
Tannic Acid
What is silver nitrate?
Cauterizing agent, especially when mixed with potassium nitrate.
What is the silver nitrate combination molded onto?
Applicator sticks
A chemical hemostatic agent that is deep brown solution of ferrous sulfate, sulfuric acid, and nitric acid diluted with water?
Monsel Solution
What are the 4 types of systemic coagulants?
Calcium Salts, Vitamin K, Antihemophilic factor, Factor IX complex
Calcium salts can not be given to patients with a history of what?
Malignant Hyperthemia
What is a fat-soluble vitamin that promotes blood clotting by increasing synthesis of coagulation factors?
Vitamin K
Vitamin K is available as ____ for oral administration or as ____ for injection.
Phytonadione (Mephyton); Vitamin K (AquaMEPHYTON)
Factor IX is a concentrate of what?
dried plasma fractions
Anticoagulants are administered in the medical setting to prevent what?
Venous thrombosis, pulmonary embolism, acute coronary occlusions after myocardial infection, and strokes caused by an embolus or cerebral blood clot.
What is the most commonly used parenteral anticoagulant?
Heparin sodium
Heparin acts by binding antithrombin ____, which greatly increases AT III's ability to inhibit the action of coagulation factors thrombin, Xa, and IXa.
III
Heparin is measured in what?
Units
Heparin is available in doses of how many units for injection?
10-10,000 units/mL
Hep-Lock catheter flush heparin is supplied in units of what?
10 & 100
Low-molecular-weight heparins are used to prevent or treat what?
DVT and PE
Fondparinux (Arixtra) is what kind of factor used for post op and long-term prophylaxis of DVT and PE in orthopedic fracture, total joint, and abdominal surgery patients.
Xa factor inhibitor
What kind of anticoagulants are used for long-term medical management of thromboembolic disease such as DVT or PE?
Oral
What are the two main types of oral anticoagulants?
Warfarin (Coumadin) and Aspirin
Coumarin derivatives act by inhibiting what activity in the liver?
Vitamin K
What agents are given intravenously in the medical setting to help dissolve blood clots?
Thrombolytics
Thrombolytics activate _____ to form plasmin, which digests fibrin.
plasminogen
Thrombolytic medications
streptokinase (Streptase), urokinase (Abbokinase,Kinlytic), alteplase (Activase), tenectplase (TNKase)