Hemostasis bleeding

Antihemophilic factor [9001-28-9] (AHF) is a protein found in normal plasma that is necessary for clot formation. It is needed for transformation of prothrombin to thrombin. Administration of AHF by injection or infusion can temporarily correct the coagulation defect present in patients with hemophilia. Antihemophilic factor VIII (Alpha Therapeutic) has been approved by the FDA as replacement therapy in patients with hemophilia B to prevent bleeding episodes, and also during surgery to correct defective hemostasis (178). 

There are a number of tissue adhesives currently approved as adjuncts to hemostasis. Each agent has specific properties which enhance intraoperative hemostasis in particular situations. All forms of surgical bleeding are not alike. Bleeding can be fast or slow, diffuse or punctate, arterial or venous, capillary or larger vessel. Thus one agent may be more efficacious than another in a specific clinical situation. 

Hemostasis is the process that stops bleeding in a blood vessel. Normal hemostasis involves a complex process of extrinsic and intrinsic factors. Figure 44-1 shows the coagulation pathway and factors involved. The copulation cascade is so named because as each factor is activated it acts as a catalyst that enhances the next reaction, with the net result being a large collection of fibrin that forms a plug in the vessel. Fibrin is the insoluble protein that is essential to clot formation. 

Hemostasis is the cessation of bleeding from a cut or severed vessel, whereas thrombosis occurs when the endothelium lining blood vessels is damaged or removed (eg, upon rupmre of an atherosclerotic plaque). These processes encompass blood clotting (coagulation) and involve blood vessels, platelet aggregation, and plasma proteins that cause formation or dissolution of platelet aggregates. 

A number of laboratory tests are available to measure the phases of hemostasis described above. The tests include platelet count, bleeding time, activated partial thromboplastin time (aPTT or PTT), prothrombin time (PT), thrombin time (TT), concentration of fibrinogen, fibrin clot stabifity, and measurement of fibrin degradation products. The platelet count quantitates the number of platelets, and the bleeding time is an overall test of platelet function. aPTT is a measure of the intrinsic pathway and PT of the extrinsic pathway. PT is used to measure the effectiveness of oral anticoagulants such as warfarin, and aPTT is used to monitor heparin therapy. The reader is referred to a textbook of hematology for a discussion of these tests. 

The main goal of recessively inherited coagulation disorder (RICD) treatment is to prevent and control spontaneous and surgery-related bleeding episodes. Specifically, therapeutic options improve hemostasis via replacement of deficient blood coagulation factors while minimizing the development of immune tolerance.20... 

Hemostasis Cessation of bleeding through natural (clot formation or constriction of blood vessels), artificial (compression or ligation), or surgical means. 

Platelets are essential for many aspects of hemostasis, or the cessation of blood loss. Several substances are found within the cytoplasm of platelets that contribute to the arrest of bleeding as well as vessel repair ... 

Hetastarch 6% has comparable plasma expansion to 5% albumin solution but is usually less expensive, which accounts for much of its use. Hetastarch should be avoided in situations in which short-term impairments in hemostasis could have adverse consequences (e.g., cardiopulmonary bypass surgery, intracranial hemorrhage), because it may aggravate bleeding due to mechanisms such as decreased factor VIII activity. 

COX-1 is found in healthy individuals and is important in maintaining a balanced physiological role in kidneys and stomach. COX-2, on the other hand, is induced in the case of inflammation where it mediates the inflammation process. Aspirin, ibuprofen, and naproxen inhibit both COX-1 and COX-2 indiscriminately. While this reduces the production of PGE2 through the inhibition of COX-2, it upsets the hemostasis function of COX-1, which has a protective function for the mucosal lining, and leads to bleeding and ulcer formation. 

Renal effects - Ketorolac is contraindicated in patients with advanced renal impairment and in patients at risk for renal failure because of volume depletion. Risk of bleeding - Ketorolac inhibits platelet function and, therefore, is contraindicated in patients with suspected or confirmed cerebrovascular bleeding, hemorrhagic diathesis, and incomplete hemostasis, and in those at high risk of bleeding. 

Ketorolac is contraindicated as prophylactic analgesia before any major surgery and is contraindicated intra-operatively when hemostasis is critical because of the increased risk of bleeding. 

Antihemophilic Factor [AHF/ Factor VIII] (Monoclate) [Antihemophilic] Uses Classic hemophilia A, von Willebrand Dz Action Provides factor VIII needed to convert prothrombin to thrombin Dose Adults Peds. 1 AHF Unit/kg T factor VIII level 2 Int Units/dL, Units required = (kg) (desired factor VIII T as % nl) X (0.5) prevent spontaneous hemorrhage = 5% nl hemostasis after trauma/surgery = 30% nl head injuries, major surgery, or bleeding = 80-100% nl Caution [C, ] Disp Inj SE Rash, fever, HA, chills, N/V Interactions None EMS None OD Unlikely... 

Most major bleeding occurs at arterial access site for cardiac catheterization prior to pulling femoral artery sheath, discontinue heparin for 3-4 hr and document activated clotting time (ACT) <180 sec or aPTT <45 sec achieve sheath hemostasis >4 hr before discharge... 

Hemostasis is the process of blood clot formation at the site of vessel injury. When a blood vessel wall breaks, the hemostatic response must be rapid, localized, and carefully regulated. Abnormal bleeding or a propensity to nonphysiologic thrombosis (i.e., thrombosis not required for hemostatic regulation) may occur when specific elements of these processes are missing or dysfunctional. The elements responsible for normal hemostasis have received extensive review. 

G. Other applications NovoSeven may be effective for acute bleeding or hemostasis during surgery. In one study NovoSeven reversed the effects of the oral anticoagulant acenocoumarol on the prothrombin time and International Normalized Ratio (INR) in healthy volunteers, without evidence of systemic coagulation. It may also transiently correct elevated prothrombin time in patients with cirrhosis-induced coagulopathy. 

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